Warning Systems – B737

Warning Lights

     

Master Caution and System Annunciator lights, left and right.

 

The Master Caution system was developed for the 737 to ease pilot workload as it was the first Boeing airliner to be produced without a flight engineer. In simple terms it is an attention getter that also directs the pilot toward the problem area concerned. The system annunciators (shown above) are arranged such that the cautions are in the same orientation as the overhead panel e.g. FUEL bottom left, DOORS bottom of third column, etc.

On the ground, the master caution system will also tell you if the condition is dispatchable or if the QRH needs to be actioned. The FCOM gives the following guidance on master caution illuminations on the ground:

Before engine start, use individual system lights to verify the system status. If an individual system light indicates an improper condition:
• check the Dispatch Deviations Procedures Guide (DDPG) or the operator equivalent to decide if the condition has a dispatch effect
• decide if maintenance is needed

If, during or after engine start, a red warning or amber caution light illuminates:
• do the respective non-normal checklist (NNC)
• on the ground, check the DDPG or the operator equivalent

If, during recall, an amber caution illuminates and then extinguishes after a master caution reset:
• check the DDPG or the operator equivalent
• the respective non-normal checklist is not needed

Pressing the system annunciator will show any previously cancelled or single channel cautions. If a single channel caution is encountered, the QRH drill should not be actioned.

Master caution lights and the system annunciator are powered from the battery bus and will illuminate when an amber caution light illuminates. Exceptions to this include a single centre fuel tank LOW PRESSURE light (requires both), REVERSER lights (requires 12 seconds) and INSTR SWITCH (inside normal FoV).

When conducting a light test, during which the system will be inhibited, both bulbs of each caution light should be carefully checked. The caution lights are keyed to prevent them from being replaced incorrectly, but may be interchanged with others of the same caption.

Keying of warning lights

 

  • Red lights – Warning – indicate a critical condition and require immediate action.
  • Amber lights – Caution – require timely corrective action.
  • Blue lights – Advisory – eg valve positions and unless bright blue, ie a valve/switch disagreement, do not require crew action.
  • Green lights – Satisfactory – indicate a satisfactory or ON condition.

 

 

Aural Warnings

Cockpit aural warnings include the fire bell, take-off configuration warning, cabin altitude, landing gear configuration warning, mach/airspeed overspeed, stall warning, GPWS and TCAS. External aural warnings are: The fire bell in the wheel well and the ground call horn in the nose wheel-well for an E & E bay overheat or IRS’s on DC. Only certain warnings can be silenced whilst the condition exists.

To test the GPWS, ensure that the weather radar is on in TEST mode and displayed on the EHSI. Pressing SYS TEST quickly will give a short confidence test, pressing for 10 seconds will give a full vocabulary test.

The GPWS pane. Click photo to hear the GPWS vocabulary test. (175kb)

AURAL WARNING PRIORITY LOGIC
MODE PRIORITY DESCRIPTION ALERT LEVEL
7 1 WINDSHEAR WINDSHEAR WINDSHEAR W
1 2 PULL-UP (SINK RATE) W
2 3 PULL-UP (TERRAIN CLOSURE) W
2A 4 PULL-UP (TERRAIN CLOSURE) W
V1 5 V1 CALLOUT I
TA 6 TERRAIN TERRAIN PULL-UP W
WXR 7 WINDSHEAR AHEAD W
2 8 TERRAIN TERRAIN C
6 9 MINIMUMS I
TA 10 CAUTION TERRAIN C
4 11 TOO LOW TERRAIN C
TCF 12 TOO LOW TERRAIN C
6 13 ALTITUDE CALLOUTS I
4 14 TOO LOW GEAR C
4 15 TOO LOW FLAPS C
1 16 SINK RATE C
3 17 DONT SINK C
5 18 GLIDESLOPE C
WXR 19 MONITOR RADAR DISPLAY C
6 20 APPROACHING MINIMUMS I
6 21 BANK ANGLE C
TCAS 22 RA (CLIMB, DESCEND, ETC.) W
TCAS 23 TA (TRAFFIC, TRAFFIC) C
TEST 24 BITE AND MAINTENANCE INFORMATION I

Radio Altimeter Callouts

Automatic rad-alt calls are a customer option on the 3-900 series. Calls can include any of the following:

2500 (“Twenty Five Hundred” or “Radio Altimeter”).
1000
500
400
300
200
100
50
40
30
20
10

“Minimums” or “Minimums, Minimums”
“Plus Hundred” when 100ft above DH
“Approaching Minimums” when 80ft above DH
“Approaching Decision Height”
“Decision Height”

Customers can also request special heights, such as 60ft.


 

Noise Levels

If is often commented how loud these callouts are. The volume level for these callouts and any other aural warnings is set so that they can still be audible at the highest ambient noise levels, this is considered to be when the aircraft is at Vmo (340kts) at 10,000ft.

The design sound pressure level at 35,000ft, M0.74, cruise thrust is 87dB at the Captains seat, compared to 90-93dB in the cabin.

Many pilots consider the 737 flightdeck to be generally loud. This is Boeings response to that charge:

“Using the flight deck noise levels measured by Boeing Noise Engineering during a typical flight profile (entire flight), a daily A-weighted sound exposure was calculated using ISO/DIS 1999 standards. This calculation indicates the time weight noise exposure is below 80 db(A) and should not cause hearing damage. Flight deck noise improvement continues to be a part of current Boeing product quality improvement activities.”

And when asked later about the particularly noisy NG:

“Boeing has conducted extensive flight tests to define the contributing noise sources for the 737 Flight Deck. Subsequently, various system and hardware modifications have been evaluated for possible improvements. Currently there are no proposed changes where the benefits are significant enough to warrant incorporation. Additional candidates are currently under study and if their merit is validated, they could be incorporated at a later date during production and retrofit.”

That said, in 2005 Boeing added 10 small vortex generators at the base of the windscreen which reduce flightdeck aerodynamic noise by 3dB. (See fuselage page for photo).

 

 

Stall Warning

Stall warning test requires AC power. Also, with no hydraulic pressure, the leading edge flaps may droop enough to cause an asymmetry signal, resulting in a failure of the stall warning system test. If this happens, switch the “B” system electric pump ON to fully retract all flaps and then repeat the test.

System test switches on the aft overhead panel

The 737-1/200’s had a different stall warning panel as shown right:

The OFF light may indicate either a failure of the heater of the angle of attack sensor a system signal failure or a power failure.

The test disc should rotate, indicating electrical continuity, when the switch is held to the test position.

737-200 Stall Warning Panel

 

TCAS

Various versions of TCAS have been fitted to the 737 since its introduction in the 1990’s. The early days of TCAS there were different methods of displaying the visuals. For the Honeywell system (Previously AlliedSignal, previous to that – Bendix/King), their most popular method for non-EFIS airplanes was to install an RA/VSI which was a mechanical VSI that had the “eyebrows” on the outer edge directing the pilot to climb (green) or stay away from (red) and use the separate Radar Indicator for the basic traffic display. Even early EFIS aircraft had the RA/VSI (see photos left & right)

TCAS is now integrated at production into the EFIS displays. The PFD/EADI will display advisories to climb, descend, or stay level since they give the vertical cue to the pilot. The ND/EHSI provides the map view looking down to show targets and their relative altitude and vertical movement relative to your aircraft.

TCAS display integrated onto the ND

 

TCAS control is from the transponder panel.

 

Weather Radar

The beamwidth of the 737 weather radar is 3.5 degrees.

To calculate the height of the cloud tops above your altitude use the following formula:

Cloud tops above a/c (ft) = range (nm) x (tilt – 1.5 deg) x 100

eg Wx at range 40nm stops painting at +2deg tilt. The tops would be 40 x 0.5 x 100 = 2000ft above your level.

Weather radar or terrain can be overlaid onto the EHSI with these switches on the classics. In the NG the overlay switches are part of the EFIS control panel. The colours may appear similar but their meanings are very different.

737 NG’s are fitted with predictive windshear system (PWS). This is available below 2300ft. You do not need weather radar to be switched on for PWS to work, since it switches on automatically when take-off thrust is set. However there is a 12 sec warm up period, so if you want PWS available for the take-off you should switch the weather radar on when you line up.

Windshear warning displayed on the ND. Notice the cone and range at which windshear is predicted.


EGPWS – Peaks Display

The Peaks display overlays EGPWS terrain information onto the EHSI. The colour coding is similar to wx radar but with several densities of each colour being used. The simplified key is:

 

Color Altitude Diff from Aircraft (ft)
Black No terrain
Cyan Zero ft MSL (Customer option)
Green -2000 to +250
Yellow -500 to +2000
Red +2000 or above
Magenta Terrain elevation unknown

The two overlaid numbers are the highest and lowest terrain elevations, in hundreds of ft amsl, currently being displayed. Here 5900ft and 800ft amsl. One of the main difference between Peaks display and others is that it will show terrain more than 2000ft below your level (eg a mountain range from cruise altitude). This can be very useful for situational awareness.

EGPWS Limitations

  • Do not use the terrain display for navigation.
  • Do not use within 15nm of an airfield not in the terrain database.

Honeywell EGPWS Pilots notes

 

PSEUProximity Switch Electronic Unit

The Proximity Switch Electronic Unit (PSEU) is a system that communicates the position or state of system components eg flaps, gear, doors, etc to other systems. The 737-NG’s are fitted with a PSEU which controls the following systems: Take-off and landing configuration warnings, landing gear transfer valve, landing gear position indicating and warning, air/ground relays, airstairs & door warnings and speedbrake deployed warning.

The PSEU light is inhibited from when the thrust levers are set for take-off power (thrust lever angle beyond 53 degrees) until 30 seconds after landing. If the PSEU light illuminates, you have a “non-dispatchable fault” and the QRH says do not take-off. In this condition the PSEU light can only be extinguished by fixing the fault. However if you only get the PSEU light on recall, you have a “dispatchable fault” which it is acceptable to go with. In this condition the PSEU light will extinguish when master caution is reset.

SFP aircraft (-800SFP / -900ER) also have an SPSEU which monitors the 2 position tailskid.

Warning Lights

     

Master Caution and System Annunciator lights, left and right.

The Master Caution system was developed for the 737 to ease pilot workload as it was the first Boeing airliner to be produced without a flight engineer. In simple terms it is an attention getter that also directs the pilot toward the problem area concerned. The system annunciators (shown above) are arranged such that the cautions are in the same orientation as the overhead panel e.g. FUEL bottom left, DOORS bottom of third column, etc.

On the ground, the master caution system will also tell you if the condition is dispatchable or if the QRH needs to be actioned. The FCOM gives the following guidance on master caution illuminations on the ground:

Before engine start, use individual system lights to verify the system status. If an individual system light indicates an improper condition:
• check the Dispatch Deviations Procedures Guide (DDPG) or the operator equivalent to decide if the condition has a dispatch effect
• decide if maintenance is needed

If, during or after engine start, a red warning or amber caution light illuminates:
• do the respective non-normal checklist (NNC)
• on the ground, check the DDPG or the operator equivalent

If, during recall, an amber caution illuminates and then extinguishes after a master caution reset:
• check the DDPG or the operator equivalent
• the respective non-normal checklist is not needed

Pressing the system annunciator will show any previously cancelled or single channel cautions. If a single channel caution is encountered, the QRH drill should not be actioned.

Master caution lights and the system annunciator are powered from the battery bus and will illuminate when an amber caution light illuminates. Exceptions to this include a single centre fuel tank LOW PRESSURE light (requires both), REVERSER lights (requires 12 seconds) and INSTR SWITCH (inside normal FoV).

When conducting a light test, during which the system will be inhibited, both bulbs of each caution light should be carefully checked. The caution lights are keyed to prevent them from being replaced incorrectly, but may be interchanged with others of the same caption.

Keying of warning lights

  • Red lights – Warning – indicate a critical condition and require immediate action.
  • Amber lights – Caution – require timely corrective action.
  • Blue lights – Advisory – eg valve positions and unless bright blue, ie a valve/switch disagreement, do not require crew action.
  • Green lights – Satisfactory – indicate a satisfactory or ON condition.

Aural Warnings

Cockpit aural warnings include the fire bell, take-off configuration warning, cabin altitude, landing gear configuration warning, mach/airspeed overspeed, stall warning, GPWS and TCAS. External aural warnings are: The fire bell in the wheel well and the ground call horn in the nose wheel-well for an E & E bay overheat or IRS’s on DC. Only certain warnings can be silenced whilst the condition exists.

To test the GPWS, ensure that the weather radar is on in TEST mode and displayed on the EHSI. Pressing SYS TEST quickly will give a short confidence test, pressing for 10 seconds will give a full vocabulary test.

The GPWS pane. Click photo to hear the GPWS vocabulary test. (175kb)

AURAL WARNING PRIORITY LOGIC
MODE PRIORITY DESCRIPTION ALERT LEVEL
7 1 WINDSHEAR WINDSHEAR WINDSHEAR W
1 2 PULL-UP (SINK RATE) W
2 3 PULL-UP (TERRAIN CLOSURE) W
2A 4 PULL-UP (TERRAIN CLOSURE) W
V1 5 V1 CALLOUT I
TA 6 TERRAIN TERRAIN PULL-UP W
WXR 7 WINDSHEAR AHEAD W
2 8 TERRAIN TERRAIN C
6 9 MINIMUMS I
TA 10 CAUTION TERRAIN C
4 11 TOO LOW TERRAIN C
TCF 12 TOO LOW TERRAIN C
6 13 ALTITUDE CALLOUTS I
4 14 TOO LOW GEAR C
4 15 TOO LOW FLAPS C
1 16 SINK RATE C
3 17 DONT SINK C
5 18 GLIDESLOPE C
WXR 19 MONITOR RADAR DISPLAY C
6 20 APPROACHING MINIMUMS I
6 21 BANK ANGLE C
TCAS 22 RA (CLIMB, DESCEND, ETC.) W
TCAS 23 TA (TRAFFIC, TRAFFIC) C
TEST 24 BITE AND MAINTENANCE INFORMATION I

Radio Altimeter Callouts

Automatic rad-alt calls are a customer option on the 3-900 series. Calls can include any of the following:

2500 (“Twenty Five Hundred” or “Radio Altimeter”).
1000
500
400
300
200
100
50
40
30
20
10

“Minimums” or “Minimums, Minimums”
“Plus Hundred” when 100ft above DH
“Approaching Minimums” when 80ft above DH
“Approaching Decision Height”
“Decision Height”

Customers can also request special heights, such as 60ft.


Noise Levels

If is often commented how loud these callouts are. The volume level for these callouts and any other aural warnings is set so that they can still be audible at the highest ambient noise levels, this is considered to be when the aircraft is at Vmo (340kts) at 10,000ft.

The design sound pressure level at 35,000ft, M0.74, cruise thrust is 87dB at the Captains seat, compared to 90-93dB in the cabin.

Many pilots consider the 737 flightdeck to be generally loud. This is Boeings response to that charge:

“Using the flight deck noise levels measured by Boeing Noise Engineering during a typical flight profile (entire flight), a daily A-weighted sound exposure was calculated using ISO/DIS 1999 standards. This calculation indicates the time weight noise exposure is below 80 db(A) and should not cause hearing damage. Flight deck noise improvement continues to be a part of current Boeing product quality improvement activities.”

And when asked later about the particularly noisy NG:

“Boeing has conducted extensive flight tests to define the contributing noise sources for the 737 Flight Deck. Subsequently, various system and hardware modifications have been evaluated for possible improvements. Currently there are no proposed changes where the benefits are significant enough to warrant incorporation. Additional candidates are currently under study and if their merit is validated, they could be incorporated at a later date during production and retrofit.”

That said, in 2005 Boeing added 10 small vortex generators at the base of the windscreen which reduce flightdeck aerodynamic noise by 3dB. (See fuselage page for photo).

Stall Warning

Stall warning test requires AC power. Also, with no hydraulic pressure, the leading edge flaps may droop enough to cause an asymmetry signal, resulting in a failure of the stall warning system test. If this happens, switch the “B” system electric pump ON to fully retract all flaps and then repeat the test.

System test switches on the aft overhead panel

The 737-1/200’s had a different stall warning panel as shown right:

The OFF light may indicate either a failure of the heater of the angle of attack sensor a system signal failure or a power failure.

The test disc should rotate, indicating electrical continuity, when the switch is held to the test position.

737-200 Stall Warning Panel

TCAS

Various versions of TCAS have been fitted to the 737 since its introduction in the 1990’s. The early days of TCAS there were different methods of displaying the visuals. For the Honeywell system (Previously AlliedSignal, previous to that – Bendix/King), their most popular method for non-EFIS airplanes was to install an RA/VSI which was a mechanical VSI that had the “eyebrows” on the outer edge directing the pilot to climb (green) or stay away from (red) and use the separate Radar Indicator for the basic traffic display. Even early EFIS aircraft had the RA/VSI (see photos left & right)

TCAS is now integrated at production into the EFIS displays. The PFD/EADI will display advisories to climb, descend, or stay level since they give the vertical cue to the pilot. The ND/EHSI provides the map view looking down to show targets and their relative altitude and vertical movement relative to your aircraft.

TCAS display integrated onto the ND

 

TCAS control is from the transponder panel.

Weather Radar

The beamwidth of the 737 weather radar is 3.5 degrees.

To calculate the height of the cloud tops above your altitude use the following formula:

Cloud tops above a/c (ft) = range (nm) x (tilt – 1.5 deg) x 100

eg Wx at range 40nm stops painting at +2deg tilt. The tops would be 40 x 0.5 x 100 = 2000ft above your level.

Weather radar or terrain can be overlaid onto the EHSI with these switches on the classics. In the NG the overlay switches are part of the EFIS control panel. The colours may appear similar but their meanings are very different.

737 NG’s are fitted with predictive windshear system (PWS). This is available below 2300ft. You do not need weather radar to be switched on for PWS to work, since it switches on automatically when take-off thrust is set. However there is a 12 sec warm up period, so if you want PWS available for the take-off you should switch the weather radar on when you line up.

Windshear warning displayed on the ND. Notice the cone and range at which windshear is predicted.


EGPWS – Peaks Display

The Peaks display overlays EGPWS terrain information onto the EHSI. The colour coding is similar to wx radar but with several densities of each colour being used. The simplified key is:

Color Altitude Diff from Aircraft (ft)
Black No terrain
Cyan Zero ft MSL (Customer option)
Green -2000 to +250
Yellow -500 to +2000
Red +2000 or above
Magenta Terrain elevation unknown

The two overlaid numbers are the highest and lowest terrain elevations, in hundreds of ft amsl, currently being displayed. Here 5900ft and 800ft amsl. One of the main difference between Peaks display and others is that it will show terrain more than 2000ft below your level (eg a mountain range from cruise altitude). This can be very useful for situational awareness.

EGPWS Limitations

  • Do not use the terrain display for navigation.
  • Do not use within 15nm of an airfield not in the terrain database.

Honeywell EGPWS Pilots notes

PSEUProximity Switch Electronic Unit

The Proximity Switch Electronic Unit (PSEU) is a system that communicates the position or state of system components eg flaps, gear, doors, etc to other systems. The 737-NG’s are fitted with a PSEU which controls the following systems: Take-off and landing configuration warnings, landing gear transfer valve, landing gear position indicating and warning, air/ground relays, airstairs & door warnings and speedbrake deployed warning.

The PSEU light is inhibited from when the thrust levers are set for take-off power (thrust lever angle beyond 53 degrees) until 30 seconds after landing. If the PSEU light illuminates, you have a “non-dispatchable fault” and the QRH says do not take-off. In this condition the PSEU light can only be extinguished by fixing the fault. However if you only get the PSEU light on recall, you have a “dispatchable fault” which it is acceptable to go with. In this condition the PSEU light will extinguish when master caution is reset.

SFP aircraft (-800SFP / -900ER) also have an SPSEU which monitors the 2 position tailskid.

Navigation – B737

Position

The aircraft has several nav positions, many of which are in use simultaneously! They can all be seen on the POS REF page of the FMC.

IRS L & IRS R Position: Each IRS computes its own position independently; consequently they will diverge slightly during the course of the flight. After the alignment process is complete, there is no updating of either IRS positions from any external sources. Therefore it is important to set the IRS position accurately in POS INIT.

GPS L & GPS R Position: (NG only) The FMC uses GPS position as first priority for FMC position updates. Note this allows the FMC to position update accurately on the ground, eg if no stand position is entered in POS INIT. This practically eliminates the need to enter a take-off shift in the TAKE-OFF REF page.

Radio Position: This is computed automatically by the FMC. Best results are achieved with both Nav boxes selected to AUTO (happens automatically on NG), thus allowing the FMC to select the optimum DME or VOR stations required for the position fix. Series 500 aircraft have an extra dedicated DME interogator (hidden) for this purpose and NG’s have two. Radio position is found from either a pair of DME stations that have the best range and geometry or from DME/VOR or even DME/LOC.The NAV STATUS page shows the current status of the navaids being tuned. Navaids being used for navigation (ie radio position) are highlighted (here WTM & OTR).

 

FMC Position: FMC navigational computations & LNAV are based upon this. The FMC uses GPS position (NG’s only) as first priority for FMC position updates, it will even position update on the ground. If GPS is not available, FMC position is biased approximately 80:20 toward radio position and IRS L. When radio updating is not available, an IRS NAV ONLY message appears. The FMC will then use a “most probable” position based on the IRS position error as found during previous monitoring when a radio position was available. The FMC position should be closely monitored if IRS NAV ONLY is in use for long periods.The POS SHIFT page shows the bearing & distance of other systems positions away from the FMC position. Use this page to force the FMC position to any of those offered.

 

RNP/ACTUAL

Actual Navigation Performance (ANP) is the FMC’s estimate of the quality of its position determination. The FMC is 95% certain the the aircraft’s actual position lies within a circle of radius ANP centred on the FMC position. Therefore the lower the ANP, the more confident the FMC is of its position estimate.

Required Navigation Performance (RNP) is the desired limit of navigational accuracy and is specified by the kind of airspace you are in. Eg for BRNAV above FL150, RNP=2.00nm. The RNP may be overwritten by crew.

ACTUAL should always be less than RNP.

If a navaid or GPS system is unreliable or giving invalid data then they can be inhibited using the NAV OPTIONS page.
There is an AFM limitation prohibiting use of LNAV when operating in QFE airspace. This is because several ARINC 424 leg types used in FMC nav databases terminate at MSL altitudes. If baro set is referenced to QFE, these legs will sequence at the wrong time and can lead to navigational errors.


EHSI & Navigation Display (ND)

 

 

EFIS Control Panel - Click to see description737-3/4/500 EFIS Control Panel

737-NG EFIS Control Panel
In the NG, if an EFIS control panel fails, you will get a DISPLAYS CONTROL PANEL annunciation on the ND. There is an additional, rather bizarre, attention getter because the altimeter will blank on the failed side, with an ALT flag, until the DISPLAYS – CONTROL PANEL switch is positioned to the good side. Note that this is not the same as the EFI switch on the -3/4/500’s which was used to switch symbol generators.

 

The -3/4/500 Electronic Horizontal Situation Indicator (Map mode) 737-NG Navigation Display (Map mode)
EHSI – Nav EHSI – Plan
EHSI – Full VOR/ILS EHSI – Expanded VOR/ILS
EHSI – Map

 

EHSI – Center Map

 

*** WARNING ***

The The ND DME readout below the VOR may not necessarily be that of the VOR which is displayed.

This photograph shows that Nav 1 has been manually tuned to 110.20 as shown in 1L of the FMC. DVL VOR identifier has been decoded by the auto-ident facility so “DVL” is displayed in large characters both on the FMC and the bottom left of the ND. Below this is displayed “DME 128” implying that this is the DME from DVL VOR.

However it can be seen on the ND that the DVL VOR is only about 70nm ahead. In fact DVL is only a VOR station and it has no DME facility, the DME was from another station on 110.20. The second station could be identified aurally by the higher pitched tone as “LRH” but was not displaying as such in line 2L of the FMC.

I only discovered this by chance as I happened to be following the aircraft progress by tuning beacons en-route (the way we used to do!). In my opinion, this illustrates the need to aurally identify any beacons, particularly DME, you may have to use, even if they are displayed as decoded.


 

Instrument Transfer

If either Nav receiver fails, the VHF NAV transfer switch may be used to display the functioning Nav information onto both EFIS and RDMI’s. With Nav transferred, the MCP course selector on the serviceable side becomes the master, but all other EFIS selections remain independent.

If an IRS fails, the IRS transfer switch is used to switch all associated systems to the functioning IRS.

1/200

3/4/500

NG’s


IRS Malfunction Codes (Classics)

Align Annunciator Malfunction Code Significance of Annunciator or Malfunction Code Recommended Action
Flashing (after 10 mins) None Failed align requirement Verify and re-enter present position
01 ISDU failed power up RAM test Replace ISDU
Steady 02 Entered latitude disagrees with latitude calculated by IRU Verify and re-enter present position. If fault persists do full align or replace IRU
02 IRU failure Replace IRU
Flashing 03 Excessive motion during align Restart a full align
Flashing (During full align) 04 Lat or Long entered is not within 1 degree of stored value Re-enter the identical position to the last position entered.
Flashing (During fast realign) 04 Lat is not within 1/2 degree or Long not within 1 deg of stored value Enter known accurate present position. If align light continues to flash, do full align.
05 Left DAA is transmitting a fault Replace left DAA.
06 Right DAA is transmitting a fault Replace right DAA.
07 Selected IRU has detected an invalid air data input. Replace DADC.
Flashing (after 10 mins) 08 Present position has not been entered Enter present position
Steady 09 Attitude mode has been selected Restart a full align. NB if ATT mode is desired, enter magnetic heading in POS INIT 1/2.
10 ISDU is not receiving power from both IRU’s. Ensure that both IRU’s are ON and receiving power.

Alternate Navigation System – ANS (If installed)

This is an option for the -3/4/500 series. ANS is an IRS based system which provides lateral navigation capability independent of the FMC. The ANS with the Control Display Units (AN/CDU) can be operated in parallel with the FMC for an independent cross-check of FMC/CDU operation.

 

Navigation Mode Selectors

The ANS is two separate systems, ANS-L & ANS-R. Each consists of its own AN/CDU and “on-side” IRS.

Each pilot has his own navigation mode selector to specify the source of navigation information to his EFIS symbol generator and flight director.

The ANS also performs computations related to lateral navigation which can provide LNAV commands to the AFDS in the event of an FMC failure.
  The IRS PROGRESS page is similar to the normal PROGRESS page except that all data is from the “on-side” IRS (L in this example).
AN/CDU Pages AN/CDU has no performance or navigation database. All waypoints must therefore be defined in terms of lat & long. The AN/CDU memory can only store 20 waypoints, these can be entered on the ground or in-flight and may be taken from FMC data using the CROSSLOAD function.

Future

In Jan 2003, the 737 became available with three new flight-deck technologies: Vertical Situation Display (VSD), Navigation Performance Scales (NPS) and Integrated Approach Navigation (IAN).

The Vertical Situation Display shows the current and predicted flight path of the airplane and indicates potential conflicts with terrain.

Navigation Performance Scales NPS use vertical and horizontal indicators to provide precise position awareness on the primary flight displays to will allow the aircraft to navigate through a narrower flight path with higher accuracy.

The Integrated Approach Navigation enhances current airplane landing approach capability by simplifying pilot procedures and potentially reducing the number of approach procedures pilots have learned in training.

For more information about NPS and IAN see the section on Flight Instruments.

 

Vertical Situation Display Vertical Situation Display

The VSD, now certified on NG’s, gives a graphical picture of the aircraft’s vertical flight path. The aim to is reduce the number of CFIT accidents; profile related incidents, particularly on non-precision approaches and earlier recognition of unstabilised approaches.

The VSD works with the Terrain Awareness and Warning System (TAWS) to display a vertical profile of the aircrafts predicted flight path (shown between the blue dashes) on the lower section of the ND. It is selected on with the DATA button on the EFIS control panel.

VSD can be retrofitted into any NG but it requires software changes to the displays and FMC and also some additional hardware displays.

Click here for presentation on VSD


ETOPS

In 1953, the United States developed regulations that prohibited two-engine airplanes from routes more than 60 min single-engine flying time from an adequate airport (FAR 121.161). These regulations were introduced based upon experience with the airliners of the time ie piston engined aircraft, which were much less reliable than modern jet aircraft. Nevertheless, the rule still stands.

ETOPS allows operators to deviate from this rule under certain conditions. By incorporating specific hardware improvements and establishing specific maintenance and operational procedures, operators can fly extended distances up to 180 min from the alternate airport. These hardware improvements were designed into Boeing 737-600/700/800/900.

The following table gives some FAA ETOPS approval times & dates:

Aircraft Series Engine ETOPS-120 approval date ETOPS-180 approval date
737-200 JT8D -9/9A Dec 1985
JT8D -15/15A Dec 1986
JT8D -17/17A Dec 1986
737-300/400/500 CFM56-3 Sept 1990
737-600/700/800/900 CFM56-7 Sept 1999
737-BBJ1/BBJ2 CFM56-7 Sept 1999

Position

The aircraft has several nav positions, many of which are in use simultaneously! They can all be seen on the POS REF page of the FMC.

IRS L & IRS R Position: Each IRS computes its own position independently; consequently they will diverge slightly during the course of the flight. After the alignment process is complete, there is no updating of either IRS positions from any external sources. Therefore it is important to set the IRS position accurately in POS INIT.

GPS L & GPS R Position: (NG only) The FMC uses GPS position as first priority for FMC position updates. Note this allows the FMC to position update accurately on the ground, eg if no stand position is entered in POS INIT. This practically eliminates the need to enter a take-off shift in the TAKE-OFF REF page.

Radio Position: This is computed automatically by the FMC. Best results are achieved with both Nav boxes selected to AUTO (happens automatically on NG), thus allowing the FMC to select the optimum DME or VOR stations required for the position fix. Series 500 aircraft have an extra dedicated DME interogator (hidden) for this purpose and NG’s have two. Radio position is found from either a pair of DME stations that have the best range and geometry or from DME/VOR or even DME/LOC.The NAV STATUS page shows the current status of the navaids being tuned. Navaids being used for navigation (ie radio position) are highlighted (here WTM & OTR).

FMC Position: FMC navigational computations & LNAV are based upon this. The FMC uses GPS position (NG’s only) as first priority for FMC position updates, it will even position update on the ground. If GPS is not available, FMC position is biased approximately 80:20 toward radio position and IRS L. When radio updating is not available, an IRS NAV ONLY message appears. The FMC will then use a “most probable” position based on the IRS position error as found during previous monitoring when a radio position was available. The FMC position should be closely monitored if IRS NAV ONLY is in use for long periods.The POS SHIFT page shows the bearing & distance of other systems positions away from the FMC position. Use this page to force the FMC position to any of those offered.

RNP/ACTUAL

Actual Navigation Performance (ANP) is the FMC’s estimate of the quality of its position determination. The FMC is 95% certain the the aircraft’s actual position lies within a circle of radius ANP centred on the FMC position. Therefore the lower the ANP, the more confident the FMC is of its position estimate.

Required Navigation Performance (RNP) is the desired limit of navigational accuracy and is specified by the kind of airspace you are in. Eg for BRNAV above FL150, RNP=2.00nm. The RNP may be overwritten by crew.

ACTUAL should always be less than RNP.

If a navaid or GPS system is unreliable or giving invalid data then they can be inhibited using the NAV OPTIONS page.
There is an AFM limitation prohibiting use of LNAV when operating in QFE airspace. This is because several ARINC 424 leg types used in FMC nav databases terminate at MSL altitudes. If baro set is referenced to QFE, these legs will sequence at the wrong time and can lead to navigational errors.


EHSI & Navigation Display (ND)

 

EFIS Control Panel - Click to see description737-3/4/500 EFIS Control Panel

737-NG EFIS Control Panel
In the NG, if an EFIS control panel fails, you will get a DISPLAYS CONTROL PANEL annunciation on the ND. There is an additional, rather bizarre, attention getter because the altimeter will blank on the failed side, with an ALT flag, until the DISPLAYS – CONTROL PANEL switch is positioned to the good side. Note that this is not the same as the EFI switch on the -3/4/500’s which was used to switch symbol generators.
The -3/4/500 Electronic Horizontal Situation Indicator (Map mode) 737-NG Navigation Display (Map mode)
EHSI – Nav EHSI – Plan
EHSI – Full VOR/ILS EHSI – Expanded VOR/ILS
EHSI – Map EHSI – Center Map

*** WARNING ***

The The ND DME readout below the VOR may not necessarily be that of the VOR which is displayed.

This photograph shows that Nav 1 has been manually tuned to 110.20 as shown in 1L of the FMC. DVL VOR identifier has been decoded by the auto-ident facility so “DVL” is displayed in large characters both on the FMC and the bottom left of the ND. Below this is displayed “DME 128” implying that this is the DME from DVL VOR.

However it can be seen on the ND that the DVL VOR is only about 70nm ahead. In fact DVL is only a VOR station and it has no DME facility, the DME was from another station on 110.20. The second station could be identified aurally by the higher pitched tone as “LRH” but was not displaying as such in line 2L of the FMC.

I only discovered this by chance as I happened to be following the aircraft progress by tuning beacons en-route (the way we used to do!). In my opinion, this illustrates the need to aurally identify any beacons, particularly DME, you may have to use, even if they are displayed as decoded.


Instrument Transfer

If either Nav receiver fails, the VHF NAV transfer switch may be used to display the functioning Nav information onto both EFIS and RDMI’s. With Nav transferred, the MCP course selector on the serviceable side becomes the master, but all other EFIS selections remain independent.

If an IRS fails, the IRS transfer switch is used to switch all associated systems to the functioning IRS.

1/200

3/4/500

NG’s


IRS Malfunction Codes (Classics)

Align Annunciator Malfunction Code Significance of Annunciator or Malfunction Code Recommended Action
Flashing (after 10 mins) None Failed align requirement Verify and re-enter present position
01 ISDU failed power up RAM test Replace ISDU
Steady 02 Entered latitude disagrees with latitude calculated by IRU Verify and re-enter present position. If fault persists do full align or replace IRU
02 IRU failure Replace IRU
Flashing 03 Excessive motion during align Restart a full align
Flashing (During full align) 04 Lat or Long entered is not within 1 degree of stored value Re-enter the identical position to the last position entered.
Flashing (During fast realign) 04 Lat is not within 1/2 degree or Long not within 1 deg of stored value Enter known accurate present position. If align light continues to flash, do full align.
05 Left DAA is transmitting a fault Replace left DAA.
06 Right DAA is transmitting a fault Replace right DAA.
07 Selected IRU has detected an invalid air data input. Replace DADC.
Flashing (after 10 mins) 08 Present position has not been entered Enter present position
Steady 09 Attitude mode has been selected Restart a full align. NB if ATT mode is desired, enter magnetic heading in POS INIT 1/2.
10 ISDU is not receiving power from both IRU’s. Ensure that both IRU’s are ON and receiving power.

Alternate Navigation System – ANS (If installed)

This is an option for the -3/4/500 series. ANS is an IRS based system which provides lateral navigation capability independent of the FMC. The ANS with the Control Display Units (AN/CDU) can be operated in parallel with the FMC for an independent cross-check of FMC/CDU operation.

Navigation Mode Selectors

The ANS is two separate systems, ANS-L & ANS-R. Each consists of its own AN/CDU and “on-side” IRS.

Each pilot has his own navigation mode selector to specify the source of navigation information to his EFIS symbol generator and flight director.

The ANS also performs computations related to lateral navigation which can provide LNAV commands to the AFDS in the event of an FMC failure.
The IRS PROGRESS page is similar to the normal PROGRESS page except that all data is from the “on-side” IRS (L in this example).
AN/CDU Pages AN/CDU has no performance or navigation database. All waypoints must therefore be defined in terms of lat & long. The AN/CDU memory can only store 20 waypoints, these can be entered on the ground or in-flight and may be taken from FMC data using the CROSSLOAD function.

Future

In Jan 2003, the 737 became available with three new flight-deck technologies: Vertical Situation Display (VSD), Navigation Performance Scales (NPS) and Integrated Approach Navigation (IAN).

The Vertical Situation Display shows the current and predicted flight path of the airplane and indicates potential conflicts with terrain.

Navigation Performance Scales NPS use vertical and horizontal indicators to provide precise position awareness on the primary flight displays to will allow the aircraft to navigate through a narrower flight path with higher accuracy.

The Integrated Approach Navigation enhances current airplane landing approach capability by simplifying pilot procedures and potentially reducing the number of approach procedures pilots have learned in training.

For more information about NPS and IAN see the section on Flight Instruments.

Vertical Situation Display Vertical Situation Display

The VSD, now certified on NG’s, gives a graphical picture of the aircraft’s vertical flight path. The aim to is reduce the number of CFIT accidents; profile related incidents, particularly on non-precision approaches and earlier recognition of unstabilised approaches.

The VSD works with the Terrain Awareness and Warning System (TAWS) to display a vertical profile of the aircrafts predicted flight path (shown between the blue dashes) on the lower section of the ND. It is selected on with the DATA button on the EFIS control panel.

VSD can be retrofitted into any NG but it requires software changes to the displays and FMC and also some additional hardware displays.

Click here for presentation on VSD


ETOPS

In 1953, the United States developed regulations that prohibited two-engine airplanes from routes more than 60 min single-engine flying time from an adequate airport (FAR 121.161). These regulations were introduced based upon experience with the airliners of the time ie piston engined aircraft, which were much less reliable than modern jet aircraft. Nevertheless, the rule still stands.

ETOPS allows operators to deviate from this rule under certain conditions. By incorporating specific hardware improvements and establishing specific maintenance and operational procedures, operators can fly extended distances up to 180 min from the alternate airport. These hardware improvements were designed into Boeing 737-600/700/800/900.

The following table gives some FAA ETOPS approval times & dates:

Aircraft Series Engine ETOPS-120 approval date ETOPS-180 approval date
737-200 JT8D -9/9A Dec 1985
JT8D -15/15A Dec 1986
JT8D -17/17A Dec 1986
737-300/400/500 CFM56-3 Sept 1990
737-600/700/800/900 CFM56-7 Sept 1999
737-BBJ1/BBJ2 CFM56-7 Sept 1999

Pneumatics – B737

737-3/500 Pneumatics Panel

See also Air Conditioning & Pressurisation

General

The pneumatic system can be supplied by engines, APU or a ground source. The manifold is normally split by the isolation valve. With the isolation valve switch in AUTO, the isolation valve will only open when an engine bleed air or pack switch is selected OFF.

Air for engine starting, air conditioning packs, wing anti-ice and the hydraulic reservoirs comes from their respective ducts. Air for pressurisation of the water tank and the aspirated TAT probe come from the left pneumatic duct. External air for engine starting feeds into the right pneumatic duct. Ground conditioned air feeds directly into the mix manifold.

The minimum pneumatic duct pressure (with anti-ice off) for normal operation is 18psi.

If engine bleed air temperature or pressure exceed limits, the BLEED TRIP OFF light will illuminate and the bleed valve will close. You may use the TRIP RESET switch after a short cooling period. If the BLEED TRIP OFF light does not extinguish, it may be due to an overpressure condition.

Bleed trip off’s are most common on full thrust, bleeds off, take-off’s. The reason is excessive leakage past the closed hi stage valve butterfly which leads to a pressure build up at the downstream port on the overpressure switch within the hi stage regulator. The simple in-flight fix is to reduce duct pressure by selecting CLB-2 and/or using engine and/or wing anti-ice.

WING-BODY OVERHEAT indicates a leak in the corresponding bleed air duct. This is particularly serious if the leak is in the left hand side, as this includes the ducting to the APU. The wing-body overheat circuits may be tested by pressing the OVHT TEST switch; both wing-body overheat lights should illuminate after a minimum of 5 seconds. This test is part of the daily inspection.

 

737-400 Pneumatics Panel

Differences

1/200’s – The PACK switches are simply OFF/ON, rather than OFF/AUTO/HIGH on all other series.

4/8/900’s – Have two recirc fans for pax comfort and PACK warning lights instead of PACK TRIP OFF. See Air conditioning for an explanation. There are also two sidewall risers either side instead of one on all other series, this is why there appear to be two missing windows forward of the engine inlet.

737-400 Sidewall risers

The hydraulic reservoirs are pressurised to ensure a positive flow of fluid reaches the pumps. A from the left manifold and B from the right. See wheel-well fwd.
 

Schematic

Schematic courtesy of Derek Watts

Click here to see a larger air conditioning & pneumatics schematic diagram for the 300/500 or 400.

Limitations

Max external air pressure: 60 psig
Max external air temp: 450°F / 232°C
One pack may be inoperative provided maximum altitude is: FL250

737-3/500 Pneumatics Panel

See also Air Conditioning & Pressurisation

General

The pneumatic system can be supplied by engines, APU or a ground source. The manifold is normally split by the isolation valve. With the isolation valve switch in AUTO, the isolation valve will only open when an engine bleed air or pack switch is selected OFF.

Air for engine starting, air conditioning packs, wing anti-ice and the hydraulic reservoirs comes from their respective ducts. Air for pressurisation of the water tank and the aspirated TAT probe come from the left pneumatic duct. External air for engine starting feeds into the right pneumatic duct. Ground conditioned air feeds directly into the mix manifold.

The minimum pneumatic duct pressure (with anti-ice off) for normal operation is 18psi.

If engine bleed air temperature or pressure exceed limits, the BLEED TRIP OFF light will illuminate and the bleed valve will close. You may use the TRIP RESET switch after a short cooling period. If the BLEED TRIP OFF light does not extinguish, it may be due to an overpressure condition.

Bleed trip off’s are most common on full thrust, bleeds off, take-off’s. The reason is excessive leakage past the closed hi stage valve butterfly which leads to a pressure build up at the downstream port on the overpressure switch within the hi stage regulator. The simple in-flight fix is to reduce duct pressure by selecting CLB-2 and/or using engine and/or wing anti-ice.

WING-BODY OVERHEAT indicates a leak in the corresponding bleed air duct. This is particularly serious if the leak is in the left hand side, as this includes the ducting to the APU. The wing-body overheat circuits may be tested by pressing the OVHT TEST switch; both wing-body overheat lights should illuminate after a minimum of 5 seconds. This test is part of the daily inspection.

737-400 Pneumatics Panel

Differences

1/200’s – The PACK switches are simply OFF/ON, rather than OFF/AUTO/HIGH on all other series.

4/8/900’s – Have two recirc fans for pax comfort and PACK warning lights instead of PACK TRIP OFF. See Air conditioning for an explanation. There are also two sidewall risers either side instead of one on all other series, this is why there appear to be two missing windows forward of the engine inlet.

737-400 Sidewall risers

The hydraulic reservoirs are pressurised to ensure a positive flow of fluid reaches the pumps. A from the left manifold and B from the right. See wheel-well fwd.

Schematic

Schematic courtesy of Derek Watts

Click here to see a larger air conditioning & pneumatics schematic diagram for the 300/500 or 400.

Limitations

Max external air pressure: 60 psig
Max external air temp: 450°F / 232°C
One pack may be inoperative provided maximum altitude is: FL250

Power Plant – B737

History

The original choice of powerplant was the Pratt & Whitney JT8D-1, but before the first order had been finalised the JT8D-7 was used for commonality with the current 727. The -7 was flat rated to develop the same thrust (14,000lb.st) at higher ambient temperatures than the -1 and became the standard powerplant for the -100. By the end of the -200 production the JT8D-17R was up to 17,400lb.st. thrust.

Auxiliary inlet doors were fitted to early JT8D’s around the nose cowl. These were spring loaded and opened automatically whenever the pressure differential between inlet and external static pressures was high, ie slow speed, high thrust conditions (takeoff) to give additional engine air and closed again as airspeed increased causing inlet static pressure to rise.

JT8D Cutaway

The sole powerplant for all 737’s after the -200 is the CFM-56. The core is produced by General Electric and is virtually identical to the F101 as used in the Rockwell B-1. SNECMA produce the fan, IP compressor, LP turbine, thrust reversers and all external accessories. The name “CFM” comes from GE’s commercial engine designation “CF” and SNECMA’s “M” for Moteurs.CFM 56 - 3 Cutaway

One problem with such a high bypass engine was its physical size and ground clearance; this was overcome by mounting the accessories on the lower sides to flatten the nacelle bottom and intake lip to give the “hamster pouch” look. The engines were moved forward and raised, level with the upper surface of the wing and tilted 5 degrees up which not only helped the ground clearance but also directed the exhaust downwards which reduced the effects of pylon overheating and gave some vectored thrust to assist take-off performance. The CFM56-3 proved to be almost 20% more efficient than the JT8D.

The NG’s use the CFM56-7B which has a 61 inch diameter solid titanium wide-chord fan, new LP turbine turbomachinery, FADEC, and new single crystal material in the HP turbine. All of which give an 8% fuel reduction, 15% maintenance cost reduction and greater EGT margin compared to the CFM56-3.

One of the most significant improvements in the powerplant has been to the noise levels. The original JT8D-9 engines in 1967 produced 75 decibel levels, enough to disrupt normal conversation indoors, within a noise contour that extended 12 miles along the take-off flight path. Since 1997 with the introduction of the 737-700’s CFM56-7B engines, the 75-decibel noise contour is now only 3.5 miles long.

The core engine (N2) is governed by metering fuel (see below), whereas the fan (N1) is a free turbine. The advantages of this include: minimised inter-stage bleeding, fewer stalls or surges and an increased compression ratio without decreasing efficiency.

This quote from CFMI in 1997:

“Since entering service in 1984, the CFM56-3 has established itself as the standard against which all other engines are judged in terms of reliability, durability, and cost of ownership. The fleet of nearly 1,800 CFM56-3-powered 737s in service worldwide have logged more than 61 million hours and 44 million cycles while maintaining a 99.98 percent dispatch reliability rate (one flight delayed or cancelled for engine-caused reasons per 5,000 departures), a .070 shop visit rate (one unscheduled shop visit per 14,286 flight hours), and an in-flight shutdown rate of .003 (one incident per 333,333 hours).”

Tech Insertion

“Tech Insertion” is an upgrade to the CFM56-5B & 7B available from early 2007. The package includes improvements to the HP compressor, combustor and HP & LP turbines. The package give a longer time on wing, about 5% lower maintenance costs, 15-20% lower oxides of nitrogen (NOx) emissions, and 1% lower fuel burn.

Tech Insertion will become the new production configuration for both the CFM56-7B and CFM56-5B. CFM is also defining potential upgrade kits that could be made available to operators by late 2007.

CFM56-7BE “Evolution”

The new CFM56-7BE Product Improvement package announced in 2009 will have the following design changes & improvements:

  • HPC outlet guide vane diffuser area ratio improved and pressure losses reduced.
  • HPT blades numbers reduced, axial chord increased, tip geometry improved. Rotor redesigned.
  • LPT blade & vane numbers reduced and profiles based on optimized loading distribution. LEAP56 incorporated.
  • Primary nozzle, plug & strut faring all redesigned.

The -7BE will be able to be intermixed with regular SAC/DAC or Tech Insertion engines subject to updated FMC, MEDB and EEC. Entry into service is planned for mid-2011

From the press 2 Aug 2010:

CFM International has won certification for its upgraded CFM56-7BE engine from the FAA and the European Aviation Safety Agency (EASA), and is working with Boeing to prepare for flight tests on a Boeing 737 starting in the fourth quarter of this year.

Entry into service is planned for mid-2011 to coincide with 737 airframe improvements that, together with the engine upgrade, are designed to provide a 2% improvement in fuel consumption. CFM provisionally scheduled engine certification by the end of the third quarter, but says development, including recently completed flight tests, have progressed faster than expected. Improvements include a new high-pressure compressor outlet guide vane diffuser, high-pressure turbine blades, disks and forward outer seal. The package also includes a new design of low-pressure turbine blades, vanes and disk.

The first full CFM56-7BE type design engine completed ground testing in January 2010, and overall completed 390 hours of ground testing, says the Franco-U.S. engine maker. In addition, the upgraded CFM completed a 60-hour certification flight test program in May on GE’s modified 747 flying testbed in Victorville, Calif.

At the recent Farnborough International Airshow, company officials said discussions are continuing with Airbus about a possible upgrade for the CFM56-5B for the A320 family based on the same technology suite. A decision on whether or not an upgraded variant will be developed for Airbus will be finalized by year-end, adds the engine maker.

Fuel

Thrust (fuel flow) is controlled primarily by a hydro-mechanical MEC in response to thrust lever movement, as fitted to the original 737-1/200’s. In the –3/4/500 series, fuel flow is further refined electronically by the PMC, which acts without thrust lever movement. The 737-NG models go one stage further with FADEC (EEC).

The 3/4/500’s may be flown with PMC’s inoperative, but an RTOW penalty (ie N1 reduction) is imposed because the N1 section will increase by approximately 4% during take-off due to windmilling effects (FOTB 737-1, Jan 1985). This reduction should save reaching any engine limits. The thrust levers should not be re-adjusted during the take-off after thrust is set unless a red-line limit is likely to be exceeded, ie you should allow the N1’s to windmill up.

Fuel is heated to avoid icing by the returning oil in the MEC.

Oil

Oil pressure is measured before the bearings, where you need it; oil temperature on return, at its hottest; and oil quantity at the tank, which drops after engine start. Oil pressure is unregulated, therefore the yellow band (13-26psi) is only valid at take-off thrust whereas the lower red line (13psi) is valid at all times. If the oil pressure is ever at or below the red line, the LOW OIL PRESSURE light will illuminate and that engine should be shut down. NB on the 737-1/200 when the oil quantity gauge reads zero, there could still be up to 5 quarts present.

Ignition

There are two independent AC ignition systems, L & R. Starting with R selected on the first flight of the day provides a check of the AC standby bus, which would be your only electrical source with the loss of thrust on both engines and no APU. Normally, in-flight, no igniters are in use as the combustion is self-sustaining. During engine start or take-off & landing, GND & CONT use the selected igniters. In conditions of moderate or severe precipitation, turbulence or icing, or for an in-flight relight, FLT should be selected to use both igniters. NG aircraft: for in-flight engine starts, GRD arms both igniters.

The 737-NG’s allow the EEC to switch the ignition ON or OFF under certain conditions:

  • ON: For flameout protection. The EEC will automatically switch on both ignition systems if a flameout is detected.
  • OFF: For ground start protection. The EEC will automatically switch off both ignition systems if a hot or wet start is detected.

Note that older 737-200s have ignition switch positions named GRD, OFF, L IGN, R IGN and FLT while newer 737s use GRD, OFF, CONT and FLT. This is why QRH uses “ON” (eg in the One Engine Inop Landing checklist) to cover both LOW IGN & CONT for operators with mixed fleets consisting of old and new versions of the 737.

737-200 Ignition panel

Engine Starting

Min duct pressure for start (Classics only): 30psi at msl, -½psi per 1000ft pressure altitude. Max: 48psi.

Min 25% N2 (or 20% N2 at max motoring) to introduce fuel; any sooner could result in a hot start. Max motoring is when N2 does not increase by more than 1% in 5 seconds.

Aborted engine start criteria:

  • No N1 (before start lever is raised to idle).
  • No oil pressure (by the time the engine is stable).
  • No EGT (within 10 secs of start lever being raised to idle).
  • No increase, or very slow increase, in N1 or N2 (after EGT indication).
  • EGT rapidly approaching or exceeding 725˚C.

An abnormal start advisory does not by itself mean that you have to abort the engine start.

Starter cutout is approx 46% N2 -3/4/500; 56% N2 -NG’s.

Starter duty cycle is:

  • First attempt: 2mins on, 20sec off.
  • Second and subsequent attempts: 2mins on, 3mins off.

Do not re-engage engine start switch until N2 is below 20%.

During cold weather starts, oil pressure may temporary exceed the green band or may not show any increase until oil temperature rises. No indication of oil pressure by the time idle RPM is achieved requires an immediate engine shutdown. At low ambient temperatures, a temporary high oil pressure above the green band may be tolerated.

When starting the engines in tailwind conditions, Boeing recommends making a normal start. Expect a longer cranking time to ensure N1 is rotating in the correct direction before moving the start lever. A higher than normal EGT should be expected, yet the same limits and procedures should apply.

Upper DU

Lower DU

Upper DU in Compact Display mode

The Compact Display mode can only be shown when the MFD ENG button is pressed for the first time after the aircraft has been completely shut down. The photo shows this display with one engine started and nicely illustrates the blank parameters which are controlled by the EEC and hence are only displayed when the EEC powers up when the associated start switch is selected to GND. During start-up the EEC’s receive electrical power from the AC transfer busses, but their normal source of power are their own alternators which cut-in when N2 is above 15%.

-200Adv Engine Instruments

Round Dial -3/400 Engine Instruments

3/4/500 EIS
NG EIS

EIS Display

The introduction of Engine Instrument System (EIS) in late 1988 gave many advantages over the electromechanical instruments present since 1967. ie a 10lb weight reduction, improved reliability, reduction in power consumption, detection of impending abnormal starts, storage of exceedances and a Built In Test Equipment (BITE) check facility.

