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FLAPS CONTROL - update required?

Started by 744, Fri, 18 Dec 2015 14:06

744


I have recently completed a company sim detail with the fault  "FLAPS CONTROL", with all flaps control units failed.

The company simulator populated the flap manoeuvring speeds on the PFD.

It would appear that aerowinx may need updating the accommodate this Boeing service bulletin as Flap Speeds continue to be shown on the aircraft/ Sim but not on the aerowinx programme when Flaps Control is selected from the malfunctions list.


The Boeing Company Seattle, Washington 98124-2207
Number  BAB-147 R2

Airplane Effectivity: All Airplanes
Subject: Triple Flap Control Unit (FCU) Failure
Reason: To inform flight crews of the effects of failure of all three FCUs.

Background Information
This bulletin does not apply to affected airplanes modified by Boeing Service
Bulletin 747-27A2386.

An operator recently experienced in-flight failure of all three FCUs. Engineering
investigation has revealed malfunction of a leading edge flap position switch
circuit can result in failure of all three FCUs with the following indications:
• the EICAS caution message FLAPS CONTROL displays
• primary and secondary flap control and position indication displays are
inoperative
• the alternate control mode remains operative, however the expanded flap
position indication does not display.
Additionally, the following other systems are affected:
• autopilots are inoperative
• flight director command bars may not display on the PFD
• flap maneuvering speeds do not display on the PFD
• outboard ailerons unlock
engine idle is limited to approach idle •
stick shaker (stall warning) margins are reduced due to reversion to a
simplified maneuvering schedule
• GPWS warning "TOO LOW FLAPS" occurs at low altitude unless the
Ground Proximity Flap Override switch is selected to OVRD.

The FLAPS CONTROL non-normal checklist has been revised to accommodate
the additional information provided in this bulletin.
Incorporation of Service Bulletin 747-27A2386 installs upgraded FCUs to prevent
failure of all three FCUs caused by malfunction of a leading edge flap position
switch circuit.

Operating Instructions
If the EICAS message FLAPS CONTROL displays, accomplish the respective
FLAPS CONTROL non-normal checklist.
NOTE: the 20 knot crosswind limit for landing has been removed from the revised
checklist.
Operations Manual Information
The FLAPS CONTROL checklist will be restored to its original configuration
after Boeing has been notified all affected airplanes in your fleet have been
modified by Service Bulletin 747-27A2386.

Administrative Information
This bulletin replaces bulletin BAB-147 R1 dated March 15, 2001. Discard BAB-
147 R1. Revise the Bulletin Record to show BAB-147 R1 "Cancelled" (CANC).
Insert this bulletin behind the Bulletin Record page in Volume 1 of your Flight
Crew Operations Manual. Amend the Bulletin Record to show bulletin BAB-147
R2 as "Incorporated" (INC).
This bulletin will be cancelled after Boeing has been notified all affected airplanes
in your fleet have been modified by SB 747-27A2386.
Please send all correspondence regarding Flight Crew Operations Manual Bulletin
status to the 747 Manager, Flight Technical Data, through the Service Requests
Application (SR App) on the MyBoeingFleet home page.
macOS BigSur V11.4

400guy

That malfunction must have made for an interesting time for the crew involved!

Hardy Heinlin

Thanks for the hint!

Quote from: 744 on Fri, 18 Dec 2015 14:06
It would appear that aerowinx may need updating the accommodate this Boeing service bulletin as Flap Speeds continue to be shown on the aircraft/ Sim but not on the aerowinx programme when Flaps Control is selected from the malfunctions list.

[...]

• flap maneuvering speeds do not display on the PFD

You mean the first sentence the other way round: "Flap Speeds continue to be shown on aerowinx but not on the aircraft/ Sim"?


Regards,

|-|ardy

744

IMO, it would now be more representative of the Boeing service bulletin if Aerowinx  shows the PFD flap speeds if or when "Flaps Control" is selected from the malfunctions page.

In the current Aerowinx version, I note that they disappear when "Flaps Control" is selected, which is now not the case with respect to modified aircraft.

Kind regards

Steve.


macOS BigSur V11.4

John H Watson

#4
QuoteAn operator recently experienced in-flight failure of all three FCUs. Engineering
investigation has revealed malfunction of a leading edge flap position switch
circuit can result in failure of all three FCUs with the following indications:

Is the failure due to the faulty LE flap position switch similar to all other types of FCU failures? (e.g. all power removed from these boxes?)

This seems like a pretty magical modification if the FCU's continue to supply the aircraft with all that data when totally dead. Note that the TE flap position (for example) is processed by the FCU's and position data is sent via FCU Arinc data bus transmitters to other systems. If the FCUs are completely unpowered (e.g. with all the FLT CONT ELEC CB's pulled), selecting ALTN Flaps will not restore flap position.

Hardy Heinlin

Quote from: 744 on Fri, 18 Dec 2015 22:17
In the current Aerowinx version, I note that they disappear when "Flaps Control" is selected, ...

I can't see this effect here. They don't disappear by any flap malfunctions. They disappear only if the FMCs have failed or when above 20000 ft.

Did you test this above 20000 ft by chance?


Cheers,

|-|ardy

744

Hi I-Iardy

Thanks for the reply. I've tried setting the "Flap control failure" both above and below 20'000ft.

Setting "Flap control failure" Not severe > 20,000 with VREF 25 Set
The UP bug appears passing 20,000A - This is correct
No flap speeds show on the PFD during the descent as the aircraft decelerates using ALTN Flaps.
My understanding, and as experienced is that this is incorrect.

Setting "Flap control failure" No severe < 20,000 with VREF 25 Set
Any flaps selected before "Flap control failure" i.e. Flap 1 show on the PFD and remain
Once "Flap control failure" is activated, no further flap speeds populate on the PFD.

In both examples, both FMS/CDU are fully operational.

Do I understand correctly that this does not occur when you run a "Flap control failure" scenario......you still get the bug speeds on the PFD?

Kind regards

Steve.
macOS BigSur V11.4

Hardy Heinlin

Hi Steve.

Quote from: 744 on Sat, 19 Dec 2015 09:00
Setting "Flap control failure" Not severe > 20,000 with VREF 25 Set
The UP bug appears passing 20,000A - This is correct
No flap speeds show on the PFD during the descent as the aircraft decelerates using ALTN Flaps.
My understanding, and as experienced is that this is incorrect.

In PSX, the 20000 ft condition is a general requirement. ALTN flaps operation will not influence this condition.

Can you confirm that, whenever ALTN flaps are active, the FMC and EIU will provide flap speed bugs to the PFD also when the aircraft is above 20000 ft?


Quote from: 744 on Sat, 19 Dec 2015 09:00
Setting "Flap control failure" No severe < 20,000 with VREF 25 Set
Any flaps selected before "Flap control failure" i.e. Flap 1 show on the PFD and remain
Once "Flap control failure" is activated, no further flap speeds populate on the PFD.

On my PSX here, under these conditions, the flap speed bugs are