The BITE check is accessed by pressing a small recessed button at the bottom of each eis panel, this is only possible when both engines N1 are below 10%. Pressing these buttons will show an LED check during which the various checks are conducted. If any of the checks fail, the appropriate code will be shown in place of the affected parameters readout. The following codes are used:

Primary EIS BITE Codes
Code Fault
ROM Read Only Memory check
RAM Random Access Memory check
FDC Frequency to Digital Converter check
ENG Engine Identity Inputs (not fuel flow)
PWR Power Monitor
MMF Maint Module Fault (fuel flow only)
RTC Real Time Clock (fuel flow only)
ERF Exceedance RAM Full (fuel flow only)
A/D Analogue to Digital Converter (fuel flow only)
ARF ARINC Receiver Fault (fuel flow only)
uP Microprocessor

Any exceedance of either N1, N2 or EGT is recorded at 1 sec intervals in a non-volatile memory along with the fuel flow at the time, this data can be downloaded by connecting an ARINC 429 bus reader. Up to 10 minutes of data can be stored. The last exceedance is also put into volatile memory and can be read straight from the EIS before aircraft electrical power is removed. This is done by pressing the primary EIS BITE button twice within 2 seconds, this will then alternately display the highest reading and the duration of the exceedance in seconds.

Secondary EIS BITE Codes
Code Fault
0- Microprocessor
1- Program Memory
2- Random Access Memory check
3- Analogue to Digital Converter
4- Power Monitor
5- 400Hz Reference Voltage
6- ARINC Receiver Fault

 

Airborne Vibration Monitors (AVM)

All series of 737 have the facility for AVM although not all 737-200’s have them fitted. The early 737-1/200’s had two vibration pickup points; One at the turbine section and one at the engine inlet there was a selector switch so that the crew could choose which to monitor. Some even had a high and low frequency filter selection switch.

From Boeing Flt Ops Review, Feb 2003: “On airplanes with AVM procedures, flight crews should also be made aware that AVM indications are not valid while at takeoff power settings, during power changes, or until after engine thermal stabilization. High AVM indications can also be observed during operations in icing conditions.”

 

High Pressure Turbine Clearance Control

The HPTCC system uses HP compressor bleed air to obtain maximum steady state HPT performance and to minimise EGT transient overshoot during rapid change of engine speed.

Variable Stator Vanes

The VSV actuation system controls primary airflow through the HP compressor by varying the angle of the inlet guide vanes and three stages of variable stator vanes.

Variable Bleed Valves

Control airflow quantity to the HP compressor. They are fully open during rapid accelerations and reverse thrust operation.

 

Dual Annular Combustors (DAC)

The CFM56-7B is available with an optional DAC system, known as the CFM56-7B/2, which considerably reduces NOx emissions. DAC have 20 double tip fuel nozzles instead of the single tip and a dual annular shaped combustion chamber. The number of nozzles in use: 20/0, 20/10 or 20/20, varies depending upon thrust required. The precise N1 ranges of the different modes varies with ambient conditions.

  • 20/20 mode – High power (cruise N1 and above)
  • 20/10 mode – Medium power
  • 20/00 mode – Low power (Idle N1)

This gives a lean fuel/air mixture, which reduces flame temperatures, and also gives higher throughput velocities which reduce the residence time available to form NOx. The net result is up to 40% less NOx emissions than a standard CFM56-7.

The first were installed on the 737-600 fleet of SAS but unfortunately were subject to resonance in the LPT-1 blades during operation in the 20/10 mode, which occurred in an N1 range usually used during descent and approach. Although there were no in-flight shutdowns, boroscope inspections revealed that the LPT blades were starting to separate. CFM quickly replaced all blades on all DAC engines with reinforced blades and have since replaced them again with a new redesigned blade.

 

Reverse Thrust

The original 737-1/200 thrust reversers were pneumatically powered clamshell doors taken straight from the 727 (shown left). When reverse was selected, 13th stage bleed air was ported to a pneumatic actuator that rotated the deflector doors and clamshell doors into position. Unfortunately they were relatively ineffective and apparently tended to push the aircraft up off the runway when deployed. This reduced the downforce on the main wheels thereby reducing the effectiveness of the wheel brakes.

By 1969 these had been changed by Boeing and Rohr to the much more successful hydraulically powered target type thrust reversers (shown right). This required a 48 inch extension to the tailpipe to accommodate the two cylindrical deflector doors which were mounted on a four bar linkage system and associated hydraulics. The doors are set 35 degrees away from the vertical to allow the exhaust to be deflected inboard and over the wings and outboard and under the wings. This ensures that exhaust and debris is not blown into the wheel-well, nor is it blown directly downwards which would lift the weight off the wheels or be re-ingested. Fortunately the new longer nacelle improved cruise performance by improving internal airflow within the engine and also reduced cruise drag. These thrust reversers are locked against inadvertent deployment by both deflector door locks and the four bar linkage being overcenter. To illustrate how poor the original clamshell system was, Boeings own data says target type thrust reversers at 1.5 EPR are twice as effective as clamshells at full thrust!

The CFM56 uses blocker doors and cascade vanes to direct fan air forwards. Net reverse thrust is defined as: fan reverser air, minus forward thrust from engine core, plus form drag from the blocker door. As this is significantly greater at higher thrust, reverse thrust should be used immediately after landing or RTO and, if conditions allow, should be reduced to idle by 60kts to avoid debris ingestion damage. Caution: It is possible to deploy reverse thrust when either Rad Alt is below 10ft – this is not recommended.

The REVERSER light shows either control valve or sleeve position disagreement or that the auto-restow circuit is activated. This light will illuminate every time the reverser is commanded to stow, but extinguishes after the stow has completed, and will only bring up master caution ENG if a malfunction has occurred. Recycling the reverse thrust will often clear the fault. If this occurs in-flight, reverse thrust will be available after landing.

The REVERSER UNLOCKED light (EIS panel) is potentially much more serious and will illuminate in-flight if a sleeve has mechanically unlocked. Follow the QRH drill, but only multiple failures will allow the engine to go into reverse thrust.

The 737-1/200 thrust reverser panel has a LOW PRESSURE light which refers to the reverser accumulator pressure when insufficient pressure is available to deploy the reversers. The blue caption between the switches is ISOLATION VALVE and illuminates when the three conditions for reverse thrust are satisfied: Engine running, Aircraft on ground & Fire switches in normal position. The guarded NORMAL / OVERRIDE switches to enable the reverse thrust to be selected on the ground with the engines stopped (for maintenance purposes).

 

 

HushKits

The first “hushkit” was not visible externally, in 1982 exhaust mixers were made available for the JT8D-15, -17 or -17R. These were fitted behind the LP turbine to mix the hot gas core airflow with the cooler bypassed fan air. This increased mixing reduced noise levels by up to 3.6 EPNdB.

Several different Stage III hushkits have been available from manufacturers Nordam (shown right) and AvAero since 1992. The Nordam comes in HGW and LGW versions.

As hushkits use more fuel, the EU tried to ban all hushkitted aircraft flying into the EU from April 2002. This was strongly opposed and the directive has been changed to allow hushkitted aircraft to use airports which will accept them.

737 classics may be fitted with hardwall forward acoustic panels which reduce noise by 1 EPNdB

 

Additional References

 

Limitations

Series 1/200 3/4/500 6/7/8/900/BBJ
Engine JT8-17A CFM56-3 CFM56-7
 
Max time limit for take-off or go-around thrust: 5 mins 5 mins * 5 mins *
Max N1 102.4% 106% 104%
Max N2 100% 105% 105%
 

Max EGT’s:

Take-off (5 min limit) 650°C 930°C 950°C
Continuous 610°C 895°C 925°C
Start 575°C 725°C 725°C
 

Oil T’s & P’s

Max temperature 165°C 165°C 155°C
15 minute limit (45 minute limit on NG) 130-165°C 160-165°C 140-155°C
Max continuous 130°C 160°C 140°C
Min oil press 40psi 13psi (warning light), 26psi (gauge) 13psi (warning light), 26psi (gauge)
Min oil quantity (at dispatch) 2.25 USG 60% full (12 US Quarts) ** 60% full (12 US Quarts) **
Starting pressures prior to starter engagement

30psi -1/2psi per 1000′ amsl

N/A
Starter duty cycle 1st attempt: 2min on, 20sec off

2nd & subsequent attempt: 2min on, 3min off

2mins on, 10secs off.
* May be increased to 10 mins if certified** See AMM Task 12-13-11-600-801

Engine Ratings

Maximum Certified Thrust – This is the maximum thrust certified during testing for each series of 737. This is also the thrust that you get when you firewall the thrust levers, regardless of the maximum rated thrust.

On the 737NG, the EEC limits the maximum certified thrust gained from data in the engine strut according to the airplane model as follows:

Aircraft Series Maximum Certified Thrust
737-600 CFM56-7B22 = 22,700lb.st
737-700 CFM56-7B24 = 24,200lb.st
737-800 CFM56-7B27 = 27,300lb.st
737-900 CFM56-7B27 = 27,300lb.st

 

Maximum Rated Thrust – This is the maximum thrust for the installed engine that the autothrottle will command. This is specified by the operator from the options in the table below.

Engine Aircraft Series Max Static Thrust (lb.st.) Bypass Ratio EGT Margin (C)
JT8D-7/7A/7B 1/200 14,000 1.10
JT8D-9/9A 1/200 14,500 1.04
JT8D-15/15A 200Adv 15,500 0.99
JT8D-17/17A 200Adv 16,000 1.02
JT8D-17R 200Adv 17,400 1.00
CFM56-3B4 500 18,500 5.0 90
CFM56-3B1 3/500 20,000 5.0 70
CFM56-3B2 3/400 22,000 5.0 50
CFM56-3C1 400 23,500 4.9 45
CFM56-7B18 600 19,500 5.5 145
CFM56-7B20 6/700 20,600 5.4 148
CFM56-7B22 6/700 22,700 5.3 150
CFM56-7B24 7/8/900 24,200 5.3 125
CFM56-7B26 7/8/900/BBJ 26,400 5.1 85
CFM56-7B27 8/900/BBJ 27,300 5.0 ?

Misc Photos

The left hand side of the CFM56-3. The large silver coloured pipe is the start air manifold with the starter located at its base. The black unit below that is the CSD. The green unit forward (left) of the CSD is the generator cooling air collector shroud, the silver-gold thing forward of that (with the wire bundle visible) is the generator, and the green cap most forward is the generator cooling air inlet.
The view into the JT8D jetpipe.The corrugated ring is the mixer unit, this is designed to thoroughly mix the bypass air with the turbine exhaust.

The exhaust cone makes a divergent flow which slows down the exhaust and also protects the rear face of the last turbine stage.

The view into the CFM56-3 jetpipe.This is the turbine exhaust area, no mixing is required as the bypass air is exhausted coaxially.
There are two fan inlet temperature sensors in the CFM56-3 engine intake. The one at the 2 o’clock position is used by the PMC and the one at the 11 o’clock position is used by the MEC. The MEC uses the signal to establish parameters to control low and high idle power schedules.The temperature data is used for thrust management and variable bleed valves, variable stator vanes & high / low pressure turbine clearance control systems.
The CFM56-7 inlet has just one fan inlet temperature probe, which is for the EEC (because there is no PMC on the NG’s).A subtle difference between the NG & classic temp probes is that the NG’s only use inlet temp data on the ground and for 5 minutes after take-off. In-flight after 5 minutes temp data is taken from the ADIRU’s.

The temperature data is used for thrust management and variable bleed valves, variable stator vanes & high / low pressure turbine clearance control systems.

The CFM56-7 spinner has a unique conelliptical profile. The first 737-3/400’s had a conical (sharp pointed) spinner but these tended to shed ice into the core. This was one of the reasons for the early limitation of minimum 45% N1 in icing conditions which made descent management quite difficult. They were later replaced with elliptical (round nosed) spinners which succeeded in deflecting the ice away from the core, but because of their larger stagnation point, were more prone to picking up ice in the first place. The conelliptical spinner of the NG’s neatly solves both problems.
The CFM56-7 tailpipe is slightly longer then the CFM56-3 and has a small tube protruding from the faring. This is the Aft Fairing Drain Tube for any hydraulic fluid, oil or fuel that may collect in there. There is also a second drain tube that does not protrude located on the inside of the fairing.
The JT8D tailpipe fitted as standard from l/n 135 onwards.The original thrust reversers were totally redesigned by Boeing and Rohr since the aircraft had inherited the same internal pneumatically powered clamshell thrust reversers as the 727 which were relatively ineffective and apparently tended to lift the aircraft off the runway when deployed! The redesign to external hydraulically powered target reversers cost Boeing $24 million but dramatically improved its short field performance which boosted sales to carriers proposing to use the aircraft as a regional jet from short runways. Also the engine nacelles were extended by 1.14m as a drag reduction measure.
The outboard side of the JT8D-9A with the cowling open.

istory

The original choice of powerplant was the Pratt & Whitney JT8D-1, but before the first order had been finalised the JT8D-7 was used for commonality with the current 727. The -7 was flat rated to develop the same thrust (14,000lb.st) at higher ambient temperatures than the -1 and became the standard powerplant for the -100. By the end of the -200 production the JT8D-17R was up to 17,400lb.st. thrust.

Auxiliary inlet doors were fitted to early JT8D’s around the nose cowl. These were spring loaded and opened automatically whenever the pressure differential between inlet and external static pressures was high, ie slow speed, high thrust conditions (takeoff) to give additional engine air and closed again as airspeed increased causing inlet static pressure to rise.

JT8D Cutaway

The sole powerplant for all 737’s after the -200 is the CFM-56. The core is produced by General Electric and is virtually identical to the F101 as used in the Rockwell B-1. SNECMA produce the fan, IP compressor, LP turbine, thrust reversers and all external accessories. The name “CFM” comes from GE’s commercial engine designation “CF” and SNECMA’s “M” for Moteurs.CFM 56 - 3 Cutaway

One problem with such a high bypass engine was its physical size and ground clearance; this was overcome by mounting the accessories on the lower sides to flatten the nacelle bottom and intake lip to give the “hamster pouch” look. The engines were moved forward and raised, level with the upper surface of the wing and tilted 5 degrees up which not only helped the ground clearance but also directed the exhaust downwards which reduced the effects of pylon overheating and gave some vectored thrust to assist take-off performance. The CFM56-3 proved to be almost 20% more efficient than the JT8D.

The NG’s use the CFM56-7B which has a 61 inch diameter solid titanium wide-chord fan, new LP turbine turbomachinery, FADEC, and new single crystal material in the HP turbine. All of which give an 8% fuel reduction, 15% maintenance cost reduction and greater EGT margin compared to the CFM56-3.

One of the most significant improvements in the powerplant has been to the noise levels. The original JT8D-9 engines in 1967 produced 75 decibel levels, enough to disrupt normal conversation indoors, within a noise contour that extended 12 miles along the take-off flight path. Since 1997 with the introduction of the 737-700’s CFM56-7B engines, the 75-decibel noise contour is now only 3.5 miles long.

The core engine (N2) is governed by metering fuel (see below), whereas the fan (N1) is a free turbine. The advantages of this include: minimised inter-stage bleeding, fewer stalls or surges and an increased compression ratio without decreasing efficiency.

This quote from CFMI in 1997:

“Since entering service in 1984, the CFM56-3 has established itself as the standard against which all other engines are judged in terms of reliability, durability, and cost of ownership. The fleet of nearly 1,800 CFM56-3-powered 737s in service worldwide have logged more than 61 million hours and 44 million cycles while maintaining a 99.98 percent dispatch reliability rate (one flight delayed or cancelled for engine-caused reasons per 5,000 departures), a .070 shop visit rate (one unscheduled shop visit per 14,286 flight hours), and an in-flight shutdown rate of .003 (one incident per 333,333 hours).”

Tech Insertion

“Tech Insertion” is an upgrade to the CFM56-5B & 7B available from early 2007. The package includes improvements to the HP compressor, combustor and HP & LP turbines. The package give a longer time on wing, about 5% lower maintenance costs, 15-20% lower oxides of nitrogen (NOx) emissions, and 1% lower fuel burn.

Tech Insertion will become the new production configuration for both the CFM56-7B and CFM56-5B. CFM is also defining potential upgrade kits that could be made available to operators by late 2007.

CFM56-7BE “Evolution”

The new CFM56-7BE Product Improvement package announced in 2009 will have the following design changes & improvements:

  • HPC outlet guide vane diffuser area ratio improved and pressure losses reduced.
  • HPT blades numbers reduced, axial chord increased, tip geometry improved. Rotor redesigned.
  • LPT blade & vane numbers reduced and profiles based on optimized loading distribution. LEAP56 incorporated.
  • Primary nozzle, plug & strut faring all redesigned.

The -7BE will be able to be intermixed with regular SAC/DAC or Tech Insertion engines subject to updated FMC, MEDB and EEC. Entry into service is planned for mid-2011

From the press 2 Aug 2010:

CFM International has won certification for its upgraded CFM56-7BE engine from the FAA and the European Aviation Safety Agency (EASA), and is working with Boeing to prepare for flight tests on a Boeing 737 starting in the fourth quarter of this year.

Entry into service is planned for mid-2011 to coincide with 737 airframe improvements that, together with the engine upgrade, are designed to provide a 2% improvement in fuel consumption. CFM provisionally scheduled engine certification by the end of the third quarter, but says development, including recently completed flight tests, have progressed faster than expected. Improvements include a new high-pressure compressor outlet guide vane diffuser, high-pressure turbine blades, disks and forward outer seal. The package also includes a new design of low-pressure turbine blades, vanes and disk.

The first full CFM56-7BE type design engine completed ground testing in January 2010, and overall completed 390 hours of ground testing, says the Franco-U.S. engine maker. In addition, the upgraded CFM completed a 60-hour certification flight test program in May on GE’s modified 747 flying testbed in Victorville, Calif.

At the recent Farnborough International Airshow, company officials said discussions are continuing with Airbus about a possible upgrade for the CFM56-5B for the A320 family based on the same technology suite. A decision on whether or not an upgraded variant will be developed for Airbus will be finalized by year-end, adds the engine maker.

Fuel

Thrust (fuel flow) is controlled primarily by a hydro-mechanical MEC in response to thrust lever movement, as fitted to the original 737-1/200’s. In the –3/4/500 series, fuel flow is further refined electronically by the PMC, which acts without thrust lever movement. The 737-NG models go one stage further with FADEC (EEC).

The 3/4/500’s may be flown with PMC’s inoperative, but an RTOW penalty (ie N1 reduction) is imposed because the N1 section will increase by approximately 4% during take-off due to windmilling effects (FOTB 737-1, Jan 1985). This reduction should save reaching any engine limits. The thrust levers should not be re-adjusted during the take-off after thrust is set unless a red-line limit is likely to be exceeded, ie you should allow the N1’s to windmill up.

Fuel is heated to avoid icing by the returning oil in the MEC.

Oil

Oil pressure is measured before the bearings, where you need it; oil temperature on return, at its hottest; and oil quantity at the tank, which drops after engine start. Oil pressure is unregulated, therefore the yellow band (13-26psi) is only valid at take-off thrust whereas the lower red line (13psi) is valid at all times. If the oil pressure is ever at or below the red line, the LOW OIL PRESSURE light will illuminate and that engine should be shut down. NB on the 737-1/200 when the oil quantity gauge reads zero, there could still be up to 5 quarts present.

Ignition

There are two independent AC ignition systems, L & R. Starting with R selected on the first flight of the day provides a check of the AC standby bus, which would be your only electrical source with the loss of thrust on both engines and no APU. Normally, in-flight, no igniters are in use as the combustion is self-sustaining. During engine start or take-off & landing, GND & CONT use the selected igniters. In conditions of moderate or severe precipitation, turbulence or icing, or for an in-flight relight, FLT should be selected to use both igniters. NG aircraft: for in-flight engine starts, GRD arms both igniters.

The 737-NG’s allow the EEC to switch the ignition ON or OFF under certain conditions:

  • ON: For flameout protection. The EEC will automatically switch on both ignition systems if a flameout is detected.
  • OFF: For ground start protection. The EEC will automatically switch off both ignition systems if a hot or wet start is detected.

Note that older 737-200s have ignition switch positions named GRD, OFF, L IGN, R IGN and FLT while newer 737s use GRD, OFF, CONT and FLT. This is why QRH uses “ON” (eg in the One Engine Inop Landing checklist) to cover both LOW IGN & CONT for operators with mixed fleets consisting of old and new versions of the 737.

737-200 Ignition panel

Engine Starting

Min duct pressure for start (Classics only): 30psi at msl, -½psi per 1000ft pressure altitude. Max: 48psi.

Min 25% N2 (or 20% N2 at max motoring) to introduce fuel; any sooner could result in a hot start. Max motoring is when N2 does not increase by more than 1% in 5 seconds.

Aborted engine start criteria:

  • No N1 (before start lever is raised to idle).
  • No oil pressure (by the time the engine is stable).
  • No EGT (within 10 secs of start lever being raised to idle).
  • No increase, or very slow increase, in N1 or N2 (after EGT indication).
  • EGT rapidly approaching or exceeding 725˚C.

An abnormal start advisory does not by itself mean that you have to abort the engine start.

Starter cutout is approx 46% N2 -3/4/500; 56% N2 -NG’s.

Starter duty cycle is:

  • First attempt: 2mins on, 20sec off.
  • Second and subsequent attempts: 2mins on, 3mins off.

Do not re-engage engine start switch until N2 is below 20%.

During cold weather starts, oil pressure may temporary exceed the green band or may not show any increase until oil temperature rises. No indication of oil pressure by the time idle RPM is achieved requires an immediate engine shutdown. At low ambient temperatures, a temporary high oil pressure above the green band may be tolerated.

When starting the engines in tailwind conditions, Boeing recommends making a normal start. Expect a longer cranking time to ensure N1 is rotating in the correct direction before moving the start lever. A higher than normal EGT should be expected, yet the same limits and procedures should apply.

Upper DU

Lower DU

Upper DU in Compact Display mode

The Compact Display mode can only be shown when the MFD ENG button is pressed for the first time after the aircraft has been completely shut down. The photo shows this display with one engine started and nicely illustrates the blank parameters which are controlled by the EEC and hence are only displayed when the EEC powers up when the associated start switch is selected to GND. During start-up the EEC’s receive electrical power from the AC transfer busses, but their normal source of power are their own alternators which cut-in when N2 is above 15%.

-200Adv Engine Instruments

Round Dial -3/400 Engine Instruments

3/4/500 EIS
NG EIS

EIS Display

The introduction of Engine Instrument System (EIS) in late 1988 gave many advantages over the electromechanical instruments present since 1967. ie a 10lb weight reduction, improved reliability, reduction in power consumption, detection of impending abnormal starts, storage of exceedances and a Built In Test Equipment (BITE) check facility.

The BITE check is accessed by pressing a small recessed button at the bottom of each eis panel, this is only possible when both engines N1 are below 10%. Pressing these buttons will show an LED check during which the various checks are conducted. If any of the checks fail, the appropriate code will be shown in place of the affected parameters readout. The following codes are used:

Primary EIS BITE Codes
Code Fault
ROM Read Only Memory check
RAM Random Access Memory check
FDC Frequency to Digital Converter check
ENG Engine Identity Inputs (not fuel flow)
PWR Power Monitor
MMF Maint Module Fault (fuel flow only)
RTC Real Time Clock (fuel flow only)
ERF Exceedance RAM Full (fuel flow only)
A/D Analogue to Digital Converter (fuel flow only)
ARF ARINC Receiver Fault (fuel flow only)
uP Microprocessor

Any exceedance of either N1, N2 or EGT is recorded at 1 sec intervals in a non-volatile memory along with the fuel flow at the time, this data can be downloaded by connecting an ARINC 429 bus reader. Up to 10 minutes of data can be stored. The last exceedance is also put into volatile memory and can be read straight from the EIS before aircraft electrical power is removed. This is done by pressing the primary EIS BITE button twice within 2 seconds, this will then alternately display the highest reading and the duration of the exceedance in seconds.

Secondary EIS BITE Codes
Code Fault
0- Microprocessor
1- Program Memory
2- Random Access Memory check
3- Analogue to Digital Converter
4- Power Monitor
5- 400Hz Reference Voltage
6- ARINC Receiver Fault

Airborne Vibration Monitors (AVM)

All series of 737 have the facility for AVM although not all 737-200’s have them fitted. The early 737-1/200’s had two vibration pickup points; One at the turbine section and one at the engine inlet there was a selector switch so that the crew could choose which to monitor. Some even had a high and low frequency filter selection switch.

From Boeing Flt Ops Review, Feb 2003: “On airplanes with AVM procedures, flight crews should also be made aware that AVM indications are not valid while at takeoff power settings, during power changes, or until after engine thermal stabilization. High AVM indications can also be observed during operations in icing conditions.”

High Pressure Turbine Clearance Control

The HPTCC system uses HP compressor bleed air to obtain maximum steady state HPT performance and to minimise EGT transient overshoot during rapid change of engine speed.

Variable Stator Vanes

The VSV actuation system controls primary airflow through the HP compressor by varying the angle of the inlet guide vanes and three stages of variable stator vanes.

Variable Bleed Valves

Control airflow quantity to the HP compressor. They are fully open during rapid accelerations and reverse thrust operation.

Dual Annular Combustors (DAC)

The CFM56-7B is available with an optional DAC system, known as the CFM56-7B/2, which considerably reduces NOx emissions. DAC have 20 double tip fuel nozzles instead of the single tip and a dual annular shaped combustion chamber. The number of nozzles in use: 20/0, 20/10 or 20/20, varies depending upon thrust required. The precise N1 ranges of the different modes varies with ambient conditions.

  • 20/20 mode – High power (cruise N1 and above)
  • 20/10 mode – Medium power
  • 20/00 mode – Low power (Idle N1)

This gives a lean fuel/air mixture, which reduces flame temperatures, and also gives higher throughput velocities which reduce the residence time available to form NOx. The net result is up to 40% less NOx emissions than a standard CFM56-7.

The first were installed on the 737-600 fleet of SAS but unfortunately were subject to resonance in the LPT-1 blades during operation in the 20/10 mode, which occurred in an N1 range usually used during descent and approach. Although there were no in-flight shutdowns, boroscope inspections revealed that the LPT blades were starting to separate. CFM quickly replaced all blades on all DAC engines with reinforced blades and have since replaced them again with a new redesigned blade.

Reverse Thrust

The original 737-1/200 thrust reversers were pneumatically powered clamshell doors taken straight from the 727 (shown left). When reverse was selected, 13th stage bleed air was ported to a pneumatic actuator that rotated the deflector doors and clamshell doors into position. Unfortunately they were relatively ineffective and apparently tended to push the aircraft up off the runway when deployed. This reduced the downforce on the main wheels thereby reducing the effectiveness of the wheel brakes.

By 1969 these had been changed by Boeing and Rohr to the much more successful hydraulically powered target type thrust reversers (shown right). This required a 48 inch extension to the tailpipe to accommodate the two cylindrical deflector doors which were mounted on a four bar linkage system and associated hydraulics. The doors are set 35 degrees away from the vertical to allow the exhaust to be deflected inboard and over the wings and outboard and under the wings. This ensures that exhaust and debris is not blown into the wheel-well, nor is it blown directly downwards which would lift the weight off the wheels or be re-ingested. Fortunately the new longer nacelle improved cruise performance by improving internal airflow within the engine and also reduced cruise drag. These thrust reversers are locked against inadvertent deployment by both deflector door locks and the four bar linkage being overcenter. To illustrate how poor the original clamshell system was, Boeings own data says target type thrust reversers at 1.5 EPR are twice as effective as clamshells at full thrust!

The CFM56 uses blocker doors and cascade vanes to direct fan air forwards. Net reverse thrust is defined as: fan reverser air, minus forward thrust from engine core, plus form drag from the blocker door. As this is significantly greater at higher thrust, reverse thrust should be used immediately after landing or RTO and, if conditions allow, should be reduced to idle by 60kts to avoid debris ingestion damage. Caution: It is possible to deploy reverse thrust when either Rad Alt is below 10ft – this is not recommended.

The REVERSER light shows either control valve or sleeve position disagreement or that the auto-restow circuit is activated. This light will illuminate every time the reverser is commanded to stow, but extinguishes after the stow has completed, and will only bring up master caution ENG if a malfunction has occurred. Recycling the reverse thrust will often clear the fault. If this occurs in-flight, reverse thrust will be available after landing.

The REVERSER UNLOCKED light (EIS panel) is potentially much more serious and will illuminate in-flight if a sleeve has mechanically unlocked. Follow the QRH drill, but only multiple failures will allow the engine to go into reverse thrust.

The 737-1/200 thrust reverser panel has a LOW PRESSURE light which refers to the reverser accumulator pressure when insufficient pressure is available to deploy the reversers. The blue caption between the switches is ISOLATION VALVE and illuminates when the three conditions for reverse thrust are satisfied: Engine running, Aircraft on ground & Fire switches in normal position. The guarded NORMAL / OVERRIDE switches to enable the reverse thrust to be selected on the ground with the engines stopped (for maintenance purposes).

HushKits

The first “hushkit” was not visible externally, in 1982 exhaust mixers were made available for the JT8D-15, -17 or -17R. These were fitted behind the LP turbine to mix the hot gas core airflow with the cooler bypassed fan air. This increased mixing reduced noise levels by up to 3.6 EPNdB.

Several different Stage III hushkits have been available from manufacturers Nordam (shown right) and AvAero since 1992. The Nordam comes in HGW and LGW versions.

As hushkits use more fuel, the EU tried to ban all hushkitted aircraft flying into the EU from April 2002. This was strongly opposed and the directive has been changed to allow hushkitted aircraft to use airports which will accept them.

737 classics may be fitted with hardwall forward acoustic panels which reduce noise by 1 EPNdB

Additional References

Limitations

Series 1/200 3/4/500 6/7/8/900/BBJ
Engine JT8-17A CFM56-3 CFM56-7
 
Max time limit for take-off or go-around thrust: 5 mins 5 mins * 5 mins *
Max N1 102.4% 106% 104%
Max N2 100% 105% 105%
Max EGT’s:
Take-off (5 min limit) 650°C 930°C 950°C
Continuous 610°C 895°C 925°C
Start 575°C 725°C 725°C
Oil T’s & P’s
Max temperature 165°C 165°C 155°C
15 minute limit (45 minute limit on NG) 130-165°C 160-165°C 140-155°C
Max continuous 130°C 160°C 140°C
Min oil press 40psi 13psi (warning light), 26psi (gauge) 13psi (warning light), 26psi (gauge)
Min oil quantity (at dispatch) 2.25 USG 60% full (12 US Quarts) ** 60% full (12 US Quarts) **
Starting pressures prior to starter engagement

30psi -1/2psi per 1000′ amsl

N/A
Starter duty cycle 1st attempt: 2min on, 20sec off

2nd & subsequent attempt: 2min on, 3min off

2mins on, 10secs off.
* May be increased to 10 mins if certified** See AMM Task 12-13-11-600-801

Engine Ratings

Maximum Certified Thrust – This is the maximum thrust certified during testing for each series of 737. This is also the thrust that you get when you firewall the thrust levers, regardless of the maximum rated thrust.

On the 737NG, the EEC limits the maximum certified thrust gained from data in the engine strut according to the airplane model as follows:

Aircraft Series Maximum Certified Thrust
737-600 CFM56-7B22 = 22,700lb.st
737-700 CFM56-7B24 = 24,200lb.st
737-800 CFM56-7B27 = 27,300lb.st
737-900 CFM56-7B27 = 27,300lb.st

Maximum Rated Thrust – This is the maximum thrust for the installed engine that the autothrottle will command. This is specified by the operator from the options in the table below.

Engine Aircraft Series Max Static Thrust (lb.st.) Bypass Ratio EGT Margin (C)
JT8D-7/7A/7B 1/200 14,000 1.10
JT8D-9/9A 1/200 14,500 1.04
JT8D-15/15A 200Adv 15,500 0.99
JT8D-17/17A 200Adv 16,000 1.02
JT8D-17R 200Adv 17,400 1.00
CFM56-3B4 500 18,500 5.0 90
CFM56-3B1 3/500 20,000 5.0 70
CFM56-3B2 3/400 22,000 5.0 50
CFM56-3C1 400 23,500 4.9 45
CFM56-7B18 600 19,500 5.5 145
CFM56-7B20 6/700 20,600 5.4 148
CFM56-7B22 6/700 22,700 5.3 150
CFM56-7B24 7/8/900 24,200 5.3 125
CFM56-7B26 7/8/900/BBJ 26,400 5.1 85
CFM56-7B27 8/900/BBJ 27,300 5.0 ?

Misc Photos

The left hand side of the CFM56-3. The large silver coloured pipe is the start air manifold with the starter located at its base. The black unit below that is the CSD. The green unit forward (left) of the CSD is the generator cooling air collector shroud, the silver-gold thing forward of that (with the wire bundle visible) is the generator, and the green cap most forward is the generator cooling air inlet.
The view into the JT8D jetpipe.The corrugated ring is the mixer unit, this is designed to thoroughly mix the bypass air with the turbine exhaust.

The exhaust cone makes a divergent flow which slows down the exhaust and also protects the rear face of the last turbine stage.

The view into the CFM56-3 jetpipe.This is the turbine exhaust area, no mixing is required as the bypass air is exhausted coaxially.
There are two fan inlet temperature sensors in the CFM56-3 engine intake. The one at the 2 o’clock position is used by the PMC and the one at the 11 o’clock position is used by the MEC. The MEC uses the signal to establish parameters to control low and high idle power schedules.The temperature data is used for thrust management and variable bleed valves, variable stator vanes & high / low pressure turbine clearance control systems.
The CFM56-7 inlet has just one fan inlet temperature probe, which is for the EEC (because there is no PMC on the NG’s).A subtle difference between the NG & classic temp probes is that the NG’s only use inlet temp data on the ground and for 5 minutes after take-off. In-flight after 5 minutes temp data is taken from the ADIRU’s.

The temperature data is used for thrust management and variable bleed valves, variable stator vanes & high / low pressure turbine clearance control systems.

The CFM56-7 spinner has a unique conelliptical profile. The first 737-3/400’s had a conical (sharp pointed) spinner but these tended to shed ice into the core. This was one of the reasons for the early limitation of minimum 45% N1 in icing conditions which made descent management quite difficult. They were later replaced with elliptical (round nosed) spinners which succeeded in deflecting the ice away from the core, but because of their larger stagnation point, were more prone to picking up ice in the first place. The conelliptical spinner of the NG’s neatly solves both problems.
The CFM56-7 tailpipe is slightly longer then the CFM56-3 and has a small tube protruding from the faring. This is the Aft Fairing Drain Tube for any hydraulic fluid, oil or fuel that may collect in there. There is also a second drain tube that does not protrude located on the inside of the fairing.
The JT8D tailpipe fitted as standard from l/n 135 onwards.The original thrust reversers were totally redesigned by Boeing and Rohr since the aircraft had inherited the same internal pneumatically powered clamshell thrust reversers as the 727 which were relatively ineffective and apparently tended to lift the aircraft off the runway when deployed! The redesign to external hydraulically powered target reversers cost Boeing $24 million but dramatically improved its short field performance which boosted sales to carriers proposing to use the aircraft as a regional jet from short runways. Also the engine nacelles were extended by 1.14m as a drag reduction measure.
The outboard side of the JT8D-9A with the cowling open.

Ice and Rain Protection

Panels

737-1/200 Ice & Rain Panel

737-3/4/500 Ice & Rain Panel

737-NG Ice & Rain Panel

Differences:

  1. No alpha vanes
  2. WAI has ground test position
  3. Engine anti-ice captions are: COWL VALVE OPEN, R VALVE OPEN, L VALVE OPEN.
  1. Alpha vanes added
  2. Now only one temp probe (many 1/200’s had two)
  3. TAT TEST button (ie aspirated probe). NB if there is no TAT TEST button you have an unaspirated probe.
  1. Static ports not heated
  2. Aux pitot added.

Window Heat

If window heat is switched ON but the ON light is extinguished, this means that heat is not being applied to the associated window. This could be because the heat controller has detected that the window is becoming overheated (normal on hot days in direct sunlight) and can be verified by touching the window. The heat will automatically be restored when the window has cooled down. To verify that window heat is still available a PWR TEST should illuminate all ON lights if the window heat switches are ON. The PWR TEST forces the temperature controller to full power but overheat protection is still available.

If an OVERHEAT light illuminates, either a window has overheated or electrical power to the window has been interrupted. The affected window heat must be switched OFF and allowed 2-5mins to cool before switching ON again. The OVHT TEST simulates an overheat condition.

 

Pitot Heat

See Instrument Probes page for explanation.

 

Wing Anti Ice

Wing anti-ice (WAI) is very effective and is normally used as a de-icing system in-flight, in applications of 1 minute. On the ground it should be used continuously in icing conditions.

The WAI switch logic is interesting, on the ground, bleed air for WAI will cut-off if either thrust lever is above the take-off warning setting, but will be restored after the thrust is reduced. This allows you to perform engine run-ups etc without having to check that the WAI is still on afterwards. The switch is solenoid held and will trip off at lift-off, this is for performance considerations as the bleed air penalty is considerable.

Note that on early systems, ie those with a GND TEST position, with the WAI switch ON on the ground, the WAI is inhibited until lift-off ie “armed”, This is opposite to the present system.

WAI, unlike engine AI, uses bleed air from the main pneumatic manifold, this is to ensure a source of bleed air during engine out operations. Only the leading edge slats have WAI (ie not leading edge flaps). The NG series outboard slat has no wing anti-ice facility (see photo) believed to be due to excessive bleed requirements. However in June 2005 it was announced that the 737-MMA will have raked wingtips with anti-ice along the full span. This is because the MMA will be spending long periods of time on patrol at low level where it will be exposed to icing conditions.

NB Where QRH ENGINE FAILURE/SHUTDOWN drills ask “If wing anti-ice is required:”, if icing conditions are anticipated, these actions should be completed in preparation for WAI use to prevent asymmetric application. There is no bleed penalty for this reconfiguration until WAI is actually used.

On the NG, if WAI is used for more than 5 secs in-flight, the SMYD will adjust the stick shaker speeds and manouvre speed bars to allow for airframe ice.

Photo: Wing ice on the outboard slat of a 737-700

Engine Anti Ice

Engine anti-ice (EAI) heats the engine cowl to prevent ice build-up, which could break off and enter the engine. The 3/4/500 spinner was originally conical to prevent ice buildup but was changed to an elliptical shape to deflect ice away from the engine core. The NG’s have the best of both worlds with a coneliptical shaped spinner (see photo left) that does both jobs. EAI should be used continuously on the ground and in the air in icing conditions. It uses 5th stage bleed air, augmented by 9th stage as required, from the associated engine. COWL ANTI-ICE lights will illuminate if an overtemp (825F) or overpressure (65psig) condition exists in either duct. In this situation thrust on the associated engine should be reduced until the light extinguishes.

Wing and engine VALVE OPEN lights use the bright blue/dim blue – valve position in disagreement / agreement logic. The wing L and R VALVE OPEN lights in particular may remain bright blue after start and during taxy. This is because they are pneumatically operated, they can be made to open with a modest amount of engine thrust.

 

Airframe Visual Icing Cues

An ice detection system is an option that is rarely taken up on the 737 so it is up to the crew to spot ice formation and take the necessary action. The following photos show some of the places where ice accretion is visible from the flight deck. Note engine anti-ice should be used whenever the temperature and visible moisture criteria are met and not left until ice is seen, to avoid inlet ice build up which may shed into the engine.

 

Under the windscreen wiper blades.

This is one of the first places that ice will form, precipitation falls on the bottom of the windscreen and runs up to the wipers.

This is not an accurate indication of the amount of icing on the airframe because of the stagnation point where the blade and windscreen meet and also because the windscreen is heated.

I would describe conditions where ice forms here as LIGHT ICING.

On the wiper nut

This is my preferred indication of airframe ice accretion. If ice is seen here it is surely also on other parts of the airframe.

The weight and aerodynamic effect of all this ice on the the airframe and control surfaces is why there is the “residual ice” penalty of several tons on the landing performance graphs “If operating in icing conditions during any part of the flight when the forecast landing temperature is below 8C, reduce the normal climb limited landing weight by xxxxkg.” (FPPM 1.3.3).

I would describe conditions where ice forms here as MODERATE ICING.

On the central windscreen pillar

For ice to form on a flat heated windscreen, conditions must be bad. You can see how the shape of the formation follows the airflow lines. You can imagine how much ice is on the rest of the aircraft, especially when you consider that most of it is unheated, particularly on the fin and stabiliser.

Vol 1 SP.16.8 states “Avoid prolonged operation in moderate to severe icing conditions.” This photo was taken at about 20,000ft climbing through the tops of rain bearing frontal cloud. The ice shown here formed in under a minute.

I would describe conditions where ice forms here as SEVERE ICING.

Non-environmental Icing

The NG’s have a problem with frost forming after landing on the wing above the tanks where fuel has been cold soaked. This is officially known as “Wing upper surface non-environmental icing”. The reason is the increased surface area of the fuel that comes into contact with the upper surface of the wing. This is because the shape of the wing fuel tanks was changed (moved outboard) to accommodate the longer landing gear that was in turn required for the increased fuselage lengths of the NG family to reduce the risk of tailstrikes! The only solution until recently has been to limit your arrival fuel to less than approx 4,000kg. Now Boeing have issued guidelines on the acceptable location and amount of upper wing frost.

The Boeing advice is as follows: “Flight crews should visually inspect the lower wing surface. If there is frost or ice on the lower surface, outboard of measuring stick 4, there may also be frost or ice on the upper surface. The distance the frost extends outboard of measuring stick 4 can be used as an indication of the extent of frost on the upper surface. It should be noted that if the thickness of the frost on the lower surface of the wing is 1/16 inch (1.5 mm) thick or less, the thickness of the frost on the upper surface will be less than 1/16 inch (1.5 mm) thick. If the thickness of the frost on the lower surface is greater than 1/16 inch (1.5 mm), then a physical inspection of the upper surface frost is required.”

737-1/200

737-1/2/3/4/500

737-NG

Wiper Controls

One of the most welcome features of the 737-NG is the improvement to the windscreen wipers. The wipers are now independent, have an intermittent position and best of all – are almost silent.

Rain Repellent

The rain repellent has been removed due to worries about the environmental effects of the “RainBoe” fluid used as it contains CFC’s. It is also poisonous and in 1991 Boeing added D-limonine which has a strong smell of orange peel into RainBoe so that leakage could be detected. There are no plans to replace the rain repellent with another liquid product even though there are safe alternatives eg “Le Bozec”.

On 25 May 1982, a 737-200Adv (PP-SMY) was written off by a heavy landing in a rainstorm. One report stated that “The pilots misuse of rain repellent caused an optical illusion”.

Since early 1994 all Boeing aircraft have been built with Surface Seal coated glass from PPG Industries which has a hydrophobic coating. The coating does deteriorate with time depending upon wiper use and windscreen cleaning methods etc, but can be re-applied.

Check out this video of a 737-900 DV window opening during the take-off roll during flight testing. Notice that a high speed abort is not necessary if the DV window opens.

Limitations

Engine anti-ice must be on when icing conditions exist or are anticipated, except during climb and cruise below -40°C SAT.

Use of wing anti-ice above FL350 may cause bleed trip off and possible loss of cabin pressure. (SP.16.8)

 

See also maintenance notes by Ferreira

 

News

13 Aug 2009 – PPG Aerospace to redesign windshields for 737NG

Boeing requests windshield liner to keep glass from flight deck in bird-strike event

HUNTSVILLE, Ala., Aug. 13, 2009 – PPG Industries’ (NYSE:PPG) aerospace transparencies business has been awarded a contract by Spirit AeroSystems to redesign the laminated glass windshields for Boeing’s Next-Generation 737 airplanes. The windshields are being redesigned at Boeing’s request to accommodate airframe improvements. To meet Boeing specifications, the redesigned windshields will be slightly smaller than the current versions and include an inboard plastic antispall liner to prevent broken glass from entering the flight deck during a bird-strike event, according to Art Scott, PPG Aerospace global sales director for commercial original-equipment transparencies. “Boeing has asked for an alternate approach to bird-strike performance for the windshields that works structurally with the 737 airframe,” Scott said. “Adding an antispall liner to the windshields for Next-Generation 737 airplanes enables Boeing to keep the structural airframe design while incorporating newer technology.” PPG will be the sole source of the redesigned windshields for production and aftermarket applications. Scott said PPG expects certification of the new-design windshields in the second quarter 2010. The windshields will be designed and manufactured at PPG’s Huntsville, Ala., facility for delivery to Wichita, Kan., where Spirit makes the fuselage for Boeing.

Panels

737-1/200 Ice & Rain Panel

737-3/4/500 Ice & Rain Panel

737-NG Ice & Rain Panel

Differences:

  1. No alpha vanes
  2. WAI has ground test position
  3. Engine anti-ice captions are: COWL VALVE OPEN, R VALVE OPEN, L VALVE OPEN.
  1. Alpha vanes added
  2. Now only one temp probe (many 1/200’s had two)
  3. TAT TEST button (ie aspirated probe). NB if there is no TAT TEST button you have an unaspirated probe.
  1. Static ports not heated
  2. Aux pitot added.

Window Heat

If window heat is switched ON but the ON light is extinguished, this means that heat is not being applied to the associated window. This could be because the heat controller has detected that the window is becoming overheated (normal on hot days in direct sunlight) and can be verified by touching the window. The heat will automatically be restored when the window has cooled down. To verify that window heat is still available a PWR TEST should illuminate all ON lights if the window heat switches are ON. The PWR TEST forces the temperature controller to full power but overheat protection is still available.

If an OVERHEAT light illuminates, either a window has overheated or electrical power to the window has been interrupted. The affected window heat must be switched OFF and allowed 2-5mins to cool before switching ON again. The OVHT TEST simulates an overheat condition.

Pitot Heat

See Instrument Probes page for explanation.

Wing Anti Ice

Wing anti-ice (WAI) is very effective and is normally used as a de-icing system in-flight, in applications of 1 minute. On the ground it should be used continuously in icing conditions.

The WAI switch logic is interesting, on the ground, bleed air for WAI will cut-off if either thrust lever is above the take-off warning setting, but will be restored after the thrust is reduced. This allows you to perform engine run-ups etc without having to check that the WAI is still on afterwards. The switch is solenoid held and will trip off at lift-off, this is for performance considerations as the bleed air penalty is considerable.

Note that on early systems, ie those with a GND TEST position, with the WAI switch ON on the ground, the WAI is inhibited until lift-off ie “armed”, This is opposite to the present system.

WAI, unlike engine AI, uses bleed air from the main pneumatic manifold, this is to ensure a source of bleed air during engine out operations. Only the leading edge slats have WAI (ie not leading edge flaps). The NG series outboard slat has no wing anti-ice facility (see photo) believed to be due to excessive bleed requirements. However in June 2005 it was announced that the 737-MMA will have raked wingtips with anti-ice along the full span. This is because the MMA will be spending long periods of time on patrol at low level where it will be exposed to icing conditions.

NB Where QRH ENGINE FAILURE/SHUTDOWN drills ask “If wing anti-ice is required:”, if icing conditions are anticipated, these actions should be completed in preparation for WAI use to prevent asymmetric application. There is no bleed penalty for this reconfiguration until WAI is actually used.

On the NG, if WAI is used for more than 5 secs in-flight, the SMYD will adjust the stick shaker speeds and manouvre speed bars to allow for airframe ice.

Photo: Wing ice on the outboard slat of a 737-700

Engine Anti Ice

Engine anti-ice (EAI) heats the engine cowl to prevent ice build-up, which could break off and enter the engine. The 3/4/500 spinner was originally conical to prevent ice buildup but was changed to an elliptical shape to deflect ice away from the engine core. The NG’s have the best of both worlds with a coneliptical shaped spinner (see photo left) that does both jobs. EAI should be used continuously on the ground and in the air in icing conditions. It uses 5th stage bleed air, augmented by 9th stage as required, from the associated engine. COWL ANTI-ICE lights will illuminate if an overtemp (825F) or overpressure (65psig) condition exists in either duct. In this situation thrust on the associated engine should be reduced until the light extinguishes.

Wing and engine VALVE OPEN lights use the bright blue/dim blue – valve position in disagreement / agreement logic. The wing L and R VALVE OPEN lights in particular may remain bright blue after start and during taxy. This is because they are pneumatically operated, they can be made to open with a modest amount of engine thrust.

Airframe Visual Icing Cues

An ice detection system is an option that is rarely taken up on the 737 so it is up to the crew to spot ice formation and take the necessary action. The following photos show some of the places where ice accretion is visible from the flight deck. Note engine anti-ice should be used whenever the temperature and visible moisture criteria are met and not left until ice is seen, to avoid inlet ice build up which may shed into the engine.

Under the windscreen wiper blades.

This is one of the first places that ice will form, precipitation falls on the bottom of the windscreen and runs up to the wipers.

This is not an accurate indication of the amount of icing on the airframe because of the stagnation point where the blade and windscreen meet and also because the windscreen is heated.

I would describe conditions where ice forms here as LIGHT ICING.

On the wiper nut

This is my preferred indication of airframe ice accretion. If ice is seen here it is surely also on other parts of the airframe.

The weight and aerodynamic effect of all this ice on the the airframe and control surfaces is why there is the “residual ice” penalty of several tons on the landing performance graphs “If operating in icing conditions during any part of the flight when the forecast landing temperature is below 8C, reduce the normal climb limited landing weight by xxxxkg.” (FPPM 1.3.3).

I would describe conditions where ice forms here as MODERATE ICING.

On the central windscreen pillar

For ice to form on a flat heated windscreen, conditions must be bad. You can see how the shape of the formation follows the airflow lines. You can imagine how much ice is on the rest of the aircraft, especially when you consider that most of it is unheated, particularly on the fin and stabiliser.

Vol 1 SP.16.8 states “Avoid prolonged operation in moderate to severe icing conditions.” This photo was taken at about 20,000ft climbing through the tops of rain bearing frontal cloud. The ice shown here formed in under a minute.

I would describe conditions where ice forms here as SEVERE ICING.

Non-environmental Icing

The NG’s have a problem with frost forming after landing on the wing above the tanks where fuel has been cold soaked. This is officially known as “Wing upper surface non-environmental icing”. The reason is the increased surface area of the fuel that comes into contact with the upper surface of the wing. This is because the shape of the wing fuel tanks was changed (moved outboard) to accommodate the longer landing gear that was in turn required for the increased fuselage lengths of the NG family to reduce the risk of tailstrikes! The only solution until recently has been to limit your arrival fuel to less than approx 4,000kg. Now Boeing have issued guidelines on the acceptable location and amount of upper wing frost.

The Boeing advice is as follows: “Flight crews should visually inspect the lower wing surface. If there is frost or ice on the lower surface, outboard of measuring stick 4, there may also be frost or ice on the upper surface. The distance the frost extends outboard of measuring stick 4 can be used as an indication of the extent of frost on the upper surface. It should be noted that if the thickness of the frost on the lower surface of the wing is 1/16 inch (1.5 mm) thick or less, the thickness of the frost on the upper surface will be less than 1/16 inch (1.5 mm) thick. If the thickness of the frost on the lower surface is greater than 1/16 inch (1.5 mm), then a physical inspection of the upper surface frost is required.”

737-1/200

737-1/2/3/4/500

737-NG

Wiper Controls

One of the most welcome features of the 737-NG is the improvement to the windscreen wipers. The wipers are now independent, have an intermittent position and best of all – are almost silent.

Rain Repellent

The rain repellent has been removed due to worries about the environmental effects of the “RainBoe” fluid used as it contains CFC’s. It is also poisonous and in 1991 Boeing added D-limonine which has a strong smell of orange peel into RainBoe so that leakage could be detected. There are no plans to replace the rain repellent with another liquid product even though there are safe alternatives eg “Le Bozec”.

On 25 May 1982, a 737-200Adv (PP-SMY) was written off by a heavy landing in a rainstorm. One report stated that “The pilots misuse of rain repellent caused an optical illusion”.

Since early 1994 all Boeing aircraft have been built with Surface Seal coated glass from PPG Industries which has a hydrophobic coating. The coating does deteriorate with time depending upon wiper use and windscreen cleaning methods etc, but can be re-applied.

Check out this video of a 737-900 DV window opening during the take-off roll during flight testing. Notice that a high speed abort is not necessary if the DV window opens.

Limitations

Engine anti-ice must be on when icing conditions exist or are anticipated, except during climb and cruise below -40°C SAT.

Use of wing anti-ice above FL350 may cause bleed trip off and possible loss of cabin pressure. (SP.16.8)

See also maintenance notes by Ferreira

News

13 Aug 2009 – PPG Aerospace to redesign windshields for 737NG

Boeing requests windshield liner to keep glass from flight deck in bird-strike event

HUNTSVILLE, Ala., Aug. 13, 2009 – PPG Industries’ (NYSE:PPG) aerospace transparencies business has been awarded a contract by Spirit AeroSystems to redesign the laminated glass windshields for Boeing’s Next-Generation 737 airplanes. The windshields are being redesigned at Boeing’s request to accommodate airframe improvements. To meet Boeing specifications, the redesigned windshields will be slightly smaller than the current versions and include an inboard plastic antispall liner to prevent broken glass from entering the flight deck during a bird-strike event, according to Art Scott, PPG Aerospace global sales director for commercial original-equipment transparencies. “Boeing has asked for an alternate approach to bird-strike performance for the windshields that works structurally with the 737 airframe,” Scott said. “Adding an antispall liner to the windshields for Next-Generation 737 airplanes enables Boeing to keep the structural airframe design while incorporating newer technology.” PPG will be the sole source of the redesigned windshields for production and aftermarket applications. Scott said PPG expects certification of the new-design windshields in the second quarter 2010. The windshields will be designed and manufactured at PPG’s Huntsville, Ala., facility for delivery to Wichita, Kan., where Spirit makes the fuselage for Boeing.

Hydraulics -B737

Pumps

The hydraulic pump panel -1/200

The 737-1/200 had system A powered by the two Engine Driven Pumps (EDP’s) and system B powered by the two Electric Motor Driven Pumps (EMDP’s). There is also a ground interconnect switch to allow system A to be powered when the engines are shut down.

 

The hydraulic pump panel -300 onwards

From the 737-300 onwards each hydraulic system had both an EDP and an EMDP for greater redundancy in the event of an engine or generator failure.

To see the hydraulic systems (pumps, reservoirs, gauges etc) see wheel-well fwd

Services Supplied

Services Supplied

System A

System B

Standby

A/P “A” A/P “B”  
Ailerons Ailerons  
Rudder Rudder Rudder
  Yaw damper Standby yaw damper (as installed)
Elev & Elev feel Elev & Elev feel  
Inboard flight spoiler Outboard flight spoiler  
Ground spoilers    
  L/E flaps & slats L/E flaps & slats (for extension only)
  T/E flaps  
PTU for autoslats Autoslats  
No1 thrust reverser No2 thrust reverser Nos 1 & 2 thrust reversers (slow)
Nose wheel steering Alt nose wheel steering  
Alternate brakes (man only) Normal (auto & man) brakes  
Landing gear Landing gear transfer unit (retraction only)  

Reservoirs

Hydraulic System B Reservoir Pressure Gauge

The hydraulic reservoirs are pressurised from the pneumatic manifold to ensure a positive flow of fluid reaches the pumps. A from the left manifold and B from the right (see wheel-well fwd). The latest 737’s (mid 2003 onwards) have had their hydraulic reservoir pressurisation system extensively modified to fix two in-service problems 1) hydraulic vapours in the flight deck caused by hydraulic fluid leaking up the reservoir pressurisation line back to the pneumatic manifold giving hydraulic fumes in the air-conditioning and 2) pump low pressure during a very long flight in a cold soaked aircraft. The latter is due to water trapped in the reservoir pressurisation system freezing blocking reservoir bleed air supply. Aircraft which have been modified (SB 737-29-1106) are recognised by only having one reservoir pressure gauge in the wheel well.

 

Fuses

Hydraulic Fuses

Also in the wheel well can be seen the hydraulic fuses. These are essentially spring-loaded shuttle valves which close the hydraulic line if they detect a sudden increase in flow such as a burst downstream, thereby preserving hydraulic fluid for the rest of the services. Hydraulic fuses are fitted to the brake system, L/E flap/slat extend/retract lines, nose gear extend/retract lines and the thrust reverser pressure and return lines.

 

Above schematic courtesy of Leon Van Der Linde. For a more detailed hydraulic schematic diagram, click here.

737-3/400 Hydraulic Gauges

On pre-EIS aircraft (before 1988) the hydraulic gauges were similar to the 737-200. There are now separate quantity gauges since the reservoirs are not interconnected and the markings have been simplified. There is now just a single brake pressure gauge showing the normal brake pressure from system B.

 

 

737-200 Hydraulic Gauges.

Notice that there is only a system A quantity gauge, this is because on the 737-1/200 system B is filled from system A reservoir. System B quantity is monitored by the amber “B LOW QUANTITY” light above. The hydraulic brake pressure gauge has two needles because system A operates the inboard brakes and system B the outboard brakes, each has an accumulator.


Quantities

This table shows the nominal quantities at different levels in the reservoirs

Aircraft Series Originals Classics NG’s
System Gauges EIS Upper CDU
A Full level 3.6 USG 100% 100% (5.7Gal / 21.6Ltrs)
Refill 2.35 USG 88% 76%
EDP Standpipe ? 22% 20%
EMDP Standpipe N/A 0% 0%
B Full level Full 100% 100% (8.2Gal / 31.1Ltrs)
Refill 3/4 88% 76%
Fill & balance line (to standby reservoir) ? 64% 72%
EDP Standpipe N/A 40% 0%
EMDP Standpipe ? 11% 0%

Eg. If you are in say a 737-300 and you notice to System B hydraulic quantity drop to 64%, then from the table above, you may suspect a leak in the balance line or standby reservoir.

Note: Refill figure valid only when airplane is on ground with both engines shutdown or after landing with flaps up during taxi-in.

The hydraulic reservoirs can be filled from the ground service connection point on the forward wall of the stbd wheel well.

Hydraulic ground service connection

Normal hydraulic pressure is 3000 psi

Minimum hydraulic pressure is 2800 psi

Maximum hydraulic pressure is 3500 psi

Normal brake accumulator precharge is 1000 psi

NB The alternate flap system will extend (but not retract) LE devices with standby hydraulic power. It will also extend or retract TE flaps with an electric drive motor but there is no asymmetry protection for this.

LGTU makes Hyd B pressure available for gear retraction when Engine No1 falls below 50% N2

 

Methods for Transfer of Hydraulic Fluid

It should go without saying that if a hydraulic system is low on quantity then you should top up that system with fresh fluid (and find out why it was low!) to avoid cross contamination. However if you really want to move fluid from one system to another here is how to do it.

A to B (1% transfer per cycle)

  1. Chock the aircraft & ensure area around stabiliser is clear.
  2. Switch both EMDP’s OFF.
  3. Release parking brakes and deplete accumulator to below 1800psi by pumping toe brakes.
  4. Switch Sys A EMDP ON and apply parking brakes.
  5. Switch Sys A EMDP OFF and depressurise through control column. (Use stabiliser rather than ailerons to prevent damage to equipment or personnel)
  6. Switch Sys B EMDP ON and release parking brakes. (Sends the fluid back to system B because the shuttle/priority valves send the fluid back to the normal brake system.)

A to B – An alternative method

  1. Chock the aircraft & ensure area around stabiliser is clear.
  2. Switch both EMDP’s ON.
  3. Switch Sys B EMDP OFF and depressurise through control column. (Use stabiliser rather than ailerons to prevent damage to equipment or personnel)
  4. Switch Sys A EMDP ON and apply parking brakes. (Uses fluid from system A)
  5. Switch Sys B EMDP ON and release parking brakes. (Sends the fluid back to system B because the shuttle/priority valves send the fluid back to the normal brake system.)

B to A (4% transfer per cycle)

  1. Ensure area around No1 thrust reverser is clear.
  2. Switch both EMDP’s OFF
  3. Switch either FLT CONTROL to SBY RUD.
  4. Select No1 thrust reverser OUT (uses standby hyd sys)
  5. Switch FLT CONTROL to ON.
  6. Switch Hyd Sys A EMDP ON.
  7. Stow No 1 thrust reverser (using sys A)

Fuel -B737

Fuel Panels

737-1/200 Fuel Panel

 

737-Classic 4-Tank Fuel Panel

 

NG Fuel Panel

 

The maximum declarable fuel capacity for tech log, nav log, etc is 16,200kgs for 3-Tank Classics, 20,800kgs for NG’s and up to 37,712kgs for BBJ’s depending upon how many tanks the customer has specified (max 12). The AFM limits are higher, but not normally achievable with standard SG’s.

The fuel panels for the various series have not changed much over the years. The NG’s have separate ENG VALVE CLOSED & SPAR VALVE CLOSED lights in place of FUEL VALVE CLOSED. The -1/200 panel also has blue VALVE OPEN lights similar to that on the crossfeed valve. The FILTER BYPASS lights were FILTER ICING on the 1/200.

The 1/200’s had heater switches; these used bleed air to heat the fuel and de-ice the fuel filter. They were solenoid held and automatically moved back to OFF after one minute.

NG: The engine spar valves and APU are normally powered by the hot battery bus but have a dedicated battery to ensure that there is always power to shut off the fuel in an emergency.

Fuel Gauges

Analogue Fuel Gauges

-1/200’s and some older -300’s

 

 

Digital Sunburst Fuel Gauges – Simmonds 4 Tank

– 3/4/500’s

Digital Sunburst Fuel Gauges – Smiths

– 3/4/500’s

Fuel Gauge Accuracy

The 737 fuel quantity indication system has the following accuracy tolerances:

737-100/-200:
FQIS accuracy: +/- 3.0%

737-300/-400/-500,
FQIS accuracy with digital indicators: +/- 2.5 %
FQIS accuracy with analog indicators: +/- 3.0%

The total tolerance for the FQIS system is based on a full tank. For example, if the fuel tank maximum capacity is 10,000 KG, then the tolerance of the gauging is 0.03 (airplane with analog indicators) * 10000 = 300 KG. The system tolerance is then +/- 300 KG at any fuel level within the tank.

The accuracy of the fuel flow transmitter is a function of the fuel flow. At engine idle, the system tolerance can be 12%. During cruise, the tolerance is less than 1.5%. The fuel flow indication is integrated over time to calculate the fuel used for each engine.

737-600/-700/-800/-900 with densitometer:
FQIS accuracy: +/- 1.0% overall
Main tanks > 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 1.5%
Main tanks < 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 1.0%

737-600/-700/-800/-900 without densitometer:
FQIS accuracy: +/- 2.0% overall
Main tanks > 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 2.5%
Main tanks < 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 2.0

The total tolerance for the FQIS system is based on a full tank. For example, if the fuel tank maximum capacity is 10,000 KG, then the tolerance of the gauging is 0.02 (airplane without a densitometer) * 10000 = 200 KG. The system tolerance is then +/- 200 KG at any fuel level within the tank.

The accuracy tolerance of the fuel flow transmitter is a function of the fuel flow. At engine idle, the system tolerance can be 12%. During cruise, the tolerance is less than 0.5%. The fuel flow indication is integrated over time to calculate the fuel used for each engine.

On the Digital Sunburst fuel gauges, pressing the “Qty test” button will start a self test of the display and the fuel quantity indicating system. After the test, each gauge will display any error codes that they may have.

Note: The gauges are still considered to be operating normally with error codes 1, 3, 5 or 7 on the Simmonds gauges or error codes 1,3 and 6 on the Smiths gauges. ie If the gauge is indicating (rather than zero) the gauge may be used.

 DU Fuel Gauges

-NG’s

 

Low fuel quantity indication illuminates below either 907 or 453kg

– NG’s

NG fuel gauges can give messages such as LOW, CONFIG or IMBAL

  Digital Fuel Quantity Indicator Error Codes – Simmonds

Error Code Fuel Quantity Indicator Reading Probable Cause Gauges considered to be operating normally?
0 Zero Missing or disconnected tank unit
1 Normal Tank contamination Yes
2 Zero Bad HI-Z lead
3 Normal Bad compensator unit wiring Yes
4 Zero Bad tank unit wiring
5 Normal Bad compensator unit Yes
6 Zero Bad tank unit
7 Normal Contamination/water in compensator Yes
8 Zero Bad fuel quantity indicator
9 Normal or zero Improperly calibrated indicator
Blank Bad fuel quantity indicator

Digital Fuel Quantity Indicator Error Codes – Smiths

Error Code Fuel Quantity Indicator Reading Probable Cause Gauges considered to be operating normally?
1 Normal Open or short in compensator LO-Z wiring Yes
2 Zero Short circuit in compensator unit
3 Normal Too much leakage in compensator unit Yes
4 Zero Open or short circuit in a LO-Z to a tank unit
5 Zero Short circuit in a tank unit
6 Normal Too much leakage in tank unit Yes
7 Zero (or ERR in flight) Calibration unit does not operate correctly
8 Blank An error in the DCTU data
9 Zero (or ERR in flight) A problem with the indicator memory
  10 Zero Open or short circuit in the HI-Z line
Dripsticks

If a fuel gauge is u/s the quantity must be determined by using the dripsticks (floatsticks in later aircraft). The classics have 5 dripsticks in each wing tank and none in the centre tank. The NG has 6 dripsticks in each wing tank and 4 in the centre tank. Because of cumulative errors it is recommended that the wings are filled once every few sectors to ensure an even fuel balance. In-flight, the GW must be periodically updated to ensure the accuracy of VNAV speeds, buffet margin and max altitude.

Floatstick

Fuel quantity is measured by using a series of capacitors in the tanks with fuel acting as the dielectric. Calibration of the fuel gauges is done by capacitance trimmers, these are adjusted to standardise the total tank capacitance and allows for the replacement of gauges. On older aircraft the trimmers were accessible from the flightdeck (below the F/O’s FMC) but they have since been removed to a safer place! Capacitance trimmers

Pumps

There are two AC powered fuel pumps in each tank; there are also EDP’s at each engine. Both fuel pump low pressure lights in any tank are required to illuminate the master caution to avoid spurious warnings at high AoA’s or accelerations. Centre tank LP lights are armed only when their pumps are ON.

Leaving a fuel pump on with a low pressure light illuminated is not only an explosion risk (see Thai and Philippine write offs) but also if a pump is left running dry for over approx 10 minutes it will lose all the fuel required for priming which will render it inoperative even when the tank is refuelled. If you switch on the centre tank pumps and the LP lights remain illuminated for more than 19 seconds then this is probably what has happened. The pumps should be switched off and considered inop until they can be re-primed.

On the 1-500’s, the centre tank pumps are located in a dry area of the wing root but on the NG’s the pumps are actually inside the fuel tank (see photo below). This is why only the NG’s are affected by AD 2002-19-52 which requires the crew to maintain certain minimum fuel levels in the center fuel tanks. You can see the location of the centre tank pumps on the forward wall of the wheel well on the NG’s, since the forward wall is actually the back of the centre fuel tank.

Note: for aircraft delivered after May 2004, centre tank fuel pumps will automatically shut off when they detect a low output pressure.

Right centre tank fuel pump on the forward wall of the wheel well – NG’s only

Centre Tank Scavange Pumps

These transfer fuel from the centre tank into tank 1 at a minimum rate of 100kg/hr, although usually nearer 200kg/hr. The trigger for the scavenge pump is different for the series as follows:

  • Originals: Only fitted after l/n 990 (Dec 1983). Operates the same as the classics.
  • Classics: Switching both centre tank pumps OFF will cause the centre tank scavenge pump to transfer centre tank fuel into tank 1 for 20 minutes.
  • NG’s: The centre tank scavenge pump starts automatically when main tank 1 is half full and its FWD pump is operating. Once started, it will continue for the remainder of the flight.

NB On the classics, when departing with less than 1,000kg of fuel in the centre tank, an imbalance may occur during the climb. This is because the RH centre tank pump will stop feeding due to the body angle so number 2 engine fuel is drawn from main tank 2, while engine 1 is still drawing fuel from the centre tank. When this “runs dry” the scavenge pump will also transfer any remaining centre tank fuel into main tank 1, thereby exacerbating the imbalance.

The APU uses fuel from the number 1 tank. If AC power is available, select the No 1 tank pumps ON for APU operation to assist the fuel control unit, especially during start. Newer –500 series aircraft have an extra, DC operated APU fuel pump in the No 1 tank which operates automatically during the start sequence. The APU burns about 160Kgs/hr with electrics and an air-conditioning pack on and this should be considered in the fuel calculations if expecting a long turnaround or waiting with pax on board for a late slot.


Fuel Temperature

Limitations: Max fuel temp +49ºC, Min fuel temp -45ºC or freezing point +3ºC, whichever is higher. Typical freezing point of Jet A1 is -47ºC. If the fuel temp is approaching the lower limits you could descend into warmer air or accelerate to increase the kinetic heating. Fuel temp is taken from main tank 1 because this will be the coldest as it has less heating from the smaller hydraulic system A.

A fuel sampling and testing kit is kept on the flight deck of all aircraft to test for water.

The NG series are prone to “Upper Wing Surface Non-environmental Icing” or “Cold Soaked Fuel Frost” CSFF. This is due to cold soaked fuel causing frost to form on the wings during the turnarounds – even in warm conditions! From July 2004 NGs have been delivered with markings on the upper surface of the wings where this frost is allowable for despatch under the following conditions:

Takeoff with CSFF on the upper wing surfaces is permissible, provided the following are met:

  • the frost on the upper surface is less than 1/16 inch (1.5 mm) thick
  • the extent of the frost is similar on both wings
  • the frost is on or between the black lines defining the permissible CSFF area
  • the outside air temperature is above freezing(0 C, 32 F)
  • there is no precipitation or visible moisture at the wing surface (rain, drizzle, snow, fog)


 

Auxiliary Fuel System

The standard number of fuel tanks is three. Classics could be fitted with an auxiliary fourth tank which was controlled from the main panel as shown at the top of the page. The 737-200Adv could also be fitted with an auxiliary tank at the forward end of the aft hold; these were available in either 3,065 or 1,421 litre capacities.

BBJ Aux fuel panel located on Capt’s & F/O’s main panels

The BBJ can have up to 9 aux fuel tanks giving it a maximum fuel quantity of 37,712kgs (83,000lbs) although in practice this would probably take you over MTOW if any payload was carried. This fuel would give a theoretical range in excess of 6200nm. The aux tanks are located at the rear of the fwd hold and the front of the aft hold, this reduces the C of G movement as fuel is loaded and used.

Aux fuel tank in aft hold of a BBJ2 (-800 fuselage)

Refuelling of the aux tanks is done by moving the guarded switch in the refuelling panel to AUX TANKS. The controls for main tanks 1 and 2 change to aft aux (AA) and fwd aux (FA) respectively.

The aux fuel system is essentially automatic. It works by transferring fuel from the aux tanks into the centre tank where it is then fed to the engines in the normal way. Flight crew can select fwd or aft tanks but normal practice is to use both to maintain C of G balance. The fwd and aft tanks are switched off when the ALERT light illuminates on the main panel.

Aux fuel control panel (Overhead panel)

There are no pumps in the aux fuel system. Cabin differential pressure (and bleed air as a backup) is used to maintain a head of pressure in the aux tanks to push the aux fuel into the centre tank.

Aux fuel control panel (Aft overhead panel)

(All Aux fuel photos: Capt D Britchford)


Ferry Tank

The 737-200 had provision for a ferry kit. This comprised a 2,000 US Gal (7,570 litre) bladder cell which attached to the seat tracks of the passenger cabin. The fuel was fed to the centre tank through a manual valve by cabin pressure.


Centre Fuel Tank Inerting

To date, two 737’s, 737-400 HS-TDC of Thai Airways on 3 Mar 2001 and 737-300 EI-BZG operated by Philippine Airlines on 5 Nov 1990 have been destroyed on the ground due to explosions in the empty centre fuel tank. The common factor in both accidents was that the centre tank fuel pumps were running in high ambient temperatures with empty or almost empty centre fuel tanks.

Even an empty tank has some unusable fuel which in hot conditions will evaporate and create an explosive mixture with the oxygen in the air. These incidents, and 15 more on other types since 1959, caused the FAA to issue SFAR88 in June 2001 which mandates improvements to the design and maintenance of fuel tanks to reduce the chances of such explosions in the future. These improvements include the redesign of fuel pumps, FQIS, any wiring in tanks, proximity to hot air-conditioning or pneumatic systems, etc.

737s delivered since May 2004 have had centre tank fuel pumps which automatically shut off when they detect a low output pressure and there have been many other improvements to wiring and FQIS. But the biggest improvement will be centre fuel tank inerting. This is universally considered to be the safest way forward, but is very expensive and possibly impractical. The NTSB recommended many years ago to the FAA that a fuel tank inerting system be made mandatory, but the FAA have repeatedly rejected it on cost grounds.

Boeing has developed a Nitrogen Generating System (NGS) which decreases the flammability exposure of the center wing tank to a level equivalent to or less than the main wing tanks. The NGS is an onboard inert gas system that uses an air separation module (ASM) to separate oxygen and nitrogen from the air. After the two components of the air are separated, the nitrogenenriched air (NEA) is supplied to the center wing tank and the oxygenenriched air (OEA) is vented overboard. NEA is produced in sufficient quantities, during most conditions, to decrease the oxygen content to a level where the air volume (ullage) will not support combustion. The FAA Technical Center has determined that an oxygen level of 12% is sufficient to prevent ignition, this is achievable with one module on the 737 but will require up to six on the 747.

On 21 Feb 2006 the Honeywell NGS was certified by the FAA after over 1000hrs flight testing on two 737-NGs. Aircraft from l/n 1935 (Aug 2006) to 2006 were delivered with basic provisions for NGS and more comprehensive provisioning up to l/n 2019. Full production cutover is scheduled for l/n 2620 onwards. The NGS requires no flight or ground crew action for normal system operation and is not dispatch critical.

NGS Panel in the wheel-well

Photo: Lonnie Ganz

This from the FAA Systems Fire Group website:

B-737 Ground / Flight Testing

A series of aircraft flight and ground tests were performed by the Federal Aviation Administration and the Boeing Company to evaluate the effectiveness of ground-based inerting (GBI) as a means of reducing the flammability of fuel tanks in the commercial transport fleet. Boeing made available a Boeing 737 for modification and testing. A nitrogen-enriched air (NEA) distribution manifold, designed, built, and installed by Boeing, allowed for deposit of the ground-based NEA into the center wing tank (CWT). The fuel tank was instrumented with gas sample tubing and thermocouples to allow for a measurement of fuel tank inerting and heating during the testing. The FAA developed an in-flight gas sampling system, integrated with eight oxygen analyzers, to continuously monitor the ullage oxygen concentration at eight different locations. Other data such as fuel load, air speed, altitude, and similar flight parameters were made available from the aircraft data bus. A series of ten tests were performed (five flight, five ground) under different ground and flight conditions to demonstrate the ability of GBI to reduce fuel tank flammability. It was demonstrated under the most hazardous condition-an empty center wing tank-that GBI would remain effective for a large portion of the flight, or until aircraft descent. However, it was also shown that the dual venting configuration of some Boeing airplanes would have to be modified to prevent loss of inerting at certain ground and flight cross flow conditions.

Download the Final Report (DOT/FAA/AR-01/63)  (4.8Mb)

 


Limitations

Max temp +49°C
Min temp -43°C or freeze pt +3°C
Max quantity 1/200: 4300 + 4100 + 4300 = 12,700kg  (2 bag ctr bays)
200Adv: 4300 + 5400 + 4300 = 14,000kg  (3 bag ctr bays)
200Adv: 4300 + 7000 + 4300 = 15,600kg  (3 bag integral)
3/4/500: 4600 + 7000 + 4600 = 16,200kg
NG’s:    3900 + 13000 + 3900 = 20,800kg
Max lateral imbalance 1/200: 680kg; All other series: 453kg
Main tanks to be full if centre contains over 453kg
For ground operation, centre tank pumps must be not be positioned to ON, unless defuelling or transferring fuel, if quantity is below 453kgs.
Centre tank pumps must be switched OFF when both LP lights illuminate.
Centre tank pumps must not be left ON unless personnel are available in the flight deck to monitor LP lights.
Centre tank pumps should not be allowed to run dry or be left running unsupervised. Crew reset of fuel pump circuit breakers in-flight is prohibited (QRH CI.2.2)

Fuel Panels

737-1/200 Fuel Panel 737-Classic 4-Tank Fuel Panel NG Fuel Panel
The maximum declarable fuel capacity for tech log, nav log, etc is 16,200kgs for 3-Tank Classics, 20,800kgs for NG’s and up to 37,712kgs for BBJ’s depending upon how many tanks the customer has specified (max 12). The AFM limits are higher, but not normally achievable with standard SG’s.

The fuel panels for the various series have not changed much over the years. The NG’s have separate ENG VALVE CLOSED & SPAR VALVE CLOSED lights in place of FUEL VALVE CLOSED. The -1/200 panel also has blue VALVE OPEN lights similar to that on the crossfeed valve. The FILTER BYPASS lights were FILTER ICING on the 1/200.

The 1/200’s had heater switches; these used bleed air to heat the fuel and de-ice the fuel filter. They were solenoid held and automatically moved back to OFF after one minute.

NG: The engine spar valves and APU are normally powered by the hot battery bus but have a dedicated battery to ensure that there is always power to shut off the fuel in an emergency.

Fuel Gauges

Analogue Fuel Gauges

-1/200’s and some older -300’s

 

Digital Sunburst Fuel Gauges – Simmonds 4 Tank

– 3/4/500’s

Digital Sunburst Fuel Gauges – Smiths

– 3/4/500’s

Fuel Gauge Accuracy

The 737 fuel quantity indication system has the following accuracy tolerances:

737-100/-200:
FQIS accuracy: +/- 3.0%

737-300/-400/-500,
FQIS accuracy with digital indicators: +/- 2.5 %
FQIS accuracy with analog indicators: +/- 3.0%

The total tolerance for the FQIS system is based on a full tank. For example, if the fuel tank maximum capacity is 10,000 KG, then the tolerance of the gauging is 0.03 (airplane with analog indicators) * 10000 = 300 KG. The system tolerance is then +/- 300 KG at any fuel level within the tank.

The accuracy of the fuel flow transmitter is a function of the fuel flow. At engine idle, the system tolerance can be 12%. During cruise, the tolerance is less than 1.5%. The fuel flow indication is integrated over time to calculate the fuel used for each engine.

737-600/-700/-800/-900 with densitometer:
FQIS accuracy: +/- 1.0% overall
Main tanks > 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 1.5%
Main tanks < 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 1.0%

737-600/-700/-800/-900 without densitometer:
FQIS accuracy: +/- 2.0% overall
Main tanks > 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 2.5%
Main tanks < 50%, -1 to 5 deg pitch, +/- 1 deg roll: +/- 2.0

The total tolerance for the FQIS system is based on a full tank. For example, if the fuel tank maximum capacity is 10,000 KG, then the tolerance of the gauging is 0.02 (airplane without a densitometer) * 10000 = 200 KG. The system tolerance is then +/- 200 KG at any fuel level within the tank.

The accuracy tolerance of the fuel flow transmitter is a function of the fuel flow. At engine idle, the system tolerance can be 12%. During cruise, the tolerance is less than 0.5%. The fuel flow indication is integrated over time to calculate the fuel used for each engine.

On the Digital Sunburst fuel gauges, pressing the “Qty test” button will start a self test of the display and the fuel quantity indicating system. After the test, each gauge will display any error codes that they may have.

Note: The gauges are still considered to be operating normally with error codes 1, 3, 5 or 7 on the Simmonds gauges or error codes 1,3 and 6 on the Smiths gauges. ie If the gauge is indicating (rather than zero) the gauge may be used.

 DU Fuel Gauges

-NG’s

 

Low fuel quantity indication illuminates below either 907 or 453kg

– NG’s

NG fuel gauges can give messages such as LOW, CONFIG or IMBAL

  Digital Fuel Quantity Indicator Error Codes – Simmonds

Error Code Fuel Quantity Indicator Reading Probable Cause Gauges considered to be operating normally?
0 Zero Missing or disconnected tank unit
1 Normal Tank contamination Yes
2 Zero Bad HI-Z lead
3 Normal Bad compensator unit wiring Yes
4 Zero Bad tank unit wiring
5 Normal Bad compensator unit Yes
6 Zero Bad tank unit
7 Normal Contamination/water in compensator Yes
8 Zero Bad fuel quantity indicator
9 Normal or zero Improperly calibrated indicator
Blank Bad fuel quantity indicator

Digital Fuel Quantity Indicator Error Codes – Smiths

Error Code Fuel Quantity Indicator Reading Probable Cause Gauges considered to be operating normally?
1 Normal Open or short in compensator LO-Z wiring Yes
2 Zero Short circuit in compensator unit
3 Normal Too much leakage in compensator unit Yes
4 Zero Open or short circuit in a LO-Z to a tank unit
5 Zero Short circuit in a tank unit
6 Normal Too much leakage in tank unit Yes
7 Zero (or ERR in flight) Calibration unit does not operate correctly
8 Blank An error in the DCTU data
9 Zero (or ERR in flight) A problem with the indicator memory
  10 Zero Open or short circuit in the HI-Z line
Dripsticks

If a fuel gauge is u/s the quantity must be determined by using the dripsticks (floatsticks in later aircraft). The classics have 5 dripsticks in each wing tank and none in the centre tank. The NG has 6 dripsticks in each wing tank and 4 in the centre tank. Because of cumulative errors it is recommended that the wings are filled once every few sectors to ensure an even fuel balance. In-flight, the GW must be periodically updated to ensure the accuracy of VNAV speeds, buffet margin and max altitude.

Floatstick

Fuel quantity is measured by using a series of capacitors in the tanks with fuel acting as the dielectric. Calibration of the fuel gauges is done by capacitance trimmers, these are adjusted to standardise the total tank capacitance and allows for the replacement of gauges. On older aircraft the trimmers were accessible from the flightdeck (below the F/O’s FMC) but they have since been removed to a safer place! Capacitance trimmers

Pumps

There are two AC powered fuel pumps in each tank; there are also EDP’s at each engine. Both fuel pump low pressure lights in any tank are required to illuminate the master caution to avoid spurious warnings at high AoA’s or accelerations. Centre tank LP lights are armed only when their pumps are ON.

Leaving a fuel pump on with a low pressure light illuminated is not only an explosion risk (see Thai and Philippine write offs) but also if a pump is left running dry for over approx 10 minutes it will lose all the fuel required for priming which will render it inoperative even when the tank is refuelled. If you switch on the centre tank pumps and the LP lights remain illuminated for more than 19 seconds then this is probably what has happened. The pumps should be switched off and considered inop until they can be re-primed.

On the 1-500’s, the centre tank pumps are located in a dry area of the wing root but on the NG’s the pumps are actually inside the fuel tank (see photo below). This is why only the NG’s are affected by AD 2002-19-52 which requires the crew to maintain certain minimum fuel levels in the center fuel tanks. You can see the location of the centre tank pumps on the forward wall of the wheel well on the NG’s, since the forward wall is actually the back of the centre fuel tank.

Note: for aircraft delivered after May 2004, centre tank fuel pumps will automatically shut off when they detect a low output pressure.

Right centre tank fuel pump on the forward wall of the wheel well – NG’s only

Centre Tank Scavange Pumps

These transfer fuel from the centre tank into tank 1 at a minimum rate of 100kg/hr, although usually nearer 200kg/hr. The trigger for the scavenge pump is different for the series as follows:

  • Originals: Only fitted after l/n 990 (Dec 1983). Operates the same as the classics.
  • Classics: Switching both centre tank pumps OFF will cause the centre tank scavenge pump to transfer centre tank fuel into tank 1 for 20 minutes.
  • NG’s: The centre tank scavenge pump starts automatically when main tank 1 is half full and its FWD pump is operating. Once started, it will continue for the remainder of the flight.

NB On the classics, when departing with less than 1,000kg of fuel in the centre tank, an imbalance may occur during the climb. This is because the RH centre tank pump will stop feeding due to the body angle so number 2 engine fuel is drawn from main tank 2, while engine 1 is still drawing fuel from the centre tank. When this “runs dry” the scavenge pump will also transfer any remaining centre tank fuel into main tank 1, thereby exacerbating the imbalance.

The APU uses fuel from the number 1 tank. If AC power is available, select the No 1 tank pumps ON for APU operation to assist the fuel control unit, especially during start. Newer –500 series aircraft have an extra, DC operated APU fuel pump in the No 1 tank which operates automatically during the start sequence. The APU burns about 160Kgs/hr with electrics and an air-conditioning pack on and this should be considered in the fuel calculations if expecting a long turnaround or waiting with pax on board for a late slot.


Fuel Temperature

Limitations: Max fuel temp +49ºC, Min fuel temp -45ºC or freezing point +3ºC, whichever is higher. Typical freezing point of Jet A1 is -47ºC. If the fuel temp is approaching the lower limits you could descend into warmer air or accelerate to increase the kinetic heating. Fuel temp is taken from main tank 1 because this will be the coldest as it has less heating from the smaller hydraulic system A.

A fuel sampling and testing kit is kept on the flight deck of all aircraft to test for water.

The NG series are prone to “Upper Wing Surface Non-environmental Icing” or “Cold Soaked Fuel Frost” CSFF. This is due to cold soaked fuel causing frost to form on the wings during the turnarounds – even in warm conditions! From July 2004 NGs have been delivered with markings on the upper surface of the wings where this frost is allowable for despatch under the following conditions:

Takeoff with CSFF on the upper wing surfaces is permissible, provided the following are met:

  • the frost on the upper surface is less than 1/16 inch (1.5 mm) thick
  • the extent of the frost is similar on both wings
  • the frost is on or between the black lines defining the permissible CSFF area
  • the outside air temperature is above freezing(0 C, 32 F)
  • there is no precipitation or visible moisture at the wing surface (rain, drizzle, snow, fog)


Auxiliary Fuel System

The standard number of fuel tanks is three. Classics could be fitted with an auxiliary fourth tank which was controlled from the main panel as shown at the top of the page. The 737-200Adv could also be fitted with an auxiliary tank at the forward end of the aft hold; these were available in either 3,065 or 1,421 litre capacities.

BBJ Aux fuel panel located on Capt’s & F/O’s main panels

The BBJ can have up to 9 aux fuel tanks giving it a maximum fuel quantity of 37,712kgs (83,000lbs) although in practice this would probably take you over MTOW if any payload was carried. This fuel would give a theoretical range in excess of 6200nm. The aux tanks are located at the rear of the fwd hold and the front of the aft hold, this reduces the C of G movement as fuel is loaded and used.

Aux fuel tank in aft hold of a BBJ2 (-800 fuselage)

Refuelling of the aux tanks is done by moving the guarded switch in the refuelling panel to AUX TANKS. The controls for main tanks 1 and 2 change to aft aux (AA) and fwd aux (FA) respectively.

The aux fuel system is essentially automatic. It works by transferring fuel from the aux tanks into the centre tank where it is then fed to the engines in the normal way. Flight crew can select fwd or aft tanks but normal practice is to use both to maintain C of G balance. The fwd and aft tanks are switched off when the ALERT light illuminates on the main panel.

Aux fuel control panel (Overhead panel)

There are no pumps in the aux fuel system. Cabin differential pressure (and bleed air as a backup) is used to maintain a head of pressure in the aux tanks to push the aux fuel into the centre tank.

Aux fuel control panel (Aft overhead panel)

(All Aux fuel photos: Capt D Britchford)


Ferry Tank

The 737-200 had provision for a ferry kit. This comprised a 2,000 US Gal (7,570 litre) bladder cell which attached to the seat tracks of the passenger cabin. The fuel was fed to the centre tank through a manual valve by cabin pressure.


Centre Fuel Tank Inerting

To date, two 737’s, 737-400 HS-TDC of Thai Airways on 3 Mar 2001 and 737-300 EI-BZG operated by Philippine Airlines on 5 Nov 1990 have been destroyed on the ground due to explosions in the empty centre fuel tank. The common factor in both accidents was that the centre tank fuel pumps were running in high ambient temperatures with empty or almost empty centre fuel tanks.

Even an empty tank has some unusable fuel which in hot conditions will evaporate and create an explosive mixture with the oxygen in the air. These incidents, and 15 more on other types since 1959, caused the FAA to issue SFAR88 in June 2001 which mandates improvements to the design and maintenance of fuel tanks to reduce the chances of such explosions in the future. These improvements include the redesign of fuel pumps, FQIS, any wiring in tanks, proximity to hot air-conditioning or pneumatic systems, etc.

737s delivered since May 2004 have had centre tank fuel pumps which automatically shut off when they detect a low output pressure and there have been many other improvements to wiring and FQIS. But the biggest improvement will be centre fuel tank inerting. This is universally considered to be the safest way forward, but is very expensive and possibly impractical. The NTSB recommended many years ago to the FAA that a fuel tank inerting system be made mandatory, but the FAA have repeatedly rejected it on cost grounds.

Boeing has developed a Nitrogen Generating System (NGS) which decreases the flammability exposure of the center wing tank to a level equivalent to or less than the main wing tanks. The NGS is an onboard inert gas system that uses an air separation module (ASM) to separate oxygen and nitrogen from the air. After the two components of the air are separated, the nitrogenenriched air (NEA) is supplied to the center wing tank and the oxygenenriched air (OEA) is vented overboard. NEA is produced in sufficient quantities, during most conditions, to decrease the oxygen content to a level where the air volume (ullage) will not support combustion. The FAA Technical Center has determined that an oxygen level of 12% is sufficient to prevent ignition, this is achievable with one module on the 737 but will require up to six on the 747.

On 21 Feb 2006 the Honeywell NGS was certified by the FAA after over 1000hrs flight testing on two 737-NGs. Aircraft from l/n 1935 (Aug 2006) to 2006 were delivered with basic provisions for NGS and more comprehensive provisioning up to l/n 2019. Full production cutover is scheduled for l/n 2620 onwards. The NGS requires no flight or ground crew action for normal system operation and is not dispatch critical.

NGS Panel in the wheel-well

Photo: Lonnie Ganz

This from the FAA Systems Fire Group website:

B-737 Ground / Flight Testing

A series of aircraft flight and ground tests were performed by the Federal Aviation Administration and the Boeing Company to evaluate the effectiveness of ground-based inerting (GBI) as a means of reducing the flammability of fuel tanks in the commercial transport fleet. Boeing made available a Boeing 737 for modification and testing. A nitrogen-enriched air (NEA) distribution manifold, designed, built, and installed by Boeing, allowed for deposit of the ground-based NEA into the center wing tank (CWT). The fuel tank was instrumented with gas sample tubing and thermocouples to allow for a measurement of fuel tank inerting and heating during the testing. The FAA developed an in-flight gas sampling system, integrated with eight oxygen analyzers, to continuously monitor the ullage oxygen concentration at eight different locations. Other data such as fuel load, air speed, altitude, and similar flight parameters were made available from the aircraft data bus. A series of ten tests were performed (five flight, five ground) under different ground and flight conditions to demonstrate the ability of GBI to reduce fuel tank flammability. It was demonstrated under the most hazardous condition-an empty center wing tank-that GBI would remain effective for a large portion of the flight, or until aircraft descent. However, it was also shown that the dual venting configuration of some Boeing airplanes would have to be modified to prevent loss of inerting at certain ground and flight cross flow conditions.

Download the Final Report (DOT/FAA/AR-01/63)  (4.8Mb)


Limitations

Max temp +49°C
Min temp -43°C or freeze pt +3°C
Max quantity 1/200: 4300 + 4100 + 4300 = 12,700kg  (2 bag ctr bays)
200Adv: 4300 + 5400 + 4300 = 14,000kg  (3 bag ctr bays)
200Adv: 4300 + 7000 + 4300 = 15,600kg  (3 bag integral)
3/4/500: 4600 + 7000 + 4600 = 16,200kg
NG’s:    3900 + 13000 + 3900 = 20,800kg
Max lateral imbalance 1/200: 680kg; All other series: 453kg
Main tanks to be full if centre contains over 453kg
For ground operation, centre tank pumps must be not be positioned to ON, unless defuelling or transferring fuel, if quantity is below 453kgs.
Centre tank pumps must be switched OFF when both LP lights illuminate.
Centre tank pumps must not be left ON unless personnel are available in the flight deck to monitor LP lights.
Centre tank pumps should not be allowed to run dry or be left running unsupervised. Crew reset of fuel pump circuit breakers in-flight is prohibited (QRH CI.2.2)

Advanced Blended Winglets -B737

Winglets

The most noticeable feature to appear on new 737s are the winglets. These are wing tip extensions which reduce lift induced drag and provide some extra lift. They have been credited to Dr Louis Gratzer formerly Chief of Aerodynamics at Boeing and now with Aviation Partners Boeing (APB). They were first flown on a 737-800 in June 1998 as a testbed for use on the BBJ. They are now available as a standard production line option for all NGs with the exception of the -600 series, for which Boeing is “continuing to assess the applicability”. They are also available as a retrofit from APB. They are 8ft 2in tall and about 4 feet wide at the base, narrowing to approximately two feet at the tip and add almost 5 feet to the total wingspan. The winglet for the Classic is slightly shorter at 7ft tall. Over half of all 737NGs have had winglets retrofitted.

Winglets are also available for Classics. The first winglet equipped 737-300 flew in Nov 2002 and gained its FAA supplemental type certificate (STC) on 30 May 2003. Winglet equipped Classics are known as Special Performance (SP).

Winglets have the potential to give the following benefits:

  • Improved climb gradient. This will enable a higher RTOW from climb limited airports (hot, high or noise abatement) or obstacle limited runways.
  • Reduced climb thrust. A winglet equipped aircraft can typically take a 3% derate over the non-winglet equivalent aircraft. This can extend engine life and reduce maintenance costs.
  • Environmentally friendly. The derate, if taken, will reduce the noise footprint by 6.5% and NOx emissions by 5%. This could give savings on airport noise quotas or fines.
  • Reduced cruise thrust. Cruise fuel flow is reduced by up to 6% giving savings in fuel costs and increasing range.
  • Improved cruise performance. Winglets can allow aircraft to reach higher levels sooner. Air Berlin notes, “Previously, we’d step-climb from 35,000 to 41,000 feet. With Blended Winglets, we can now climb direct to 41,000 feet where traffic congestion is much less and we can take advantage of direct routings and shortcuts which we could not otherwise consider.”
  • Good looks. Winglets bring a modern look and feel to aircraft, and improve customers’ perceptions of the airline.

If winglets are so good, you may wonder why all 737s don’t have them. In fact 85% of all new 737s are now built with winglets, particularly the 800 and 900 series and of course all BBJs. It comes down to cost versus benefits. Winglets cost about $725,000USD and take about 1 week to install which costs an extra $25-80,000USD. Once fitted, they add 170-235kg (375-518lbs) to the weight of the aircraft, depending upon whether they were installed at production or a retrofit. The fuel cost of carrying this extra weight will take some flying time each sector to recover, although this is offset by the need to carry less fuel because of the increased range. In simple terms, if your average sector length is short (less than one hour) you wont get much the benefit from winglets – unless you need any of the other benefits such as reduced noise or you regularly operate from obstacle limited runways.

There is a small difference in rotation rate for aircraft with winglets installed and, as a result, the crew needs to be cautious of pitch rate. There is approximately a ½ unit take-off trim change between non-winglet and winglet aircraft so the green band is slightly different for winglet aircraft. Finally, the dry “maximum demonstrated” crosswind limit is slightly reduced with winglets to 34kts. According to APB this is because “the FAA will only let us document the max winds experienced during flight test… so if we had been able to find more crosswind, then the 33kts might have been more. There appears to be no weather cocking effect due to winglets.”

Other winglet News Stories

An excellent article by Boeing in Aero 17 is available at:

http://www.boeing.com/commercial/aeromagazine/aero_17/winglet_story.html

Next-Generation 737 Production Winglets

Description
Winglets are wing tip extensions which provide several benefits to airplane operators. The winglet option increases the Next-Generation 737’s lead as the newest and most technologically advanced airplane in its class. These new technology winglets are now available on 737-800s as well as on the Boeing Business Jet (737-700 and 737-800).

There are two types of winglet available, Boeing’s own built into the wing at the time of manufacture and the APB winglet as a retrofit.

Benefits
Depending on the airplane, its cargo, the airline’s routes and other factors, winglets have the potential to give:IMPROVED TAKEOFF PERFORMANCE

By allowing a steeper climb, winglets pay off in better takeoff performance, especially from obstacle-limited, high, hot, weight-limited, and/or noise-restricted airports. Performance Improved climb gradients increase 737-800 allowable takeoff weight (TOW).

Some examples include:

  • Chicago-Midway: ~1,600 lb additional TOW
  • Lanzarote (Canary Islands): ~3,500 lb additional TOW
  • Albuquerque, Denver, and Salt Lake City: ~4,400 lb additional TOW

REDUCED ENGINE MAINTENANCE COSTS

Better climb performance also allows lower thrust settings, thus extending engine life and reducing maintenance costs. Lower Required Thrust Levels Extend On-Wing Life.

Takeoff – Winglets allow up to 3% incremental derate.

Cruise – Cruise thrust levels are reduced by up to 4%.

FUEL SAVINGS

Winglets lower drag and improve aerodynamic efficiency, thus reducing fuel burn. Depending on the missions you fly, blended winglets can improve cruise fuel mileage up to 6 percent, especially important during a time of rising fuel prices.

INCREASED PAYLOAD RANGE

The addition of Aviation Partners Blended Winglets to the 737 Next Generation has demonstrated drag reduction in the 5 to 7% range that measurably increases range and fuel efficiency . In addition, the Blended Winglets allow the 737-NG to take off from higher, hotter airports with increased payload.

Series Range (nm) Normal Range (nm) With Winglets
-700 3250 3634
-800 2930 3060
-900 2670 2725

ENVIRONMENTALLY FRIENDLY

With winglets, you can be a good neighbour in the community you serve. They enhance performance at noise-restricted airports and cut the affected area by 6.5 percent, saving you money on airport noise quotas or fines. By reducing fuel consumption, winglets help lower NOx emissions by 5%.

IMPROVED OPERATIONAL FLEXIBILITY

By increasing Payload Range and Overall Performance, Blended Winglets add flexibility to fleet operations and route selection. Air Berlin notes, “Previously, we’d step-climb from 35,000 to 41,000 feet. With Blended Winglets, we can now climb direct to 41,000 feet where traffic congestion is much less and we can take advantage of direct routings and shortcuts which we could not otherwise consider.”

MODERN DRAMATIC APPEARANCE

Blended Winglets bring a modern look and feel to aircraft, and improve customers’ perceptions of the reliability and modernity of the Airline.

Dimensions
Each winglet is 8 feet long and 4 feet in width at the base, narrowing to approximately two feet at the tip.

Added wingspan
Winglets add approximately 5 feet to the airplane’s total wingspan – from 112 feet 7 inches to 117 feet 2 inches. (All Next-Generation 737 models have the same wingspan.)

Weight
Each winglet weighs about 132 pounds. Increased weight to the airplane for modifying wing and installing winglets is about 480 pounds.

Airplane provisions
Structural modifications to accommodate the winglet include strengthening the wing’s centre section and other internal strengthening on the wing. These enhancements are done in the normal production process. Various systems changes have also been made to accommodate winglet installation.

Offerability
Production and retrofit winglets for the Next-Generation 737s are available through Boeing (production) and Aviation Partners Boeing (retrofit). Aviation Partners Boeing (APB) is a joint venture partnership between Boeing and Aviation Partners Inc. (API).

Certification
Retrofit FAA Supplemental Type Certificate (STC) was granted to APB on 3/23/2001. LBA (German regulatory agency) STC was granted to APB on 5/4/2001. JAA STC was granted May 2001. Boeing PLOD (program letter of definition) was granted 5/9/2001 by both the FAA and JAA for Boeing production.

Availability
737-700, 737-800, 737-900, 737-BBJ – available now. Deliveries began May 2001. Initial customers included: South African Airways, Air Berlin, American Trans Air, Polynesian Airlines, and Hainan Airlines – both through direct purchase and leasing options via ILF, GATX, GE Capital Corp., and Flightlease.

Operational Considerations
There is a small difference in rotation rate for airplanes with winglets installed and, as a result, the crew needs to be cautious of pitch rate. There is also approximately a ½ unit take-off trim change between non-winglet and winglet aircraft so the green band is slightly different for winglet aircraft.


737-200 Mini-Winglets

  This is a 737-200Adv, L/N 628, fitted with mini-winglets. This is part of the Quiet Wing Corp flap modification kit which gained its FAA certification in 2005. The package includes drooping the TE flaps by 4 degrees and the ailerons by 1 degree to increase to camber of the wing. Benefits include:

  • Payload Increase of up to 5,000 lbs.
  • Range Increase up to 3%
  • Fuel Savings up to 3%
  • Improved Takeoff/Landing Climb Gradients
  • Reduced Takeoff/Landing Field Length
  • Improved High Altitude Takeoff/Landing Capability
  • Improved Hot Climate Performance
  • Reduced Stall Speeds by 4-5kts

Photo: Julian Whitelaw


News Stories

30 Apr 2007 – APB selects UK supplier as it launches 767-300ER programme with American order UK-based GKN Aerospace has been selected by Aviation Partners Boeing (APB) as a new supplier of the US company’s blended winglets for the rapidly expanding Boeing 737 “Classic” and newly launched 767 retrofit programmes, while United Airlines is poised to start retrofitting its 757s.

The aerostructures specialist joins APB winglet supplier Kawasaki Heavy Industries. Winglets for the 737 Next Generation. Despite the much-needed addition of GKN, APB says the 737 Classic retrofit line is sold out through 2009 at the rate of six shipsets a month. “We’re still going to ramp up as fast as we can, but it will be the end of this year or early next before they can begin providing the first parts,” says APB vice-president sales Patrick LaMoria.


26 Dec 2006 – Aviation Partners Boeing Launches 737-900 Blended Winglet Program

With program launch of Aviation Partners Boeing 737-900 Blended Winglets, and first deliveries slated for December 2007, the world’s airways will soon be making room for even more Blended Winglet Performance Enhanced airplanes. Launch customers Continental Airlines, KLM and Alaska Airlines plan to complete the retrofit of their 737- 900s by the end of the first quarter of 2008.

“We’ve had a great deal of customer interest in 737-900 Blended Winglets and this important new program gives more of our operators commonality and the ability to fly with 100% Blended Winglet equipped 737NG fleets,” says Aviation Partners Boeing CEO John Reimers. “This program is off to a very strong start and we anticipate that the remaining handful of operators of the 737-900 will be unable to ignore the tremendous value Blended Winglets add to the aircraft.”

Benefits of Aviation Partners Boeing’s Visible Technology are nothing short of dramatic in fuel savings, improved performance and environmental advantages. Given average aircraft utilization rates, operators will save over 100,000 gallons (380,000 liters) of fuel per aircraft per year resulting in a payback on investment of less than 3 years. Noise footprint, on takeoff and landing, is reduced by an average of 6.5% while engine emissions of carbon dioxide and nitrous oxides are lowered on the order of 5.0%.

“Blended Winglets will give KLM improved range and payload on many longer stage lengths in its European Network,” says KLM’s Vice President of Fleet Services Rene Kalmann. “Further this decision fits in KLM’s Corporate Social Responsibility policy to invest in environmental protection that goes beyond regulatory compliance.”

For KLM Royal Dutch Airlines, Blended Winglet equipped 737-900s will continue to provide important fuel savings while adding to fleet commonality — the airline will be installing 21 additional Blended Winglet Systems on the 737-800 beginning in March 2007. All 737-800s in KLM’s fleet will be Winglet equipped by February 2008.

“Continental remains steadfast in its efforts to improve aircraft performance and reduce fuel usage. Equipping our 737-900s with Blended Winglets moves us closer to that goal,” says John Greenlee, Managing Director of Fleet Planning for Continental. “The fuel efficiency improvements offered by Blended Winglets coupled with our young fleet provide Continental with a natural hedge against volatile fuel prices.”

For Continental Airlines, Blended Winglet equipped 737-900s will complement the carrier’s existing winglet equipped aircraft, which include 100% of its 737-700s, 737-800s and 757-200s. To date the airline has installed winglets on 182 aircraft and plans to add over 100 additional Systems in the next few years as it will soon begin retrofitting winglets onto its 737 Classic fleet while continuing to take new 737NG aircraft with winglets, including the new 737-900ER.

“Our long-haul flying will benefit greatly from the fuel savings and payload advantages provided by blended winglets,” said Scott Ridge, Alaska Airlines’ managing director of technical operations and support. “We’ve seen the value of the winglets on our other next-generation 737s and look forward to achieving similar efficiencies with our -900s.”

Alaska’s order for 9 shipsets of 737-900 Blended Winglets adds to their current order of: 19 737-700’s and 37 737-800’s of which 33 are already in service.

By year-end 2006, over 1500 Blended Winglet Shipsets will be in service with over 100 airlines in more than 40 countries on 6 continents. Currently, 65% of in-service fleet of 737-700s, and 57% of in-service 737-800s, are Blended Winglet Equipped. By 2010, with over 4500 airliners upgraded, APB anticipates that Blended Winglet Technology will have saved commercial airlines over 2 billion gallons of fuel.


5 Apr 2005 – MAS to install winglets for Boeing

The Boeing Co. signed a deal with Malaysia’s national carrier yesterday to set up a regional winglet modification center outside the capital, Kuala Lumpur, a Boeing official said.

Aviation Partners Boeing and Malaysia Airlines Engineering sealed the agreement yesterday in Kuala Lumpur, agreeing to operate the first center in Southeast Asia to install fuel-saving winglet technology on Boeing’s 737s.

The pact will enable the engineering firm to become a one-stop shop for airlines, said Craig McCallum, sales director of Aviation Partners Boeing.

More than 100 aircraft are expected to go through the Malaysian center for conversion in the next three to four years, McCallum said. The facility will cater to the needs of airliners from countries such as Indonesia, India and Malaysia.

Boeing will provide all manufacturing and engineering support, tools and training to the center.

The announcement comes amid rumors that Malaysian Airlines is considering buying 737-800s. However, Boeing denied any link between the airline’s purchase order and the facility deal.

The Malaysia facility will be the fourth in the Asia-Pacific region, joining facilities in China, Hong Kong and New Zealand.

“Growth in blended winglet sales has been nothing short of spectacular lately, and much of this growth has been in the Asia-Pacific region,” Mike Marino, Aviation Partners Boeing CEO, said in a statement.

Introduced in 1999, the winglet technology has become popular because of the significant fuel savings it provides for aircraft — ranging from 100,000 to 250,000 gallons per year per aircraft. The winglet system is currently available for Boeing 737s, and efforts are under way to offer them on 757s, 767s and 777s in the future.


14 Jan 2005 – Hapag-Lloyd Original Launch Customer Comes Back for More APB Blended Winglets

Hapag-Lloyd Flug, a member of the TUI Group and the launch customer for Boeing 737-800 Blended Winglets 4 years ago, has ordered 10 additional Blended Winglet Systems. The Boeing Company will install the Blended Winglets as Buyer Furnished Equipment (BFE) on new 737-800s to be delivered between January 2006 and May 2007. Hapag-Lloyd operates a 100% Blended Winglet Equipped fleet of 737-800s. After 4 years of enjoying dramatic fuel savings, along with measurable performance and environmental benefits made possible with Blended Winglet Technology, this leading charter operator is sold on the benefits of Aviation Partners Boeing Technology.

“This important order is a real affirmation of the outstanding value of our product,” says Aviation Partners Boeing CEO Mike Marino. “Hapag-Lloyd, our most experienced customer, has an intimate understanding of the compelling value of Blended Winglet Technology.”

Hapag-Lloyd enjoys a wide range of operational benefits with Aviation Partners Boeing’s patented* Blended Winglet Technology. At current fuel prices the fuel savings alone translates into a Blended Winglet Payback of under 4 years. Additional important benefits include greater payload-range capability and environmental advantages in terms of reduced engine emissions and reduced noise on takeoff.

Aviation Partners Boeing Vice President of Sales & Contracts Patrick LaMoria reports that Hapag-Lloyd needed no convincing to come in with its second Blended Winglet order. “Hapag-Lloyd’s experience operating with Blended Winglet Technology has made including them with every new Boeing aircraft they operate a very simple decision.”

By mid-2005 over half of all Boeing 737-800 and 700 series aircraft will be equipped with Aviation Partners Boeing Blended Winglets.


7 Oct 2004 – Continental Airlines to Take Shipset #500 for NG Boeing 737-800

While delivery of shipset 500 is a milestone in the history of Aviation Partners Boeing, it’s just a hint of things to come as the global airline industry transitions to patented* Blended Winglet Technology.

Blended Winglet Equipped Boeing aircraft are now flying on every continent. Current orders and options stand at over 1200 shipsets with a potential universe of 10,500 Boeing aircraft in the retrofit market alone.

“We’re only in the early stages in terms of meeting the growing demand for Performance Enhancing Blended Winglet Technology. But, it’s a significant beginning,” says Aviation Partners Boeing CEO Mike Marino. “Blended Winglet Equipped commercial aircraft save fuel, operate with enhanced performance due to a higher lift wing, and are measurably more environmentally friendly. Today’s 500 Blended Winglet Equipped 737 are saving over 50 million gallons of fuel each year. If all Boeing aircraft worldwide were retrofitted with Blended Winglet Systems worldwide fuel savings would be close to 1.8 billion gallons each year.”

Aviation Partners Inc. developed Blended Winglet Technology in the early 1990s. Sized for maximum performance, and with a wider sweep transition between wing and winglet, Blended Winglets are typically 80% more effective than today’s conventional angular winglet systems. Typical operator benefits include fuel savings of up to 5%, depending upon flight profile, improved performance from high and hot airfields, faster time to climb, lowered engine emissions and a 6.5% reduction in takeoff noise footprint.

“The future is as exciting for us as it is for our customers worldwide who look forward to improving the performance, fuel savings and overall return on investment of their aircraft,” says Aviation Partners Boeing Chairman Joe Clark. “We believe that anytime you can improve the productivity and environmental benefits of an existing airplane, it’s a wise investment.”


10 Jul 2003 – Air Plus Comet Becomes World’s First Operator of Boeing 737-300 with Winglets

Air Plus Comet yesterday became the world’s first operator of a Boeing 737-300 with advanced-technology blended winglets and the latest carrier in Spain operating Boeing airplanes.

The winglets, which curve out and up from the plane’s wing tips, improve an airplane’s performance and allow it to fly more than 185km farther than a 737-300 without winglets. Winglets also offer excellent environmental benefits, including reduced fuel use, takeoff and landing noise, and in-flight engine emissions.

“As the first worldwide customer for the new 737-300 blended winglet, we will be the first to experience the fuel savings and environmental benefits they bring,” said Alejandro Avila, Air Plus Comet technical director.

The 737-300, leased from Aircraft Leasing Management, was delivered today. Headquartered in Madrid, Air Plus Comet provides long-distance charter flights between Spain and European locations and the Americas. It began operations in 1997.

Aviation Partners Boeing, a joint venture of Boeing and Aviation Partners, Inc., developed the winglets. The winglets can be installed on 737-300, -400, -700 and -800 models. More than 28 carriers fly nearly 300 winglet-equipped 737s.


18 Feb 2003 – 737-300 Winglet Certification Delay

The STC for a retrofited winglet on the 737-300 has been delayed due to problems discovered during the low speed handling phase of flight testing in Arizona. The winglets were producing handling deficiencies near V2 at high gross weights caused by flow separation around the transition to the winglet. Possible solutions include aerodynamic to the wingtips and outboard vortex generators.


5 Dec 2002 – Blended winglet Boeing 737 makes European inroads

Sobelair, a Belgian charter operation, is leasing its first Boeing 737-800 with blended winglets.

The winglet gives the Wichita-made 737 reducing wing drag, and making the wing more aerodynamically efficient, officials say.

“Sobelair flies particularly long routes to destinations in Africa, the Mediterranean and the Middle East,” says Aviation Partners Boeing sales director Patrick LaMoria, who is handling the lease.

By the end of 2002, close to 200 Boeing Next-Generation 737s will be equipped with APB’s patented Blended Winglet Technology. Following introduction of Blended Winglet Systems for Classic Series 737s, mid-2003, APB will certify Blended Winglet Systems for the 747-400.


Oct 2002 – Boeing 737-300 Blended Winglets Delivered

Kawasaki delivered its first Blended Winglets. to Aviation Partners Boeing (APB) in October. Kawasaki is designing, developing and manufacturing the patented innovative winglets for the Boeing 737-300/400/500 models under an official agreement inked with APB in October last year (see Feb. 2002 Business Activities).

Blended winglets, which are made of a high-tech composite material specially developed for aircraft, are attached to the tips of the wings to enhance performance by extending flight ranges, reducing noise and making other improvements. Winglets are already a standard feature on the Boeing Business Jet. The Boeing 737-700/800 models and Gulfstream’s GII Business Jets have also been equipped with them. It is anticipated that they will also be fitted to a wider range of Boeing’s existing aircraft, including the 747, 757 and 767 fleets. There are currently 1,000 Boeing 737-300 jetliners in operation around the globe. The winglets will be available as an option for those Boeing aircraft being retrofitted.

Kawasaki used its proprietary KMS- 6115 composite material to create the latest winglets. KMS-6115 is made from high-performance carbon fibers and toughened epoxy resin, with much greater tensile and compressive strength than conventional composite materials. This is the first time KMS-6115 will be used in a Boeing aircraft.


26 Feb 2002 – Partnership with Boeing ‘starting to take off’

Seattle PI —

If you choose to sleep with an elephant, just be careful it doesn’t roll over during the night. The advice, and warning, came from a well regarded aerospace executive of a small company who years ago lay down with an industry giant for a promising joint venture. It proved a painful experience. The executive mentioned the elephant adage recently when talking about Joe Clark, founder of Aviation Partners, a small Seattle company that developed revolutionary blended winglets that attach to the end of an airplane wing to improve performance.

Clark has been sleeping with an elephant since the 1999 Paris Air Show. It was there that Clark and The Boeing Co., the biggest aerospace company and commercial airplane maker on the planet, announced the formation of Aviation Partners Boeing, a joint venture to put Clark’s blended winglets on 737 jetliners. While acknowledging there have been “growing pains,” “cultural clashes” and “learning experiences,” Clark also said the partnership with Boeing is “really starting to take off.”

A growing number of next generation 737 operators around the world have opted for the blended winglets, which can boost fuel efficiency by as much as 4 percent. And they have helped Boeing win orders over Airbus. One of Boeing’s most important order victories last year was the decision by Qantas, Australia’s flagship carrier, to buy 15 737-800s and take options for at least 40 more. People close to the deal said the blended winglets offered on the Boeing plane gave it a small but important performance edge over the Airbus A320 on new long-haul domestic routes planned by Qantas. The blended winglets are offered as a retrofit for the 737-700 and the bigger 737-800. They are offered by Boeing as a factory-installed option only on the 737-800. So far, more than 80 next generation 737s have been equipped with blended winglets, along with about 60 Boeing Business Jets, a modified version of the 737 commercial jetliner. The winglets are standard equipment on all Boeing Business Jets. Clark expects that another 180 next generation 737s will be equipped with the blended winglets this year. Of those, about 50 will probably be factory-installed in Renton, he said. About a dozen airlines are either flying winglet-equipped 737s or have them on order. “We are talking actively with another dozen airlines,” Clark said during a recent interview at his Aviation Partners office near the King County Airport terminal at Boeing Field. “We will be announcing more orders soon.”

Clark is even talking with the military and defense contractors. He met recently met with officials at Northrop Grumman about putting blended winglets on the Global Hawk unmanned aerial vehicle that has been used in Afghanistan. The winglets would add about two hours of flight time for the Global Hawk, Clark said. “Every plane should be designed with winglets,” Clark said.

Winglets were common on business and commercial jets before Aviation Partners arrived on the scene. But those traditional winglets, found on all Airbus models and the Boeing 747-400, rise at a sharp angle from the wing. Blended winglets gently curve up, as if they are part of the wing. Winglets were first developed by NASA in the 1960s to help reduce drag. Increasing the wing span can produce the same results. But wings of jetliners can’t get any longer and still fit at airport gates. What’s more, increasing wing span means structural changes that add weight. So far, the only U.S. carrier with 737s equipped with blended winglets is American Trans Air. But Clark recently presented his friend John Kelly, chairman of Alaska Airlines, with a small model of a 737-700 with blended winglets. The two men have known each other since the days when Clark teamed with Milt Kuolt in 1981 to form Horizon Air, a regional carrier later sold to Alaska. The model Clark gave to Kelly was painted in the livery of Alaska Airlines, with the Eskimo logo on the winglets. “A picture is worth a thousand words,” Clark said, explaining why he was giving the model to Kelly.

Continental is another 737-700 operator being wooed. The 737 is the world’s most frequently flown jetliner. More than 4,000 have been built. Later this year, the blended winglets are to be certified by the Federal Aviation Administration for the older “classic” 737s, starting with the 737-300. Certification will follow for the 737-400 and 737-500. His company’s business plan includes blended winglets for the 757, 767 and 747, Clark said, as well as for the MD-80 series. “The retrofit market is huge,” Clark said. “Our schedule is to certify the classic 737s this year, the 747 next year, the 767 after that and then the 757.”

The winglets designed for the next generation 737 are about 8 feet high. Bernie Gratzer, former chief aerodynamicist at Boeing who was part of Clark’s team at Aviation Partners that developed the blended winglets, said the 747 flight tests showed the winglets reduced drag by about 6.3 percent. That can mean substantial fuel savings for an airline. Clark has been approached by operators of older 747s, asking about retrofitting their planes with the blended winglets. “We think we can save them about a million gallons of fuel a year per plane,” he said. But Boeing is not sold on blended winglets, at least for its bigger jets. Boeing engineers developed a raked tip, which does not bend upward like a winglet, for the 767-400 and will use those raked tips for the longer-range 777-300 now in development. And Boeing is considering raked tips, not blended winglets, for future longer-range versions of its 747-400. “Why put raked tips on a 747? That’s a good question,” said Gratzer, who retired from Boeing in 1986 and later was a professor at the University of Washington’s aeronautics and astronautical department. “We don’t really understand why they (Boeing) would do that,” he added. But it was not so long ago that many engineers at Boeing scoffed at the notion that winglets would do anything other than give the 737 a more sexy appearance. After all, wasn’t that why all those rich guys who could afford private jets wanted ones with winglets?

At the Paris Air Show in 1997, Boeing’s Borge Boeskov approached Clark about blended winglets on the planned Boeing Business Jet, a next generation 737-700 with the strengthened wing of the 737-800. Clark’s subsequent business proposal for Boeskov said the Boeing Business Jet would get from 4 to 5 percent better performance with blended winglets. “The corporate guys like the looks of these things because they differentiate the product, but frankly my engineers have told me they don’t work,” Borge told Clark. So Clark told Boeskov his small company would foot the bill to design winglets for the Boeing Business Jet if Boeskov would test fly them on the plane. Unable to get Boeing engineers to go along, Boeskov turned to the German carrier Hapag-Lloyd, a longtime Boeing 737 customer. Hapag-Lloyd supplied one of its new 737s, and the results were better than Clark had predicted — a nearly 7 percent reduction in drag. Hapag-Lloyd is now one of those customers operating 737s with blended winglets.

Clark, who is not at all shy about expressing his opinions, is careful in talking about the challenges he has faced working with the world’s largest aerospace company on an idea that Boeing’s best and brightest once rejected. “They are a big bureaucracy and we sometimes want to get things done quickly,” Clark said of the joint venture with Boeing. He credited Alan Mulally, Boeing’s commercial boss, with helping change attitudes within the company. “Since Alan has gotten behind this, it has changed overnight,” Clark said. “We talked about five months ago and he said he would really get behind the winglets program. “Since then, sales have really taken off. Our relationship with everyone at Boeing has gotten much better.” Then he added, “Of course, we still have our differences.” So far, though, the elephant has not rolled over.


8 February 2002 – Kawasaki of Japan will build 737 winglets

Friday, February 8, 2002

SEATTLE POST-INTELLIGENCER STAFF AND NEWS SERVICES

TOKYO — Kawasaki Heavy Industries Ltd., Japan’s second-biggest aerospace company, said it will develop wingtips for Boeing Co. 737s, adding to an existing cooperation with the company.

Kawasaki Heavy will make blended winglets, which increase fuel efficiency and range, the companies said. The companies didn’t provide financial details.

Owners of 737s, of which more than 1,900 are in service around the world, will be able to fit the wingtips onto their planes, the release said.


SEATTLE, Sept. 11, 2001 –The first Boeing 737-700 arrived in Kenya Monday, making Kenya Airways the first airline anywhere in the world to operate a 737-700 with blended winglets. Kenya Airways is expected to put the airplane into service later this month. The airplane will be leased through GE Capital Aviation Services.”Our goal is to become the premier airline of choice in Africa and provide more frequency for passengers,” said Isaac Omolo Okero, chairman for Kenya Airways. “The 737’s economics and low maintenance cost will help us continue to provide the best service to destinations throughout Africa.”

The retrofitted blended winglets on the 737-700 curve out and up from the wingtip, reducing aerodynamic drag and boosting performance. Some of the potential improvements include better fuel burn, increased range, improved takeoff performance and obstacle clearance. Working with Aviation Partners Inc., Boeing developed the blended winglet technology for the 737 airplane.

“The addition of the winglets on the 737-700 will provide Kenya Airways with a superior product,” said Kevin Bartelson, chief operating officer for Aviation Partners Boeing. “The new 737-700 with winglets will add value to operators and provide a technologically advanced product with a reputation for superior reliability.”

The family of 737s consisting of the 737-600, -700, -800 and -900 is the newest design and the most technologically advanced in the single-aisle market.

“Kenya Airways’ selection of the 737 airplane will help reduce its fleet costs, which directly affects the airline’s bottom line,” said Doug Groseclose, senior vice president of International Sales, Boeing Commercial Airplanes. “With the new 737s, Kenya Airways can continue to offer its customers a quality product and on-time in-service performance.”

The airplanes are designed to fly higher, faster, farther, quieter and with greater fuel efficiency than previous 737 models — and the competition.

Kenya Airways, one of the fastest growing and most profitable airlines in Africa, will use the new 737 to fly to key destinations in Africa and other domestic routes on the continent. There are more than 130 Boeing 737s operating in Africa and more than 4,000 737s in service today.


Boeing 737 Advanced-Technology Winglets Make World Debut

SEATTLE, May 21, 2001 — Boeing Next-Generation 737-800 advanced-technology winglets made their world debut in revenue service last week with German carrier Hapag-Lloyd Flug.

Hanover-based Hapag-Lloyd became the first airline in the world to fly 737-800s equipped with the cost-effective, environmentally friendly wingtip extensions on commercial routes. The carrier uses 737-800s with winglets on routes from Germany to Mediterranean destinations.

The new winglets on the Boeing 737-800 curve out and up from the wingtip, reducing aerodynamic drag and boosting performance. They add about 5 feet (1.5 meters) to the airplane’s total wingspan and allow the airplane to fly up to 130 nautical miles (240 kilometers) further.

“The winglets on our 737-800s will cut the airplane’s already low fuel consumption, emissions and takeoff noise and make them even more eco-friendly,” said Wolfgang Kurth, Hapag-Lloyd managing director. “Less fuel means more range and gives us the opportunity to open new markets”

The fuel consumption of the 737-800s without winglets in Hapag-Lloyd’s fleet already is as low as 2.1 liters per 100 seat kilometers. “We expect the winglets to decrease fuel burn even further – by up to 5 percent in cruise – and reduce the noise affected area by 6.5 percent,” Kurth said.

Winglets also have the potential to increase the optimum cruise altitude of the airplane, reduce engine maintenance costs, improve takeoff performance, and increase the weight the airplane can carry by .55 of a ton to 3.3 tons (.5 of a ton to 3 metric tons).

“Next-Generation 737 winglets have proven their value in service on privately owned Boeing Business Jets, and now Hapag-Lloyd will see firsthand the unmatched benefits winglets can bring to commercial operators,” said Toby Bright, Boeing Commercial Airplanes senior vice president for Europe and Russia. “Hapag-Lloyd, which was the first airline to order the new-technology 737-800s back in 1994, will once again make history as a company that quickly recognizes the importance of technological improvements in aviation.”

Hapag-Lloyd has started to retrofit its fleet of 27 Boeing 737-800s with winglets.

Winglets initially were developed for use on the Boeing Business Jet, an adapted Next-Generation 737-700 with 737-800 wings, by Aviation Partners, Inc. (API). During the design process, Boeing and API formed a joint venture that further developed the design. The joint venture is called Aviation Partners Boeing (APB).

Building a quieter, more fuel-efficient airplane was a top priority for Boeing engineers who initially designed the 737-800 and other members of the Next-Generation 737 family. The model’s new CFM56-7 engines produced by CFMI, a joint venture of General Electric Co. of the United States and Snecma of France, meet community noise restrictions well below current Stage 3 limits and below expected Stage 4 limits. Emissions also are reduced beyond required standards.


Winglets boost to Boeing 737–800 performance

SEATTLE, Feb. 18, 2000 – The Boeing Company announced today that it is offering Next-Generation 737-800 customers a new, advanced-technology winglet as a standard option.

The winglet will allow a new airplane that already flies farther, higher and more economically than competing products to extend its range, carry more payload, save on fuel and benefit the environment. The first Boeing 737-800 with winglets is expected to be delivered in the spring of 2001. All subsequent 737-800s will be equipped with structurally enhanced wings that will make it easier for owners of standard 737-800s to retrofit those jetliners with winglets.

“The key to product leadership is to create a superior product, then continually improve it in ways that add value to customers,” said John Hayhurst, vice president and general manager, 737 programs. “With this new winglet, the Next-Generation 737 will remain the most advanced airplane family in its class for the 21st century, just as it was for the 20th.”

A Next-Generation 737-800 equipped with the new winglet will be able to fly farther, burn 3 percent to 5 percent less fuel, or carry up to 6,000 pounds more payload. Other benefits include a reduction in noise near airports, lower engine-maintenance costs, and improved takeoff performance at high-altitude airports and in hot climate conditions.

The winglets weigh about 120 pounds each. They are made of high-tech carbon graphite, an advanced aluminum alloy and titanium. The winglet is eight feet long and tapers from its four-foot wide base to a width of two feet at the tip. Unlike traditional winglets typically fitted at abrupt angles to the wing, this new advanced “blended” design gently curves out and up from the wing tip, reducing aerodynamic drag and boosting performance.

The 737-800 winglet was developed initially for the Boeing Business Jet (BBJ), which also features the state-of-the-art 737-800 wing. This winglet will be available initially as an option on the 162-passenger 737-800. Formal availability of the winglet will follow quickly on other models that feature the 737-800 wing, including the 737-700C and the 737-900. The applicability of the winglet to Next-Generation 737-600 and 737-700 models is being assessed.

The blended-winglet technology was developed by Aviation Partners Inc. of Seattle. In 1999, during the design of the BBJ winglet, Aviation Partners and The Boeing Company formed Aviation Partners Boeing (APB), a joint venture that completed and owns the design. APB is developing the capability to make the winglet available as a retrofit for airplanes already in service.


SEATTLE, Oct. 23, 2000 – German carrier Hapag-Lloyd Flug became the first airline to fly the Boeing 737-800 with blended winglets. The test flight took place Sept. 26 2000 in Seattle.


First BBJ flight with winglets

Feb 22, 1999

 


Boeing Business Jets Announces Winglets Test

SEATTLE, June 4, 1998— Boeing Business Jets announced today that it has been testing the use of winglets on a Boeing 737-800 for possible application on the new Boeing Business Jet (BBJ).The winglets are being tested as a possible range-performance enhancement for the BBJ. Designed and manufactured by Seattle-based Aviation Partners Inc., the two 8-foot high, blended and vertically mounted winglets are attached to the end of each wing of the airplane.

“The Boeing Business Jet’s 6,200 nautical-mile range already ranks it with the leading business airplanes in its class,” said Borge Boeskov, president of Boeing Business Jets. “We want to test the application of winglets as a way of making a world-class product even better. We are testing to determine whether winglets will provide a range-performance enhancement by reducing drag.”

The BBJ is a derivative of the Next-Generation 737-700, combining the -700 fuselage with the strengthened wings and landing gear of the larger and heavier 737-800. This combination gives the BBJ a range of 7,140 statute miles (6,200 nautical miles, 11,480 kilometers).

“As a special-use airplane for executive teams and private owners, the BBJ will fly much longer routes – up to 14 hours nonstop – than commercially operated Boeing 737s,” Boeskov said. “These are the routes where winglets would have the best opportunity for performance improvements.”

In addition to performance, winglets will give the Boeing Business Jet a look that will set it apart from other business and commercial jets of its size.

“We want the BBJ to stand out, and we want it to look distinctive among all other business jets,” Boeskov said.

Boeskov said the first phase of flight-testing will be completed this week. Whether winglets will be used on the BBJ will be determined following evaluation of testing data.

Major assembly of the first BBJ fuselage was recently completed in Wichita, Kan., while work on the first wings and other components is progressing in the Puget Sound area. The airplane’s first flight is scheduled for August. Boeing Business Jets is a joint venture between The Boeing Company and General Electric Co.

l. Over half of all 737NGs have had winglets retrofitted.
See more details about the book

All of the information, photographs & schematics from this website and much more is now available in a 370 page, 8.5″ x 11″ book available here.

Updated 3 Sept 11

Winglets are also available for Classics. The first winglet equipped 737-300 flew in Nov 2002 and gained its FAA supplemental type certificate (STC) on 30 May 2003. Winglet equipped Classics are known as Special Performance (SP).

Winglets have the potential to give the following benefits:

  • Improved climb gradient. This will enable a higher RTOW from climb limited airports (hot, high or noise abatement) or obstacle limited runways.
  • Reduced climb thrust. A winglet equipped aircraft can typically take a 3% derate over the non-winglet equivalent aircraft. This can extend engine life and reduce maintenance costs.
  • Environmentally friendly. The derate, if taken, will reduce the noise footprint by 6.5% and NOx emissions by 5%. This could give savings on airport noise quotas or fines.
  • Reduced cruise thrust. Cruise fuel flow is reduced by up to 6% giving savings in fuel costs and increasing range.
  • Improved cruise performance. Winglets can allow aircraft to reach higher levels sooner. Air Berlin notes, “Previously, we’d step-climb from 35,000 to 41,000 feet. With Blended Winglets, we can now climb direct to 41,000 feet where traffic congestion is much less and we can take advantage of direct routings and shortcuts which we could not otherwise consider.”
  • Good looks. Winglets bring a modern look and feel to aircraft, and improve customers’ perceptions of the airline.

If winglets are so good, you may wonder why all 737s don’t have them. In fact 85% of all new 737s are now built with winglets, particularly the 800 and 900 series and of course all BBJs. It comes down to cost versus benefits. Winglets cost about $725,000USD and take about 1 week to install which costs an extra $25-80,000USD. Once fitted, they add 170-235kg (375-518lbs) to the weight of the aircraft, depending upon whether they were installed at production or a retrofit. The fuel cost of carrying this extra weight will take some flying time each sector to recover, although this is offset by the need to carry less fuel because of the increased range. In simple terms, if your average sector length is short (less than one hour) you wont get much the benefit from winglets – unless you need any of the other benefits such as reduced noise or you regularly operate from obstacle limited runways.

There is a small difference in rotation rate for aircraft with winglets installed and, as a result, the crew needs to be cautious of pitch rate. There is approximately a ½ unit take-off trim change between non-winglet and winglet aircraft so the green band is slightly different for winglet aircraft. Finally, the dry “maximum demonstrated” crosswind limit is slightly reduced with winglets to 34kts. According to APB this is because “the FAA will only let us document the max winds experienced during flight test… so if we had been able to find more crosswind, then the 33kts might have been more. There appears to be no weather cocking effect due to winglets.”

Other winglet News Stories

An excellent article by Boeing in Aero 17 is available at:

http://www.boeing.com/commercial/aeromagazine/aero_17/winglet_story.html

Next-Generation 737 Production Winglets

Description
Winglets are wing tip extensions which provide several benefits to airplane operators. The winglet option increases the Next-Generation 737’s lead as the newest and most technologically advanced airplane in its class. These new technology winglets are now available on 737-800s as well as on the Boeing Business Jet (737-700 and 737-800).

There are two types of winglet available, Boeing’s own built into the wing at the time of manufacture and the APB winglet as a retrofit.

Benefits
Depending on the airplane, its cargo, the airline’s routes and other factors, winglets have the potential to give:IMPROVED TAKEOFF PERFORMANCE

By allowing a steeper climb, winglets pay off in better takeoff performance, especially from obstacle-limited, high, hot, weight-limited, and/or noise-restricted airports. Performance Improved climb gradients increase 737-800 allowable takeoff weight (TOW).

Some examples include:

  • Chicago-Midway: ~1,600 lb additional TOW
  • Lanzarote (Canary Islands): ~3,500 lb additional TOW
  • Albuquerque, Denver, and Salt Lake City: ~4,400 lb additional TOW

REDUCED ENGINE MAINTENANCE COSTS

Better climb performance also allows lower thrust settings, thus extending engine life and reducing maintenance costs. Lower Required Thrust Levels Extend On-Wing Life.

Takeoff – Winglets allow up to 3% incremental derate.

Cruise – Cruise thrust levels are reduced by up to 4%.

FUEL SAVINGS

Winglets lower drag and improve aerodynamic efficiency, thus reducing fuel burn. Depending on the missions you fly, blended winglets can improve cruise fuel mileage up to 6 percent, especially important during a time of rising fuel prices.

INCREASED PAYLOAD RANGE

The addition of Aviation Partners Blended Winglets to the 737 Next Generation has demonstrated drag reduction in the 5 to 7% range that measurably increases range and fuel efficiency . In addition, the Blended Winglets allow the 737-NG to take off from higher, hotter airports with increased payload.

Series Range (nm) Normal Range (nm) With Winglets
-700 3250 3634
-800 2930 3060
-900 2670 2725

ENVIRONMENTALLY FRIENDLY

With winglets, you can be a good neighbour in the community you serve. They enhance performance at noise-restricted airports and cut the affected area by 6.5 percent, saving you money on airport noise quotas or fines. By reducing fuel consumption, winglets help lower NOx emissions by 5%.

IMPROVED OPERATIONAL FLEXIBILITY

By increasing Payload Range and Overall Performance, Blended Winglets add flexibility to fleet operations and route selection. Air Berlin notes, “Previously, we’d step-climb from 35,000 to 41,000 feet. With Blended Winglets, we can now climb direct to 41,000 feet where traffic congestion is much less and we can take advantage of direct routings and shortcuts which we could not otherwise consider.”

MODERN DRAMATIC APPEARANCE

Blended Winglets bring a modern look and feel to aircraft, and improve customers’ perceptions of the reliability and modernity of the Airline.

Dimensions
Each winglet is 8 feet long and 4 feet in width at the base, narrowing to approximately two feet at the tip.

Added wingspan
Winglets add approximately 5 feet to the airplane’s total wingspan – from 112 feet 7 inches to 117 feet 2 inches. (All Next-Generation 737 models have the same wingspan.)

Weight
Each winglet weighs about 132 pounds. Increased weight to the airplane for modifying wing and installing winglets is about 480 pounds.

Airplane provisions
Structural modifications to accommodate the winglet include strengthening the wing’s centre section and other internal strengthening on the wing. These enhancements are done in the normal production process. Various systems changes have also been made to accommodate winglet installation.

Offerability
Production and retrofit winglets for the Next-Generation 737s are available through Boeing (production) and Aviation Partners Boeing (retrofit). Aviation Partners Boeing (APB) is a joint venture partnership between Boeing and Aviation Partners Inc. (API).

Certification
Retrofit FAA Supplemental Type Certificate (STC) was granted to APB on 3/23/2001. LBA (German regulatory agency) STC was granted to APB on 5/4/2001. JAA STC was granted May 2001. Boeing PLOD (program letter of definition) was granted 5/9/2001 by both the FAA and JAA for Boeing production.

Availability
737-700, 737-800, 737-900, 737-BBJ – available now. Deliveries began May 2001. Initial customers included: South African Airways, Air Berlin, American Trans Air, Polynesian Airlines, and Hainan Airlines – both through direct purchase and leasing options via ILF, GATX, GE Capital Corp., and Flightlease.

Operational Considerations
There is a small difference in rotation rate for airplanes with winglets installed and, as a result, the crew needs to be cautious of pitch rate. There is also approximately a ½ unit take-off trim change between non-winglet and winglet aircraft so the green band is slightly different for winglet aircraft.


737-200 Mini-Winglets

  This is a 737-200Adv, L/N 628, fitted with mini-winglets. This is part of the Quiet Wing Corp flap modification kit which gained its FAA certification in 2005. The package includes drooping the TE flaps by 4 degrees and the ailerons by 1 degree to increase to camber of the wing. Benefits include:

  • Payload Increase of up to 5,000 lbs.
  • Range Increase up to 3%
  • Fuel Savings up to 3%
  • Improved Takeoff/Landing Climb Gradients
  • Reduced Takeoff/Landing Field Length
  • Improved High Altitude Takeoff/Landing Capability
  • Improved Hot Climate Performance
  • Reduced Stall Speeds by 4-5kts

Photo: Julian Whitelaw


News Stories

30 Apr 2007 – APB selects UK supplier as it launches 767-300ER programme with American order UK-based GKN Aerospace has been selected by Aviation Partners Boeing (APB) as a new supplier of the US company’s blended winglets for the rapidly expanding Boeing 737 “Classic” and newly launched 767 retrofit programmes, while United Airlines is poised to start retrofitting its 757s.

The aerostructures specialist joins APB winglet supplier Kawasaki Heavy Industries. Winglets for the 737 Next Generation. Despite the much-needed addition of GKN, APB says the 737 Classic retrofit line is sold out through 2009 at the rate of six shipsets a month. “We’re still going to ramp up as fast as we can, but it will be the end of this year or early next before they can begin providing the first parts,” says APB vice-president sales Patrick LaMoria.


26 Dec 2006 – Aviation Partners Boeing Launches 737-900 Blended Winglet Program

With program launch of Aviation Partners Boeing 737-900 Blended Winglets, and first deliveries slated for December 2007, the world’s airways will soon be making room for even more Blended Winglet Performance Enhanced airplanes. Launch customers Continental Airlines, KLM and Alaska Airlines plan to complete the retrofit of their 737- 900s by the end of the first quarter of 2008.

“We’ve had a great deal of customer interest in 737-900 Blended Winglets and this important new program gives more of our operators commonality and the ability to fly with 100% Blended Winglet equipped 737NG fleets,” says Aviation Partners Boeing CEO John Reimers. “This program is off to a very strong start and we anticipate that the remaining handful of operators of the 737-900 will be unable to ignore the tremendous value Blended Winglets add to the aircraft.”

Benefits of Aviation Partners Boeing’s Visible Technology are nothing short of dramatic in fuel savings, improved performance and environmental advantages. Given average aircraft utilization rates, operators will save over 100,000 gallons (380,000 liters) of fuel per aircraft per year resulting in a payback on investment of less than 3 years. Noise footprint, on takeoff and landing, is reduced by an average of 6.5% while engine emissions of carbon dioxide and nitrous oxides are lowered on the order of 5.0%.

“Blended Winglets will give KLM improved range and payload on many longer stage lengths in its European Network,” says KLM’s Vice President of Fleet Services Rene Kalmann. “Further this decision fits in KLM’s Corporate Social Responsibility policy to invest in environmental protection that goes beyond regulatory compliance.”

For KLM Royal Dutch Airlines, Blended Winglet equipped 737-900s will continue to provide important fuel savings while adding to fleet commonality — the airline will be installing 21 additional Blended Winglet Systems on the 737-800 beginning in March 2007. All 737-800s in KLM’s fleet will be Winglet equipped by February 2008.

“Continental remains steadfast in its efforts to improve aircraft performance and reduce fuel usage. Equipping our 737-900s with Blended Winglets moves us closer to that goal,” says John Greenlee, Managing Director of Fleet Planning for Continental. “The fuel efficiency improvements offered by Blended Winglets coupled with our young fleet provide Continental with a natural hedge against volatile fuel prices.”

For Continental Airlines, Blended Winglet equipped 737-900s will complement the carrier’s existing winglet equipped aircraft, which include 100% of its 737-700s, 737-800s and 757-200s. To date the airline has installed winglets on 182 aircraft and plans to add over 100 additional Systems in the next few years as it will soon begin retrofitting winglets onto its 737 Classic fleet while continuing to take new 737NG aircraft with winglets, including the new 737-900ER.

“Our long-haul flying will benefit greatly from the fuel savings and payload advantages provided by blended winglets,” said Scott Ridge, Alaska Airlines’ managing director of technical operations and support. “We’ve seen the value of the winglets on our other next-generation 737s and look forward to achieving similar efficiencies with our -900s.”

Alaska’s order for 9 shipsets of 737-900 Blended Winglets adds to their current order of: 19 737-700’s and 37 737-800’s of which 33 are already in service.

By year-end 2006, over 1500 Blended Winglet Shipsets will be in service with over 100 airlines in more than 40 countries on 6 continents. Currently, 65% of in-service fleet of 737-700s, and 57% of in-service 737-800s, are Blended Winglet Equipped. By 2010, with over 4500 airliners upgraded, APB anticipates that Blended Winglet Technology will have saved commercial airlines over 2 billion gallons of fuel.


5 Apr 2005 – MAS to install winglets for Boeing

The Boeing Co. signed a deal with Malaysia’s national carrier yesterday to set up a regional winglet modification center outside the capital, Kuala Lumpur, a Boeing official said.

Aviation Partners Boeing and Malaysia Airlines Engineering sealed the agreement yesterday in Kuala Lumpur, agreeing to operate the first center in Southeast Asia to install fuel-saving winglet technology on Boeing’s 737s.

The pact will enable the engineering firm to become a one-stop shop for airlines, said Craig McCallum, sales director of Aviation Partners Boeing.

More than 100 aircraft are expected to go through the Malaysian center for conversion in the next three to four years, McCallum said. The facility will cater to the needs of airliners from countries such as Indonesia, India and Malaysia.

Boeing will provide all manufacturing and engineering support, tools and training to the center.

The announcement comes amid rumors that Malaysian Airlines is considering buying 737-800s. However, Boeing denied any link between the airline’s purchase order and the facility deal.

The Malaysia facility will be the fourth in the Asia-Pacific region, joining facilities in China, Hong Kong and New Zealand.

“Growth in blended winglet sales has been nothing short of spectacular lately, and much of this growth has been in the Asia-Pacific region,” Mike Marino, Aviation Partners Boeing CEO, said in a statement.

Introduced in 1999, the winglet technology has become popular because of the significant fuel savings it provides for aircraft — ranging from 100,000 to 250,000 gallons per year per aircraft. The winglet system is currently available for Boeing 737s, and efforts are under way to offer them on 757s, 767s and 777s in the future.


14 Jan 2005 – Hapag-Lloyd Original Launch Customer Comes Back for More APB Blended Winglets

Hapag-Lloyd Flug, a member of the TUI Group and the launch customer for Boeing 737-800 Blended Winglets 4 years ago, has ordered 10 additional Blended Winglet Systems. The Boeing Company will install the Blended Winglets as Buyer Furnished Equipment (BFE) on new 737-800s to be delivered between January 2006 and May 2007. Hapag-Lloyd operates a 100% Blended Winglet Equipped fleet of 737-800s. After 4 years of enjoying dramatic fuel savings, along with measurable performance and environmental benefits made possible with Blended Winglet Technology, this leading charter operator is sold on the benefits of Aviation Partners Boeing Technology.

“This important order is a real affirmation of the outstanding value of our product,” says Aviation Partners Boeing CEO Mike Marino. “Hapag-Lloyd, our most experienced customer, has an intimate understanding of the compelling value of Blended Winglet Technology.”

Hapag-Lloyd enjoys a wide range of operational benefits with Aviation Partners Boeing’s patented* Blended Winglet Technology. At current fuel prices the fuel savings alone translates into a Blended Winglet Payback of under 4 years. Additional important benefits include greater payload-range capability and environmental advantages in terms of reduced engine emissions and reduced noise on takeoff.

Aviation Partners Boeing Vice President of Sales & Contracts Patrick LaMoria reports that Hapag-Lloyd needed no convincing to come in with its second Blended Winglet order. “Hapag-Lloyd’s experience operating with Blended Winglet Technology has made including them with every new Boeing aircraft they operate a very simple decision.”

By mid-2005 over half of all Boeing 737-800 and 700 series aircraft will be equipped with Aviation Partners Boeing Blended Winglets.


7 Oct 2004 – Continental Airlines to Take Shipset #500 for NG Boeing 737-800

While delivery of shipset 500 is a milestone in the history of Aviation Partners Boeing, it’s just a hint of things to come as the global airline industry transitions to patented* Blended Winglet Technology.

Blended Winglet Equipped Boeing aircraft are now flying on every continent. Current orders and options stand at over 1200 shipsets with a potential universe of 10,500 Boeing aircraft in the retrofit market alone.

“We’re only in the early stages in terms of meeting the growing demand for Performance Enhancing Blended Winglet Technology. But, it’s a significant beginning,” says Aviation Partners Boeing CEO Mike Marino. “Blended Winglet Equipped commercial aircraft save fuel, operate with enhanced performance due to a higher lift wing, and are measurably more environmentally friendly. Today’s 500 Blended Winglet Equipped 737 are saving over 50 million gallons of fuel each year. If all Boeing aircraft worldwide were retrofitted with Blended Winglet Systems worldwide fuel savings would be close to 1.8 billion gallons each year.”

Aviation Partners Inc. developed Blended Winglet Technology in the early 1990s. Sized for maximum performance, and with a wider sweep transition between wing and winglet, Blended Winglets are typically 80% more effective than today’s conventional angular winglet systems. Typical operator benefits include fuel savings of up to 5%, depending upon flight profile, improved performance from high and hot airfields, faster time to climb, lowered engine emissions and a 6.5% reduction in takeoff noise footprint.

“The future is as exciting for us as it is for our customers worldwide who look forward to improving the performance, fuel savings and overall return on investment of their aircraft,” says Aviation Partners Boeing Chairman Joe Clark. “We believe that anytime you can improve the productivity and environmental benefits of an existing airplane, it’s a wise investment.”


10 Jul 2003 – Air Plus Comet Becomes World’s First Operator of Boeing 737-300 with Winglets

Air Plus Comet yesterday became the world’s first operator of a Boeing 737-300 with advanced-technology blended winglets and the latest carrier in Spain operating Boeing airplanes.

The winglets, which curve out and up from the plane’s wing tips, improve an airplane’s performance and allow it to fly more than 185km farther than a 737-300 without winglets. Winglets also offer excellent environmental benefits, including reduced fuel use, takeoff and landing noise, and in-flight engine emissions.

“As the first worldwide customer for the new 737-300 blended winglet, we will be the first to experience the fuel savings and environmental benefits they bring,” said Alejandro Avila, Air Plus Comet technical director.

The 737-300, leased from Aircraft Leasing Management, was delivered today. Headquartered in Madrid, Air Plus Comet provides long-distance charter flights between Spain and European locations and the Americas. It began operations in 1997.

Aviation Partners Boeing, a joint venture of Boeing and Aviation Partners, Inc., developed the winglets. The winglets can be installed on 737-300, -400, -700 and -800 models. More than 28 carriers fly nearly 300 winglet-equipped 737s.


18 Feb 2003 – 737-300 Winglet Certification Delay

The STC for a retrofited winglet on the 737-300 has been delayed due to problems discovered during the low speed handling phase of flight testing in Arizona. The winglets were producing handling deficiencies near V2 at high gross weights caused by flow separation around the transition to the winglet. Possible solutions include aerodynamic to the wingtips and outboard vortex generators.


5 Dec 2002 – Blended winglet Boeing 737 makes European inroads

Sobelair, a Belgian charter operation, is leasing its first Boeing 737-800 with blended winglets.

The winglet gives the Wichita-made 737 reducing wing drag, and making the wing more aerodynamically efficient, officials say.

“Sobelair flies particularly long routes to destinations in Africa, the Mediterranean and the Middle East,” says Aviation Partners Boeing sales director Patrick LaMoria, who is handling the lease.

By the end of 2002, close to 200 Boeing Next-Generation 737s will be equipped with APB’s patented Blended Winglet Technology. Following introduction of Blended Winglet Systems for Classic Series 737s, mid-2003, APB will certify Blended Winglet Systems for the 747-400.


Oct 2002 – Boeing 737-300 Blended Winglets Delivered

Kawasaki delivered its first Blended Winglets. to Aviation Partners Boeing (APB) in October. Kawasaki is designing, developing and manufacturing the patented innovative winglets for the Boeing 737-300/400/500 models under an official agreement inked with APB in October last year (see Feb. 2002 Business Activities).

Blended winglets, which are made of a high-tech composite material specially developed for aircraft, are attached to the tips of the wings to enhance performance by extending flight ranges, reducing noise and making other improvements. Winglets are already a standard feature on the Boeing Business Jet. The Boeing 737-700/800 models and Gulfstream’s GII Business Jets have also been equipped with them. It is anticipated that they will also be fitted to a wider range of Boeing’s existing aircraft, including the 747, 757 and 767 fleets. There are currently 1,000 Boeing 737-300 jetliners in operation around the globe. The winglets will be available as an option for those Boeing aircraft being retrofitted.

Kawasaki used its proprietary KMS- 6115 composite material to create the latest winglets. KMS-6115 is made from high-performance carbon fibers and toughened epoxy resin, with much greater tensile and compressive strength than conventional composite materials. This is the first time KMS-6115 will be used in a Boeing aircraft.


26 Feb 2002 – Partnership with Boeing ‘starting to take off’

Seattle PI —

If you choose to sleep with an elephant, just be careful it doesn’t roll over during the night. The advice, and warning, came from a well regarded aerospace executive of a small company who years ago lay down with an industry giant for a promising joint venture. It proved a painful experience. The executive mentioned the elephant adage recently when talking about Joe Clark, founder of Aviation Partners, a small Seattle company that developed revolutionary blended winglets that attach to the end of an airplane wing to improve performance.

Clark has been sleeping with an elephant since the 1999 Paris Air Show. It was there that Clark and The Boeing Co., the biggest aerospace company and commercial airplane maker on the planet, announced the formation of Aviation Partners Boeing, a joint venture to put Clark’s blended winglets on 737 jetliners. While acknowledging there have been “growing pains,” “cultural clashes” and “learning experiences,” Clark also said the partnership with Boeing is “really starting to take off.”

A growing number of next generation 737 operators around the world have opted for the blended winglets, which can boost fuel efficiency by as much as 4 percent. And they have helped Boeing win orders over Airbus. One of Boeing’s most important order victories last year was the decision by Qantas, Australia’s flagship carrier, to buy 15 737-800s and take options for at least 40 more. People close to the deal said the blended winglets offered on the Boeing plane gave it a small but important performance edge over the Airbus A320 on new long-haul domestic routes planned by Qantas. The blended winglets are offered as a retrofit for the 737-700 and the bigger 737-800. They are offered by Boeing as a factory-installed option only on the 737-800. So far, more than 80 next generation 737s have been equipped with blended winglets, along with about 60 Boeing Business Jets, a modified version of the 737 commercial jetliner. The winglets are standard equipment on all Boeing Business Jets. Clark expects that another 180 next generation 737s will be equipped with the blended winglets this year. Of those, about 50 will probably be factory-installed in Renton, he said. About a dozen airlines are either flying winglet-equipped 737s or have them on order. “We are talking actively with another dozen airlines,” Clark said during a recent interview at his Aviation Partners office near the King County Airport terminal at Boeing Field. “We will be announcing more orders soon.”

Clark is even talking with the military and defense contractors. He met recently met with officials at Northrop Grumman about putting blended winglets on the Global Hawk unmanned aerial vehicle that has been used in Afghanistan. The winglets would add about two hours of flight time for the Global Hawk, Clark said. “Every plane should be designed with winglets,” Clark said.

Winglets were common on business and commercial jets before Aviation Partners arrived on the scene. But those traditional winglets, found on all Airbus models and the Boeing 747-400, rise at a sharp angle from the wing. Blended winglets gently curve up, as if they are part of the wing. Winglets were first developed by NASA in the 1960s to help reduce drag. Increasing the wing span can produce the same results. But wings of jetliners can’t get any longer and still fit at airport gates. What’s more, increasing wing span means structural changes that add weight. So far, the only U.S. carrier with 737s equipped with blended winglets is American Trans Air. But Clark recently presented his friend John Kelly, chairman of Alaska Airlines, with a small model of a 737-700 with blended winglets. The two men have known each other since the days when Clark teamed with Milt Kuolt in 1981 to form Horizon Air, a regional carrier later sold to Alaska. The model Clark gave to Kelly was painted in the livery of Alaska Airlines, with the Eskimo logo on the winglets. “A picture is worth a thousand words,” Clark said, explaining why he was giving the model to Kelly.

Continental is another 737-700 operator being wooed. The 737 is the world’s most frequently flown jetliner. More than 4,000 have been built. Later this year, the blended winglets are to be certified by the Federal Aviation Administration for the older “classic” 737s, starting with the 737-300. Certification will follow for the 737-400 and 737-500. His company’s business plan includes blended winglets for the 757, 767 and 747, Clark said, as well as for the MD-80 series. “The retrofit market is huge,” Clark said. “Our schedule is to certify the classic 737s this year, the 747 next year, the 767 after that and then the 757.”

The winglets designed for the next generation 737 are about 8 feet high. Bernie Gratzer, former chief aerodynamicist at Boeing who was part of Clark’s team at Aviation Partners that developed the blended winglets, said the 747 flight tests showed the winglets reduced drag by about 6.3 percent. That can mean substantial fuel savings for an airline. Clark has been approached by operators of older 747s, asking about retrofitting their planes with the blended winglets. “We think we can save them about a million gallons of fuel a year per plane,” he said. But Boeing is not sold on blended winglets, at least for its bigger jets. Boeing engineers developed a raked tip, which does not bend upward like a winglet, for the 767-400 and will use those raked tips for the longer-range 777-300 now in development. And Boeing is considering raked tips, not blended winglets, for future longer-range versions of its 747-400. “Why put raked tips on a 747? That’s a good question,” said Gratzer, who retired from Boeing in 1986 and later was a professor at the University of Washington’s aeronautics and astronautical department. “We don’t really understand why they (Boeing) would do that,” he added. But it was not so long ago that many engineers at Boeing scoffed at the notion that winglets would do anything other than give the 737 a more sexy appearance. After all, wasn’t that why all those rich guys who could afford private jets wanted ones with winglets?

At the Paris Air Show in 1997, Boeing’s Borge Boeskov approached Clark about blended winglets on the planned Boeing Business Jet, a next generation 737-700 with the strengthened wing of the 737-800. Clark’s subsequent business proposal for Boeskov said the Boeing Business Jet would get from 4 to 5 percent better performance with blended winglets. “The corporate guys like the looks of these things because they differentiate the product, but frankly my engineers have told me they don’t work,” Borge told Clark. So Clark told Boeskov his small company would foot the bill to design winglets for the Boeing Business Jet if Boeskov would test fly them on the plane. Unable to get Boeing engineers to go along, Boeskov turned to the German carrier Hapag-Lloyd, a longtime Boeing 737 customer. Hapag-Lloyd supplied one of its new 737s, and the results were better than Clark had predicted — a nearly 7 percent reduction in drag. Hapag-Lloyd is now one of those customers operating 737s with blended winglets.

Clark, who is not at all shy about expressing his opinions, is careful in talking about the challenges he has faced working with the world’s largest aerospace company on an idea that Boeing’s best and brightest once rejected. “They are a big bureaucracy and we sometimes want to get things done quickly,” Clark said of the joint venture with Boeing. He credited Alan Mulally, Boeing’s commercial boss, with helping change attitudes within the company. “Since Alan has gotten behind this, it has changed overnight,” Clark said. “We talked about five months ago and he said he would really get behind the winglets program. “Since then, sales have really taken off. Our relationship with everyone at Boeing has gotten much better.” Then he added, “Of course, we still have our differences.” So far, though, the elephant has not rolled over.


8 February 2002 – Kawasaki of Japan will build 737 winglets

Friday, February 8, 2002

SEATTLE POST-INTELLIGENCER STAFF AND NEWS SERVICES

TOKYO — Kawasaki Heavy Industries Ltd., Japan’s second-biggest aerospace company, said it will develop wingtips for Boeing Co. 737s, adding to an existing cooperation with the company.

Kawasaki Heavy will make blended winglets, which increase fuel efficiency and range, the companies said. The companies didn’t provide financial details.

Owners of 737s, of which more than 1,900 are in service around the world, will be able to fit the wingtips onto their planes, the release said.


SEATTLE, Sept. 11, 2001 –The first Boeing 737-700 arrived in Kenya Monday, making Kenya Airways the first airline anywhere in the world to operate a 737-700 with blended winglets. Kenya Airways is expected to put the airplane into service later this month. The airplane will be leased through GE Capital Aviation Services.”Our goal is to become the premier airline of choice in Africa and provide more frequency for passengers,” said Isaac Omolo Okero, chairman for Kenya Airways. “The 737’s economics and low maintenance cost will help us continue to provide the best service to destinations throughout Africa.”

The retrofitted blended winglets on the 737-700 curve out and up from the wingtip, reducing aerodynamic drag and boosting performance. Some of the potential improvements include better fuel burn, increased range, improved takeoff performance and obstacle clearance. Working with Aviation Partners Inc., Boeing developed the blended winglet technology for the 737 airplane.

“The addition of the winglets on the 737-700 will provide Kenya Airways with a superior product,” said Kevin Bartelson, chief operating officer for Aviation Partners Boeing. “The new 737-700 with winglets will add value to operators and provide a technologically advanced product with a reputation for superior reliability.”

The family of 737s consisting of the 737-600, -700, -800 and -900 is the newest design and the most technologically advanced in the single-aisle market.

“Kenya Airways’ selection of the 737 airplane will help reduce its fleet costs, which directly affects the airline’s bottom line,” said Doug Groseclose, senior vice president of International Sales, Boeing Commercial Airplanes. “With the new 737s, Kenya Airways can continue to offer its customers a quality product and on-time in-service performance.”

The airplanes are designed to fly higher, faster, farther, quieter and with greater fuel efficiency than previous 737 models — and the competition.

Kenya Airways, one of the fastest growing and most profitable airlines in Africa, will use the new 737 to fly to key destinations in Africa and other domestic routes on the continent. There are more than 130 Boeing 737s operating in Africa and more than 4,000 737s in service today.


Boeing 737 Advanced-Technology Winglets Make World Debut

SEATTLE, May 21, 2001 — Boeing Next-Generation 737-800 advanced-technology winglets made their world debut in revenue service last week with German carrier Hapag-Lloyd Flug.

Hanover-based Hapag-Lloyd became the first airline in the world to fly 737-800s equipped with the cost-effective, environmentally friendly wingtip extensions on commercial routes. The carrier uses 737-800s with winglets on routes from Germany to Mediterranean destinations.

The new winglets on the Boeing 737-800 curve out and up from the wingtip, reducing aerodynamic drag and boosting performance. They add about 5 feet (1.5 meters) to the airplane’s total wingspan and allow the airplane to fly up to 130 nautical miles (240 kilometers) further.

“The winglets on our 737-800s will cut the airplane’s already low fuel consumption, emissions and takeoff noise and make them even more eco-friendly,” said Wolfgang Kurth, Hapag-Lloyd managing director. “Less fuel means more range and gives us the opportunity to open new markets”

The fuel consumption of the 737-800s without winglets in Hapag-Lloyd’s fleet already is as low as 2.1 liters per 100 seat kilometers. “We expect the winglets to decrease fuel burn even further – by up to 5 percent in cruise – and reduce the noise affected area by 6.5 percent,” Kurth said.

Winglets also have the potential to increase the optimum cruise altitude of the airplane, reduce engine maintenance costs, improve takeoff performance, and increase the weight the airplane can carry by .55 of a ton to 3.3 tons (.5 of a ton to 3 metric tons).

“Next-Generation 737 winglets have proven their value in service on privately owned Boeing Business Jets, and now Hapag-Lloyd will see firsthand the unmatched benefits winglets can bring to commercial operators,” said Toby Bright, Boeing Commercial Airplanes senior vice president for Europe and Russia. “Hapag-Lloyd, which was the first airline to order the new-technology 737-800s back in 1994, will once again make history as a company that quickly recognizes the importance of technological improvements in aviation.”

Hapag-Lloyd has started to retrofit its fleet of 27 Boeing 737-800s with winglets.

Winglets initially were developed for use on the Boeing Business Jet, an adapted Next-Generation 737-700 with 737-800 wings, by Aviation Partners, Inc. (API). During the design process, Boeing and API formed a joint venture that further developed the design. The joint venture is called Aviation Partners Boeing (APB).

Building a quieter, more fuel-efficient airplane was a top priority for Boeing engineers who initially designed the 737-800 and other members of the Next-Generation 737 family. The model’s new CFM56-7 engines produced by CFMI, a joint venture of General Electric Co. of the United States and Snecma of France, meet community noise restrictions well below current Stage 3 limits and below expected Stage 4 limits. Emissions also are reduced beyond required standards.


Winglets boost to Boeing 737–800 performance

SEATTLE, Feb. 18, 2000 – The Boeing Company announced today that it is offering Next-Generation 737-800 customers a new, advanced-technology winglet as a standard option.

The winglet will allow a new airplane that already flies farther, higher and more economically than competing products to extend its range, carry more payload, save on fuel and benefit the environment. The first Boeing 737-800 with winglets is expected to be delivered in the spring of 2001. All subsequent 737-800s will be equipped with structurally enhanced wings that will make it easier for owners of standard 737-800s to retrofit those jetliners with winglets.

“The key to product leadership is to create a superior product, then continually improve it in ways that add value to customers,” said John Hayhurst, vice president and general manager, 737 programs. “With this new winglet, the Next-Generation 737 will remain the most advanced airplane family in its class for the 21st century, just as it was for the 20th.”

A Next-Generation 737-800 equipped with the new winglet will be able to fly farther, burn 3 percent to 5 percent less fuel, or carry up to 6,000 pounds more payload. Other benefits include a reduction in noise near airports, lower engine-maintenance costs, and improved takeoff performance at high-altitude airports and in hot climate conditions.

The winglets weigh about 120 pounds each. They are made of high-tech carbon graphite, an advanced aluminum alloy and titanium. The winglet is eight feet long and tapers from its four-foot wide base to a width of two feet at the tip. Unlike traditional winglets typically fitted at abrupt angles to the wing, this new advanced “blended” design gently curves out and up from the wing tip, reducing aerodynamic drag and boosting performance.

The 737-800 winglet was developed initially for the Boeing Business Jet (BBJ), which also features the state-of-the-art 737-800 wing. This winglet will be available initially as an option on the 162-passenger 737-800. Formal availability of the winglet will follow quickly on other models that feature the 737-800 wing, including the 737-700C and the 737-900. The applicability of the winglet to Next-Generation 737-600 and 737-700 models is being assessed.

The blended-winglet technology was developed by Aviation Partners Inc. of Seattle. In 1999, during the design of the BBJ winglet, Aviation Partners and The Boeing Company formed Aviation Partners Boeing (APB), a joint venture that completed and owns the design. APB is developing the capability to make the winglet available as a retrofit for airplanes already in service.


SEATTLE, Oct. 23, 2000 – German carrier Hapag-Lloyd Flug became the first airline to fly the Boeing 737-800 with blended winglets. The test flight took place Sept. 26 2000 in Seattle.


First BBJ flight with winglets

Feb 22, 1999

 


Boeing Business Jets Announces Winglets Test

SEATTLE, June 4, 1998— Boeing Business Jets announced today that it has been testing the use of winglets on a Boeing 737-800 for possible application on the new Boeing Business Jet (BBJ).The winglets are being tested as a possible range-performance enhancement for the BBJ. Designed and manufactured by Seattle-based Aviation Partners Inc., the two 8-foot high, blended and vertically mounted winglets are attached to the end of each wing of the airplane.

“The Boeing Business Jet’s 6,200 nautical-mile range already ranks it with the leading business airplanes in its class,” said Borge Boeskov, president of Boeing Business Jets. “We want to test the application of winglets as a way of making a world-class product even better. We are testing to determine whether winglets will provide a range-performance enhancement by reducing drag.”

The BBJ is a derivative of the Next-Generation 737-700, combining the -700 fuselage with the strengthened wings and landing gear of the larger and heavier 737-800. This combination gives the BBJ a range of 7,140 statute miles (6,200 nautical miles, 11,480 kilometers).

“As a special-use airplane for executive teams and private owners, the BBJ will fly much longer routes – up to 14 hours nonstop – than commercially operated Boeing 737s,” Boeskov said. “These are the routes where winglets would have the best opportunity for performance improvements.”

In addition to performance, winglets will give the Boeing Business Jet a look that will set it apart from other business and commercial jets of its size.

“We want the BBJ to stand out, and we want it to look distinctive among all other business jets,” Boeskov said.

Boeskov said the first phase of flight-testing will be completed this week. Whether winglets will be used on the BBJ will be determined following evaluation of testing data.

Major assembly of the first BBJ fuselage was recently completed in Wichita, Kan., while work on the first wings and other components is progressing in the Puget Sound area. The airplane’s first flight is scheduled for August. Boeing Business Jets is a joint venture between The Boeing Company and General Electric Co.

Flight Management Computer – B737

Introduction

First introduced on the series 200 in Feb 1979 as the Performance Data Computer System (PDCS), the Flight Management Computer (FMC) was a huge technological step forward. Smiths Industries (formerly Lear Seigler) has supplied all FMCs installed on the 737.

The PDCS was developed jointly by Boeing and Lear Seigler in the late 1970’s. It enabled EPR and ASI bugs to be set by the computer and advise on the optimum flight level, all for best fuel economy. It was trialed on two in-service aircraft, a Continental 727-200 and a Lufthansa 737-200 for nine months in 1978 with regular line crews and a flight data observer. The 737-200 showed average fuel savings of 2.95% with a 2 minute increase in trip time over an average 71 minute flight. The 727 gave a 3.94% fuel saving because of its longer sector lengths. The PDCS quickly became standard fit and many were also retrofitted. By 1982 the autothrottle had been devised and thrust levers could be automatically driven to the values specified by the PDCS.

The true FMC was introduced with the 737-300 in 1984 this kept the performance database and functions but also added a navigation database which interacts with the autopilot & flight director, autothrottle and IRSs. The integrated system is known as the Flight Management System (FMS) of which the FMC is just one component. Most aircraft have just one FMC, but there is an option to have two this is usually only taken by operators into MNPS airspace eg Oceanic areas. The FMS can be defined as being capable of four dimensional area navigation (latitude, longitude, altitude & time) while optimising performance to achieve the most economical flight possible.

The photograph above is of the Control Display Unit (CDU), which is the pilot interface to the FMC. There are normally 2 CDUs but only one FMC. Think of it as having two keyboards connected to the one PC. The CDU in the photograph has a DIR INTC key at the beginning of the second row but some have a MENU key. This key gives access to the subsystems such as FMC, ACARS, DFDMU, etc.

In its most basic form, the FMC has a 96k word navigation database, where one word is two bytes (ie a 16 bit processor). This was increased to 192k words in 1988, 288k in 1990, 1 million in 1992 and is now at 4 Mega words for the 737-NG with Update 10.7. The navigation database is used to store route information which the autopilot will fly when in LNAV mode. When given data such as ZFW & MACTOW, it takes inputs from the fuel summation unit to give a gross weight and best speeds for climb, cruise, descent, holding, approach, driftdown etc. These speeds can all be flown directly by the autopilot & autothrottle in VNAV mode. It will also compute the aircrafts position based upon inputs from the IRSs, GPS and radio position updating.

The latest FMC – Model 2907C1, has a Motorola 68040 processor running at 60MHz (30Mhz bus clock speed), with 4Mb static RAM and 32Mb for program & database.


FMC Databases

An FMC has three databases: Software options (OP PROGRAM), Model/Engine data base (MEDB) and Navigation data base (NDB), all of which are stored on an EEPROM memory card. These databases can all be updated via the data loader.

The Software options database includes the operational program and its update, plus any company specific differences. For a full list of all FMC software updates and their features, please refer to the book.

The MEDB holds all the performance data for V speeds, min & max speeds in climb, cruise & descent, fuel consumptions, altitude capability etc.

The NDB is comprised of Permanent, Supplemental (SUPP) and Temporary (REF). The Permanent database cannot be modified by crew. There are four types of data: Waypoint, Navaid, Airport and Runway. Runway data is only held in the permanent database.

There is capacity in the SUPP and REF databases for up to 40 waypoints, 40 navaids and 6 airports. SUPP data can only be entered on the ground. It is then stored indefinitely but crew may delete individual data or the whole database. Any existing SUPP data should be checked for accuracy before flight using the SUMMARY option (U6+ only) or DELeted and re-entered, cross-checking any Lat & Longs between both crew members. All Temporary (REF) data is automatically deleted after flight completion.

When entering navaids into either the REF NAV DATA or SUPP NAV DATA database, you will be box prompted for a four letter “CLASS” classification code. The following table should be used:

Navaid Classification Codes

Box Numbers

VHF Navaids 1 2 3 4
VOR V
TACAN Ch 17-59, 70-117 T
MILITARY TACAN Ch 1-16, 60-69 M
DME D
ILS/DME I
Terminal T
Low Altitude L
High Altitude H
Use unrestricted by range or altitude U
Scheduled Weather Broadcast B
No Voice on Navaid Frequency W
Automatic Trans Weather Broadcast A

Eg. To create a new en-route VOR/DME, the Class code would be VDHW.


 

FMC Pages

Green: CRT, White: LCD

Pre-Flight Preparation Pages

The contents page. Pages required for the departure are listed on the left hand side.This INIT/REF INDEX page (shown right) is from an U6.2 aircraft equipped with ACARS and IRS navigation. Selecting MSG RECALL allows the recall of deleted CDU scratchpad messages whose set logic is still valid. ALTN DEST allows the entry of selected alternate airports.
The NG (U7+) has some extra options available.

The OFFSET function is used in-flight to fly parallel to a portion of the route. This may be used to avoid the turbulent wake of the aircraft ahead or to increase separation with opposite direction traffic.

5R will offer MAINT when on the ground, see below for some of these pages.

The contents page.

IDENT: Check aircraft model and engine rating is what you are flying, especially if your airline operates a mixed fleet. Also check the database effectivity and expiry dates. Software update number is given in brackets, here U10.5A. U10 was specifically designed for the 737-NG but can be used on classics.

The prompt at 6R leads onto POS INIT

POS INIT is used to enter the aircraft position into the IRS’s for alignment. The Lat & Longs of REF AIRPORTS & GATES are held in the database and do not need typing in but should be cross-checked against published data.
Routes are usually entered by inputting the CO ROUTE. Eg AMSLPLRPL = Amsterdam to Liverpool Repetitive Flight Plan. If the company route is not recognised the route can be entered manually by filling in the VIA & TO columns.
In-flight the OFFSET option will be available on U7 onwards. See below to use this to access the hidden NEAREST AIRPORTS and ALTERNATE DESTS pages.
After the route is entered, press the DEP ARR button on the CDU to access the departures and arrivals for the ends of the route.
This is a typical arrivals page and allows selection of the required SID, Transition and approach. These are denoted by <ACT> when they have been selected.
The PERF INIT page is completed before fight and gives the FMC the data to calculate leg times & fuels and the optimum & max altitudes.

Cost Index is the ratio of the time-related operating costs of the aircraft vs. the cost of fuel. If CI is 0 the FMC gives maximum range airspeed and minimum trip fuel. If CI is max the FMC gives Vmo/Mmo for climb & cruise; descent is restricted to 330kts to give an overspeed margin. The range of CI is 0-200 (Classics) and 0-500 (NGs).

CRZ WIND is actually used for both climb wind and cruise wind. If you enter the forecast top-of-climb wind before departure the FMC will recalculate your climb speed accordingly. When in the cruise if you enter the average cruise wind, the time and fuel calculations will be updated. If you do not enter anything here the FMC will assume still air.

In-Flight Pages

Standard take-off page for PF. Speeds & assumed temperature must be entered manually from performance tables. TO SHIFT should be entered if departing from an intersection as this is used to update the FMC positionwhen TOGA is pressed at the start of the take-off roll.Notice that the reduced takeoff N1’s (90.5/89.6) are different for each engine. This is because when the photo was taken only one pack (the right) was running.
Used for entry of de-rates, where allowed.
This is the N1 Limit page pre-U10. Provides thrust limit and reduced climb thrust selection. This is usually automatic but manual selections can be made here.

The most common use is either to select a reduced climb thrust (1 or 2) after a full power take-off to reduce engine wear or to delete the reduced climb thrust to get a high rate of climb.

One of the most useful pages in the Boeing FMC and has just been updated to six pages in update 10.6. The fix can be anything in the database ie airfield, beacon or waypoint. An abeam point can be constructed (as illustrated) or a radial or range circle can be displayed on the EHSI. Surprisingly, there is no equivalent page on the Airbus.

Climb Pages

Standard ECON CLB page. 302 (Kts IAS) is highlighted indicating that this is the target speed, this will automatically change over to mach (0.597 in this case) during the climb. Other climb modes are available with keys 5 & 6, L & R.CLB-1 indicates that the autothrottle is commanding a reduced thrust climb power (reduces N1 by approx 3% = 10% thrust reduction). CLB-2 is a reduction of a further 10% ie 20% total. The reduced climb thrust setting gradually increases to full climb power by 15,000ft.
Selecting MAX RATE from a climb page will show this page with the target speed not highlighted and the ERASE option available until the EXEC button is pressed. If EXEC is pressed you can return to ECON by line selecting it.
Selecting MAX ANGLE from a climb page will show this page with the target speed not highlighted and the ERASE option available until the EXEC button is pressed. If EXEC is pressed you can return to ECON by line selecting it.
Selecting ENG OUT on a climb page gives the following choice of LT or RT engines.
When the LT or RT engine has been selected this page shows your MAX ALT (climb or driftdown alt) TGT SPD and max cont N1. This is a useful page to check if flying over ground above 15,000ft. Remember the altitude penalties for anti-ice.The EXEC light will now be illuminated, if you press it you will lose all VNAV info. Select ERASE to return to the two engine CLB/CRZ pages.

Cruise Pages

Standard PF in-flight cruise page. The target speed (highlighted) is the ECON speed which is derived from the cost index and winds.

The fuel at EGLL figure is blank because either it is being recalculated or there is a route discontinuity.

 

Selecting ENG OUT on the cruise page will give this page which asks you to select which engine is inop.

After selecting the appropriate engine, the FMC will calculate your driftdown target speed and stabilisation altitude. It is worthwhile making this check before crossing over areas of high terrain. Do not press EXEC at any stage otherwise you will lose VNAV information, these actions can be undone by selecting ERASE.
Selecting LRC gives Long Range Cruise speed. This is calculated as 99% of the maximum range speed for a given weight & altitude in still air conditions. It is used in preference to MRC because it is a more stable speed and hence gives less autothrottle movement.

LRC takes no account of winds so it may give a higher fuel burn than ECON. It also takes no account of operating costs; hence it has little practical value.

Descent Pages

FPA is the actual flight path angle of the aircraft, it is zero in this example because the aircraft is in level flight. It is typically 3 to 4 degrees in a descent.

V/B is the required vertical bearing to reach the WPT/ALT ie TIGER/16000. This would be an altitude restriction in the LEGS page that you could enter (or delete) manually or with the ALT INTV button on the MCP if fitted.

V/S is the required vertical speed to make good the V/B.

As you approach your ToD the FPA will remain at zero (because the aircraft is in level flight), but the V/B and V/S will both increase until the V/B is at about 3 to 4 degrees, or whatever the FMC has calculated is the optimum value. If VNAV is engaged the aircraft will descend with a FPA equal to the V/B. The actual V/S will however be slightly different to the computed V/S because V/S changes during the descent.

FMC position can be forced to any of the other positions at this page.
You can either select a waypoint from the legs page or use PPOS (Present POSition) on which to base the hold. The database will give the turn direction & inbound course. Leg time will be that appropriate to your altitude . Target speed will default to the best speed which will be that for max endurance. Hold avail is calculated from the present fuel, fuel flow and reserves figure entered into the PERF INIT page.
Very rarely used. Sets min & max speed limits for climb, cruise & descent.
Very useful howgozit page, but don’t trust the fuel summation unit! it always overreads by approx 1-200kgs. For an accurate arrival fuel subtract 2-300kgs to allow for this and the drag of flying slower than the optimum speed whilst on the approach.
Very rarely used but can be used to try to reach a waypoint at a specific time.
PROGRESS 3/3: Standard landing page for PF. Especially useful for giving crosswind component and SAT in icing conditions. Confusingly this page has now been moved to 2/4 on U10.7, so instead of selecting Progress-Prev Page you now have to select Progress-Next Page.

APPROACH REF: Standard landing page for PNF. Vref is calculated from the current gross weight, pedants may wish to overwrite the GROSS WT with the predicted GW for landing.Vref is “hardened” by line-selecting it over itself which will cause it to be displayed on the speed tape.

IRS Navigation Pages (If installed)

The following pages are only available on ANS equipped aircraft.

Similar to ACT RTE LEGS.
Similar to PROGRESS.
Similar to ACT RTE DATA.

Maintenance Pages

Caution do not access these pages without engineering supervision.

Hidden Pages

These are various pages hidden away in most FMC’s that are not always immediately available to the pilots, I suspect because there would be a surcharge to their airlines to use them. There are some ingenious ways of getting to these pages by careful use of simultaneous CDU entries.

This is not a hidden page, but it is the way into them. You can bring up this OFFSET page either from RTE or INIT/REF INDEX.

1. Have this page displayed on both CDU’s.

2. Enter any offset but do not execute.

3. Simultaneously press ERASE on both CDU’s.

These steps will bring ALTERNATE DESTS. (See below)

You can enter up to 5 alternates here, selecting 1R to 5R against any entered alternate will show the info below…
All the diversion data is now shown based on you flying direct to this alternate from present position (VIA DIRECT). Selecting MISSED APP will show the same data but calculated from the missed approach point.Selecting nearest airports will give…
This extremely useful page takes a couple of minutes to calculate but will list the nearest airports in the database in order of DTG.

Once again, line selection of 1R to 5R will give more useful diversion information as shown below.

All the diversion data is now shown based on you flying direct to this airport from present position (VIA DIRECT). Selecting MISSED APP will show the same data but calculated from the missed approach point.Selecting INDEX to return to the normal pages.

Contents

See more details about the book

All of the information, photographs & schematics from this website and much more is now available in a 370 page, 8.5″ x 11″ book available here.

Updated 3 Sept 11

Introduction

First introduced on the series 200 in Feb 1979 as the Performance Data Computer System (PDCS), the Flight Management Computer (FMC) was a huge technological step forward. Smiths Industries (formerly Lear Seigler) has supplied all FMCs installed on the 737.

The PDCS was developed jointly by Boeing and Lear Seigler in the late 1970’s. It enabled EPR and ASI bugs to be set by the computer and advise on the optimum flight level, all for best fuel economy. It was trialed on two in-service aircraft, a Continental 727-200 and a Lufthansa 737-200 for nine months in 1978 with regular line crews and a flight data observer. The 737-200 showed average fuel savings of 2.95% with a 2 minute increase in trip time over an average 71 minute flight. The 727 gave a 3.94% fuel saving because of its longer sector lengths. The PDCS quickly became standard fit and many were also retrofitted. By 1982 the autothrottle had been devised and thrust levers could be automatically driven to the values specified by the PDCS.

The true FMC was introduced with the 737-300 in 1984 this kept the performance database and functions but also added a navigation database which interacts with the autopilot & flight director, autothrottle and IRSs. The integrated system is known as the Flight Management System (FMS) of which the FMC is just one component. Most aircraft have just one FMC, but there is an option to have two this is usually only taken by operators into MNPS airspace eg Oceanic areas. The FMS can be defined as being capable of four dimensional area navigation (latitude, longitude, altitude & time) while optimising performance to achieve the most economical flight possible.

The photograph above is of the Control Display Unit (CDU), which is the pilot interface to the FMC. There are normally 2 CDUs but only one FMC. Think of it as having two keyboards connected to the one PC. The CDU in the photograph has a DIR INTC key at the beginning of the second row but some have a MENU key. This key gives access to the subsystems such as FMC, ACARS, DFDMU, etc.

In its most basic form, the FMC has a 96k word navigation database, where one word is two bytes (ie a 16 bit processor). This was increased to 192k words in 1988, 288k in 1990, 1 million in 1992 and is now at 4 Mega words for the 737-NG with Update 10.7. The navigation database is used to store route information which the autopilot will fly when in LNAV mode. When given data such as ZFW & MACTOW, it takes inputs from the fuel summation unit to give a gross weight and best speeds for climb, cruise, descent, holding, approach, driftdown etc. These speeds can all be flown directly by the autopilot & autothrottle in VNAV mode. It will also compute the aircrafts position based upon inputs from the IRSs, GPS and radio position updating.

The latest FMC – Model 2907C1, has a Motorola 68040 processor running at 60MHz (30Mhz bus clock speed), with 4Mb static RAM and 32Mb for program & database.


FMC Databases

An FMC has three databases: Software options (OP PROGRAM), Model/Engine data base (MEDB) and Navigation data base (NDB), all of which are stored on an EEPROM memory card. These databases can all be updated via the data loader.

The Software options database includes the operational program and its update, plus any company specific differences. For a full list of all FMC software updates and their features, please refer to the book.

The MEDB holds all the performance data for V speeds, min & max speeds in climb, cruise & descent, fuel consumptions, altitude capability etc.

The NDB is comprised of Permanent, Supplemental (SUPP) and Temporary (REF). The Permanent database cannot be modified by crew. There are four types of data: Waypoint, Navaid, Airport and Runway. Runway data is only held in the permanent database.

There is capacity in the SUPP and REF databases for up to 40 waypoints, 40 navaids and 6 airports. SUPP data can only be entered on the ground. It is then stored indefinitely but crew may delete individual data or the whole database. Any existing SUPP data should be checked for accuracy before flight using the SUMMARY option (U6+ only) or DELeted and re-entered, cross-checking any Lat & Longs between both crew members. All Temporary (REF) data is automatically deleted after flight completion.

When entering navaids into either the REF NAV DATA or SUPP NAV DATA database, you will be box prompted for a four letter “CLASS” classification code. The following table should be used:

Navaid Classification Codes

Box Numbers

VHF Navaids 1 2 3 4
VOR V
TACAN Ch 17-59, 70-117 T
MILITARY TACAN Ch 1-16, 60-69 M
DME D
ILS/DME I
Terminal T
Low Altitude L
High Altitude H
Use unrestricted by range or altitude U
Scheduled Weather Broadcast B
No Voice on Navaid Frequency W
Automatic Trans Weather Broadcast A

Eg. To create a new en-route VOR/DME, the Class code would be VDHW.


FMC Pages

Green: CRT, White: LCD

Pre-Flight Preparation Pages

The contents page. Pages required for the departure are listed on the left hand side.This INIT/REF INDEX page (shown right) is from an U6.2 aircraft equipped with ACARS and IRS navigation. Selecting MSG RECALL allows the recall of deleted CDU scratchpad messages whose set logic is still valid. ALTN DEST allows the entry of selected alternate airports.
The NG (U7+) has some extra options available.

The OFFSET function is used in-flight to fly parallel to a portion of the route. This may be used to avoid the turbulent wake of the aircraft ahead or to increase separation with opposite direction traffic.

5R will offer MAINT when on the ground, see below for some of these pages.

The contents page.

IDENT: Check aircraft model and engine rating is what you are flying, especially if your airline operates a mixed fleet. Also check the database effectivity and expiry dates. Software update number is given in brackets, here U10.5A. U10 was specifically designed for the 737-NG but can be used on classics.

The prompt at 6R leads onto POS INIT

POS INIT is used to enter the aircraft position into the IRS’s for alignment. The Lat & Longs of REF AIRPORTS & GATES are held in the database and do not need typing in but should be cross-checked against published data.
Routes are usually entered by inputting the CO ROUTE. Eg AMSLPLRPL = Amsterdam to Liverpool Repetitive Flight Plan. If the company route is not recognised the route can be entered manually by filling in the VIA & TO columns.
In-flight the OFFSET option will be available on U7 onwards. See below to use this to access the hidden NEAREST AIRPORTS and ALTERNATE DESTS pages.
After the route is entered, press the DEP ARR button on the CDU to access the departures and arrivals for the ends of the route.
This is a typical arrivals page and allows selection of the required SID, Transition and approach. These are denoted by <ACT> when they have been selected.
The PERF INIT page is completed before fight and gives the FMC the data to calculate leg times & fuels and the optimum & max altitudes.

Cost Index is the ratio of the time-related operating costs of the aircraft vs. the cost of fuel. If CI is 0 the FMC gives maximum range airspeed and minimum trip fuel. If CI is max the FMC gives Vmo/Mmo for climb & cruise; descent is restricted to 330kts to give an overspeed margin. The range of CI is 0-200 (Classics) and 0-500 (NGs).

CRZ WIND is actually used for both climb wind and cruise wind. If you enter the forecast top-of-climb wind before departure the FMC will recalculate your climb speed accordingly. When in the cruise if you enter the average cruise wind, the time and fuel calculations will be updated. If you do not enter anything here the FMC will assume still air.

In-Flight Pages

Standard take-off page for PF. Speeds & assumed temperature must be entered manually from performance tables. TO SHIFT should be entered if departing from an intersection as this is used to update the FMC positionwhen TOGA is pressed at the start of the take-off roll.Notice that the reduced takeoff N1’s (90.5/89.6) are different for each engine. This is because when the photo was taken only one pack (the right) was running.
Used for entry of de-rates, where allowed.
This is the N1 Limit page pre-U10. Provides thrust limit and reduced climb thrust selection. This is usually automatic but manual selections can be made here.

The most common use is either to select a reduced climb thrust (1 or 2) after a full power take-off to reduce engine wear or to delete the reduced climb thrust to get a high rate of climb.

One of the most useful pages in the Boeing FMC and has just been updated to six pages in update 10.6. The fix can be anything in the database ie airfield, beacon or waypoint. An abeam point can be constructed (as illustrated) or a radial or range circle can be displayed on the EHSI. Surprisingly, there is no equivalent page on the Airbus.

Climb Pages

Standard ECON CLB page. 302 (Kts IAS) is highlighted indicating that this is the target speed, this will automatically change over to mach (0.597 in this case) during the climb. Other climb modes are available with keys 5 & 6, L & R.CLB-1 indicates that the autothrottle is commanding a reduced thrust climb power (reduces N1 by approx 3% = 10% thrust reduction). CLB-2 is a reduction of a further 10% ie 20% total. The reduced climb thrust setting gradually increases to full climb power by 15,000ft.
Selecting MAX RATE from a climb page will show this page with the target speed not highlighted and the ERASE option available until the EXEC button is pressed. If EXEC is pressed you can return to ECON by line selecting it.
Selecting MAX ANGLE from a climb page will show this page with the target speed not highlighted and the ERASE option available until the EXEC button is pressed. If EXEC is pressed you can return to ECON by line selecting it.
Selecting ENG OUT on a climb page gives the following choice of LT or RT engines.
When the LT or RT engine has been selected this page shows your MAX ALT (climb or driftdown alt) TGT SPD and max cont N1. This is a useful page to check if flying over ground above 15,000ft. Remember the altitude penalties for anti-ice.The EXEC light will now be illuminated, if you press it you will lose all VNAV info. Select ERASE to return to the two engine CLB/CRZ pages.

Cruise Pages

Standard PF in-flight cruise page. The target speed (highlighted) is the ECON speed which is derived from the cost index and winds.

The fuel at EGLL figure is blank because either it is being recalculated or there is a route discontinuity.

Selecting ENG OUT on the cruise page will give this page which asks you to select which engine is inop.
After selecting the appropriate engine, the FMC will calculate your driftdown target speed and stabilisation altitude. It is worthwhile making this check before crossing over areas of high terrain. Do not press EXEC at any stage otherwise you will lose VNAV information, these actions can be undone by selecting ERASE.
Selecting LRC gives Long Range Cruise speed. This is calculated as 99% of the maximum range speed for a given weight & altitude in still air conditions. It is used in preference to MRC because it is a more stable speed and hence gives less autothrottle movement.

LRC takes no account of winds so it may give a higher fuel burn than ECON. It also takes no account of operating costs; hence it has little practical value.

Descent Pages

FPA is the actual flight path angle of the aircraft, it is zero in this example because the aircraft is in level flight. It is typically 3 to 4 degrees in a descent.

V/B is the required vertical bearing to reach the WPT/ALT ie TIGER/16000. This would be an altitude restriction in the LEGS page that you could enter (or delete) manually or with the ALT INTV button on the MCP if fitted.

V/S is the required vertical speed to make good the V/B.

As you approach your ToD the FPA will remain at zero (because the aircraft is in level flight), but the V/B and V/S will both increase until the V/B is at about 3 to 4 degrees, or whatever the FMC has calculated is the optimum value. If VNAV is engaged the aircraft will descend with a FPA equal to the V/B. The actual V/S will however be slightly different to the computed V/S because V/S changes during the descent.

FMC position can be forced to any of the other positions at this page.
You can either select a waypoint from the legs page or use PPOS (Present POSition) on which to base the hold. The database will give the turn direction & inbound course. Leg time will be that appropriate to your altitude . Target speed will default to the best speed which will be that for max endurance. Hold avail is calculated from the present fuel, fuel flow and reserves figure entered into the PERF INIT page.
Very rarely used. Sets min & max speed limits for climb, cruise & descent.
Very useful howgozit page, but don’t trust the fuel summation unit! it always overreads by approx 1-200kgs. For an accurate arrival fuel subtract 2-300kgs to allow for this and the drag of flying slower than the optimum speed whilst on the approach.
Very rarely used but can be used to try to reach a waypoint at a specific time.
PROGRESS 3/3: Standard landing page for PF. Especially useful for giving crosswind component and SAT in icing conditions. Confusingly this page has now been moved to 2/4 on U10.7, so instead of selecting Progress-Prev Page you now have to select Progress-Next Page.

APPROACH REF: Standard landing page for PNF. Vref is calculated from the current gross weight, pedants may wish to overwrite the GROSS WT with the predicted GW for landing.Vref is “hardened” by line-selecting it over itself which will cause it to be displayed on the speed tape.

IRS Navigation Pages (If installed)

The following pages are only available on ANS equipped aircraft.

Similar to ACT RTE LEGS.
Similar to PROGRESS.
Similar to ACT RTE DATA.

Maintenance Pages

Caution do not access these pages without engineering supervision.

Hidden Pages

These are various pages hidden away in most FMC’s that are not always immediately available to the pilots, I suspect because there would be a surcharge to their airlines to use them. There are some ingenious ways of getting to these pages by careful use of simultaneous CDU entries.

This is not a hidden page, but it is the way into them. You can bring up this OFFSET page either from RTE or INIT/REF INDEX.

1. Have this page displayed on both CDU’s.

2. Enter any offset but do not execute.

3. Simultaneously press ERASE on both CDU’s.

These steps will bring ALTERNATE DESTS. (See below)

You can enter up to 5 alternates here, selecting 1R to 5R against any entered alternate will show the info below…
All the diversion data is now shown based on you flying direct to this alternate from present position (VIA DIRECT). Selecting MISSED APP will show the same data but calculated from the missed approach point.Selecting nearest airports will give…
This extremely useful page takes a couple of minutes to calculate but will list the nearest airports in the database in order of DTG.

Once again, line selection of 1R to 5R will give more useful diversion information as shown below.

All the diversion data is now shown based on you flying direct to this airport from present position (VIA DIRECT). Selecting MISSED APP will show the same data but calculated from the missed approach point.Selecting INDEX to return to the normal pages.

Flight Instruments – B737

NG Flight Instruments

The NG’s have 6 Display Units (DU’s), these display the flight instruments; navigation, engine and some system displays. They are controlled by 2 computers – Display Electronics Units (DEU’s). Normally DEU 1 controls the Captains and the Upper DU‘s whilst DEU 2 controls the F/O’s and the lower DU’s. The whole system together is known as the Common Display System (CDS).

The DU’s normally display the PFD’s outboard, ND’s inboard, engine primary display centre (upper) and engine secondary display lower. Although they can be switched around into almost any other configuration with the DU selector (shown left).

The CDS FAULT annunciation will only occur on the ground prior to the second engine start, it is probably a DEU failure but is in any case a no-go item. If a DEU fails in-flight, the remaining DEU will automatically power all 6 DU’s and a DSPLY SOURCE annunciation will appear on both PFD’s. The nomenclature requirements for these annunciations were developed by Boeing Flight Deck Crew Operations engineers during the early design phase of the 737NG program. The intent of the design function is as follows:
· The CDS FAULT message is intended to be activated on ground to tell the maintenance crew or air crew that the airplane is in a non-dispatchable condition.
· The DISPLAY SOURCE message is annunciated in air to tell the crew that all the primary display information is from one source and should be compared with all other data sources (standby instruments, raw data, etc.) to validate its accuracy.
Since the DISPLAY SOURCE message is intended to be activated in air and CDS FAULT is intended to be activated on ground, air/ground logic is used by CDS to determine which message is appropriate. The air/ground logic system uses a number of inputs to determine airplane state. One of the inputs used is “engines running”. CDS uses the “engines running” logic as the primary trigger for changing the CDS FAULT message to its in-air counterpart. The “engines running” logic is used in case the air/ground data isn’t correct as a result of other air/ground sensing faults.

The DISPLAYS – SOURCE selector is only used on the ground for maintenance purposes (to make all 6 DU’s be powered by either DEU 1 or 2). This may be why the switch is a different shape to the other three; if not, it is still a good way to remember that this is a switch that pilots should not touch!

 

Instrument transfer switches – NG

The DISPLAYS CONTROL PANEL annunciation merely indicates that an EFIS control panel has failed. There is an additional, rather bizarre, attention getter because the altimeter will blank on the failed side, with an ALT flag, until the DISPLAYS – CONTROL PANEL switch is positioned to the good side. Note that this is not the same as the EFI switch on the -3/4/500’s which was used to switch symbol generators.

EFIS Control Panel – NG

PFD – Primary Flight Display – NG

The speed tape shows minimum and maximum operating speeds. The maximum operating speed provides a 0.3g manouvre margin to high speed buffet. The minimum operating speed is computed from the SMYD as follows: The SMYD has two flavours of Min manouvre speed. The first is identified as Vmnvr, the second as Vbl (low speed buffet). The transition from Vmnvr to Vbl is dependent on gross weight, but in general Vmnver is output below 22,000 feet and Vbl above that altitude. Although not used directly in the calculation of Vmnvr, once the airplane starts flying, gross weight becomes a factor indirectly (in the calculation of Vmnvr) via the load factor calculation. FMC Gross Weight is used by the SMYD in the switching logic from Vmnvr (min man speed) to Vbl.

One of the many customer PFD options is an analogue/digital angle of attack display. The red line is the angle for stick shaker activation, the green band is the range of approach AoA.

 

CDS Block Points

The 737NG Common Display System has had several software updates to incorporate additional features, improvements to existing features and bug fixes. Each new update is known as a Block Point. eg BP98 to BP06. A list of each of their features is given in the book.

 

New Approach Formats

With increased navigational accuracy available and hardware/software improvements on the 737, many new types of approaches have been developed. Cat IIIb, LNAV/VNAV, RNAV(GPS), RNAV(RNP), IAN, GLS.

Cat IIIB ILS Is very similar to the current ILS display except that rollout guidance will display as “ROLLOUT” (armed) underneath the VOR/LOC annunciation. A new MFD button labelled “C/R” (Clear/Recall) is required to display system messages on the upper display unit. These messages could be either “NO LAND 3” or “NO AUTOLAND”. Note Cat IIIa is still possible with a NO LAND 3 advisory. In this case green “LAND 2” annunciations will appear on both outboard display units.

LNAV/VNAV most non-precision approaches which are in the FMC database may be flown to MDA in LNAV/VNAV. Look for the coded GP angle in the LEGS pages.

NPS (Navigation Performance scales) combine the display of ANP/RNP with LNAV/VNAV deviation to give either a Cat I approach of its own or a transition to an approach. Note: NPS provides crew awareness of airplane position with respect to the intended path and RNP. They are not required for VNAV approaches, which may be flown with standard displays.

IAN (Integrated Approach Navigation) gives an ILS look-alike display and allows the pilot to fly the approach like an ILS, ie by selecting APP on the MCP. It is a Cat I only approach system which uses the FMC to transmit IAN deviations to the autopilot and display system. Flight path guidance is from navigation radios, FMC or a combination of both. The type of approach must first be selected in the FMC. The flight mode annunciations will vary depending upon the source of the navigation guidance as follows:

Approach FMA
Localiser based approaches:
IGS VOR/LOC & G/S
ILS with G/S out, LOC, LDA, SDF VOR/LOC & G/P
B/C LOC BCRS & G/P

If FMC is used for course guidance:

GPS, RNAV FAC & G/P
VOR, NDB, TACAN FAC & G/P

Where FAC = Final Approach Course and G/P = Glidepath.

GNSS Landing System (GLS) Approaches use GPS and a ground based augmentation system (GBAS) to give signals similar to ILS signals and will probably replace ILS in the future. Certified May 2005, it is initially Cat I but will become Cat IIIB and should have the capability for curved approaches.

Most of the above approaches require FMC U10.5+, CDS BP02+, FCC -709+ and DFDAU & EGPWS.


Classic Flight Instruments

737-300 Non-EFIS F/O flight instruments

The first 737-300’s were not fitted with EFIS and the flight instruments were almost identical to the 737-200Adv. The yellow warning lights above the ADI are the instrument comparator warnings. The FMA annunciations were all contained in the panel above the ASI

Non-EFIS FMA

 

The big Gotcha with SP-177 equipped 737-200Advs and non-EFIS Classics were the HSI source selectors, sometimes referred to as “Killer Switches”. These were located either side of the MCP and changed the HSI to show deviation either from the LNAV or ILS/VOR track. It is vitally important that these switches are set to VOR/ILS before commencing an approach otherwise you will still be indicating LNAV deviation rather than LLZ deviation.

HSI Source selector

HSI source selector switch

 

The 737-300’s were soon available with EFIS, an option which most operators took. The EADI included a speed tape, radio altimeter, groundspeed indicator, and FMA annunciations. The EHSI has a selectable display either to represent the old HSI or a moving map display. See navigation section for details.

737-300 EFIS Captains flight instruments

The flight instruments use information from 2 Air Data Computers -Classics / Inertial Reference Units -NG’s, which have separate pitot-static sources. The ADC/ADIRU’s are powered whenever the AC busses are powered.

Aspirated TAT probes can either be identified visually (see below) or by the presence of a TAT test button on the pitot-static panel. To get an approximate OAT indication on the ground an air-conditioning pack must be on, whereas unaspirated probes require the pitot heat to be off.

TAT Probe – UnaspiratedPerforated with large hole at rear TAT Probe – AspiratedUnperforated and no large hole at rear

The flight recorder starts when the first engine oil pressure rises. It will continue to record for as long as electrical power is available.

EFIS

If display unit cooling is lost, then after a short time the Electronic Attitude Display Indicator (EADI) colours will appear magenta and the WXR DSPY caption will be shown on the EHSI. This can be rectified by selecting ALTERNATE equip cooling supply and/or exhaust fans. The NG’s use Honeywell flat panel displays rather than the CRT’s of the classics and have the advantages of being lighter, more reliable and consume less power, although they are more expensive to produce.

The 737-3/4/500 EADI display, with fast/slow indicator.

 

EADI – Standard

The 737-3/4/500 EADI display, with speed tape.

 

EADI – Speed Tape
The 737-3/4/500 EADI display, with speed tape but no rolling digit curser.

 


Overheating of an individual display unit will cause that unit to blank until it cools down when it will return. If 2 display units on one side blank then the problem is with that symbol generator, SG FAIL will annunciate in the centre of both displays. The display can be restored by using the EFIS transfer switch. This will enable the remaining symbol generator to display onto both sides, the output is controlled through the EFIS control panel of the good side. Caution: the autopilot will disengage when the EFI switch is repositioned.

 

Instrument transfer switches – 3/4/500

 


Standby Flight Instruments

The standby airspeed indicator & altimeter uses aux pitot & alternate static sources and no ADC/ADIRU’s.

 

  

The Integrated Standby Flight Display started to appear in 2003 to replace the mechanical standby artificial horizon and ASI/Altimeter. Personally I find the new ASI & Altimeter much easier to read but the ILS more difficult. The + – buttons are just brightness controls.

The ISFD also sends inertial data to the FCCs which use the data during CAT IIIB approaches, landings and go-around.

Interestingly the ISFD cannot be switched off from the flightdeck – even by pulling the ISFD c/b on the p18 panel. It has its own dedicated battery and the ISFD c/b only removes power from the battery charger, so let us hope that one does not start to smoke in-flight! The battery will give 150 mins of power.

Standby Compass

Finally, if all else fails there is a standby magnetic compass!


Head-Up Display

Head-up Guidance System installed in the 737-NG

HGS was certified for the 737 by the US FAA in 1994 to allow Cat IIIA landings down to 200m RVR and take-offs in 90m. The first production 737 HGS was fitted to a 737-300 of Morris Air (later bought by Southwest) delivered September 1995. The 737 is still the only airliner to be production fitted with HUD.

HGS Panel
Primary Mode Display

 

Cat III at 50ft


Flight Data Recorder (FDR)

The FDR is located above the ceiling above the rear galley. There have been several different models of FDR in the life of the 737 which can collect anything from 30 minutes to hundreds of hours of data of 8 to hundreds of parameters.

Early FDR’s, as fitted to 737-200’s, comprised metal scribes which etched their data into a 150ft long roll of metal foil. These would last about 300hrs but only recorded vertical acceleration, heading, IAS and altitude, plus binary traces such as date, flight number and time of R/T transmissions. A gauge on the panel (see below) shows the recording hours remaining before the foil spool needs replacing.

737-200 FDR panel

Later Digital FDR’s (late 200’s & classics) record onto a 1/4-inch wide, 450 feet long magnetic tape and the newest Solid State FDR’s (later classics & NG’s) record data onto memory chips.

Late model 737-3/4/500 FDR’s record 25 hours of data. The protective casing includes an inner aluminium cover, isothermal protection shield, an outer stainless steel casing and an exterior stainless steel dust cover. This enables it to withstand a crush force of 20,000 pounds per axis, and provides impact protection of 1000 g’s for 5 msec. It is protected from heat by an isothermal insulation which maintains the inner chamber at a safe temperature. It also has an underwater location device that transmits under water for a minimum of 30 days.

The FDR of the 737-NG is similar to that described above but can withstand 3400 g’s of impact, 20,000ft depth of water and temperatures of 1,100C for 30mins.

The FDR starts recording as soon as the first engine oil pressure rises.


Electronic Flight Bag (EFB)

EFB is becoming the latest “must-have” device in the cockpit. They have the ability to do the following tasks:

  • Calculate take-off or landing performance.
  • Calculate weight & balance.
  • Contain the aircraft technical log.
  • Store navigation charts & plates.
  • Store company manuals, FCOMs, crew notices, etc.
  • Retrieve & display weather.
  • Display checklists.
  • Display on-board video surveillance cameras.

The advantages to crew are the accuracy of the data and ease of use. The advantages to the airlines are the cost benefits of a less paper cockpit and real time data transfer.

There are three classes of EFB:

  • Class 1: Fully portable. Eg a laptop.
  • Class 2: Portable but connected to the aircraft during normal operations. Eg tablet & docking station.
  • Class 3: Installed (non-removable) equipment.

BBJ Avionics

The Boeing Business Jet stands at a crossroads in avionics technology—exploiting all the flight deck systems available to airlines operating the 737, while serving as a showcase for advanced bizjet avionics that air carriers may one day want.

The BBJ often serves as a pathfinder for the latest systems that eventually could find their way onto commercial 737 flight decks.

Improved situational awareness is a case in point. Gulfstream, for example, pioneered the use of enhanced vision systems (EVS) with a forward-looking infrared (Flir) camera on large-cabin bizjets. This allows pilots to look through a head-up display (HUD) to see Flir imagery of a runway at night and in smoke, haze, rain and snow (but not in large-droplet fog).

The enhanced vision capability is more than just a safety feature. The FAA allows business jet pilots to use EVS images to fly as low as 100 ft. AGL (instead of 200 ft. during a Category-1 approach) before having to see the runway visually. Currently, airline pilots can’t do this. However, the FAA and the European Aviation Safety Agency are considering changing this rule to allow airlines to descend to 100 ft. with EVS, according to several avionics company officials. This could happen as early as next year.

There’s already substantial airline interest in enhanced vision, says Steve Taylor, the BBJ chief pilot. “I’ll wager if the FAA grants that OK to the airlines [for 100 ft. ], they will be beating on our door,” he adds.

Rockwell Collins is working with Boeing on the EVS program. And Max-Viz Inc., of Portland, Ore., is developing a multisensor, uncooled camera to meet a Rockwell Collins specification. It has both a short-wave and a long-wave infrared sensor and a visible-light camera in one unit.

The BBJ also will have a new version of the Rockwell Collins HGS-4000, called the -4000E. This modification of the head-up guidance system includes new hardware and software to allow the display of video imagery from the Flir camera. The BBJ has head-up guidance for the pilot as a standard feature, while the system is optional on the 737NG. Taylor says every avionics system that’s optional on the airline version of the 737 is standard on the BBJ.

Meanwhile, Rockwell Collins just began flight testing the BBJ enhanced vision system on its Sabreliner test­bed, and the EVS will be flown on a customer’s BBJ during the winter. Certification should occur in mid-2008. Should airlines become more interested in having it on a 737NG, it wouldn’t take much additional work to commercialize the system, says Taylor. “The aircraft certification rules are the same—Part 25,” he notes, so the certification effort on the BBJ should transfer easily to the 737NG.

The plan is to display the EVS imagery not only on the HGS for the pilot but also on one of the six Honeywell cockpit displays (the one on the pedestal so the copilot also can see the Flir imagery).

Taylor notes that head-up guidance systems made their first entry at Boeing on the BBJ and then moved to the commercial aircraft production line. But earlier, HUDs were already flying on existing airline aircraft because carriers such as Southwest and Alaska Airlines had installed them as retrofit items.

However, avionics is not the only area where technical innovation started in the BBJ program and was then incorporated on commercial transports. Winglets, a key fuel-saving device, is an example. “In a sense, we are a Skunk Works for commercial airplanes,” says Taylor.

As for the next big thing in business aviation, it will likely be another situational-awareness advance called synthetic vision. A 3D digital map of the terrain and obstacles ahead of the aircraft will be shown to the pilots of Gulfstream business jets soon, thanks to Honeywell. Rockwell Collins is developing a similar system for Bombardier. This Aviation Week & Space Technology pilot saw a Honeywell prototype last year on a Cessna Citation V (AW&ST Oct. 16, 2006, p. 66). Our night flight passed over the Phoenix area where I attended U.S. Air Force pilot training in the early 1970s. The view out the windscreen was often pitch-black, with mountains below shrouded in darkness. But I could see the “synthetic” terrain on the primary flight display created from a database that portrayed the scene ahead as if it were broad daylight. In 1971, a T-38 crashed into a nearby mountain in the era before synthetic vision.

A key question is, How long will it take for the huge safety advance of synthetic vision to show up on commercial flight decks? Since I no longer fly T-38s, I have to travel economy class on narrow- or wide-body jets. If airline pilots had EVS and SVS, I would feel safer as a passenger flying into airports surrounded by high terrain. But as with EVS and the possible FAA rule change on 100 ft., SVS will need a business case to earn its way onto an airline flight deck. At the moment, it’s not clear what that rationale will be.

Taylor says technology specialists at Boeing are looking at synthetic vision, and he believes its adaptation will follow a path similar to the one for enhanced vision. In the business jet market, “the customer base is much more interested in technology and willing to pay for it,” he notes.

Another way the BBJ benefits from 737 avionics is that the standard-fit radar is an airline-class system—Rockwell Collins’ multiscan WXR2100, which is flying with 100 airlines. It’s a more capable system than many of the radars currently installed in business jets. Keith Stover, Rockwell Collins’ radar marketing manager, says the main benefit for BBJ pilots is automatic adjustment of the radar as well as ground-clutter suppression.

In September, Rockwell Collins said it will provide a multiscan radar for bizjets to accommodate the smaller antenna sizes they need of 12 and 18 in. So this is an example of airline-class avionics technology flowing to business aviation by way of the BBJ flight deck. The airline version, which is already standard on the BBJ, has a 28-in. antenna and includes wind shear protection.

Last summer, I flew on a BBJ over the North Atlantic. During the flight, Rockwell Collins radar engineers were perfecting new software to allow the multiscan radar to improve its automatic detection of storms in a particular region (AW&ST July 9, p. 44). This new geographic-discrimination software will be available soon on the BBJ.

Additional fuel tanks are added after the aircraft leaves the factory and goes to DeCrane Aerospace at Sussex County Airport in Georgetown, Del. This is also where the new enhanced vision system will be fitted.

NG Flight Instruments

The NG’s have 6 Display Units (DU’s), these display the flight instruments; navigation, engine and some system displays. They are controlled by 2 computers – Display Electronics Units (DEU’s). Normally DEU 1 controls the Captains and the Upper DU‘s whilst DEU 2 controls the F/O’s and the lower DU’s. The whole system together is known as the Common Display System (CDS).

The DU’s normally display the PFD’s outboard, ND’s inboard, engine primary display centre (upper) and engine secondary display lower. Although they can be switched around into almost any other configuration with the DU selector (shown left).

The CDS FAULT annunciation will only occur on the ground prior to the second engine start, it is probably a DEU failure but is in any case a no-go item. If a DEU fails in-flight, the remaining DEU will automatically power all 6 DU’s and a DSPLY SOURCE annunciation will appear on both PFD’s. The nomenclature requirements for these annunciations were developed by Boeing Flight Deck Crew Operations engineers during the early design phase of the 737NG program. The intent of the design function is as follows:
· The CDS FAULT message is intended to be activated on ground to tell the maintenance crew or air crew that the airplane is in a non-dispatchable condition.
· The DISPLAY SOURCE message is annunciated in air to tell the crew that all the primary display information is from one source and should be compared with all other data sources (standby instruments, raw data, etc.) to validate its accuracy.
Since the DISPLAY SOURCE message is intended to be activated in air and CDS FAULT is intended to be activated on ground, air/ground logic is used by CDS to determine which message is appropriate. The air/ground logic system uses a number of inputs to determine airplane state. One of the inputs used is “engines running”. CDS uses the “engines running” logic as the primary trigger for changing the CDS FAULT message to its in-air counterpart. The “engines running” logic is used in case the air/ground data isn’t correct as a result of other air/ground sensing faults.

The DISPLAYS – SOURCE selector is only used on the ground for maintenance purposes (to make all 6 DU’s be powered by either DEU 1 or 2). This may be why the switch is a different shape to the other three; if not, it is still a good way to remember that this is a switch that pilots should not touch!

Instrument transfer switches – NG

The DISPLAYS CONTROL PANEL annunciation merely indicates that an EFIS control panel has failed. There is an additional, rather bizarre, attention getter because the altimeter will blank on the failed side, with an ALT flag, until the DISPLAYS – CONTROL PANEL switch is positioned to the good side. Note that this is not the same as the EFI switch on the -3/4/500’s which was used to switch symbol generators.

EFIS Control Panel – NG

PFD – Primary Flight Display – NG

The speed tape shows minimum and maximum operating speeds. The maximum operating speed provides a 0.3g manouvre margin to high speed buffet. The minimum operating speed is computed from the SMYD as follows: The SMYD has two flavours of Min manouvre speed. The first is identified as Vmnvr, the second as Vbl (low speed buffet). The transition from Vmnvr to Vbl is dependent on gross weight, but in general Vmnver is output below 22,000 feet and Vbl above that altitude. Although not used directly in the calculation of Vmnvr, once the airplane starts flying, gross weight becomes a factor indirectly (in the calculation of Vmnvr) via the load factor calculation. FMC Gross Weight is used by the SMYD in the switching logic from Vmnvr (min man speed) to Vbl.

One of the many customer PFD options is an analogue/digital angle of attack display. The red line is the angle for stick shaker activation, the green band is the range of approach AoA.

CDS Block Points

The 737NG Common Display System has had several software updates to incorporate additional features, improvements to existing features and bug fixes. Each new update is known as a Block Point. eg BP98 to BP06. A list of each of their features is given in the book.

New Approach Formats

With increased navigational accuracy available and hardware/software improvements on the 737, many new types of approaches have been developed. Cat IIIb, LNAV/VNAV, RNAV(GPS), RNAV(RNP), IAN, GLS.

Cat IIIB ILS Is very similar to the current ILS display except that rollout guidance will display as “ROLLOUT” (armed) underneath the VOR/LOC annunciation. A new MFD button labelled “C/R” (Clear/Recall) is required to display system messages on the upper display unit. These messages could be either “NO LAND 3” or “NO AUTOLAND”. Note Cat IIIa is still possible with a NO LAND 3 advisory. In this case green “LAND 2” annunciations will appear on both outboard display units.

LNAV/VNAV most non-precision approaches which are in the FMC database may be flown to MDA in LNAV/VNAV. Look for the coded GP angle in the LEGS pages.

NPS (Navigation Performance scales) combine the display of ANP/RNP with LNAV/VNAV deviation to give either a Cat I approach of its own or a transition to an approach. Note: NPS provides crew awareness of airplane position with respect to the intended path and RNP. They are not required for VNAV approaches, which may be flown with standard displays.

IAN (Integrated Approach Navigation) gives an ILS look-alike display and allows the pilot to fly the approach like an ILS, ie by selecting APP on the MCP. It is a Cat I only approach system which uses the FMC to transmit IAN deviations to the autopilot and display system. Flight path guidance is from navigation radios, FMC or a combination of both. The type of approach must first be selected in the FMC. The flight mode annunciations will vary depending upon the source of the navigation guidance as follows:

Approach FMA
Localiser based approaches:
IGS VOR/LOC & G/S
ILS with G/S out, LOC, LDA, SDF VOR/LOC & G/P
B/C LOC BCRS & G/P

If FMC is used for course guidance:

GPS, RNAV FAC & G/P
VOR, NDB, TACAN FAC & G/P

Where FAC = Final Approach Course and G/P = Glidepath.

GNSS Landing System (GLS) Approaches use GPS and a ground based augmentation system (GBAS) to give signals similar to ILS signals and will probably replace ILS in the future. Certified May 2005, it is initially Cat I but will become Cat IIIB and should have the capability for curved approaches.

Most of the above approaches require FMC U10.5+, CDS BP02+, FCC -709+ and DFDAU & EGPWS.


Classic Flight Instruments

737-300 Non-EFIS F/O flight instruments

The first 737-300’s were not fitted with EFIS and the flight instruments were almost identical to the 737-200Adv. The yellow warning lights above the ADI are the instrument comparator warnings. The FMA annunciations were all contained in the panel above the ASI

Non-EFIS FMA

The big Gotcha with SP-177 equipped 737-200Advs and non-EFIS Classics were the HSI source selectors, sometimes referred to as “Killer Switches”. These were located either side of the MCP and changed the HSI to show deviation either from the LNAV or ILS/VOR track. It is vitally important that these switches are set to VOR/ILS before commencing an approach otherwise you will still be indicating LNAV deviation rather than LLZ deviation.

HSI Source selector

HSI source selector switch

The 737-300’s were soon available with EFIS, an option which most operators took. The EADI included a speed tape, radio altimeter, groundspeed indicator, and FMA annunciations. The EHSI has a selectable display either to represent the old HSI or a moving map display. See navigation section for details.

737-300 EFIS Captains flight instruments

The flight instruments use information from 2 Air Data Computers -Classics / Inertial Reference Units -NG’s, which have separate pitot-static sources. The ADC/ADIRU’s are powered whenever the AC busses are powered.

Aspirated TAT probes can either be identified visually (see below) or by the presence of a TAT test button on the pitot-static panel. To get an approximate OAT indication on the ground an air-conditioning pack must be on, whereas unaspirated probes require the pitot heat to be off.

TAT Probe – UnaspiratedPerforated with large hole at rear TAT Probe – AspiratedUnperforated and no large hole at rear

The flight recorder starts when the first engine oil pressure rises. It will continue to record for as long as electrical power is available.

EFIS

If display unit cooling is lost, then after a short time the Electronic Attitude Display Indicator (EADI) colours will appear magenta and the WXR DSPY caption will be shown on the EHSI. This can be rectified by selecting ALTERNATE equip cooling supply and/or exhaust fans. The NG’s use Honeywell flat panel displays rather than the CRT’s of the classics and have the advantages of being lighter, more reliable and consume less power, although they are more expensive to produce.

The 737-3/4/500 EADI display, with fast/slow indicator.

 

EADI – Standard

The 737-3/4/500 EADI display, with speed tape.

 

EADI – Speed Tape
The 737-3/4/500 EADI display, with speed tape but no rolling digit curser.

 


Overheating of an individual display unit will cause that unit to blank until it cools down when it will return. If 2 display units on one side blank then the problem is with that symbol generator, SG FAIL will annunciate in the centre of both displays. The display can be restored by using the EFIS transfer switch. This will enable the remaining symbol generator to display onto both sides, the output is controlled through the EFIS control panel of the good side. Caution: the autopilot will disengage when the EFI switch is repositioned.

Instrument transfer switches – 3/4/500

 


Standby Flight Instruments

The standby airspeed indicator & altimeter uses aux pitot & alternate static sources and no ADC/ADIRU’s.

  

The Integrated Standby Flight Display started to appear in 2003 to replace the mechanical standby artificial horizon and ASI/Altimeter. Personally I find the new ASI & Altimeter much easier to read but the ILS more difficult. The + – buttons are just brightness controls.

The ISFD also sends inertial data to the FCCs which use the data during CAT IIIB approaches, landings and go-around.

Interestingly the ISFD cannot be switched off from the flightdeck – even by pulling the ISFD c/b on the p18 panel. It has its own dedicated battery and the ISFD c/b only removes power from the battery charger, so let us hope that one does not start to smoke in-flight! The battery will give 150 mins of power.

Standby Compass

Finally, if all else fails there is a standby magnetic compass!


Head-Up Display

Head-up Guidance System installed in the 737-NG

HGS was certified for the 737 by the US FAA in 1994 to allow Cat IIIA landings down to 200m RVR and take-offs in 90m. The first production 737 HGS was fitted to a 737-300 of Morris Air (later bought by Southwest) delivered September 1995. The 737 is still the only airliner to be production fitted with HUD.

HGS Panel
Primary Mode Display

Cat III at 50ft


Flight Data Recorder (FDR)

The FDR is located above the ceiling above the rear galley. There have been several different models of FDR in the life of the 737 which can collect anything from 30 minutes to hundreds of hours of data of 8 to hundreds of parameters.

Early FDR’s, as fitted to 737-200’s, comprised metal scribes which etched their data into a 150ft long roll of metal foil. These would last about 300hrs but only recorded vertical acceleration, heading, IAS and altitude, plus binary traces such as date, flight number and time of R/T transmissions. A gauge on the panel (see below) shows the recording hours remaining before the foil spool needs replacing.

737-200 FDR panel

Later Digital FDR’s (late 200’s & classics) record onto a 1/4-inch wide, 450 feet long magnetic tape and the newest Solid State FDR’s (later classics & NG’s) record data onto memory chips.

Late model 737-3/4/500 FDR’s record 25 hours of data. The protective casing includes an inner aluminium cover, isothermal protection shield, an outer stainless steel casing and an exterior stainless steel dust cover. This enables it to withstand a crush force of 20,000 pounds per axis, and provides impact protection of 1000 g’s for 5 msec. It is protected from heat by an isothermal insulation which maintains the inner chamber at a safe temperature. It also has an underwater location device that transmits under water for a minimum of 30 days.

The FDR of the 737-NG is similar to that described above but can withstand 3400 g’s of impact, 20,000ft depth of water and temperatures of 1,100C for 30mins.

The FDR starts recording as soon as the first engine oil pressure rises.


Electronic Flight Bag (EFB)

EFB is becoming the latest “must-have” device in the cockpit. They have the ability to do the following tasks:

  • Calculate take-off or landing performance.
  • Calculate weight & balance.
  • Contain the aircraft technical log.
  • Store navigation charts & plates.
  • Store company manuals, FCOMs, crew notices, etc.
  • Retrieve & display weather.
  • Display checklists.
  • Display on-board video surveillance cameras.

The advantages to crew are the accuracy of the data and ease of use. The advantages to the airlines are the cost benefits of a less paper cockpit and real time data transfer.

There are three classes of EFB:

  • Class 1: Fully portable. Eg a laptop.
  • Class 2: Portable but connected to the aircraft during normal operations. Eg tablet & docking station.
  • Class 3: Installed (non-removable) equipment.

BBJ Avionics

The Boeing Business Jet stands at a crossroads in avionics technology—exploiting all the flight deck systems available to airlines operating the 737, while serving as a showcase for advanced bizjet avionics that air carriers may one day want.

The BBJ often serves as a pathfinder for the latest systems that eventually could find their way onto commercial 737 flight decks.

Improved situational awareness is a case in point. Gulfstream, for example, pioneered the use of enhanced vision systems (EVS) with a forward-looking infrared (Flir) camera on large-cabin bizjets. This allows pilots to look through a head-up display (HUD) to see Flir imagery of a runway at night and in smoke, haze, rain and snow (but not in large-droplet fog).

The enhanced vision capability is more than just a safety feature. The FAA allows business jet pilots to use EVS images to fly as low as 100 ft. AGL (instead of 200 ft. during a Category-1 approach) before having to see the runway visually. Currently, airline pilots can’t do this. However, the FAA and the European Aviation Safety Agency are considering changing this rule to allow airlines to descend to 100 ft. with EVS, according to several avionics company officials. This could happen as early as next year.

There’s already substantial airline interest in enhanced vision, says Steve Taylor, the BBJ chief pilot. “I’ll wager if the FAA grants that OK to the airlines [for 100 ft. ], they will be beating on our door,” he adds.

Rockwell Collins is working with Boeing on the EVS program. And Max-Viz Inc., of Portland, Ore., is developing a multisensor, uncooled camera to meet a Rockwell Collins specification. It has both a short-wave and a long-wave infrared sensor and a visible-light camera in one unit.

The BBJ also will have a new version of the Rockwell Collins HGS-4000, called the -4000E. This modification of the head-up guidance system includes new hardware and software to allow the display of video imagery from the Flir camera. The BBJ has head-up guidance for the pilot as a standard feature, while the system is optional on the 737NG. Taylor says every avionics system that’s optional on the airline version of the 737 is standard on the BBJ.

Meanwhile, Rockwell Collins just began flight testing the BBJ enhanced vision system on its Sabreliner test­bed, and the EVS will be flown on a customer’s BBJ during the winter. Certification should occur in mid-2008. Should airlines become more interested in having it on a 737NG, it wouldn’t take much additional work to commercialize the system, says Taylor. “The aircraft certification rules are the same—Part 25,” he notes, so the certification effort on the BBJ should transfer easily to the 737NG.

The plan is to display the EVS imagery not only on the HGS for the pilot but also on one of the six Honeywell cockpit displays (the one on the pedestal so the copilot also can see the Flir imagery).

Taylor notes that head-up guidance systems made their first entry at Boeing on the BBJ and then moved to the commercial aircraft production line. But earlier, HUDs were already flying on existing airline aircraft because carriers such as Southwest and Alaska Airlines had installed them as retrofit items.

However, avionics is not the only area where technical innovation started in the BBJ program and was then incorporated on commercial transports. Winglets, a key fuel-saving device, is an example. “In a sense, we are a Skunk Works for commercial airplanes,” says Taylor.

As for the next big thing in business aviation, it will likely be another situational-awareness advance called synthetic vision. A 3D digital map of the terrain and obstacles ahead of the aircraft will be shown to the pilots of Gulfstream business jets soon, thanks to Honeywell. Rockwell Collins is developing a similar system for Bombardier. This Aviation Week & Space Technology pilot saw a Honeywell prototype last year on a Cessna Citation V (AW&ST Oct. 16, 2006, p. 66). Our night flight passed over the Phoenix area where I attended U.S. Air Force pilot training in the early 1970s. The view out the windscreen was often pitch-black, with mountains below shrouded in darkness. But I could see the “synthetic” terrain on the primary flight display created from a database that portrayed the scene ahead as if it were broad daylight. In 1971, a T-38 crashed into a nearby mountain in the era before synthetic vision.

A key question is, How long will it take for the huge safety advance of synthetic vision to show up on commercial flight decks? Since I no longer fly T-38s, I have to travel economy class on narrow- or wide-body jets. If airline pilots had EVS and SVS, I would feel safer as a passenger flying into airports surrounded by high terrain. But as with EVS and the possible FAA rule change on 100 ft., SVS will need a business case to earn its way onto an airline flight deck. At the moment, it’s not clear what that rationale will be.

Taylor says technology specialists at Boeing are looking at synthetic vision, and he believes its adaptation will follow a path similar to the one for enhanced vision. In the business jet market, “the customer base is much more interested in technology and willing to pay for it,” he notes.

Another way the BBJ benefits from 737 avionics is that the standard-fit radar is an airline-class system—Rockwell Collins’ multiscan WXR2100, which is flying with 100 airlines. It’s a more capable system than many of the radars currently installed in business jets. Keith Stover, Rockwell Collins’ radar marketing manager, says the main benefit for BBJ pilots is automatic adjustment of the radar as well as ground-clutter suppression.

In September, Rockwell Collins said it will provide a multiscan radar for bizjets to accommodate the smaller antenna sizes they need of 12 and 18 in. So this is an example of airline-class avionics technology flowing to business aviation by way of the BBJ flight deck. The airline version, which is already standard on the BBJ, has a 28-in. antenna and includes wind shear protection.

Last summer, I flew on a BBJ over the North Atlantic. During the flight, Rockwell Collins radar engineers were perfecting new software to allow the multiscan radar to improve its automatic detection of storms in a particular region (AW&ST July 9, p. 44). This new geographic-discrimination software will be available soon on the BBJ.

Additional fuel tanks are added after the aircraft leaves the factory and goes to DeCrane Aerospace at Sussex County Airport in Georgetown, Del. This is also where the new enhanced vision system will be fitted.

Fire Protection – B737

Engines

Overheat / Fire Protection Panel  3-900 series

Overheat / Fire Protection Panel  -200C series. Notice fwd & aft cargo smoke detectors.

Engine & APU fire detection – Battery bus

Engine, APU & Cargo fire extinguishing – Hot battery bus.

There are two fire detection loops in each engine. Failure of both loops in one engine will illuminate the FAULT light. The individual loops can be checked by selecting A or B on the OVHT DET switches.

Fire switches will unlock in the following situations:

  1. Overheat detected
  2. Fire detected
  3. During an OVHT/FIRE test
  4. Pressing manual override buttons

Pulling a fire switch will do the following:

  1. Arm firing circuits
  2. Allow fire switch to be rotated for discharge
  3. Close engine fuel shut-off valve.
  4. Trip the associated GCR (i.e. switches off the generator)
  5. Close hydraulic supply to EDP & disarms its LP light (Not if APU)
  6. Close engine bleed air valve (If APU will also close air inlet door)
  7. Close thrust reverser isolation valve (Not if APU)

The engine fire bottles (NG)

 

Wheel-Well

There is a wheel-well fire detection system but although the engine fire bottles are located in the wheel-well, there is no extinguishing system for a wheel-well fire. (Suggest extend gear & land ASAP).

 

APU

The APU only has one bottle. This may be checked externally by looking for the two discharge discs (red for thermal overpressure & yellow for extinguisher discharge) and the pressure sight glass (where fitted) on the aft stbd fuselage.

 

 

 

Cargo Compartment (Optional)

Cargo Fire Panel

Cargo Fire Panel – Alternative version

The cargo holds have dual-loop smoke detectors powered by DC bus 1 & 2. There is only one cargo fire bottle, it is powered by the hot battery bus and can be discharged into either the fwd or aft hold. On later 737NG’s the cargo fire smoke detector sends a signal to the cabin pressure control system. This triggers the cabin pressure to descend at 750 slfpm which helps prevent smoke penetration into the passenger cabin from the lower lobe. (This function is inhibited on the ground.)

Cargo Hold Smoke Detector

Lavatory Smoke Detection (Optional)

Some 737’s have a warning light on the flight deck to warn of smoke in the lavatory. If the smoker is in the forward lav you can usually smell it on the flight deck within seconds without a warning light.

 

Passenger Compartment (Optional)

The cargo 737’s had a pressurisation feature which allowed the crew to pressurise or unpressurise the passenger compartment for smoke clearance.

 


Engines

Overheat / Fire Protection Panel  3-900 series

Overheat / Fire Protection Panel  -200C series. Notice fwd & aft cargo smoke detectors.

Engine & APU fire detection – Battery bus

Engine, APU & Cargo fire extinguishing – Hot battery bus.

There are two fire detection loops in each engine. Failure of both loops in one engine will illuminate the FAULT light. The individual loops can be checked by selecting A or B on the OVHT DET switches.

Fire switches will unlock in the following situations:

  1. Overheat detected
  2. Fire detected
  3. During an OVHT/FIRE test
  4. Pressing manual override buttons

Pulling a fire switch will do the following:

  1. Arm firing circuits
  2. Allow fire switch to be rotated for discharge
  3. Close engine fuel shut-off valve.
  4. Trip the associated GCR (i.e. switches off the generator)
  5. Close hydraulic supply to EDP & disarms its LP light (Not if APU)
  6. Close engine bleed air valve (If APU will also close air inlet door)
  7. Close thrust reverser isolation valve (Not if APU)

The engine fire bottles (NG)

Wheel-Well

There is a wheel-well fire detection system but although the engine fire bottles are located in the wheel-well, there is no extinguishing system for a wheel-well fire. (Suggest extend gear & land ASAP).

APU

The APU only has one bottle. This may be checked externally by looking for the two discharge discs (red for thermal overpressure & yellow for extinguisher discharge) and the pressure sight glass (where fitted) on the aft stbd fuselage.

Cargo Compartment (Optional)

Cargo Fire Panel

Cargo Fire Panel – Alternative version

The cargo holds have dual-loop smoke detectors powered by DC bus 1 & 2. There is only one cargo fire bottle, it is powered by the hot battery bus and can be discharged into either the fwd or aft hold. On later 737NG’s the cargo fire smoke detector sends a signal to the cabin pressure control system. This triggers the cabin pressure to descend at 750 slfpm which helps prevent smoke penetration into the passenger cabin from the lower lobe. (This function is inhibited on the ground.)

Cargo Hold Smoke Detector

Lavatory Smoke Detection (Optional)

Some 737’s have a warning light on the flight deck to warn of smoke in the lavatory. If the smoker is in the forward lav you can usually smell it on the flight deck within seconds without a warning light.

Passenger Compartment (Optional)

The cargo 737’s had a pressurisation feature which allowed the crew to pressurise or unpressurise the passenger compartment for smoke clearance.

See also NG engineering notes by M Ferreira

Emergency Equipment – B737

Flight Crew Oxygen

When conducting the oxygen mask flow & intercom check, monitor the crew oxygen pressure gauge to ensure a steady flow as any fluctuations may be due to an obstruction in the system. Give a long check of the flow on the first flight of the day in case the crew oxygen shut off valve has been closed. A short check may sound OK but you may be hearing the residual oxygen left in the lines rather than fresh oxygen from the bottle.

Oxygen Panel -300+ Oxygen Panel -1/200

 

  Crew Oxygen Shutoff Valve (Not installed on NG’s)

The F/O should ensure that the crew oxygen shutoff valve, located at the bottom outside of the P6 panel, is open (anticlockwise) and ideally backed off by half a turn to avoid damage to the seal. This should be done during the cockpit preparation, particularly in airlines where it is the practice to close this valve overnight.

Minimum Crew Oxygen Dispatch Pressure (FPPM 2.2.14)
Temp Number of Crew
O2 Bottle Size C 2 3 4
39 cu ft 0 1130 1645
15 1190 1735
30 1250 1825
76 cu ft 0 620 890 1155
15 655 940 1220
30 690 990 1280
114 cu ft 0 445 620 800
15 470 655 840
30 495 690 885
 

 

Crew oxygen pressure on aft overhead panel should be checked against MEL 35-1 or FPPM 2.2.14. The minimum despatch quantity varies with size of bottle, bottle temp and number of flightdeck crew.

The minimum amount of oxygen is based upon one hour of normal flight at a cabin altitude of 8000ft for one pilot with the diluter set to NORMAL (76 cu ft bottle).

Crew oxygen is stored in a bottle in the forward hold. On older aircraft (pre 1990 ish) there is a servicing point on the outside (see photo below) however on most access is gained through the forward hold.

All aircraft have a green discharge disc on the outside to warn crews if the bottle has discharged from overpressure. This should be checked on every walkaround.

Oxygen Servicing Point on Lower Fwd Fuselage

 

737-1/500 Oxygen Mask Deployed

 

Flight Crew Oxygen Mask

The oxygen regulator has three modes:

Normal: Red latch on left is up – Gives air/oxygen mix on demand. Use if no fumes are present eg decompression.

100%: Push red latch on left down – Gives 100& oxygen on demand. Use if smoke or fumes are present.

Emergency: Rotate red knob clockwise – Gives 100% oxygen under pressure. Used to clear mask & goggles of fumes and should also be used if aircraft is depressurised above 39,000ft.

737-200 crew oxy panel
Passenger Service Unit – PSU

 

Passenger Oxygen

Classics & NG’s: Will deploy automatically above 14,000ft cabin alt or when switched on from the aft overhead panel. No oxygen will flow in a PSU until a mask in that PSU has been pulled. Passenger oxygen should not be used as smoke hoods as the air inhaled is a mixture of oxygen and cabin air and there is a significant fire hazard with oxygen in the cabin.

There is 12 minutes supply of oxygen in each PSU, this is based upon:

  • 0.3 min delay at 37,000ft
  • 3.1 min descent to 14,000ft
  • 7.6 min hold at 14,000ft
  • 1.0 min descent to 10,000ft

Passenger oxygen on 737-1/200’s is supplied by two oxygen bottles in the forward hold. The capacity varies with operator but is typically 76.5 cu ft each. Oxygen bottle pressure is indicated on the aft overhead panel.

Aft Attendant Panel

 

Emergency Exit Lights

When armed, will illuminate if power is lost to DC bus 1. They can also be switched on from the aft flight attendant panel. Whenever these lights are on, they are being powered from their own individual Ni-Cad batteries and will only last for 10mins.

Smoke Hood (Drager)

After pulling the toggle, the oxygen generator will operate for less than 30 secs. Don’t worry! The oxygen remains in a closed loop system within the mask and filter to prevent contamination from the outside air. It is filtered twice, on inhalation and again on exhalation, and is breathable for approximately 20mins.

Life Jacket

Do not inflate until you are outside the aircraft as it will impede your exit and you could puncture it as you leave.

 

Cockpit Fire Extinguisher

Is BCF and works by removing oxygen from the fire triangle of oxygen – heat – fuel. As it does not directly cool the fire, when oxygen returns, so could the fire. To operate, remove ring and press down on top lever. Hold upright and beware, BCF fumes are toxic.

Slide

Serviceability check includes the pressure gauge.

Tip: Be extremely careful to remember to disarm any door slides you may have armed on flights without cabin crew eg ferry flights or air-tests.

Note that the slides are not certified as emergency floatation equipment although Boeing say that an inflated slide could be buoyant, and useful as a floatation device and handgrips are positioned along the sides of the slide.

Flight Crew Oxygen

When conducting the oxygen mask flow & intercom check, monitor the crew oxygen pressure gauge to ensure a steady flow as any fluctuations may be due to an obstruction in the system. Give a long check of the flow on the first flight of the day in case the crew oxygen shut off valve has been closed. A short check may sound OK but you may be hearing the residual oxygen left in the lines rather than fresh oxygen from the bottle.

Oxygen Panel -300+ Oxygen Panel -1/200
  Crew Oxygen Shutoff Valve (Not installed on NG’s)

The F/O should ensure that the crew oxygen shutoff valve, located at the bottom outside of the P6 panel, is open (anticlockwise) and ideally backed off by half a turn to avoid damage to the seal. This should be done during the cockpit preparation, particularly in airlines where it is the practice to close this valve overnight.

Minimum Crew Oxygen Dispatch Pressure (FPPM 2.2.14)
Temp Number of Crew
O2 Bottle Size C 2 3 4
39 cu ft 0 1130 1645
15 1190 1735
30 1250 1825
76 cu ft 0 620 890 1155
15 655 940 1220
30 690 990 1280
114 cu ft 0 445 620 800
15 470 655 840
30 495 690 885
Crew oxygen pressure on aft overhead panel should be checked against MEL 35-1 or FPPM 2.2.14. The minimum despatch quantity varies with size of bottle, bottle temp and number of flightdeck crew.

The minimum amount of oxygen is based upon one hour of normal flight at a cabin altitude of 8000ft for one pilot with the diluter set to NORMAL (76 cu ft bottle).

Crew oxygen is stored in a bottle in the forward hold. On older aircraft (pre 1990 ish) there is a servicing point on the outside (see photo below) however on most access is gained through the forward hold.

All aircraft have a green discharge disc on the outside to warn crews if the bottle has discharged from overpressure. This should be checked on every walkaround.

Oxygen Servicing Point on Lower Fwd Fuselage

737-1/500 Oxygen Mask Deployed

Flight Crew Oxygen Mask

The oxygen regulator has three modes:

Normal: Red latch on left is up – Gives air/oxygen mix on demand. Use if no fumes are present eg decompression.

100%: Push red latch on left down – Gives 100& oxygen on demand. Use if smoke or fumes are present.

Emergency: Rotate red knob clockwise – Gives 100% oxygen under pressure. Used to clear mask & goggles of fumes and should also be used if aircraft is depressurised above 39,000ft.

737-200 crew oxy panel
Passenger Service Unit – PSU

Passenger Oxygen

Classics & NG’s: Will deploy automatically above 14,000ft cabin alt or when switched on from the aft overhead panel. No oxygen will flow in a PSU until a mask in that PSU has been pulled. Passenger oxygen should not be used as smoke hoods as the air inhaled is a mixture of oxygen and cabin air and there is a significant fire hazard with oxygen in the cabin.

There is 12 minutes supply of oxygen in each PSU, this is based upon:

  • 0.3 min delay at 37,000ft
  • 3.1 min descent to 14,000ft
  • 7.6 min hold at 14,000ft
  • 1.0 min descent to 10,000ft

Passenger oxygen on 737-1/200’s is supplied by two oxygen bottles in the forward hold. The capacity varies with operator but is typically 76.5 cu ft each. Oxygen bottle pressure is indicated on the aft overhead panel.

Aft Attendant Panel

Emergency Exit Lights

When armed, will illuminate if power is lost to DC bus 1. They can also be switched on from the aft flight attendant panel. Whenever these lights are on, they are being powered from their own individual Ni-Cad batteries and will only last for 10mins.

Smoke Hood (Drager)

After pulling the toggle, the oxygen generator will operate for less than 30 secs. Don’t worry! The oxygen remains in a closed loop system within the mask and filter to prevent contamination from the outside air. It is filtered twice, on inhalation and again on exhalation, and is breathable for approximately 20mins.

Life Jacket

Do not inflate until you are outside the aircraft as it will impede your exit and you could puncture it as you leave.

Cockpit Fire Extinguisher

Is BCF and works by removing oxygen from the fire triangle of oxygen – heat – fuel. As it does not directly cool the fire, when oxygen returns, so could the fire. To operate, remove ring and press down on top lever. Hold upright and beware, BCF fumes are toxic.

Slide

Serviceability check includes the pressure gauge.

Tip: Be extremely careful to remember to disarm any door slides you may have armed on flights without cabin crew eg ferry flights or air-tests.

Note that the slides are not certified as emergency floatation equipment although Boeing say that an inflated slide could be buoyant, and useful as a floatation device and handgrips are positioned along the sides of the slide.

Communication

Audio Control Panel

This type of ACP has cylindrical button volume controls, others have sliders.

Radio/Int works in the same way as the rocker switch on the control column. ie in the INT position bypasses the mic selector to transmit on the flt interphone.

The filter switch, Voice-Both-Range, allows better reception of either voice or morse identifiers on NAV & ADF radios. Check that this switch has not been left in the V position if you can’t get an ident.

Mask/Boom simply selects either mask or boom mic. Check this if nobody can hear you transmit – especially after your oxy mask mic check!

Alt/Norm in the ALT position puts the ACP into degraded mode. If the Capts ACP is in degraded mode, he can only transmit on VHF1 through mask or boom and can only receive VHF1 at a preset level. The F/O’s ACP in degraded mode is the same but uses VHF2. Note aural warnings will still be heard over the speaker.

 

-200 ACP ACP with sliders

VHF Radio

Most 737’s have three VHF radios and at least one HF radio. This unit allows for selection of any of those at this station. The TEST button is a squelch and is used to hear faint stations that do not have the strength to breakthrough. If you switch the panel OFF at the same time as TEST is applied this holds the test condition thereby allowing you to hear faint stations without having to hold down the test button – very useful for copying distant weather!


MMR PanelPhoto Niklas Andreae

Nav Radio

There are very many different Nav radio boxes in the worlds 737’s the second shown here is teh new Multi-mode nav panel which is used to tune VORs, ILS, & GLS. More details about their use in the Navigation section.

 


Marker Beacons

The markers are pre-tuned to their 75MHz frequency and illuminate when overflown. The marker tone can also be heard if selected on the ACP.


Selective Calling, SELCAL

The SELCAL light will illuminate and a two-tone chime sounds if the aircraft is being selcal’d on either HF or VHF.

This particular panel is a very old unit and most operators have had to improvise the method of radio connections to it. Typically, in the past, diodes would be used to “OR” the VHFs together to illuminate one of the lights.  Over the last 15 years, the vast majority of the SELCAL panels have a light for each of the radios (VHF-1, VHF-2, VHF-3, HF-1, HF-2) and in some cases, include the Attendant call, and SATCOM call.


 

Cockpit Voice Recorder

The CVR records the headset and microphone of all 3 ASP’s and the ambient cockpit sounds all on separate channels. The recordings start with the first rise in engine oil pressure and go onto a 120 or 30min (as fitted) continuous loop tape until 5mins after last engine shutdown. In the event of an incident crews are advised to pull the CVR c/b after final stop to avoid automatic erasure. It is illegal to stop the CVR in flight. The CVR is located in the aft cargo hold.

 


The External Power Hatch is located beneath the F/O’s DV window. It is used by groundcrew to connect the Ground Power Unit and headset for pushback communications with Flight Interphone.

The service interphone is used by engineers to communicate with the service interphone stations inside the aircraft. Note that the Service Interphone switch on the aft overhead panel must be switched ON for this use.

There is also a pilot call button and a nose-wheelwell light switch to assist the groundcrew to insert the steering bypass pin.


Service Interphone

The switch on the aft overhead panel activates the external jacks to the service interphone system. Normal internal service interphone operation is unaffected by switch position.


Transponder with integrated TCAS.

 

Number pad transponder.Note: Mode S transponders will be mandatory in Europe after March 2007.

ELT


The blue CALL light on the overhead panel illuminates and a single-tone chime sounds when either the cabin crew (service interphone) or ground crew (flight or service interphone) are calling the flight deck.


ACARS


Aircraft Data Loader – Used to load FMC database, download flight data eg FLIDRAS, etc.


IFE BITE panel. Located above door 2R

Antennae

Antenna and static discharge wicks should be inspected carefully on the walkaround for integrity and burns, especially if lightning or St Elmo’s fire has been observed.

Please note that the above location diagrams are only a guide as the antenna fitted depends upon the customer avionics options. Eg some NG’s do not have ADF but do have SATCOM or IFTS/Airphone.

Limitations

There are various frequencies listed in the limitations section as not to be used. These are due to interference from other systems. For instance the EEC’s affect VHF 120.00Mhz, there is a service bulletin (SB 737-73-1010) which will eliminate this. The HF frequency limitations are the result of interference caused by cabin entertainment systems.

Pressurization

Digital Cabin Pressure Control System (DCPCS)

The aircraft is pressurised by bleed air supplied to the packs and controlled by outflow valves.

The auto system will fail if either:

  1. Cabin altitude exceeds 13,875ft CPCS; 15,800ft DCPCS.
  2. Cabin rate of climb or descent exceeds 1890 sea level fpm CPCS; 2000 sea level fpm DCPCS.
  3. Loss of AC power (transfer bus 1) to auto computer for more than 3 secs CPCS. Loss of DC power (DC bus 1/2) to auto computer DCPCS.
  4. Differential pressure exceeds 8.3 psi CPCS, 8.75 psi DCPCS.
  5. Other fault in pressurisation controller.

Cabin Pressure Control System (CPCS) installed in a 737-200C. Notice the extra SMOKE CLEARANCE controls.

Digital pressurisation controllers have two automatic systems (AUTO & ALTN) instead of a standby system, these alternate every flight. If the auto system fails, the standby / alternate system will automatically take over. The AUTO FAIL light will remain illuminated until the mode selector is moved to STBY / ALTN (tidy but not necessary). On CPCS panels, the cabin rate selector, for use in standby mode, adjusts cabin rate of change of altitude between 50 and 2000fpm, the index is approx 300fpm.

If you have to return to your departure airfield, do not adjust the pressurisation panel. You will get the OFF SCHD DESC light, but the controller will program the cabin to land at the take-off field elevation. If the flight alt selector is pressed, this facility will be lost.

In manual mode, you drive the outflow valve directly. The sense of the spring-loaded switch can be remembered by:

“Moving the switch towards the centre of the aircraft keeps the air inside.”

The 737NG pressurization schedule is designed to meet FAR requirements as well as maximize cabin structure service life. The pressurization system uses a variable cabin pressure differential schedule based on airplane cruise altitude to meet these design requirements. At cruise altitudes at or below FL 280, the max differential is 7.45 PSI. which will result in a cabin altitude of 8000’ at FL280. At cruise altitudes above FL280 but below FL370, the max differential is 7.80 PSI. which will result in a cabin altitude of 8000’ at FL370. At cruise altitudes above FL 370, the max differential is 8.35 PSI. which will result in a cabin altitude of 8000’ at FL410. This functionality is different from other Boeing models which generally use a fixed max differential schedule thus can maintain lower cabin altitudes at cruise altitudes below the maximum certified altitude.

In all 737’s the pressurisation system ensures that the cabin altitude does not climb above approx 8,000ft in normal operation. However in 2005 the BBJ will be certified to a reduced cabin altitude of 6,500ft at 41,000ft thereby increasing passenger comfort. The payback for this is a 20% reduction in airframe life cycles, ie from the standard 75,000 down to 60,000 cycles. This is not a problem for a low utilisation business jet but would be unacceptable in airline operation where some aircraft are operating 10 sectors a day.

 

Cabin Altitude Warning

The cabin altitude warning horn will sound when the cabin altitude exceeds 10,000ft. It is an intermittent horn which sounds like the take-off config warning horn. It can be inhibited by pressing the ALT HORN CUTOUT button. Note the pax oxygen masks will not drop until 14,000ft cabin altitude although they can be dropped manually at any time.

Following the Helios accident where the crew did not correctly identify the cabin altitude warning horn, new red “CABIN ALTITUDE” and “TAKEOFF CONFIG” warning lights were fitted to the P1 & P3 panels to supplement the existing aural warning system.

Cabin altitude light

Photo – Frode Lund

High Altitude Landing System

This is a customer option for operations into airfields with elevation of up to 14,500ft (12,000ft on some versions). There are also enhancements to the DCPS, an extra hour of emergency oxygen and the cabin altitude warning horn is inhibited.

 

Limitations

Max differential pressure:

Series Max Diff
1/200’s 7.5psi
200Adv’s 7.8psi
Classics 8.65psi
NG’s 9.1psi

Max differential pressure for takeoff & landing: 0.125 psi

Max negative differential pressure: -0.1 psi


 

Pressurisation Valves

Main Outflow Valve

Controlled by the pressurisation system. Regulates the cabin pressure by adjusting the outflow of cabin air.

Early outflow valves (shown here) opened into the fuselage.

Later outflow valves opened out from the fuselage.

From Dec 2003 onwards, the main outflow valve was given teeth to reduce aerodynamic noise. Its frightening appearance should also help to deter people from putting their hands in the opening.

Pressure (Safety) Relief Valves

These two valves, located above and below the main outflow valve, protect the aircraft structure against overpressure if the pressurisation control system fails. they are set at Originals 8.5psi, Classics: 8.65psi , NG’s: 8.95psi.

Negative Pressure Relief Valve

Prevents vacuum damage to aircraft during a rapid descent. It is a spring loaded flapper valve that opens inwards at -1.0psid. You can check this on a walkaround by pressing it in like a letterbox.

Flow Control Valve (Classic) / Overboard Exhaust Valve(NG)

Open on the ground (check this on a walkaround) to provide E&E bay cooling and also in-flight at less than 2psi differential pressure. You can often hear this valve opening on descent when the differential pressure passes 2psi. The OEV also opens when the recirculation fan (R recirc fan on the 8/900) is switched off to assist in smoke clearance.

Strictly speaking, this is an exhaust port. The actual Flow Control Valve / Overboard Exhaust Valve is located further upstream.

Forward Outflow Valve – Classics only

This is is a vent for the E & E bay air after it has been circulated around the forward cargo compartment when in-flight (The E & E bay air is exhausted from the flow control valve when in the ground). The valve opens when the recirculation fan (R recirc fan on the 400) is off (smoke clearance mode) or when the main outflow valve is not completely closed (ie low diff pressure). It is located just below and aft of the fwd passenger door.

Note the NG’s do not have a FOV. In-flight, equipment air is circulated around the forward cargo compartment and discharged from the main outflow valve

Digital Cabin Pressure Control System (DCPCS)

The aircraft is pressurised by bleed air supplied to the packs and controlled by outflow valves.

The auto system will fail if either:

  1. Cabin altitude exceeds 13,875ft CPCS; 15,800ft DCPCS.
  2. Cabin rate of climb or descent exceeds 1890 sea level fpm CPCS; 2000 sea level fpm DCPCS.
  3. Loss of AC power (transfer bus 1) to auto computer for more than 3 secs CPCS. Loss of DC power (DC bus 1/2) to auto computer DCPCS.
  4. Differential pressure exceeds 8.3 psi CPCS, 8.75 psi DCPCS.
  5. Other fault in pressurisation controller.

Cabin Pressure Control System (CPCS) installed in a 737-200C. Notice the extra SMOKE CLEARANCE controls.

Digital pressurisation controllers have two automatic systems (AUTO & ALTN) instead of a standby system, these alternate every flight. If the auto system fails, the standby / alternate system will automatically take over. The AUTO FAIL light will remain illuminated until the mode selector is moved to STBY / ALTN (tidy but not necessary). On CPCS panels, the cabin rate selector, for use in standby mode, adjusts cabin rate of change of altitude between 50 and 2000fpm, the index is approx 300fpm.

If you have to return to your departure airfield, do not adjust the pressurisation panel. You will get the OFF SCHD DESC light, but the controller will program the cabin to land at the take-off field elevation. If the flight alt selector is pressed, this facility will be lost.

In manual mode, you drive the outflow valve directly. The sense of the spring-loaded switch can be remembered by:

“Moving the switch towards the centre of the aircraft keeps the air inside.”

The 737NG pressurization schedule is designed to meet FAR requirements as well as maximize cabin structure service life. The pressurization system uses a variable cabin pressure differential schedule based on airplane cruise altitude to meet these design requirements. At cruise altitudes at or below FL 280, the max differential is 7.45 PSI. which will result in a cabin altitude of 8000’ at FL280. At cruise altitudes above FL280 but below FL370, the max differential is 7.80 PSI. which will result in a cabin altitude of 8000’ at FL370. At cruise altitudes above FL 370, the max differential is 8.35 PSI. which will result in a cabin altitude of 8000’ at FL410. This functionality is different from other Boeing models which generally use a fixed max differential schedule thus can maintain lower cabin altitudes at cruise altitudes below the maximum certified altitude.

In all 737’s the pressurisation system ensures that the cabin altitude does not climb above approx 8,000ft in normal operation. However in 2005 the BBJ will be certified to a reduced cabin altitude of 6,500ft at 41,000ft thereby increasing passenger comfort. The payback for this is a 20% reduction in airframe life cycles, ie from the standard 75,000 down to 60,000 cycles. This is not a problem for a low utilisation business jet but would be unacceptable in airline operation where some aircraft are operating 10 sectors a day.

Cabin Altitude Warning

The cabin altitude warning horn will sound when the cabin altitude exceeds 10,000ft. It is an intermittent horn which sounds like the take-off config warning horn. It can be inhibited by pressing the ALT HORN CUTOUT button. Note the pax oxygen masks will not drop until 14,000ft cabin altitude although they can be dropped manually at any time.

Following the Helios accident where the crew did not correctly identify the cabin altitude warning horn, new red “CABIN ALTITUDE” and “TAKEOFF CONFIG” warning lights were fitted to the P1 & P3 panels to supplement the existing aural warning system.

Cabin altitude light

Photo – Frode Lund

High Altitude Landing System

This is a customer option for operations into airfields with elevation of up to 14,500ft (12,000ft on some versions). There are also enhancements to the DCPS, an extra hour of emergency oxygen and the cabin altitude warning horn is inhibited.

Limitations

Max differential pressure:

Series Max Diff
1/200’s 7.5psi
200Adv’s 7.8psi
Classics 8.65psi
NG’s 9.1psi

Max differential pressure for takeoff & landing: 0.125 psi

Max negative differential pressure: -0.1 psi


Pressurisation Valves

Main Outflow Valve

Controlled by the pressurisation system. Regulates the cabin pressure by adjusting the outflow of cabin air.

Early outflow valves (shown here) opened into the fuselage.

Later outflow valves opened out from the fuselage.

From Dec 2003 onwards, the main outflow valve was given teeth to reduce aerodynamic noise. Its frightening appearance should also help to deter people from putting their hands in the opening.

Pressure (Safety) Relief Valves

These two valves, located above and below the main outflow valve, protect the aircraft structure against overpressure if the pressurisation control system fails. they are set at Originals 8.5psi, Classics: 8.65psi , NG’s: 8.95psi.

Negative Pressure Relief Valve

Prevents vacuum damage to aircraft during a rapid descent. It is a spring loaded flapper valve that opens inwards at -1.0psid. You can check this on a walkaround by pressing it in like a letterbox.

Flow Control Valve (Classic) / Overboard Exhaust Valve(NG)

Open on the ground (check this on a walkaround) to provide E&E bay cooling and also in-flight at less than 2psi differential pressure. You can often hear this valve opening on descent when the differential pressure passes 2psi. The OEV also opens when the recirculation fan (R recirc fan on the 8/900) is switched off to assist in smoke clearance.

Strictly speaking, this is an exhaust port. The actual Flow Control Valve / Overboard Exhaust Valve is located further upstream.

Forward Outflow Valve – Classics only

This is is a vent for the E & E bay air after it has been circulated around the forward cargo compartment when in-flight (The E & E bay air is exhausted from the flow control valve when in the ground). The valve opens when the recirculation fan (R recirc fan on the 400) is off (smoke clearance mode) or when the main outflow valve is not completely closed (ie low diff pressure). It is located just below and aft of the fwd passenger door.

Note the NG’s do not have a FOV. In-flight, equipment air is circulated around the forward cargo compartment and discharged from the main outflow valve

New Q400 for SpiceJet

Bombardier Aerospace announced on August 27, 2011 that India’s low-cost carrier, SpiceJet has taken delivery of the first two of 15 Q400 NextGen turboprops ordered in December 2010.

 


Bombardier

“SpiceJet’s order was a breakthrough for our Q400 NextGen turboprop in the Indian market, and Bombardier’s portfolio of commercial aircraft and customer services continues to be well positioned to support the development of India’s airline network,” said Chet Fuller, Senior Vice President, Sales, Marketing and Asset Management, Bombardier Commercial Aircraft, during a ceremony held yesterday at Bombardier Aerospace’s Toronto facility, where the Q400 NextGen aircraft is manufactured.

The airline will use the aircraft for high-frequency, point-to-point services to regional cities, complementing its larger jet aircraft fleet that connect major Indian cities. SpiceJet currently serves 22 destinations in India, Nepal and Sri Lanka.

SpiceJet has also signed a 10-year agreement under Bombardier’s comprehensive SmartParts program that will provide a wide spectrum of cost-per-flight-hour maintenance for the airline’s full fleet of Q400 NextGen aircraft.

Boeing Introduces the 737 MAX

Boeing Introduces the 737 MAX

Boeing has unveiled the 737 MAX, the name of the new engine variant of the 737.

 


Boeing

The new aircraft family – 737 MAX 7, 737 MAX 8 and 737 MAX 9 – builds on the Next-Generation 737 and will consist of the of the Boeing Sky Interior.

According to Boeing the 737 MAX will deliver big fuel savings and a 7 percent advantage in operating costs over future competing aircraft as a result of optimised CFM International LEAP-1B engines, more efficient structural design and lower maintenance requirements.

The 737 has more than 9,000 orders to date and Boeing forecasts global demand for more than 23,000 aircraft in the 737’s market segment over the next 20 years at a value of nearly $2 trillion.

9/11 Changed Commercial Aviation

Related Content

  • The author with his corporate jet.The author with his corporate jet.

Yahoo! is asking Americans how September 11 changed them. Below is an account from a reader.

As a professional pilot, my life has been strongly impacted by the attacks on 9/11. On September 11, 2001, I was a flight instructor for a training academy in Florida. That morning, I was in the school’s computer lab when the Internet connection went down.

A short time later, a student said he had heard on the news that an airplane had hit the World Trade Center. My first assumption was that it had been an accident involving a small general aviation aircraft. When reports of a second airplane hitting the WTC came in, I realized that it was a deliberate attack.

[Your story: How has September 11 changed you?]

I went to the cafeteria, where a television was showing news coverage of the attacks in New York, as well as the attack on the Pentagon. There were rumors of more hijackings and another plane crash in Pennsylvania.

I distinctly remember that many of the school’s Saudi students were also in the cafeteria that day. While the Americans were somber and angry, the Saudis seemed almost enthusiastic. They were speaking excitedly in Arabic, which was causing the Americans in the crowd to become even more angry.

In the days that followed, the school was shut down for almost a week as the government kept private airplanes grounded. The local newspaper reported FBI raids on houses occupied by several of the Saudi students and their families. I saw Army soldiers with automatic weapons in the terminal the next time that I flew home.

The following year, I was hired by the airlines. By then, the armed guards were gone, replaced by TSA screeners. In our new-hire ground school, the subject of hijackings and security figured prominently. Where the old strategy was to comply with a hijacker’s demands, the new strategy was now to land the airplane before the Air Force shot us down. In an act of self-preservation and defiance of al-Qaida, I became one of the pilots trained to carry a pistol in the cockpit.

The years of upheaval in the airline industry that followed wreaked havoc on my career. The post-9/11 recession led to airline bankruptcies and mergers. I was furloughed from my first airline job before the company went out of business. I found a new job at a second airline, but industry stagnation and another impending bankruptcy made me rethink my career goals. I left the company to start flying corporate jets.

Ten years and two kids later, my career goal has changed from flying heavy airliners to maintaining financial stability and quality life. Part of this is due to growing more mature, but a large part is also due to the fact that the world has changed since 2001. Even as we are distracted by the failing economy, there are still legions of terrorists who want to inflict the maximum death and destruction possible upon us.

Airlines Testing iPads as EFBs

Airlines Testing iPads as EFBs

Airlines are taking their paperless cockpits a step further, deploying Apple iPads to operate as electronic flight bags (EFB) to display operating manuals, nav charts, flight checklists and more.

A number of airlines, including United, Continental, British Airways and Alaska Airlines, over the last six months have been a part of this digital conversion of using the 1.5-pound iPad to replace traditional flight manuals.

Several companies are designing apps for the iPad, to convert the tablet to a Class 1 or Class 2 EFB. Boeing subsidiary Jeppesen developed the Mobile FliteDeck, which includes interactive data-driven en route navigation information and worldwide geo-referenced terminal charts. Additionally, the tablet will eliminate a pilot’s luggage load, which will reduce the risk of injury while on duty by carrying less and easing lifting hazards.

United Continental Holdings distributed 11,000 iPads, with the Jeppesen app, to all United and Continental pilots Aug. 23, a first for major network carriers. All pilots will have the device by the end of the year.

“The paperless flight deck represents the next generation of flying,” said Capt. Fred Abbott, United’s senior vice president of flight operations. “The introduction of iPads ensures our pilots have essential and real-time information at their fingertips at all times throughout the flight.”

British Airways says the iPad will help cabin crew as well as pilots.

“It gives cabin crew a whole library of information at their fingertips including timetables, safety manuals and customer service updates,” the airline said in an Aug. 17 statement. “It also means any issues can be logged with ground-based colleagues around the network prior to departure so solutions can be delivered while the flight is airborne.”

The iPad is being trialed with 100 British Airline cabin crews, with an aim to roll it out to all senior crewmembers across the airline in the coming months.

FAA issued regulations for use the iPad and other suitable tablet computing devices as EFBs, in InFO AFS-430, issued May 13, 2011. The FAA authorized a certificated operator to use an iPad as a Class 1 EFB a few months prior to the InFo’s release.

The iPad is not approved or certified by the FAA, as it is a commercial-off-the-shelf (COTS) electronic hardware, however, it can be authorized for use by a principal operations inspector if it meets the EFB criteria discussed in the Flight Standards Information Management System (FSIMS), volume 4, chapter 15, section 1 and AC-120-76A.

Boeing officially launches re-engined 737

Boeing will proceed with development of the re-engined 737 after its board of directors approved its launch based on order commitments for 496 aircraft from five airlines.

Boeing said that it has seen “overwhelming demand” for the new aircraft. It promised a fuel burn 4% lower than the Airbus A320neo.

 

 

 © Boeing

The new 737-family will be powered by CFM International LEAP-1B engines.

Deliveries are scheduled to begin in 2017.

 

 © Boeing

Boeing has named Bob Feldmann vice-president and general manager of the programme and Michael Teal has been named vice-president, chief project engineer and deputy programme manager.

NTSB: Emirates 777 continued flight after loud bang, messages

The US National Transportation Safety Board revealed in a preliminary report issued 30 August that an Emirates Boeing 777-200ER crew continued a 5h flight from Moscow’s Domodedovo airport to Dubai on 5 March after hearing a “loud bang” and receiving several error messages on departure.

Pilots of Flight 132 (A6-EMH) reported the incident after landing at Dubai, according to the General Civil Aviation Authority (GCAA) of the United Arab Emirates, the authority handling the investigation.

“Following the bang a number of status messages were annunciated, these messages occurred over a 16 minute time as per the Boeing AHM (airplane health management) data,” the report stated.

Messages indicated a problem with the right Rolls-Royce Trent 800 engine, and included a thrust asymmetry compensation message that is issued when the flight control computer automatically uses rudder input counter the yaw effects of a failed engine.

Four additional messages were received on departure, followed by two AHM messages after landing.

Flightglobal’s ACAS database shows that the 14-year-old aircraft is owned by Veling and has Trent 884-17 engines, members of the Trent 800 family. As of 31 May, the aircraft had accumulated 61,581 hours and 12,945 cycles, according to ACAS.

Inspection of the aircraft in Dubai revealed “a large section” of the right engine’s inboard fan duct and thrust reverser were missing, starting at the trailing edge and ripping forward.

Overall, officials estimated that 2.8-3.7m2 (30-40ft2) section of engine covering to be missing, along with the primary exhaust nozzle outer skin. The primary nozzle inner skin had been “holed in several locations at the 12 to 1 o’clock position,” the report stated.

External to the engine, the one tyre on the main landing gear “was observed to have a large cut to the sideway” of approximately 36cm (14in), officials said. Examination of the aircraft and engine was to continue but the results have not yet been posted.

The report does not discuss what procedures the Emirates crew followed after hearing the bang and receiving the AHM annunciations or whether the aircraft should have been returned to Domodedovo.

Boeing to deliver first 747-8F to Cargolux on 19 Sept

Boeing will deliver the first 747-8 freighter to launch customer Cargolux on 19 September, followed by delivery of the second aircraft to the cargo carrier two days later on 21 September.

Cargolux will fly its first 747-8F on the morning of 19 September and put it into revenue service after the delivery at Paine Field in Everett, Washington. The airline has 13 747-8Fs on order.

“It’s so exciting to be able to deliver two of these amazing airplanes to Cargolux in one week,” said Elizabeth Lund, vice president and general manager of the 747 programme. “Cargolux has been a great partner for many years, and we so appreciate its deep commitment to this program.”

Cargolux’s president and CEO Frank Reimen said: “We were pioneering the cargo industry when we put the first 747-400 freighter into revenue service in 1993. This is what we do once again with the 747-8 freighter, which is ultimately a testimony of our good and long-standing partnership with Boeing.”

Boeing learns lessons for 737 from 787 overruns

Boeing’s cautious approach on the programme envisages a timescale that ranges between 64 and 76 months, depending on its first delivery in 2017 considerably longer than the airframer’s original 48 month launch-to-delivery plan for the clean-sheet 787.

“One of things we’ve learned on the 747 and 787 programmes is we want to make sure that any date that we quote is the date that we can meet. And I’d rather under-promise and over-deliver, rather than over-promise and under-deliver,” said Jim Albaugh, Boeing Commercial Airplanes ceo.

 

 © Boeing
The model incorporates Boeing’s minimum change to the family, but integrates the new higher bypass engine

With 496 commitments mostly from non-US customers, but including 100 from American Airlines Boeing is off to a later, but galloping start in the narrowbody market share battle against Airbus, with 1,200 commitments for the Airbus A320neo family.

Boeing says it is armed with a 16% fuel burn advantage over today’s A320 and 4% advantage over the A320neo, providing a 7% edge in operating costs.

FAMILY AFFAIR

The aircraft, now a family of three, replacing the 737-700, -800 and -900 with the the re-designated 737-7, -8 and -9, will be powered by CFM International’s Leap-1B engine, maintaining the engine-maker’s exclusivity on the type held since the 737-300 received its first order in March 1981.

That engine and its final fan size will guide the performance of the updated jet, as it goes head-to-head against the 78in and 81in fans offered by the Leap-X1A and Pratt & Whitney PW1100G, respectively, on the A320neo.

Boeing has narrowed its choices to two 168cm or 173cm (66in or 68in) and a final decision is expected in the “next several weeks”, Albaugh said.

At issue, the airframer must maintain a 43cm (17in) ground clearance underneath its nacelles to avoid contact with taxiway lighting. Boeing’s current CFM56-7BE engine, at 156cm (61in), provides 15cm of margin, before requiring changes to the aircraft’s nose gear, prompting changes across the airframe.

“Certainly with the 66 [inches] there’s no modifications, and I think even with the 68 [inches] a very low probability we’ll have to touch the front gear,” said Albaugh, who added that the Leap-1B is 1012% more efficient than the CFM56-7BE it will replace.

The balancing act for Boeing is minimising the amount of change to the 737 family to integrate the new higher bypass engine.

“With a bigger fan you get more efficiency because of the bypass ratio. But also what you find with the bigger fan is what you find is you get more weight and more drag,” he added.

As it fully develops its final schedule, Boeing’s fan size decision, and the resulting airframe design changes, are factored into its plan. If it chooses the largest fan, said Albaugh, “we have that built into our reserve for the development of this programme”.

TAKING THE LEAD

At the helm of the programme is Bob Feldmann, who most recently ran Boeing’s Surveillance and Engagement unit on the defence side of its business, where he guided the P-8A Poseidon’s development, itself a heavily modified 737-800.

The programme’s deputy and chief engineer Michael Teal, formerly chief engineer on the 747-8 re-engining programme, is tasked with limiting the scope of work on the Max to only those changes related to the engine, limiting any change in certification.

Albaugh said Boeing has no plans to change the flight deck, a direct request from customers, but as he sought to “make this the simplest re-engine possible”, he said the aircraft will for the first time feature limited fly-by-wire elements, a traditionally costly undertaking in both dollars and certification requirements.

 

 © Boeing
The trio 737-7, -8 and -9 are powered by the Leap 1B engine

The challenge then for Boeing, is to rein in on its own culture, where big technological leaps on the 787 and 747-8 lead to the company’s resulting schedule woes.

“The one thing we do want to make sure we have with this airplane is compatibility with the [737NG], compatibility with airplanes we’ve already delivered,” Albaugh said.

As it attempts to keep its design limited, the airframer is simultaneously looking at transforming its final assembly operations for the updated jet, potentially moving it to a facility other than its Renton, Washington site – home to every 737 built since 1968.

Dreamliner Receives FAA, EASA Certification

Boeing received certification for the 787 Dreamliner from the U.S. Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA) during a ceremony at its Everett, Washington facility. 


Boeing

FAA Administrator Randy Babbitt presented the U.S. Type Certificate, which verifies that the 787 has been tested and found to be in compliance with all federal regulations, to 787 Chief Pilot Mike Carriker and 787 Vice President and Chief Project Engineer Mike Sinnett, both of whom have worked on the program since the day it began.

Babbitt presented the amended Production Certificate 700 to John Cornish, vice president of 787 Final Assembly & Delivery, and Barb O’Dell, vice president of Quality for the 787 program. The Production Certificate adds the 787 to the list of Boeing Commercial Airplane production systems that have been found to be compliant with all federal regulations.

Boeing Commercial Airplanes President and CEO Jim Albaugh said, “Certification is a milestone that validates what we have promised the world since we started talking about this airplane. This airplane embodies the hopes and dreams of everyone fortunate enough to work on it. Their dreams are now coming true.”

Patrick Goudou, executive director of EASA, presented Dan Mooney, vice president of 787-8 Development, and Terry Beezhold, former leader of the 787 Airplane Level Integration Team, with the European Type Certificate for the 787.

 

First 777-200LR for Air Austral

Reunion Island-based Air Austral received its first Boeing 777-200LR at a ceremony on August 26, 2011.


Boeing

The 777-200LR is one of the newest members of the 777 family and has the capability to connect non-stop virtually any two cities in the world. Air Austral’s 777-200LR will enable the airline to fly non-stop from Mayotte, a French Department north of Madagascar, to Paris.

Air Austral currently operates a fleet of six 777-300ERs and 777-200ERs. With this delivery, Air Austral becomes the second carrier in Africa to take delivery of the 777-200LR.

 

CFM International Statement on Boeing 737 New Engine Family Launch

WEST CHESTER, Ohio – 30 August 2011 – This morning, The Boeing Company made the announcement below regarding the Board of Director’s approval to launch the new engine variant of the Boeing 737 powered by CFM International’s LEAP-1B engine.

“Our relationship with Boeing goes back more than 30 years and even we could not have predicted the phenomenal success the CFM-powered Boeing 737 program has enjoyed,” said CFM President and CEO Jean-Paul Ebanga. “This is the best-selling aircraft/engine combination in aviation history. I believe we have achieved that status because we have consistently worked together to refine and improve the airplane/engine combination. This new airplane will provides exceptional operating economics and provide customers with unprecedented levels of efficiency and environmental responsibility while maintaining the legacy of aviation’s most reliable product line.

“The CFM-powered 737 aircraft being delivered today represents three decades of leading-edge technical innovation and we look forward to taking that technology to a whole new level with the LEAP-powered 737.”

The LEAP-1B will be the exclusive powerplant for the new 737 variant, with the engine uniquely optimized for the airplane. CFM has been collaborating with Boeing on various engine options for either a new or re-engined 737 aircraft since 2005. The two companies are now working to define the final LEAP-1B engine configuration.
google-site-verification: googlebf725b9559e7dd2d.html
Since 1984, CFM has provided the sole powerplant for all Boeing 737 models from the Classic 737-300/-400/-500 to the Next-Generation 737-600/-700/-800/-900/-900ER and the BBJ. To date, more than 8,900 737s have been ordered, of which more than 7,700 are powered by CFM.

Hamburg Recruits And Trains For The Future

The aging aviation workforce is a global problem, even in a high-tech hub like Hamburg. But the city is trying harder than ever to attract young workers to northern Germany before next-generation aircraft roll off the production line. That’s why Hamburg engaged in a public-private partnership with Airbus and Lufthansa Technical Training to develop the Hamburg Centre of Aviation Training, which opened in late May.

The 3,000-sq.-meter facility houses mechanic classes for 800 vocational students as well as engineering courses for more than 2,000 university students in aerospace engineering. Instructors from Airbus and Lufthansa Technical Training will offer classes to students through private and public institutions while they continue their separate training programs. Many of the courses encourage students to practice hands-on cabin modifications and design components—an opportunity made possible by an Airbus A300 fuselage section donated by Airbus.

Cristoph Meyerrose, managing director of Lufthansa Technical Training, says that his company is designing new courses especially for cabin component specialists. Although suppliers will provide some cabin systems for students to practice installing in the aircraft, the center will go a step further to teach them how to construct new prototypes.

“The purpose of the students being in the center is that they’re doing their own design and not getting material from companies,” says Meyerrose. The center also will offer extensive opportunities for both new and seasoned technicians to work with new materials like carbon fiber composites, which will make up much of future aircraft. Other courses on avionics and inflight entertainment devices will provide training on new types of electronic systems.

The team of aviation companies and institutions went to aviation clusters such as Toulouse, Montreal, and Seattle to draw inspiration for how to attract younger workers to the aviation industry. Meyerrose says it is important that Hamburg look beyond Germany for new students and focus on attracting interest from all over Europe.

“Companies need to understand the demographic situation is something we have to face and find methods to work against it,” says Meyerrose. “We have to open borders to let people come from other countries.”

An Aircraft Maintenance Engineer(AME) is a blend of mechanical aptitude and technical skills

An Aircraft Maintenance Engineer (AME) is a person authorized to maintain and certify in written airworthiness standards of an aircraft. An AME should possess high degree of responsibility and accuracy of mechanical aptitude and technical skills to undertake such responsibility and uplift that kind of maintenance work on any aircraft.

AMEs Responsibilities:

Aircraft Maintenance Engineer (AME)
  •  Certifying the airworthiness of airframe, piston and turbine engines, electrical/electronics systems, propellers and rotary systems
  • To carry out periodic inspections and troubleshooting aircraft structural, mechanical or electrical systems to identify problems
  • Repairing systems within the tolerance limits according to specifications, technical drawings, manuals and established procedures
  • Repairing and overhauling aircraft structural, mechanical or electrical systems
  • Installing or modifying aircraft engines, mechanical, hydraulic,electrical, flight control, fuel and pneumatic systems
  • Dismantling airframes, aircraft engines or other aircraft systems for repair, overhaul, inspection and reassembly
  • Supervising, performing and documenting routine maintenance
  • AMEs generally work regular office hours, but may sometimes work overtime hours when deadlines arise.
AMEs Personal Characteristics:
  •  Good eyesight and hearing
  •  Good observation skills and an ability to concentrate for longer periods of time and strong problem-solving skills
  •  Good hand-eye coordination along with accurate to the smallest details
  •  Good team work coordination and make decisions independently, often under pressure
  • A must physical fitness and stamina to work for extended period of times
  • The ability to get hold of situation and to follow instructions provided in written or blueprint form, and to interpret the same
  • Good management and organizational skills
  • A self motivator, a keen interest on latest trends in Aviation is appreciable
  • Aircraft Maintenance Engineers should be able to visualize problems in three dimensions form and have the knack of selecting the right kind of tools, equipments and machinery to perform task requiring high degree of precision, analyzing data and troubleshooting snags and organized methods for theirs work.
AMEs Pay Check:

An AME plays a vital role in engineering discipline in aviation organization and by virtue of big responsibilities involved in maintaining aircraft, an AME is high ranked, drawing excellent pay and perks (usually between$45,000 and $55,000 plus per year) and enjoying good facilities. A well structured career progression is ensured for an AME. With a type of rated license and experience, an Aircraft Maintenance Engineer assumes very high positions like Chief Managers Maintenance Dept., Chief Manager Quality Control and General Managers, and finally can be positioned as a Head of the Engineering services and they receive pay between $120,000 and $145,000 plus per year.

Here the dreams are unlimited. Give your dreams a wing to catch and soar into new heights of success.
Up Up All The Way …

Is it Aircraft Maintenance Engineering or Aeronautical Engineering or Commercial License Pilot?

Is it Aircraft Maintenance Engineering or Aeronautical Engineering or Commercial License Pilot?

1.who is paid most?
2.which is most glamorous profession?
3.who has most responsibility?
4.who is considered as no:1 in aviation?
5.who will be having most knowledge about airplanes?

Pilot

1.who is paid most?

A. Pilots: As a pilot, I know from first-hand experience that starting wages for civilian pilots are very poor. Typically a pilot’s first job fresh off the lot is a flight instructor (CFI, CFII, MEI) for a flight school, and they make about 12k a year. This is not because of the hourly wage is so low, but the fact that they are only paid when in two roles (flight time, and ground). Also, it is possible for someone to make a living flight instructing, but this is usually someone who has thousands of hours of experience who usually owns his or her own plane.

To further restrict the pilot’s income, they have daily time restrictions on the amount a flight instructor can fly Once a flight instructor builds up enough time to go to the airlines, they will usually get picked up at a regional with a starting salary of 18-20k a year with a raise to 26-30k. With that said, it takes several years for a pilot to see a financial gain for the thousands of dollars and astronomical amount of time and energy they invested, but eventually, the pay reaching in the 90-120k plus a year range.

B.Aeronautical Engineers: I do not have first-hand experience for the salaries of aeronautical engineers, but I found on the below listed website that the typical salaries start around 24-150k.
http://www.avjobs.com/salaries-wages-pay…

C.A&P (airframe and power plant) Mechanics as they are called in the US have an average salary range of 35k-85k. I have several friends who are A&P’s and their salaries reflect the data on the listed site.
http://www.avjobs.com/salaries-wages-pay…

2.which is most glamorous profession?

In comparative analysis, all three (designer, operator, repairer), play an equally role, and the absents of all three are detrimental the aviation industry, along side the rest of the elemental functions of aviation infrastructure, DESPITE what others say about their individual roles which they believe and portray to be most vital.

3.who has most responsibility?

Again, all three share equally
independent levels of responsibility,

4.who is considered as no:1 in aviation?

No one in my opinion, we are all part of and intricate system

5.who will be having most knowledge about airplanes?

There are different levels and understandings of knowledge, which again are equally important with respect to the common goal of safety and reliability. The pilots have a unique knowledge and understanding to the operation of the aircraft that goes beyond a computer generated representation of an aircraft design, where as the mechanic, has a different set of vital skills that also extend beyond the classroom.

Then there’s the engineer, who uses their knowledge of Science and mathematics to bring the idea to life and produce the next generation of airplanes.

Unfortunately there have been countless, misunderstandings between R&D and operations where there was something overlooked or not considered at all, which have let to catastrophic failures. This problem was alleviated when manufacturers started having the two departments work together where they could share their unique knowledge. On top of that, advanced computer software added to the reduction of abnormalities.

AIRCRAFT MAINTENANCE ENGINEERING

In final words my personal note is in slight favor of Aircraft Maintenance Engineering.
AIRCRAFT MAINTENANCE ENGINEERING IS GOOD AS YOU COULD KNOW MANY DIFFERENCE OF THE OPERATIONS IN MAINTENANCE. To be true this career is not so exiting.
The work of Aircraft Maintenance Engineer may not be exiting and glamorous but Aircraft Maintenance Engineers are just as vital to the aviation industry. Without AMEs you can’t even imagine to fly.  
Aircraft Maintenance Engineers are the nuts and bolts of aviation.
I hope this is helpful ..

Aircraft Maintenance Engineer Apprenticeship.”You learn as you work”.

As a first step after coming out of maintenance technical schools. Completing of 2  1/2 years of theory cum practical on light aircraft, now you need to get onjob aircraft maintenance training for further heavy aeroplane experience to eligible for ame paper 3 examinations.

Aircraft Maintenance Apprenticeship

Have you ever put yourself a genuine question, what is Apprenticeship?
Well, apprentice will be employed to undertake education and training within a company that prepares for your progression  career.

Companies provides the skills and knowledge that you will use in your future career. Apprenticeships in the engineering industry enable you to progress as quickly as you are able.

Here are some online websites assuring you providing APPRENTICESHIP:

  • A GTO is a group training organization – a one stop shop for all your apprenticeship and traineeship needs.
  • The Web site where Engineering employers and apprentices meet

Airbus A380 WOW! The World’s only twin-deck, two-decaisle Airliner,Largest Aircraft makes first Commercial Landing in India

The Indira Gandhi International Airpot Terminal 3 has witnessed the largest aircraft of the world, the airbus A380 first commercial landing. T3 terminal is A380-compatible runway and passenger boarding bridges.

Aircraft Maintenance Engineering

Here on Thursday at IGI Airport rain held up the landing for about half an hour.Aircraft supposed to land at 255 p.m., landed at roughly 3.35 p.m.

An Emirates official said: “We organised this flight to promote the A380 in India and give an idea to people about what it is like.” However, India will have to wait before Emirates commences regular A380 operations in the country as the airline has no such immediate plans.

Incidentally, it was the Kingfisher Airlines which first flew in the A380 to India in 2007.

The A380, which is the world’s only twin-deck, two-aisle airliner, is to be less polluting to the environment compared to other aircraft of same cader. It offers better fuel economy per passenger mile than most hybrid passenger cars and also produces less noise.

The aircraft has two decks. The business and first class seats are on the upper deck of the Emirates A380 while economy seats are on the lower or main deck.

Free Aircraft and Aeronautical Technician and Aerospace Engineering Education Consultancy – from an Expert

Free Education Consultancy on Bachelors Engineering Degree in Aircraft Engineering, Bachelors of Science (B.Sc), and Degree in Aeronautical & Aerospace Engineering after Intermediate Studies.

Anyone interested in Free Consultancy for getting admissions in Aircraft Maintenance Engineer (AMEs) please feel free to contact Dr. Singh. His guidance and consultancy can help you get admissions for AMEs approved by Director General of Civil Aviation (D.G.C.A).

Wernher von Braun, with the F-1 engines of the...Dr.Singh is a leading Consultant in Aeronautical and Aircraft Engineering Education for Colleges and Universities in Northern India.For the first time in the history of Consultancy in Education one can rely only upon Dr. D Singh. In times of tough competition and career race we have so many options to choose from, but the right ones to guide us are very rare.

The beauty of the details is that it also provides you with future job prospects worldwide, in addition to case studies of individual and other information on Aircraft and Aeronautical Technician & Engineers.

All you need to do is, just send in your requests to Dr. Singh through this website.

Online Data Entry Work From Home Most Profitible and Easiest to Make Money

 

Data Entry Work

Data Entry Work From Home
Doing part time data entry jobs from home is just right platform for students to earn those extra money.

  • No need to wait for those Money Orders from Home.
  • Those little earned money reliefs you and your family.
  • You will have your own pocket money i.e better living expenses.

If you are one of the thousands of people looking to work in an online data entry position there is no need to worry.

The field of online data entry positions is taking a turn for the better with a promising future that lies ahead.

Types of online data entry positions that you could look into include word processors, typists, transcribers, encoders and more. There are several websites that offer these positions in all different forms.

On the other hand, if you like the idea of working for yourself, choosing when and how long you will work today. If you want the freedom to take a nap at 3:30 pm and begin your work day at 1:00 am in the morning, you should look into this type of work at home opportunity. Here are some of the

Benefits of working from your home.

More economical:

Most people who add up the true cost of going out to a job are appalled at how little of the earnings actually can be applied against their living expenses.

Prerequisites:

All that is required are a computer, internet connectivity, knowledge to operate the computer, little bit of typing skills as it requires to process and manage large number of data and last but not the least aptitude to take up data entry jobs.

Good communication, data organizing skills, and as said typing skills add value to the work performed.

They may have to edit the information; proof read the content for accuracy and update databases ensure the documents are error free. Also, there are many types of data entry jobs like the attorney’s legal briefs to be entered,medical records or medical transcriptions where the data will be in the form of voice which have to be converted into records, court or legal documents etc.

Remember that if you are searching for a legitimate data entry at home job, you will not be asked to give any cash for sort of placement fee. You should keep in mind that you are looking for a job and that this company should be the ones who will pay you instead of you giving out cash. By entering this opportunity, it would probably open doors for you to a wider and greater opportunity for working for job at home.

Data entry jobs online:

Many freelance job sites on the net that offer data entry jobs online.There is no registration fee charged for registering as the main purpose is to get the information of the person who is going to do data entry jobs like name, address, areas of interest etc.The job is offered to the person who bids for the lowest amount. Thus data entry jobs can be got online. The time spent on such data entry jobs is very valuable as every second makes the person earn money.

Twitter Entries
Twitter has fast become one of the biggest online communities where people connect with each other and share information with one another. This is the reason why more and more people want to be on Twitter but when they do join, they don’t really know what to post. This is where you can come in. You can get paid to maintain a Twitter account and online data entry jobs like this are one in a million. Just think how easy it is to place in 140 character entries including links just to direct people to other websites!

There are people making $2000 – $3000 per month through Data entry work.

Never Late. Just google search, find best data entry projects and earn those extra cash🙂

Chosen Aircraft Maintenance Engineering or Aerospace/Aeronautical Engineering As A Profession, Then Be An AeroModeller

Are you a student of aerospace engineering or aircraft maintenance engineering, then take Aeromodeling as a hobby and model aviation as a extra curriculum subject.
DSC_9096
Aeromodeling introduces flying theory in a wide spectrum-

  • Better understanding of theory regarding the flight characteristics
  • Knowledge of the terms lift, drag, angle of attack, stall
  • Practical hands on experience, how a modern aircraft fly?
  • Above all you will get recognize the sophisticated technology regarding today’s aviation.

Go with model aeroplanes. Take aeromodeling as a hobby and i assure the above, model aviation will provide immense skills and sufficient knowledge on all technical aspects of aircraft and aircraft basic assemble and construction.

Why Aeromodeling?

  • Aerodeling takes you more closer to aviation.
  • Assembling,construction and flying model aeroplanes is very educational experience.
  • Flying models construction techniques are replica and borrowed from vintage full-sized aircraft(although models rarely use metal structures)

These construction consists:

  • Forming and framing of the model planes using thin strips of light wood such as balsa.
  • Covering model plane with fabric and subsequently doping the fabric to form a light and sturdy frame airtight.
  • Model with high scale construction techniques consists of using formers and longerons, for the fuselage and spars and ribs for the wings and tail surfaces.

The aeromodeling involves design,building and flying of model airplanes or helicopters. It also gives a primary introduction to the world of aerodynamics, designing,electronics engined technology includes both piston and jet engines,wood crafting and the technology of new materials.

Most importantly you will brush up and get revision of paper-2 and paper-3 of aircraft maintenance engineering licensed examinations and lots of semester portion will be covered for aerospace engineering.

You will come to know:

  • Basics of assembling,construction and flying which covers syllabus for Paper-II(Aircraft General Engineering And Maintenance Practices) and Paper-III Category A(Light and Heavy Aircraft)
  • Calculation of C.G position

Now,i hope they are good reasons for you to take aeromodling as a hobby.As you progress in aeromodeling and before you undergo on-job training or apprenticeship in last semester, you will have real technical data and real feel of aircraft.

Aircraft Maintenance Engineering is not a glamor profession and with passion if you have chosen this as a career then you need to make ways to come closer to it.Aeromodeling is one of the best way to do that..

Believe you will start loving your profession either as a student of aerospace engineering or aircraft maintenance engineering or as an on-job training.

Be a AeroModeller! Loads of creativity is involved in it. You’ll say “I’m loving it”.

I hope you enjoyed reading this post, in coming series of aeromodeling i will try to put more insights on history of aeromodeling.

Aircraft Maintenance Engineering is NOT a Glamor Profession like Other Aviation Career’s

The fascination for aviation made you to choose Aircraft Maintenance Engineering as your profession and is why millions of people work in aviation.

But the hard part is many students lose interest as they get understand insight professionalism of maintenance engineer in aviation and to added employment opportunities are less.

If you are unhappy with the choice of doing aircraft maintenance engineering license course and tired for not things going in your way, then make an early exits.

Better late than never, take a decision and wind up things. Start a new career.

Say frankly you might be got lost passion in aircraft maintenance engineering, but aviation isn’t just aircraft maintenance, or “piloting.” Aviation is an entire world above and beyond the cockpit.

Aviation is aircraft design, systems engineering, test piloting, search and rescue, human factors, air traffic control, jet mechanics, electrical engineering, computer systems, airport management, space exploration, customer service, and much more!

Be in aviation they are better options in aviation sector. But the sad part is we never encourage our self to do so and get diversified to new horizons of opportunities.

As said take decision and they are good number of universities and colleges across India and in abroad to count aircraft maintenance engineering experience and based on that experience you can earn a aircraft maintenance license degree or a B.Tech degree in aeronautical engineering.

Now neither nor less to say having a b.tech degree in hands have a lot many career options than just being an AME engineer with 10+2 qualification.

My sincere advice is to do degree on distance education and if you had completed your aircraft maintenance engineering course and has some aviation working experience, then find out colleges and universities providing aviation related degree programs.

Mean while, in coming articles i will come up with information on universities and colleges providing aviation programs based on aircraft maintenance engineering license.
Hope you all enjoyed the post.

Happy AME!


Aviation Management Programs includes Airport Management and Engineering

Career Opportunities with a BBA/MBA degree in the Aviation sector

Students with aviation/airport management degree seek careers in airline operations includes:

  • Flight dispatch
  • Station management
  • Air cargo administration
  • Flight schedule coordination

  • Public relations
  • Marketing or customer service

and even seek positions with state or government aviation agencies. If you are not interested a career in aviation sector, you can transferable to many other business and engineering related industries such as events management, hospitality and tourism.

Airport Manager Fresher salary: Freshers earn a salary package of 200000 – 300000 per year in domestic airlines, while as a fresher in international aviation the salary package may even go to 400000 – 600000 per year.

Size of the Indian Aviation Industry?

Passenger growth has grown from 40m to 110m in the last 5 yrs and is expected to grow to 150m by 2020. Indian carriers have 480 aircraft on order for delivery by 2012, which compares with a fleet size of 310 aircraft operating in the country today.

Approx 2.5 – 5 lakhs jobs in the Indian Aviation Industry.

Positions available in the Aviation Sector

  • Airport Services Manager/ Airport Manager
  • International Logistics Manager
  • Airport Services Supervisor
  • In-Flight Instructor
  • Guest Services Manager
  • Procurement Consultants
  • Transportation Manager

 

Schools of Aviation Management:

Institute of Logistics & Aviation Management
offer programs :
BBA in Aviation and Travel Tourism

Logistic and Aviation Management
Avalon Academy of Aviation – An Aptech brand
Offer University Diplomas and MBA Degrees in Airport Management
certified professional in Ground Staff Services
certified professional in Cabin Crew Services
certified professional in Travel & Tourism
The Singapore Aviation Academy(SAA)
offer programs:
School of Aviation Management
School of Aviation Safety & Security
School of Air Traffic Services
School of Airport Emergency Services

Fellowships
The Singapore Aviation Academy has tie-ups with international funding agencies and works closely with the Singapore Government  to secure training fellowships for developing countries.

History of Aviation: Leonardo da Vinci made the First Real Studies of Flight in the 1480’s – The Ornithopter

 

1485 Leonardo da Vinci – The Ornithopter

Leonardo da Vinci made the first real studies of flight in the 1480’s. He had over 100 drawings that illustrated his theories on flight.

Leonardo da Vinci’s Ornithopter
The Ornithopter flying machine was never actually created. It was a design that Leonardo da Vinci created to show how man could fly. The modern day helicopter is based on this concept.

Early Efforts of Flight

Around 400 BC – China
The discovery of the kite that could fly in the air by the Chinese started humans thinking about flying. Kites were used by the Chinese in religious ceremonies. They built many colorful kites for fun, also. More sophisticated kites were used to test weather conditions. Kites have been important to the invention of flight as they were the forerunner to balloons and gliders.

Humans try to fly like birds
For many centuries, humans have tried to fly just like the birds. Wings made of feathers or light weight wood have been attached to arms to test their ability to fly. The results were often disastrous as the muscles of the human arms are not like a birds and can not move with the strength of a bird.

Hero and the Aeolipile
Aeolipile The ancient Greek engineer, Hero of Alexandria, worked with air pressure and steam to create sources of power. One experiment that he developed was the aeolipile which used jets of steam to create rotary motion.
Hero mounted a sphere on top of a water kettle. A fire below the kettle turned the water into steam, and the gas traveled through pipes to the sphere. Two L-shaped tubes on opposite sides of the sphere allowed the gas to escape, which gave a thrust to the sphere that caused it to rotate.

Joseph and Jacques Montgolfier- the First Hot Air Balloon 1783
The brothers, Joseph Michel and Jacques Etienne Montgolfier, were inventors of the first hot air balloon. They used the smoke from a fire to blow hot air into a silk bag. The silk bag was attached to a basket. The hot air then rose and allowed the balloon to be lighter-than-air.

In 1783, the first passengers in the colorful balloon were a sheep, rooster and duck. It climbed to a height of about 6,000 feet and traveled more than 1 mile. After this first success, the brothers began to send men up in balloons. The first manned flight was on November 21, 1783, the passengers were Jean-Francois Pilatre de Rozier and Francois Laurent.

George Cayley – 1799 – 1850’s
Over 50 years he made improvements to the gliders. He changed the shape of the wings so that the air would flow over the wings correctly. He designed a tail for the gliders to help with the stability. He tried a biplane design to add strength to the glider. He also recognized that there would be a need for power if the flight was to be in the air for a long time.
George Cayley worked to discover a way that man could fly. He designed many different versions of gliders that used the movements of the body to control. A young boy, whose name is not known, was the first to fly one of his gliders.

19th And 20th Century Efforts
Otto Lilienthal 1891
German engineer, Otto Lilienthal, studied aerodynamics and worked to design a glider that would fly. He was the first person to design a glider that could fly a person and was able to fly long distances.

He was fascinated by the idea of flight. Based on his studies of birds and how they fly, he wrote a book on aerodynamics that was published in 1889 and this text was used by the Wright Brothers as the basis for their designs.After more than 2500 flights, he was killed when he lost control because of a sudden strong wind and crashed into the ground.

Samuel P. Langley 1891
Samuel Langley was an astronomer, who realized that power was needed to help man fly. He built a model of a plane, which he called an aerodrome, that included a steam-powered engine. In 1891, his model flew for 3/4s of a mile before running out of fuel.

Langley received a $50,000 grant to build a full sized aerodrome. It was too heavy to fly and it crashed. He was very disappointed. He gave up trying to fly. His major contributions to flight involved attempts at adding a power plant to a glider. He was also well known as the director of the Smithsonian Institute in Washington, DC

Orville and Wilbur Wright and the First Flight 1903
Orville and Wilbur Wright were very deliberate in their quest for flight. First, they spent many years learning about all the early developments of flight. They completed detailed research of what other early inventors had done. They read all the literature that was published up to that time. Then, they began to test the early theories with balloons and kites. They learned about how the wind would help with the flight and how it could affect the surfaces once up in the air.
The next step was to test the shapes of gliders much like George Cayley did when he was testing the many different shapes that would fly. They spent much time testing and learning about how gliders could be controlled.

They designed and used a wind tunnel to test the shapes of the wings and the tails of the gliders. After they found a glider shape that consistently would fly in the tests in the North Carolina Outer Banks dunes, then they turned their attention to how to create a propulsion system that would create the lift needed to fly.
The early engine that they used generated almost 12 horsepower.

The Wright Brother’s Flyer

The “Flyer” lifted from level ground to the north of Big Kill Devil Hill, at 10:35 a.m., on December 17, 1903. Orville piloted the plane which weighed six hundred and five pounds..


Actual Flight of The Flyer at Kitty Hawk
The first heavier-than-air flight traveled one hundred twenty feet in twelve seconds. The two brothers took turns during the test flights. It was Orville’s turn to test the plane, so he is the brother that is credited with the first flight.

Humankind was now able to fly! During the next century, many new airplanes and engines were developed to help transport people, luggage, cargo, military personnel and weapons. The 20th century’s advances were all based on this first flight at Kitty Hawk by the American Brothers from Ohio.

Is Aeronautical Engineering is a Branch of Aerospace Engineering? Do you know First Airplane was designed by a Pair of Bicycle Makers?

What is Aeronautical Engineering?
Aeronautical Engineering is a sub-branch of aerospace engineering. Though few people often interchange these two terms. Basically aeronautical involve activity of designing, developing and constructing of machine planes that can fly, as commonly know by aircraft.

The aeronautical engineers primarily responsible for creation of safer and more energy efficient economical methods for travelling including aircraft, helicopters, satellites, missiles and spacecrafts.
These includes science of propulsion and aerodynamics, even it covers the development and selection of materials and equipment that are utilized in aircraft.

Aero Engineer’s are part of the designing process to make the fastest vehicle. Eg: Airplanes that weighs over a million pounds can ease into the air and spacecraft travels 17.000 miles an hour.

What do Aeronautical Engineers do?
Aero engineers bring concept into reality by emphasising on the design of aerofoils(wings). Propulsion is another aspect in aeronautical engineering. The force of propulsion helps an airplane to remain in flight, and encompasses the design and development of engines. These two basic principles are considered when choice of material for aircraft design, strenght and weight. Selection of material is a crucial area of specialization for the aeronautical engineering

As a Aero graduates you can specialize in any areas including:
Structural designing, Flight mechanic and control system, Aerodynamics, Instrumentation and communication, Manufacturing and maintenance.

Wright Brothers bicycle

Aeronautical Engineering Career Opportunities:
Commercial aviation industry
Government defence forces
Flight crew in both commercial and defence aviation
Research institutes
Space exploration centres.

Aeronautical Engineers Employers includes:
Aer Lingus, Airbus the Air Corps, FLS Aerospace, Rolls Royce and Ryanair to name but a few.

Aeronautical Engineering Future Prospects:
Create new, innovative methods of transportation to meet future demands.
Improve safety of an aircraft travel with more energy-efficient, economical methods
Develop and manufactures rockets and satellites.
Research and development formula one racing cars.
Perform and supervising the design of military aircraft.

Aeronautical Engineering salary: The average aeronautical engineer earns over $90,000 a year.

The first airplane was designed by a pair of bicycle makers, who worked on it largely as a hobby.
Wright Brothers bicycle on display at the National Air and Space Museum.

Aircraft Maintenance Engineering Specialization in one year Approved By Civil Aviation Authority of Singapore(CAAS) Cat A1

If you are interested in a career in Aircraft Maintenance Engineering and would rise to the challenge of maintaining a plane, and Looking for Specialization in Aircraft Maintenance Engineering or a B.Eng(Hons) in Aircraft Maintenance Engineering or Higher Certification in Aerospace Maintenance( Aircraft Maintenance), then the below courses are for you:

Air Transport Training College(ATTC) is a one stop professinal solutions for Aviation Training. AATC is a professional development centre of the sigapore institute of aerospace engineers. Air Transport Training College(ATTC) provides professinal training in aerospace engineering and aviation management. The college awards Diplomas, Masters and Specialization degrees.

ATTC COURSE:

Specialist Diploma in Aircraft Maintenance and Engineering (SAME)

Course Description: The SAME Programme fully meets the requirements of skills required for the Aerospace industry as well as providing you with the basic knowledge needed to be employed in an aircraft line maintenance environment.

Course Duration: Full-Time one year (2 semesters)

CAREER PROSPECT: Students who graduate with the diploma and obtained the CAAS SAR-66 Cat A1 License* will find prospect for employment in the Aerospace industry locally and internationally. one year of additional relevant Aircraft Maintenance Experience is required

COURSE FEES: SGD(Singapore Dollar) 18500 + 7% GST*

Foundation Degree in Aircraft Engineering (FdEng)

Course Objectives: This is a 2 year full-time degree programme designed to cover the basic knowledge requirements for the SAR Part 66 Cat B 1.1 license and the FdEng requirements of Kingston University London. Successful Graduates from this FdEng programme will have the option to proceed to a 3rd year at  Kingston University London towards a BEng(Hons) in Aircraft Engineering.

CAREER PROSPECT: Students who graduate with the B.Eng(Hons) and obtained the CAAS SAR-66 Cat A1 License* will find prospect for employment in the Aerospace industry locally and internationally.

Course Duration: Two years Full-Time

COURSE FEES: Course Fee : SGD (Singapore Dollar) 22,500 (per year) + 7% GST*

Professional Diploma in Aircraft Maintenance and Engineering (PAME)

Course Objectives: The PAME programme is built on an established programme with a leading university in the United Kingdom, and the course delivered is base knowledge requirements of the SAR Part 66 Category A syllabus of the Civil Aviation Authority of Singapore(CAAS).

CAREER PROSPECT: Students find for employment in the Aerospace industry locally and internationally.

Course Duration: Part-time one year (2 semesters)

COURSE FEES: SGD (Singapore Dollar) 3,145.80 payable in 1 instalment

More information visit: http://www.attc.edu.sg/

Besides the above courses Air Transport Training College(ATTC) also conducts:

Bachelor Of Engineering Science in Aerospace Operations(B.Eng Sc AeroOPS)
Higher Certificate In Aerospace Maintenance (Aircraft Maintenance – Engine/Engine Component Repair & Overhaul) Course
Professional Certificate in Aerospace Workshop Operations (Electives) course

WSQ Aerospace: Basic Aviation Skills (Gas Turbine) Course


“Pratt & Whitney provides Singapore Airlines Cargo with EcoPower® Engine Wash- Reduce Carbon dioxide (CO2) emissions and Fuel burn.”

Singapore Airlines Cargo continually improving Environmental performance.

Tan Kai Ping, president of Singapore Airlines Cargo said, “We Strengthens Commitment to Environment With Pratt & Whitney EcoPower® Engine Wash- reducing carbon dioxide (CO2) emissions and fuel burn.

MRO ASIA – Singapore, – Singapore Airlines Cargo has signed a three-year agreement for Pratt & Whitney’s environmentally friendly EcoPower engine wash service. The washes will be performed by Eagle Services ASIA, a joint venture between Pratt & Whitney and Singapore Airlines Engineering Company, for the airline’s PW4000-94” engines powering its fleet of Boeing 747-400 freighter aircraft. Pratt & Whitney is a United Technologies Corp. (NYSE:UTX) company.

Singapore Airlines Cargo, a wholly owned subsidiary of Singapore Airlines formed in 2001, is one of the world’s largest operators of B747-400 freighters. Singapore Airlines Cargo flies more than 600 flights a week throughout its network of over 70 cities in more than 30 countries around the world.

“Pratt & Whitney is to provide Singapore Airlines Cargo with a quick and effective way to further advance its environmental performance,” said Andrew Tanner, vice president, Product Line Management, Pratt & Whitney. “EcoPower engine wash provides quantifiable environmental and economical benefits. This is demonstrated by the more than 15,200 washes performed on 54 different engine models.”

Pratt & Whitney’s EcoPower Engine Environmental and Economical benefits:
  • Engine wash system reduces fuel burn by as much as 1.2 percent, eliminating approximately three pounds of carbon dioxide emissions for every pound of fuel
  • Also decreasing engine gas temperature thus increasing the amount of time an engine can stay on wing

Pratt & Whitney is a world leader in the design, manufacture and service of aircraft engines, space propulsion systems and industrial gas turbines. United Technologies, based in Hartford, Conn., is a diversified company providing high technology products and services to the global aerospace and commercial building industries.

EcoPower is a registered trademark of United Technologies Corporation.

Tips for Proper Aircraft Tire Maintenance – Goodyear Expert

Aircraft tire/wheel assemblies can lose up to 5 percent of their pressure each day.
When it comes to aircraft tire maintenance, few people in the industry have visited more hangars and seen all manner of service work and maintenance procedures than Goodyear Aviation’s Rob Robson.

Robson is a Product Support Manager for The Goodyear Tire & Rubber Company, and for more than 10 years he’s been immersed in aircraft tire product support for everything from piston singles to helicopters and fighter jets.

By his own count, Robson has witnessed numerous aircraft tire maintenance procedures and has inspected hundreds of worn tires. He has seen firsthand the ill effects of improper maintenance. As a result, Robson can offer valuable advice for those who wish to better understand how proper aircraft tire maintenance can help to deliver more landings.

The most important factor of any aircraft tire maintenance program is maintaining proper inflation pressure.

According to Robson, the problems created by incorrect inflation can be severe. Over inflation often leads to uneven tread wear and reduced traction, makes the tread more susceptible to cutting, and places greater stress on aircraft wheels. Under inflation creates faster tread wear on the shoulders, damages the tire’s innerliner, and greatly increases the stress and flex heating in the tire that can lead to tire failure.

“Because aircraft tire/wheel assemblies can lose up to 5 percent of their pressure each day, they need to be checked daily, or before each flight, with a calibrated pressure gauge when the tire is at ambient temperature (not heated by taxiing). Any tire that’s been run more than 10 percent underinflated should be removed from service,” Robson said. The industry veteran also recommends filling tubeless assemblies with nitrogen instead of air because it’s dry and non-combustible.

Another key area of aircraft tire maintenance:

  • Lookout for no harmful chemicals are used or spilled on the tires.
  • Keep hangar floors clean of all debris to avoid foreign object damage to the tires.
  • It is also important to inspect the tires closely, in addition to checking tire pressure, during pre-flights to check for any damage to the tires from service.

Aero Engine Triple Spool Design minimize Engine Surges is the majar advantage of 3 Spool Concept

Major advantage of triple spool design is it’s ability to minimize engine surges thus they are the most efficient engine flying.


As mentioned by JETPILOT, namely that the more spools you have, the better because then they will be allowed to spin at their own speed given their spool mass.

Let’s say you’re at takeoff power with for example a double spool engine. The heavy N1 spool is turning at it’s own RPM and so is the lighter N2. Now you chop off the power. The lighter N2 will drop in RPM much quicker then the heavy N1 with it’s huge fan. So what happens is that the N1 compressors are feeding way too much air to the second (HP) compressor.

Where is all that excess air gonna go ?
Well in extreme cases you can have a very damaging engine surge in which air will flow in the wrong way through the engine. Most of todays engines have very sophisticated computer controlled “bypass doors” that let the air escape from the compressor casing.
But the chance of engine surges always remains. If you have three spools, the weight difference is spread over 3 spools thus drastically reducing the chance of engine surges.

Aircraft Maintenance Engineering 3-Spool-Engine Concept

Aircraft Engine Maintenance 3-Spool-Engine Concepts

What is triple spool design on the RB211? what are the advantages/disadvantages?

A 3 spool engine is one that has three sets of compressors before the combustor and three sets of turbines behind it.

A spool is made up of a compressor and a corresponding turbine used to extract the power from the exhaust gasses to turn the compressor.

Each spool is given a name. N1, N2, and N3. N1 is the large fan section in front of the engine. N2 is the low pressure compressor section. And N3 is the high pressure compressor section. Some engines incorporate N2 And N3 into one rotating mass and call it N2. Hence the double spool engine.

Each section of the compressor wants to rotate at it’s own speed, and if allowed to do so as in a triple spool engine, it is able to operate more efficiently. It can turn at it’s optimum speed, and not have to compromise between the optimum speed for the N2 and N3 sections when attached in the double spool engine.

All modern engine have 2 sets of compressors (HP and LP) and a fan section providing a vast majority of the thrust.

In a 2 spool motor the HP section and the LP section are joined. The number of spools in an engine tells how many sets of compressor blades and corresponding sets of turbine blades the engine has. A single spool engine has one set of each, a double spool engine has two sets of each, and a triple spool engine has three sets of each.

3 Spool Engine advantages and disadvantages:

  • More sets of blades results in a greater engine weight, but the corresponding increase in thrust possible more than offsets the weight increase.

The drawbacks of a 3 spool engine are increased weight, complexity, and cost to purchase and overhaul, but they are the most efficient engine flying.

Aerostat System Capable of carrying Electro-Optic and COMINT payloads for Surveillance – DRDO

DRDO Demonstrates Indigenous Aerostat System

The DRDO demonstrated its indigenously designed and developed aerostat system capable of carrying electro-optic and COMINT payloads for surveillance. Trials of the system have been concluded on Saturday, December 25, 2010. These included surveillance all over Agra and interception of variety of communications. ELINT and RADAR payloads are also being developed indigenously. This platform is a result of development of a number of high end technologies in the field of aerodynamic design of balloon, fabrics, fabrication, hydraulic winch, electro-optic tether, high pressure helium cylinder manifold, active pressure control system etc in association with large and medium sized Industrial partners.

The system has been designed, developed and integrated by the Aerial Delivery Research & Development Establishment (ADRDE), Agra Cantt, a premier laboratory under the Defence Research & Development Organization (DRDO) working in the field of parachutes, lighter than air systems, floatation systems and aircraft arrester barriers. ADRDE has developed and supplied various types of parachutes for wide range of applications viz. Paradropping men, weapons, Combat Vehicles, Stores etc, braking of fighter Aircraft and Recovery of payloads pertaining to missiles, UAV and space missions. Over the last few years, ADRDE has diversified into the field of lighter-than-Air (LTA) technologies and developed small and medium size Aerostats. Recently, ADRDE has developed a state-of-the-art medium size helium filled Aerostat and successfully test flown up to one km altitude at Agra.

Dr. Prahlada, DS & CC R&D (Aerospace & Services Interaction) congratulated the team and brought out the facts that ADRDE had graduated from a laboratory designing and developing balloons, parachutes and heavy air-drop systems to developing systems of systems. The complete balloons systems, ground based command and control systems, and payloads have been integrated for full exploitation. The gimbals, with 360 degree azimuth freedom and high degree freedom in elevation is highly stabilized and can carry out steering, scanning and tracking with high precision. The payload also carries thermal camera for surveillance during night and in low visibility condition. The electronic intelligence payload carries a communication intelligence system for capturing and analyzing all types of communications in air. 

Health monitoring of aerostat and simultaneous command and controlling of payload from ground control station has been demonstrated. The system will be useful for three services, paramilitary forces as well as have civilian applications including disaster management. This milestone comes in the wake of new generation high altitude aerostats/airships that will be developed by DRDO.

Masters in Aviation at Gulf Center for Aviation Studies (abu dhabi aviation)

GCAS is endorsed by the General Civil Aviation Authority (GCAA) of the UAE, and the International Civil Aviation Organization (ICAO).

abu dhabi Aviation | Courses in Aviation | Diploma in Aviation | Degree in Aviation | Aviation Management Courses | Masters in Aviation | Civil Aviation Course | University of Aviation

Gulf Center for Aviation Studies (abu dhabi aviation)
College name:   Gulf Center for Aviation Studies
Director’s name:    Mohammed Al Bulooki (General Manager)
Executive body or owner:     Abu Dhabi Airports Company (ADAC)
Date founded:     December 2008
Type of institute:     private college
College location / area:   Abu Dhabi International Airport, Al Bateen Airport
Postal address     PO Box 94449, Abu Dhabi, UAE
Telephone     +971-2-5053560
Fax     +971-2-5758300
Email   training@gcas.ae
Website     www.gcas.ae
Curriculum:  UAE/International
Qualifications:     Masters, aviation short courses

Gulf Centre for Aviation Studies degrees, programs, and training courses

* Masters Degree in Aviation Management Courses and Airport (Masters in Aviation)
* Short courses in civil aviation course, aviation regulations, airport management and operations, cargo operations, aviation security and safety, diploma in aviation, degree in aviation, etc

 Aircraft Maintenance Engineering Specialization Singapore(CAAS)

Emirates International Airline

Aviation Executive Programs:
* Airport Commercial Revenues
* Airport Economics, Charges and Regulation
* Airport Executive Leadership Programme (AELP)
* Airport Marketing
* Introduction to the Air Transport Industry
* Introduction to the Airline Business

Aviation Business Training Courses (Aviation Management Courses)

* ACI / ICAO Airport User Charges
* Airport Carbon Management
* Airport Certification and Standards
* Airport Energy Management
* Airport Management Professional Accreditation Programme – AMPAP
* Airport Master Planning
* Airport Non-Aeronautical Revenues
* Airport Privatization
* Airport Security
* Airside Safety Training Course
* Auditing Techniques in Relation to Ground Operations
* Developing Customer Service Culture at Airports: Measuring and Benchmarking the Results
* Emergency Response Planning Workshop
* GASR Aerodrome Safety Training Course
* GSN Module 1 – Safety Management Systems
* GSN Module II – ACI Airside Safety and Operations
* GSN Module 3 – Emergency Planning and Crisis Management
* Human Factors in Aviation
* International Aviation Law and Policy Training
* Introduction to Accident and Incident Investigation
* Introduction to Air Traffic Control
* Introduction to the Air Transport Business
* Introduction to the Air Transport Industry
* Introduction to the Airline Management Business
* Introduction to the Airport Business
* ISAGO Training for Ground Service Providers
* Managing Airports Sustainability
* Managing Service Quality at Airports
* Management of Aviation Security
* PRM Training for Airport Management & PRM Project Managers
* PRM Training for Trainers Airport Facilities
* PRM Training for Trainers Check-in and Gate staff
* Quality Management – Principles and Practice in an Aviation Environment
* Regulatory Auditing Techniques
* Safety Assessment of Foreign Aircraft
* Safety Management Systems
* Security Risk and Crisis Management
* Station Ground Handling Management
* Understanding ICAO Annex 14
* Victim Support and Media Management
* Wildlife Hazard and Prevention Management

* The Gulf Centre for Aviation Studies (GCAS) was awarded certification on 29 June 2010 by the UAE General Civil Aviation Authority (GCAA) to provide civil aviation security courses at its Al Bateen Executive Airport airport, in line with training guidelines legislated by UAE Civil Aviation Law (press release 30 June 2010).

* GCAS is an aviation training center in Abu Dhabi, owned by the Abu Dhabi Airports Company (ADAC), offering short courses, executive programs, and with plans to offer degree programs in association with international universities.

* GCAS partnerships include the Airport Council International (ACI), the International Air Transport Association (IATA), the Joint Aviation Authorities of Europe Training Organization (JAA-TO), and the Airport Council International (ACI).

* GCAS facilities include training rooms, conference and lecture rooms, WiFi wireless internet, business center, library, dining and catering facilities.

* Gulf Centre for Aviation Studies (GCAS) established in partnership with the UAE General Civil Aviation Authority (GCAA), the International Civil Aviation Organization (ICAO) and the Abu Dhabi Airports Company (ADAC) – press release 20 December 2008.

Note:

  1.  Fees, facilities, education quality varies widely. Allow extra fees for visa, transport, accommodation.
  2. Salaries, accommodation, other benefits for lecturer jobs vary substantially. Check contracts carefully for medical, housing, flight allowances, etc.

Best Airport in the World: Hyderabad’s Rajiv Gandhi International AirportBest Airport in the World: Hyderabad’s Rajiv Gandhi International Airport

Hyderabad, Delhi Airports Ranked Best

New Delhi: Hyderabad’s Rajiv Gandhi International Airport has been ranked first and Delhi’s Indira Gandhi International Airport the fourth in an international ranking of the best airports in the world, GMR Group, which operates these airports, said on Wednesday.

The company said its Hyderabad and Delhi airports have been ranked first and the fourth best in their respective categories in the latest ASQ rankings of the Airports Council International (ACI).

The rankings were determined through a survey of over three lakh passengers at participating ASQ airports, based on customer feedback measured on a range of services and customer experience at an airport from the moment of arrival to departure gate.

While Hyderabad retained its number one position for the second year in a row, the ranking features some of the well-known airports of the world like Incheon airport in Seoul, South Korea, Changi airport in Singapore, and Shanghai Pudong airport in China.

Rolls-Royce will Supply Trent 700 Engines to Singapore Airlines

Rolls-Royce Wins $1BN Order From Singapore Airlines

Rolls-Royce, the global power systems company, has won a $1bn order from Singapore Airlines to supply Trent 700 engines to power 15 Airbus A330 aircraft, Along with TotalCare® services support.

Rolls-Royce, the global power systems company, has won a $1bn order from Singapore Airlines to supply Trent 700 engines to power 15 Airbus A330 aircraft, Along with TotalCare® services support.

Singapore Airlines already operates 19 Trent 700-powered A330s, the first of which was delivered in 2009.

The Trent 700 is the most fuel efficient, cleanest and quietest engine on the A330. Since it entered service in 1995, Rolls-Royce has continued to improve its performance by incorporating advanced technology from the Trent 900 and Trent 1000. These enhancements have delivered a one per cent reduction in fuel consumption, which saves 800 tonnes of CO2 per aircraft, per year.

Nick Devall, Rolls-Royce, Chief Commercial Officer – Civil Aerospace, said: “The Trent 700 has proven itself to be the most efficient engine for the Airbus A330. Our continuous investment in the improvement of our products has ensured that the Trent 700 is the clear leader in the market. Singapore Airlines has been a great partner and we are delighted to extend this relationship further.”

The Trent 700, the only engine designed specifically for the A330, has won more than 75 per cent of orders in the last three years. More than 1,300 Trent 700 engines are now in service or on order.

Online Bsc in Aviation

Online Aviation Degrees | Online Aviation | Degrees in Aviation | Bsc in Aviation
Bachelor of Science in Aviation
Do You posses Commercial Pilot’s Certificate then apply for Degree in Aviation

Liberty University Online offers a unique, online opportunity to earn your Bachelor of Science in Aeronautics. This program is designed for students who possess a commercial pilot’s certificate but have not earned a bachelor’s degree. Liberty offers seven advanced online aviation courses that combine with the credits received for a commercial certificate to complete the required aeronautical classes. If a student has not previously completed the required general education and investigative studies, those courses are also conveniently offered through Liberty University Online. This degree will prepare students to become commercial pilots, corporate pilots and missionary pilots. This unique degree enables Liberty University Online to fulfill a need for an online aeronautics degree for students worldwide.

Liberty University’s Bachelor of Science in Aeronautics equips students with a practical understanding of aviation and effective aeronautical decision-making skills necessary to serve as a commercial, military or missionary pilot. As a student of the largest flight school in Virginia, you will develop a comprehensive knowledge for safe and effective flight operations subject to weather, aero-medical issues and legal responsibilities.

Students interested in pursuing this degree must possess a commercial pilot’s certificate or be an Air Transport Pilot.

Liberty has become the world’s largest evangelical university and has never lost sight of its mission – equipping men and women with Christ-centered education to impact their world and workplace. Liberty is the World’s Largest Christian University.

Liberty University is accredited by the Commission on Colleges of the Southern Association of Colleges and Schools to award Associate, Bachelor, Master, and Doctoral degrees.

Potential Career Options

Commercial Pilot

Missionary Pilot

Military Pilot

Corporate Pilot

Certified Flight Instructor

Aircraft Maintenance Engineering License issued by the DGCA , is recognized in Middle East Countries?

A student of Aircraft Maintenance Engineering in India and want to work in Emirates Airlines or GAMCO or Saudi Arabia any other Gulf Aircraft Maintenance Companies. Is DGCA recognized in middle east countries?

This is the common query, all AME students has,

” I am currently undergoing an apprentice program in India. will my license be recognized or do i have to appear for examinations there”?
The U.A.E GCAA will almost certainly not validate it, and they also have a policy where they

reserve the right not to validate any aircraft maintenance engineering license that is under 5
years old. So even if you do finish you apprenticeship, and even if they were to have a goodday

and accept an aircraft maintenance enginering license from India you may yet fall into the 5
years license holder rules.

If you do want to work in say Dubai and look for a position with Emirates I would suggest that
you may want to look for a technicians position there and sit you GCAA exams as you can.

I don’t want to sound too harsh or mean here but I would also suggest that you brush up on you
written English. If you were to answer an exam question in English using the standard you demonstrate above you really will fail, regardless of the content of the answer.

That said good luck in making your way into the bigger world

Requirements for GCAA exams – experience …if any?

To eligible the GCAA exams, have 3.5 years experience appropriate to the category that you have applied for, be over 21 and pay 200dhs for the exam.
When you apply they will ask for your training certificates and a record of experience,logbook

and make sure DGCA is recognized there, because ON JOB TRAINING has to be done at a DGCA recognised country.

Post Graduate Aircraft Maintenance Engineering Courses in Australia

In Western Australia, there are around 450 aircraft maintenance engineers, most of whom work in the Perth metropolitan area. While only 5% of aircraft maintenance engineers are female.

Established in 1887, the Royal Melbourne Institute of Technology is a member of the Australian Technology Network and Global U8 Consortium.

The Royal Melbourne Institute of Technology University is one of Australia’s leading educational institutions, producing some of the country’s most employable graduates.
Located in the heart of Melbourne city, RMIT has an international reputation for excellence in work-relevant education an

Qualification: Graduate Certificates and Graduate Diplomas
Awarding body: Royal Melbourne Institute of Technology University (RMIT)

Course Description: Program focuses on specialization of aircraft maintenance functions. Designed for both local and international students who require postgraduate in aircraft maintenance engineering management systems.

Program Integrates: the human factor and threat and error management issues into the technical aspects.
Program Includes: guidance of knowledge on development and skills to deal with organisational changes aimed at establishing a culture of society.

Graduate will learn outcome of decisions and competitively positioned for advancement with aerospace manufactures for example: Rolls-Royce, Boeing, Pratt and Whitney, Airbus, Bombardier, British Aerospace, airlines and maintenance and repair organizations (MRO), within a regional and international levels.

Requirements: Student must have a first degree or similar experience. Evidence of further professional development through in-house or external run training.

Study level – graduate in aircraft maintenance engineering certificate and graduate PG diploma’s in aircraft maintenance management.
Study category – Aircraft Maintenance Engineering courses
Study mode – Full time, Distance/Online, Part time
Duration – one year/six months

Venue address:
RMIT University
City Campus
GPO Box 2476
MELBOURNE
Victoria

RMIT University Review: The academic program is designed with up to date content. The lecturers consist of highly experience.
Overall experience: The academic program for aircraft maintenance engineering is designed with up to date content. Make sure you speak to lecturers before applying, at open days. Don’t go into the course thinking that you are the best, lecturers will put you in your place very quickly.

d high quality research, and engagement with the needs of industry and community.A vibrant alumni community now stretches across more than 100 countries.

FARNBOROUGH: Aero secrets of Boeing’s new Dreamliner

The Farnborough debut of Boeing’s latest 787 derivative has enabled details of the aircraft’s aerodynamic advances to be examined close up.

The 787-9 is the first Boeing airliner to be equipped with hybrid laminar-flow control (HLFC), which is a feature of its fin and tailplane. This drag-reducing aerodynamic technology looks set to become standard on all future Boeing products, as it will also equip the 787-10 and 777X family.

Boeing is reluctant to talk much about the system and will not disclose how much benefit it delivers, saying only that it is “significant”. The manufacturer does, however, confirm that the system uses suction to delay the transition of the airflow boundary layer from laminar flow into turbulent flow.

“Both Airbus and Boeing have been working on that for decades and I think Boeing has finally found the ingredients to the ‘secret sauce’ to make that work,” 787 deputy chief project engineer on 787 derivative development, Ed Petkus told Flightglobal earlier this year.

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While HLFC is incorporated into the 787-10, there is “no firm plan” to introduce it on the -8, according to Mark Jenks, vice-president of 787 development. “We certainly could. There’s a business case we have to run – it’s a function of how many more -8s are we going to build and the detail cost to put it on.”

As these images comparing the 787-8 and -9 show, the only discernible pieces of the HLFC system are the small doors inboard on the underside of each tailplane and either side of the fin. Flightglobal understands that these panels have two sets of hinges allowing them to tilt both ways like saloon bar doors. The system then generates suction to maintain the laminar flow.

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Another interesting feature of the 787-9 is its high-lift system, which has been adapted from the 787-8 to cater for higher operating weights. Although the wing’s planform and flaps are identical to the -8, the -9 is offered with three additional flap settings (10, 17 and 18), meaning that there are a total of nine positions (excluding “up”), compared with six on the 787-8 (see image below).

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QUIRKY DOZEN: The 12 strangest-looking aircraft ever built

The Airbus A300-based Beluga is this week celebrating 20 years of transporting aircraft sections between the company’s European plants. Named after the white whale because of their distinctive shape, the fleet of five Belugas carry out more than 60 flights each week between 11 sites.

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To mark the anniversary, we have chosen our 12 oddest-shaped aircraft.

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Kamov

KAMOV KA-32

Designed by Russian Helicopters’ Kamov bureau, the Ka-32 is a derivative of the military Ka-27 and its variants are used for a range of missions including firefighting, medevac and heavylift cargo operations. We could have chosen many other unusual-looking rotorcraft, but the Ka-32’s coaxial design makes it highly distinctive.

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Piaggio

PIAGGIO P.1HH HAMMERHEAD

The curvy Italian shapes of its sister Avanti twin-pusher may turn heads on the ramp, but transformed into an unmanned surveillance platform, the P.1HH certainly stands out among other bizarrely-shaped UAVs. Launched at the Paris air show in 2013, Piaggio has high hopes for the medium-altitude, long-endurance type.

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SHORT SKYVAN

The Belfast-build SC.7 is a 19-seat, high-wing turboprop, used primarily for cargo transport and, due to its rather boxy-shape, known by its pilots as “the shed”. Some 153 examples were manufactured between 1963 and 1986. Although it frequently tops ugliest aircraft polls, the Skyvan proved a useful workhorse.

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Boeing

MCDONNELL XF-85

The Goblin was intended to fit in the bomb bay of the B-36 long range bomber and provide protection when it flew beyond the escort range of fighters. If enemy aircraft were detected, the Goblin would be released via a harness. Engagement over, it would return to the bay via a trapeze. Two test aircraft were commissioned at the end of the Second World War but the project was cancelled in 1949, with the fighter never having been used.

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BEECH STARSHIP

Opinions differ on whether the Wichita-built Starship was a thing of beauty or a massive folly. Commercially, certainly, it was a flop, with only 53 of the composite, canard, design, twin-pusher business aircraft produced in the 1980s and early 1990s. In 2003, Raytheon Aircraft and the Federal Aviation Administration said they wanted to recall all Starships to scrap them, as the airframer could no longer support them.

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VOUGHT V-173

The so-called Flying Pancake was designed during the Second World War and was a near vertical take-off and landing military aircraft with a flat, disc-like body. Only one example was ever built and it flew in 1942. Its last flight was in 1947 when the project was cancelled.

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Boeing

BOEING 747 LCF

Seattle‘s version of the Beluga, the Dreamlifter, based on the 747-400, has a large cargo door on the aft fuselage and is used to transport assemblies of the 787 Dreamliner between production plants and final assembly in Everett, Washington. It first flew in 2006.

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British Caledonian

AVIATION TRADERS CARVAIR

Back in the 1960s, transporting wealthy travellers and their cars was big business. Freddie Laker’s Aviation Traders struck upon the idea of converting surplus four-engine Douglas DC-4s into car transporters, with capacity for 25 passengers, loaded at the front.The Carvair first flew in 1961 but the fact that of 21 built, eight were involved in crashes perhaps says everything you need to know about their reliability.

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christopherblizzard/Flickr

ADAM A700

In the early 2000s boom in business aircraft start-ups, Adam Aircraft developed the A700 jet and its A500 piston-powered sister. The six-seat A700 had two Williams FJ33s mounted on the fuselage and twin, wing-mounted booms supporting aft twin rudders, linked by a high horizontal stabiliser. Adam went bankrupt in 2008.

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ATG

ATG JAVELIN

Another victim of the business aircraft downturn, Colorado-based Aviation Technology Group abandoned its Javelin personal jet in 2008 when it went bankrupt. The design is not particularly vulgar, but the fact that it was a business jet disguised as a fighter made it particularly unusual.

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Soviet Navy

ROSTISLAV ALEXEYEV EKRANOPLAN

This highly-secretive Russian Cold War aircraft began life in the sixties and was uncovered by US intelligence in 1966. Known as the Caspian Sea Monster, the eight-engine 37.6m-wingspan personnel carrier, designed by the Rotislav Alexeyev bureau, used wing in ground effect technology to skim over water, evading enemy radar. Only one example is thought to have entered service.

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BillyPix

EDGLEY OPTICA

Designed in the 1970s as a postgraduate engineering project by British inventor John Edgley, the Optica’s bubble cockpit sits ahead of its engine and fan, giving the crew 270 degree horizontal vision and almost complete downward vision. It flew for the first time in 1979 and 22 examples were built under various company owners. At this year’s Farnborough air show, Edgley himself, who once again owns the rights to the aircraft, was looking for a buyer for the design.

Ryanair orders up to 200 197-seat 737 Max jets

Irish budget carrier Ryanair is ordering up to 200 Boeing 737 Max aircraft, which will be configured with a higher-density seat layout unveiled by the airframer earlier this year.

Ryanair is ordering 100 firm aircraft and placing options on another 100, the carrier says. The jets will be fitted with 197 seats.

The airline will take delivery of the jets – branded as the ‘Max 200’ – from 2019 to 2024.

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Ryanair

All 737 Max variants are powered by CFM International Leap-1B engines.

Ryanair had already disclosed it was holding talks over a possible Max agreement, following its order for 175 Boeing 737-800s last year.

The 737-800 has a maximum capacity of 189 seats and Ryanair had expressed strong interest in a 200-seat version of the re-engined Max 8.

Boeing revealed during the Farnborough air show in July that it would offer such an aircraft, through modifications to the exit-door arrangement.

ETOPS – Extended-range Twin-engine Operational Performance Standards

ETOPS

ETOPS is an acronym for Extended-range Twin-engine Operational Performance Standards, an International Civil Aviation Organization (ICAO) rule permitting twin-engine commercial air transporters to fly routes that, at some points, are farther than a distance of 60 minutes’ flying time from an emergency or diversion airport with one engine inoperative.

This rule allows twin-engine airliners—such as the Airbus A300, A310, A32X, A330 and A350 families, and theBoeing 737, 757, 767, 777 and 787—to fly long-distance routes that were previously off-limits to twin-engine aircraft. ETOPS operation has no direct correlation to water or distance over water. It refers to single-engine flight times between diversion airfields—regardless as to whether such fields are separated by water or land.

 

 

Early ETOPS experience

The FAA and the ICAO concluded that it is safe for a properly designed twin-engined airliner to conduct intercontinental transoceanic flights. The guidelines issued form the ETOPS regulations.

The FAA was the first to approve ETOPS guidelines in 1985. It spelled out conditions that need to be fulfilled for a grant of 120 minutes’ diversion period, which is sufficient for direct transatlantic flights. Today, ETOPS forms the bulk of transatlantic flights.

The FAA gave the first ETOPS rating in May 1985 to TWA for the B767 service between St. Louis andFrankfurt, allowing TWA to fly its aircraft up to 90 minutes away from the nearest airfield: this was later extended to 120 minutes after a federal evaluation of the airline’s operating procedures.

 

 

ETOPS extensions

In 1988, the FAA amended the ETOPS regulation to allow the extension to a 180-minute diversion period subject to stringent technical and operational qualifications. This made 95% of the Earth’s surface available to ETOPS flights. The first such flight was conducted in 1989. This set of regulations was subsequently adopted by the Joint Aviation Authorities (JAA), ICAO and other regulatory bodies.

In this manner the B737, 757 and 767 series and the Airbus A300-600, 310, 320 and 330 series were approved for ETOPS operations. The success of ETOPS aircraft like 767 and 777 killed the intercontinental trijets. This ultimately led Boeing to end the MD-11 program a few years after Boeing’s merger with McDonnell Douglas, as well as to scale down the production of its own Boeing 747.

The cornerstone of the ETOPS approach are the statistics that show that the turbine itself is an inherently reliable component, and it is the engine ancillaries that have a lower reliability rating. Therefore an engine for a modern twin jet airliner has twin sets of all ancillaries mounted in the engine, which gives the required reliability rating.

The North Atlantic airways are the most heavily used oceanic routes in the world. Most North Atlantic airways are covered by ETOPS 120-minute rules, removing the necessity of using 180-minute rules. However, many of the North Atlantic diversion airports, especially those in Iceland and Greenland, are subject to adverse weather conditions making them unavailable for use. As the 180-minute rule is the upper limit, the JAA has given 15% extension to the 120-minute rules to deal with such contingencies, giving the ETOPS-138min, thereby allowing ETOPS flights with such airports closed.

ETOPS240 and beyond are now permitted[1] on a case-by-case basis, with regulatory bodies in nations ranging from the USA, to Australia, to New Zealand adopting said regulatory extension. Authority is only granted to operators of two-engine airplanes between specific city pairs. The certificate holder must have been operating at 180 minute or greater ETOPS authority for at least 24 consecutive months, of which at least 12 consecutive months must be at 240-minute ETOPS authority with the airplane-engine combination in the application.

 

 

Early ETOPS

The regulations allow an airliner to have ETOPS-120 rating on its entry into service. ETOPS-180 is only possible after 1 year of trouble-free 120-minute ETOPS experience. Boeing has convinced the FAA that it could deliver an airliner with ETOPS-180 on its entry into service. This process is called Early ETOPS. Thus the B777 was the first aircraft to carry an ETOPS rating of 180 minutes at its introduction.

The JAA, however disagreed and the Boeing 777 was rated ETOPS-120 in Europe on its entry into service. European airlines operating the 777 must demonstrate one year of trouble-free 120-minutes ETOPS experience before obtaining 180-minutes ETOPS for the 777.

 

 

ETOPS exclusions

Private jets are exempted from ETOPS by the FAA, but are subject to the ETOPS 120-minute rule in JAA’s jurisdiction. Several commercial airline routes are still off-limits to twinjets because of ETOPS regulations. There are routes traversing the South Pacific (e.g. Auckland,New Zealand – Santiago, Chile), Southern Indian Ocean (e.g. Perth, Western Australia -Johannesburg, South Africa) and Antarctica.

 

 

Beyond ETOPS-180

Effective February 15, 2007, the FAA ruled that US-registered twin-engined airplane operators can fly over most of the world other than the South Polar Region, a small section in the South Pacific, and the North Polar area under certain winter weather conditions provided that the inflight shutdown rate is 1 in 100,000 engine hours. This limit is more stringent than ETOPS-180 (2 in 100,000 engine hours).

The qualified aircraft must have appropriate fire-suppression systems, adequate oxygen supplies for crew and passengers (to continue high altitude flight) in the event of depressurisation, and automated defibrillators. Weather reporting, training, and diversion accommodation requirements remain unchanged. Since aircraft occasionally divert for non-engine mechanical problems or passenger medical emergencies, the rule requires that airplane systems be able to support lengthy diversions in remote and sometimes harsh environments. The rules do not apply to 3- or 4-engined cargo aircraft or twinjets freed from ETOPS constraints.

EASA distinguishes between twin-engine (ETOPS) and aircraft with 3 or 4 engines. Rules governing such aircraft (3 or 4 engines) are covered under LROPS rules. LROPS would demand similar rules with regard to emergency oxygen and fire-suppression. EASA is expected to release rules for ETOPS and LROPS in 2008.

 

 

ETOPS ratings

The following ratings are awarded under current regulations according to the capability of the airline:

  • ETOPS-75
  • ETOPS-90
  • ETOPS-120/138
  • ETOPS-180/207

However, ratings for ETOPS type approval are fewer. They are:

  • ETOPS-90, which keeps pre-ETOPS Airbus A300B4 legally operating under current rules
  • ETOPS-120/138
  • ETOPS-180/207, which covers 95% of the Earth’s surface.

 

 

Approval for ETOPS

ETOPS approval is a two-step process. Firstly: the airframe and engine combination must satisfy the basic ETOPS requirements during its type certification. This is called ETOPS type approval. Such tests may include shutting down an engine and flying the remaining engine during the complete diversion time. Often such tests are performed in the middle of the oceans. It must be demonstrated that, during the diversion flight, the flight crew is not unduly burdened by extra workload due to the lost engine and that the probability of the remaining engine failing is extremely remote. For example, if an aircraft is rated for ETOPS-180, it means that it should be able to fly with full load and just one engine for 3 hours.

Secondly: An operator who conducts ETOPS flights must satisfy his own country’s aviation regulators about his ability to conduct ETOPS flights. This is called ETOPS operational certification and involves compliance with additional special engineering and flight crew procedures on top of the normal engineering and flight procedures. Pilots and engineering staff must be qualified and trained for ETOPS. An airline with extensive experience operating long distance flights may be awarded ETOPS operational approval immediately, others may need to demonstrate ability through a series of ETOPS proving flights.

Regulators closely watch the ETOPS performance of both type certificate holders and their affiliated airlines. Any technical incidents during an ETOPS flight must be recorded. From the data collected , the reliability of the particular airframe-engine combination is measured and statistics published. The figures must be within limits of type certifications. Of course, the figures required for ETOPS-180 will always be more stringent than ETOPS-120. Unsatisfactory figures would lead to a downgrade, or worse, suspension of ETOPS capabilities either for the type certificate holder or the airline.

 

 

References

Aircraft Polar Route Operations

Polar Route Operations

A. Introduction

1. New cross-polar routes connect eastern and interior regions of North America to Asian cities via Polar Region which provides an attractive shortcut to Asia (Polar 1, 2, 3 and 4).

2. The advantages are obvious; it reduces the flight time, increase the payload and also there is the absence of turbulence.

3. Polar routes operate under extreme temperatures in the Artic environment where suitable and alternate airports are limited.

4. There are many major Airlines operating the polar routes, notably United, Continental, Northwest, Delta, Air Canada. Air China, Russia KrasAir and Cathay Pacific.

5. The following should be considered when conducting polar routes operation:
A) Regulatory guidance
B) En route alternate airport
C) Cold fuel management
D) Communication and navigation

B. Regulatory guidance

1. Obtain info from local authority and FAA on the specific requirement to conduct polar operations i.e. approval and to provide flight plan – Flight Ops

2. Prepare the Airline Recovery Plan for unplanned diversion that address the care & safety of crew at the diversion airport and provide the plan to transport crew from that airport – Flight Ops

3. Prepare the Long Range Flight Crew Rest Plan and a clear progression of pilot-in-command authority – Flight Ops

4. Liaise with Boeing to develop a Fuel temperature analysis and monitoring program – Engineering

5. Verify that acft is fitted with effective communication system i.e. VHF(Voice and data link), HF(Primary) & SATCOM (Back-up) – Engineering

6. Amend Minimum Equipment Lists (MEL) to indicate the following equip/systems are required for north polar operations dispatch – Engineering
1) FQIS (include fuel tank temperature indicating system)
2) Auto-throttle system
3) Autopilot
4) Communication systems i.e. HF and VHF (Voice & ACARS), (SATCOM – backup system)

7. Conduct training for flight crew and maintenance on Polar Route Operation (i.e. QFE, QNH and meter altimetry, cold temp alt correction proc, fuel management proc, weather pattern and cold weather anti-exposure suits) – Flight Ops and Engineering

8. Ensure a minimum of two (2) cold weather anti-exposure suits to be on board the acft – Engineering

9. Conduct an DCA-observed validation flight in order to receive authorization to conduct polar operations – Flight Ops

10. In the event of any emergency landing for aircraft flying over substantially uninhabited land areas in polar conditions are likely to be met MCAR scale V, which requires the following:
1) One survival beacon radio apparatus,
2) Marine type pyrotechnical distress signal
3) 100 gm of glucose toffee tablets for each 4 persons on board
4) Half liter of fresh water in durable containers for each 4 persons on board
5) First aid equipment
6) One stove suitable for use with acft fuel for every 75 persons
7) One cooking utensil in which snow or ice can be melted, two snow shovels and two ice saws
8) Single or multiple sleeping bags
9) Artic survival kit

C. En Route Alternate Airports

1. Flight Ops to identify the alternate airports along a routes which must have
a capability such as airplane can land safely at the existing runway, diverted airplane can be cleared from the runway, crew are able to deplane in a safe manner, facilities near the airport and recovery plan can be executed and completed within 12 to 48 hrs after diversion – Flight Ops

D. Cold Fuel Management

1. Verify that MD-11 is fitted with fuel temperature probe located in the outboard compartment of tank no 3 and in the horizontal stabilizer tank and Low Fuel Temperature indicator is displayed on Display Unit – Engineering

E. Communication and Navigation

1. Polar route operations require VHF and HF systems to communicate with ATC. SATCOM should be considered only as a backup as it is not available above 82 deg north latitude.

2. Aircraft entering Russian airspace on Polar 1 and Polar 2 are controlled by the Murmansk ATC center near the Finnish border and those entering Polar 3 and Polar 4 are under Magadan’s watch located in Russia’s east coast.

3. GPS and IRUs provide navigation over the polar route. Aircraft is recommended to equipped with dual GPS and triple IRUs; which is fitted on MD11.

References:
i) Aero Magazine of Oct 2001
ii) OPSPEC B055 on North Polar Operations in the Air Transport Operations Inspectors Handbook Order 8400.10, Volume 3
iii) Civil Aviation Regulations (CAR)

Fuel Boost Pump Wire Chafing

Title: Fuel Boost Pump Wire Chafing

Aircraft Model: 737-100,-200,-300,-400,-500
Other Models: 707, 727

Issue Status: Open
Applicability: All 737-200/-300/-400/-500 airplanes

Description:
During the first repeat inspection after initial inspection per AD 99-21-15 and SB 737-28A1120, the #1 aft (left wing tank) fuel boost pump wiring of a 737-300 airplane was found with chafing through the Teflon sleeving into wiring insulation at three different locations. Approximately 21000 hours had accumulated since the wire bundle was initially replaced.

Boeing considers this an Airplane Level safety issue because chafing completely through the wire insulation may cause arcing within the conduit and possible burn through, leading to a potential ignition source.

In a 727 incident under investigation by the Indian government, wire bundle damage was discovered in the fuel tank conduit after an explosion that occurred on the ground in the left wing fuel tank. Approximately 10000 hours had accumulated since incorporation of AD 99-12-52. It is not known if chafing played a role in the 727 event.

Background:
Airworthiness Directives 99-21-15 (737), 99-12-52 (727) and 2001-17-20 (707) require removal of the fuel boost pump wiring from the in-tank conduit(s) for the boost pumps in main tanks number 1 and 2, and the center tank boost pumps, and a detailed visual inspection to detect damage of the wiring in accordance with Boeing alert service bulletins 737-28A1120, 727-28A0126 and 707A3500. These ADs also require repeat inspections, at intervals not to exceed 30,000 flight hours after accomplishment of the initial inspection. The 737 Classic aircraft have four conduits with wire bundles running to the fuel pumps; the 727 has eight and the 707 has ten.

Status:
Boeing is continuing to expedite root cause investigation including removal of the 737 aircraft conduit from the in-service aircraft for laboratory investigation.

The FAA has opened a planned AD worksheet. An FAA Immediately Adopted Rules (IAR) is anticipated to mandate the interim action that Boeing defines via service bulletin 737-28A1263(ECD TBD).

Compliance time is to be determined taking into consideration risk mitigation, operator impact and very large fleet size. To date, a compliance time of 90-120 days has been suggested by the FAA for the interim action, to be finalized based on parts availability, etc.

Boeing does not plan to release a service bulletin until parts are available.

Interim Action:
Boeing plans to address the 737 Classic first, immediately followed by 727. The 707 is also under review.

Accomplish within 90-120 days (to be confirmed) after new service bulletin and parts are available:

1- Remove and inspect all fuel boost pump wiring from the boost pump connectors to the splices on the front wing spar

2- Replace all Teflon sleeving with sleeving which has smaller OD than the conduit ID.

3- Replace all four conductor, unjacketed, or BMS13-51 wires with BMS13-60 jacketed wiring. Remove ground wire if found installed.

4- If any wire damage or arcing indications are found, inspect conduit (boroscope), leak check per AMM, and repair or replace the conduit.

5- Clean inside of conduit prior to installing the reworked/new wire bundle.

Do not use talcum powder as a wire pulling lubricant. S/B will specify the type of lubricant(s) to use

Report all inspection results to Boeing

Operator Action:
Incorporate service bulletin 737-28A1263 (when released), report all inspection results to Boeing, and comment on the FTEI bulletin board item EM-06-00063 with relevant information, if available.

Part Information:
Boeing is planning parts kits consisting of a roll of wire and a roll of sleeving in airplane ship set quantity.

A limited supply of miscellaneous parts will also be available at Boeing (separate from the kits) to support this inspection (conduits, connectors, splices, contacts, etc.).

References:
Service Related Problem (SRP) 727-SRP-28-0113
Service Related Problem (SRP) 737-SRP-28-0113
Fleet Team Emerging Issue (FTEI) EM-06-00063, dated 06-JUL-2006
Airworthiness Directive (AD) 99-12-52 (727)
Airworthiness Directive (AD) 99-21-15 (737)
Service Bulletin (SB) 737-28A1120, dated 24-APR-1998

Aviation Safety – Determination of an Unsafe Condition

Aviation Safety – Determination of an Unsafe Condition

It is important to note that these guidelines are not exhaustive.  However, this material is intended to provide guidelines and examples that will cover most cases, taking into account the applicable certification requirements.

  1. INTRODUCTION.

Certification or approval of a product, part or appliance is a demonstration of compliance with requirements which are intended to ensure an acceptable level of safety.  This demonstration however includes certain accepted assumptions and predicted behaviours, such as:

–           fatigue behaviour is based on analysis supported by test,

–           modelling techniques are used for Aircraft Flight Manual performances calculations,

–           the systems safety analyses give predictions of what the systems failure modes, effects and probabilities may be,

–           the system components reliability figures are predicted values derived from general experience, tests or analysis,

–           the crew is expected to have the skill to apply the procedures correctly, and

–           the aircraft is assumed to be maintained in accordance with the prescribed instructions for continued airworthiness (or maintenance programme), etc.

In service experience, additional testing, further analysis, etc., may show that certain initially accepted assumptions are not correct.  Thus, certain conditions initially demonstrated as safe, are revealed by experience as unsafe.  In this case, it is necessary to mandate corrective actions in order to restore a level of safety consistent with the applicable certification requirements.

  1. GUIDELINES FOR ESTABLISHING IF A CONDITION IS UNSAFE.

The following paragraphs give general guidelines for analysing the reported events and determining if an unsafe condition exists, and are provided for each type of product, part or appliance subject to a specific airworthiness approval: type-certificates (TC) or Design Changes for aircraft, engines or propellers, or Technical Standard Orders (TSO).

This analysis may be qualitative or quantitative, i.e. formal and quantitative safety analyses may not be available for older or small aircraft.  In such cases, the level of analysis should be consistent with that required by the airworthiness requirements and may be based on engineering judgement supported by service experience data.

2.1       Analysis method for aircraft.

2.1.1   Accidents or incidents without any aircraft, engines, system, propeller or part or appliance malfunction or failure.

When an accident/incident does not involve any component malfunction or failure but when a crew human factor has been a contributing factor, this should be assessed from a man-machine interface standpoint to determine whether the design is adequate or not.  Paragraph 2.5 gives further details on this aspect.

2.1.2   Events involving an aircraft, engines, system, propeller or part or appliance failure, malfunction or defect.

The general approach for analysis of in service events caused by malfunctions, failures or defects will be to analyse the actual failure effects, taking into account previously unforeseen failure modes or improper or unforeseen operating conditions revealed by service experience.

These events may have occurred in service, or have been identified during maintenance, or been identified as a result of subsequent tests, analyses, or quality control.

These may result from a design deficiency or a production deficiency (non conformity with the type design), or from improper maintenance.  In this case, it should be determined if improper maintenance is limited to one aircraft, in which case an airworthiness directive may not be issued, or if it is likely to be a general problem due to improper design and/or maintenance procedures, as detailed in paragraph 2.5.

  1. A)        Flight.

An unsafe condition exists if:

–           There is a significant shortfall of the actual performance compared to the approved performance (taking into account the accuracy of the performance calculation method), or

–           The handling qualities, although having been found to comply with the applicable airworthiness requirements at the time of initial approval, are subsequently shown by service experience not to comply.

  1. B)        Structural or mechanical systems.

An unsafe condition exists if the deficiency may lead to a structural or mechanical failure which:

–           Could exist in a Principal Structural Element that has not been qualified as damage tolerant.  Principal Structural Elements are those which contribute significantly to carrying flight, ground, and pressurisation loads, and whose failure could result in a catastrophic failure of the aircraft.

–           Could exist in a Principal Structural Element that has been qualified as damage tolerant, but for which the established inspections, or other procedures, have been shown to be, or may be, inadequate to prevent catastrophic failure.

–           Could reduce the structural stiffness to such an extent that the required flutter, divergence or control reversal margins are no longer achieved.

–           Could result in the loss of a structural piece that could damage vital parts of the aircraft, cause serious or fatal injuries to persons other than occupants.

–           Could, under ultimate load conditions, result in the liberation of items of mass that may injure occupants of the aircraft.

–           Could jeopardise proper operation of systems and may lead to hazardous or catastrophic consequences, if this effect has not been taken adequately into account in the initial certification safety assessment.

  1. C)        Systems.

The consequences of reported systems components malfunctions, failures or defects should be analysed.

For this analysis, the certification data may be used as supporting material, in particular systems safety analyses.

The general approach for analysis of in service events caused by systems malfunctions, failures or defects will be to analyse the actual failure effects.

As a result of this analysis, an unsafe condition will be assumed if it cannot be shown that the safety objectives for hazardous and catastrophic failure conditions are still achieved, taking into account the actual failure modes and rates of the components affected by the reported deficiency.

The failure probability of a system component may be affected by:

–           A design deficiency (the design does not meet the specified reliability or performance).

–           A production deficiency (non conformity with the certified type design) that affects either all components, or a certain batch of components.

–           Improper installation (for instance, insufficient clearance of pipes to surrounding structure).

–           Susceptibility to adverse environment (corrosion, moisture, temperature, vibrations etc.).

–           Ageing effects (failure rate increase when the component ages).

–           Improper maintenance.

When the failure of a component is not immediately detectable (hidden or latent failures), it is often difficult to have a reasonably accurate estimation of the component failure rate since the only data available are usually results of maintenance or flight crew checks.  This failure probability should therefore be conservatively assessed.

As it is difficult to justify that safety objectives for the following systems are still met, a deficiency affecting these types of systems may often lead to a mandatory corrective action:

–           back up emergency systems, or

–           fire detection and protection systems (including shut off means).

Deficiencies affecting systems used during an emergency evacuation (emergency exits, evacuation assist means, emergency lighting system …) and to locate the site of a crash (Emergency Locator Transmitter) will also often lead to mandatory corrective action.

  1. D)        Others.

In addition to the above, the following conditions are considered unsafe:

–           There is a deficiency in certain components which are involved in fire protection or which are intended to minimise / retard the effects of fire / smoke in a survivable crash, preventing them to perform their intended function (for instance, deficiency in cargo liners or cabin material leading to non-compliance with the applicable flammability requirements).

–           There is a deficiency in the lightning or High Intensity Radiated Fields protection of a system which may lead to hazardous or catastrophic failure conditions.

–           There is a deficiency which could lead to a total loss of power or thrust due to common mode failure.

If there is a deficiency in systems used to assist in the enquiry following an accident or serious incident (e.g., Cockpit Voice Recorder, Flight Data Recorder), preventing them to perform their intended function, the DCA may take mandatory action.

2.2       Engines.

The consequences and probabilities of engine failures have to be assessed at the aircraft level in accordance with paragraph 2.1, and also at the engine level for those failures considered as Hazardous in the design code such as CS E-510 or FAR 33.

The latter will be assumed to constitute unsafe conditions, unless it can be shown that the consequences at the aircraft level do not constitute an unsafe condition for a particular aircraft installation.

2.3       Propellers.

The consequences and probabilities of propeller failures have to be assessed at the aircraft level in accordance with paragraph 2.1, and also at the propeller level for those failures considered as hazardous in the design code such as CS P-150.

The latter will be assumed to constitute unsafe conditions, unless it can be shown that the consequences at the aircraft level do not constitute an unsafe condition for a particular aircraft installation.

2.4       Parts and appliances.

The consequences and probabilities of equipment failures have to be assessed at the aircraft level in accordance with paragraph 2.1.

2.5       Human factors aspects in establishing and correcting unsafe conditions.

This paragraph provides guidance on the way to treat an unsafe condition resulting from a maintenance or crew error observed in service.

It is recognised that human factors techniques are under development.  However, the following is a preliminary guidance on the subject.

Systematic review should be used to assess whether the crew or maintenance error raises issues that require regulatory action (whether in design or other areas), or should be noted as an isolated event without intervention.  This may need the establishment of a multidisciplinary team (designers, crews, human factors experts, maintenance experts, operators etc.)

The assessment should include at least the following:

–           Characteristics of the design intended to prevent or discourage incorrect assembly or operation;

–           Characteristics of the design that allow or facilitate incorrect operation,

–           Unique characteristics of a design feature differing from established design practices;

–           The presence of indications or feedback that alerts the operator to an erroneous condition;

–           The existence of similar previous events, and whether or not they resulted (on those occasions) in unsafe conditions;

–           Complexity of the system, associated procedures and training (has the crew a good understanding of the system and its logic after a standard crew qualification programme?);

–           Clarity/accuracy/availability/currency and practical applicability of manuals and procedures;

–           Any issues arising from interactions between personnel, such as shift changeover, dual inspections, team operations, supervision (or lack of it), or fatigue.

Apart from a design change, the corrective actions, if found necessary, may consist of modifications of the manuals, inspections, training programmes, and/or information to the operators about particular design features.  The local authority i.e. DCA may decide to make mandatory such corrective action if necessary.

Design Organization Approval (DOA)

Design Organization Approval (DOA)

Part 1 – Obligation to the international requirements to ensure aviation safety

1) ICAO convention under Annex 6 (Operation of Aircraft) Part 1 Chapter 8 (Aeroplane Maintenance) para 8.6 states “ALL MODIFICATIONS AND REPAIRS SHALL COMPLY WITH AIRWORTHINESS REQUIREMENTS ACCEPTABLE TO THE STATE OF REGISTRY. PROCEDURES SHALL BE ESTABLISHED TO ENSURE THAT THE SUBSTANTIATING DATA SUPPORTING COMPLIANCE WITH THE AIRWORTHINESS REQUIREMENTS ARE RETAINED.

2) MCAR Regulation 27 – A certificate of airworthiness issued in respect of an aircraft shall cease to be in force if the aircraft, or such of its equipment as is necessary for the airworthiness of the aircraft, is overhauled, repaired or modified, or if any part of the aircraft or of such equipment is removed or is replaced otherwise than in a manner and with material of a type approved by the Director General either generally or in relation to a class of aircraft or to the particular aircraft.

Part 2 – Design Approval

1) Modification and Repair per ICAO Document 9760

• Modification is “A MODIFICATION TO AN AERONAUTICAL PRODUCT MEANS A CHANGE TO THE TYPE DESIGN WHICH IS NOT A REPAIR”

• Type Design is “DRAWINGS, SPECIFICATIONS NECESSARY TO DEFINE THE CONFIGURATION AND ITS DESIGN FEATURES, REPORTS ON ANALYSIS AND TESTS UNDERTAKEN TO SUBSTANTIATE COMPLIANCE WITH THE APPLICABLE REQUIREMENTS AND INFORMATION, MATERIALS AND PROCESSES USED IN THE CONSTRUCTION”

• Repair is “A DESIGN CHANGE TO AN AERONAUTICAL PRODUCT INTENDED TO RESTORE IT TO AN AIRWORTHY CONDITIONS AND TO ENSURE THAT THE AIRCRAFT CONTINUE TO COMPLY WITH THE DESIGN ASPECTS OF THE AIRWORTHINESS REQUIREMENTS USED FOR THE ISSUANCE OF A TYPE CERTIFICATE FOR THAT AIRCRAFT TYPE AFTER IT HAS BEEN DAMAGED OR SUBJECTED TO WEAR”

• CAR 1996 Regulation 27 para 7 stated aircraft C of A become invalid, if the design change does not comply with the required airworthiness requirements.

2) Design Organization Approval (DOA)

• The local authority i.e. DCA / DGCA is not a Design Organization. Therefore DCA / DGCA cannot accept responsibility for the design.

• DOA is approval for an organization to provide reports and certify that the design of an acft, equipment or any part thereof or modification or repair schemes complies with DCA / DGCA requirements.

• JAR/EASA 21 – SUBPART J (DESIGN ORGANIZATIONS APPROVAL). The principles of both JAR/EASA and BCAR are similar. However, JAR/EASA has been developed more comprehensive than BCAR, i.e. Design Assurance System has been introduced in JAR/EASA.

• Benefit being approved as DOA is being granted privileges with responsibilities and may perform certification and airworthiness activities on behalf of DCA through the following granted privileges:

– Release certification documents without verification by DCA / DGCA
– Classify modifications and repairs
– Approve minor modifications and repairs
– DOA may issue information or instructions stating that the technical content is approved.
– For Modifications undertaken by organisations that are appropriately approved for the task and who have demonstrated a consistent and satisfactory level of competence for the type of work involved, then future similar Modifications may be classified as Minor by the DCA / DGCA.
– Efficient use of industry and DCA / DGCA time, resulting in lower costs.

• DOA shall be headed by an Accountable Manager (Chief Executive or Equivalent) and with full efficient coordination between their units/sections.

• Scope of work – The organization must have
– sufficient personnel with the right qualification, knowledge and experience.
– appropriate tools (Software), equipments (computer) and facility (i.e. office space, lab, flight test center)

3) Design Organization Manual (DOM)

• Policy/procedure of carrying out design activities and management of DOA
– Classification of Major/Minor
– Development of reports/drawings/Test Schedule
– Verification of Design Data
– Inservice difficulty reporting
– Correction action
– Internal Audit
– Retention of designs records
– Design Assurance systems (DAS)

4) Design Assurance System (DAS)

• A DOA shall demonstrate that it has established and is able to maintain a Design Assurance System (DAS) for the control and supervision of the design, and of design changes, of products, parts and appliances covered by the approval.

• The DAS shall be such as to enable the organization;
– To ensure the design of the products, parts and appliances or the design changes thereof, comply with the applicable type certification basis.
– Ensure that its responsibilities are properly discharged.
– Independently monitor the compliance with, and adequacy of, the documented procedures of the system (DOM). The monitoring shall include a feed back system to a person having the responsibilities to ensure corrective actions.

• DAS shall include an independent checking function of the showing of compliance on the basis of which the organization submits compliance statement and associated document to DCA / DGCA.

Part 3 – Certification of Modification/Repair

1) A modification or repair must meet two standards; the acft type certification rules and the performance rules.

2) Data Package is a set of documents required for the justification / accomplishment of the modification such as:

• Standard documents; i.e. Certification plan (for complex modification), Modification documents, SOC, CCD (if applicable) and Manuals amendments (if applicable)

• Type Design documents ; i.e. Drawings, Specifications, Information on dimensions, materials and processes, Airworthiness limitations and any other data necessary to describe the modification.

• Substantiating data; i.e. Test and analysis reports and Justification reports

3) Approved Data is a data which has been investigated and approved by an acceptable authority such as FAA, JAA and UK CAA and divided into two categories:- OEM data and Non OEM data.

• The data packages are only considered as an approved data provided the limitations, including applicability of an approved data are met.

4) FAA Form 8110-3 approved by FAA Designated Engineering Representatives (DER) i.e. OEM DER is accepted as approved data but require DCA installation approval. Consultants DER require review because it has similar status as the Non-OEM STCs.

5) Statement of Compliance (SOC) is a form used as the top-level document for the data package. SOC form shall be signed by a Design Approval signatory or authorized person.

 

B727 & B737 Window Heat Controller

 

A) Reason for the study

 

1)       B727/737 Window heat controller unit (WHCU) p/n 231-2 (alt p/n 65-52803-8, 83000-05602, 10-61833-2) was among the top 5 unscheduled component removal for 4 consequences months from Nov 2007 till Feb 2008.  These studies analyze common reasons of such failures from year 2005 till Nov 2007 to enhance its reliability.

2)       There are various P/Ns (various OEMs) of Window Heat Controller Unit (WHCU) installed on B727/B737. All P/Ns are fully interchangeable.

P/N

Boeing P/N

OEM

231-2

Nil

Astronic

83000-05601 / -05602

10-61833-2

Koito

65-52803-8

Nil

BAE Systems

3)       There were 4 units of WHCU installed on 727 (and B737) airplane which for pilot and co-pilot No. 1 and No. 2 windows. The WHCU located at E5-1 electrical rack. It consists of temp controller which a solid state device that performs overheat control and temp control, overheat relay which direct 115V AC power from window heat CB to temp controller when energized and transformer which provide high voltage for heating window.

 

 

B) Data

1)       Repair and Findings Data from 1st Jan 2005 till 31st May 2008 were reviewed and has been classified into various types of common defect and shop findings; s/n and aircraft with repeated removals. Total 43 units were removed unscheduled with 30 DC and 13 DNC. None were scrapped or overhauled.

Defect Confirm

Defect Not Confirm

30 (69.8 %)

13 (30.2%)

2)       Unscheduled removals unit in 2005, 2006, 2007 and 2008 (till May) are shown below:

Year

2005

2006

2007

2008 (till May)

Removal Units

12

10

19

2

3)       MTBUR for B737 is 2935 hrs and for B727 is 4112 hrs. The average MTBUR is 3838 hrs. Design MTBUR for WHCU p/n 83000-05602 is 14046 hrs while MTBF is 29200 hrs.

C) Current Maintenance Program

B737

B727

Description

Every ‘C’ chk (Card: C-102A-2)

Every ‘C’ chk            (Card: 72C1-E-2-4-016)

Inspect cabin control window anti-icing syst for components such as window heat power relay, anti-ice control panel, heat conductive coating, thermal switches and heat sensors for security, wiring condition and evidence of overheat.

Every ‘C’ chk (Card: C-103A-1)

 

Inspect window heat control unit (4 places) installed on the E3 rack for security of installation, condition of wiring, cleanliness and evidence of overheat / moisture.

 

D) OEM comments.

Email from Boeing and OEM are described below:

1)        Boeing via email dated April, 30 and May, 9 provided comments per below:

  1. a) Boeing has not received any reports from other operator similar to WHCU defects.
  2. b) Boeing provides current MTBF reported from Koito is 29200 hrs.
  3. c) Boeing has limited knowledge of the Astronics p/n 231-5 due to this is an STC mod and therefore the p/n is not reflected in Boeing IPC.
  4. d) There is no BAE p/n that equivalent to Boeing improved p/n 10-61833-6.
  5. e) Boeing recommends to upgrades WHCU to the newest Koito p/n 83000-05604 (Boeing p/n 10-61833-6). Boeing drawing provides data allowing this p/n to be installed to B727 airplane. The IPC rev July 2008 will reflect the p/n 83000-05604 usage on 727-200 airplanes.
  6. a) OEM does not track the MTBUR and MTBF of Window heat controller unit p/n 231-2.
  7. b) 231-5 is the latest WHCU p/n produce by Astronics. It is fully interchangeable with p/n 231-2 with an addition of BITE circuits.
  8. c) Suspect the latest mods (Mod L or M depending on the age of the unit) have not been  incorporated for serial number that have failures of parts in the output transistor section (Q26, 27, 28)
  9. d) Astronics has produced 16 SBs related to WHCU p/n 231-2. Refer attachment 7B for modification history from p/n 231-1 to 231-2 mod ‘M’.
  10. e) Astronics only do repair and re-certify origin WHCU p/n 231-x from astronics or all predecessor company names for astronics. 
  11. f) Astronics provide recommendation per below:
  12. Due to cooling air system accumulates dust and dirt which creates thermal stress on the unit, operator is recommended to review the maintenance chk task to inspect the cooling system and cleaning the dust and dirt in E&E compartment to keep dust from clogging the units.
  13. Operator to record mod level for each WHCU installed on the fleet.
  14. Any units had RV1-4 or F1 changed should have Q1 changed as well or there is risk of recurrence of the problem.
  15. b) Since most of the operators has already incorporated new WHCU p/n: 83000-05604, there is no news about p/n 83000-05602 recent few years.
  16. c) P/n 83000-05604 has a BITE function while -05602 has not. The other differences are the weight of unit. -05604 weight is 4.3 kg while -05602 is 3.7 kg.
  17. d) Koito recommended below:
  18. To upgrade p/n 83000-05602 to -05604 (Boeing pn 10-61833-6). Info: p/n 83000-05604 is interchangeable with -05602. P/n 83000-05602 is no longer produce by Koito.
  19. Send repair or overhaul’s WHCU to Koito repair station or Aviation Technical Services, Inc (formerly Goodrich ATS).
  20. All new purchase of Koito WHCU must be obtained from AAxico.
  21. a) No expected MTBUR and no recommended improved part number from repairer.
  22. b) Other operators do not have low time failure (LTF) for window heat controller p/n 231-2.
  23. c) Two units (S/n 478 & 6205) LTF was warranty denied.

2)    Comments from Astronics Advanced Eletronics Systems (previously known as General Dynamics or Olin or Pacific Electro Dynamics)

3)    Comments from Koito Mfg

a)        Design MTBUR for WHCU p/n 83000-05602 is 14046 hrs.

4)    Comments from Aero Technology

1)        S/n 478 was repaired at 1st time visit.  Nil faults found for 2nd shop visit.  

2)        S/n 6205 found internal damaged due to excessive heat on Oct 07. 1 month later the unit was sent for repair and found different circuit board had failed. It appears that the second failure was also caused by an excessive heat.

  1. d) Unable to offer exchange with upgraded p/n due to no stock available.

E) Findings and Discussion.

1)       16 out of 43 WHCU unscheduled removals were caused by overheat. From the study, overheat will affect the window and cause the window to crack. 5 unscheduled removals due to CBs tripped can also cause window to overheat.  

Reason for Removals

%age

Total

DC

DNC

Overheat / fail overheat test

37.2

16

13

3

Nil heating / inop

25.6

11

9

2

Nil control / nil indication / not regulating / not function

11.6

5

3

2

CB tripped

11.6

5

2

3

Window cracked / arching

9.3

4

1

3

Green light intermittent

4.7

2

2

0

 

Total

43

30

13

 

2)       29 (67.4%) units were sent to Aero Tech for repair, 6 (14%) to Aero Instrument, Avborne 3, High Tech Avionic 1 and Aero Control Avionic and ST Aero 2 each. Most of units were sent to Aero Tech due to low flat rate compare to other vendor.

 

Aero Tech

Aero Instrument

Aero Control Avionic

Avborne

ST Aero

High Tech Avionics

Total

2005

4

1

2

3

2

12

2006

9

1

10

2007

15

4

19

2008

1

1

2

Total

29 (67.4%)

6 (14%)

2 (4.65%)

3 (7%)

2 (4.65%)

1 (2.3%)

43

3)       Currently there were 57 units installed on the fleet which 47.4% was manufactured by Astronics, 33.3% by BAE system and 17.5% by Koito.

4)       The S/Ns show the repeated removals are 478 (4 removals), M01372 (3 removals), 662, 1607, 1634, 3718, 5126, 6205, 7142 and 7145 (2 removals each s/n).

5)       Most of the WHCU (47.4%) belongs to Astronic. However, Boeing has limited knowledge of the unit and cannot determine the replacement of part 231-2 with 231-5.

6)       All of Astronics p/n 231-2 was not upgraded to latest mod L or M.

7)       Koito unit is the most recommended p/n due to 50% of the unit is in good condition and only one was removed unscheduled for the last 1 year. Furthermore, Boeing only recognizes Koito p/n compared to Astronics or BAEp/n.

8)       BAE p/n 65-52803-8 had shown only 5 units removed unscheduled last year (2007). Compared to Astronics and Koito, BAE WHCU reported fewer problems. However, the OEM (BAE) is NOT contactable. 

F) Recommendations

1)       To advice repairer;  unit found with varistor (RV1-4) or fuse (F1) defect/damaged, transistor Q1 must be replaced to prevent from tripping and overheat shutdown

2)       To evaluate upgrading Koito WHCU p/n 83000-05602 to the newest p/n 83000-05604 (Boeing p/n 10-61833-6)

3)       S/n 7097, to incorporate mod K at next shop visit

4)       S/ns 662, 2749, 3486 and 7142 to incorporate latest mod L or M at next shop visit.

5)       Close monitoring for WHCU s/n: 478, 6205 and M01372 that have low time failure (LTF) last year. Scrapped or exchange for those s/n that have more than 3 LTF within 2 years (until June 2009).

6)       Should spares need to order extra WHCU, always purchase latest version pn: 83000-05604 alt pn: 10-61833-6 from Aaxico (Koito prefer seller).

7)       Inform the maint crew to follow the troubleshooting chart in AMM 30-41-02 figure 101 before make a decision to replace the WHCU due to failure. Ensure that the window temperatures are below 75°F and No. 2 windows are closed and latched before using the troubleshooting chart.

8)       Review maintenance task (‘C’ chk and ‘B’ chk) to inspect the cooling system and cleaning the E&E from dust and dirt.  

G) Conclusions

1)     Operator Window Heat Controller Unit (WHCU) MTBUR is 3838 hrs which is lower than the design MTBUR (14046 hrs).

2)     Aging is the main reason of the unscheduled removals.

References:

Email from Aero Tech dated 22, 29 April, 28 May 2008

Email from Astronics dated 6 and 7 May 2008

Email from Boeing dated 30 April, 9 and 31 May 2008

Email from Koito dated 23 May 2008, 14 and 17 June 2008

Email from Aviation Technical Services dated 24 May 2008

Email from Aaxico dated 26 May 2008

ISAR No. 93-10 dated 30 September 1993

ISAR No. 90-11 dated 12 December 1990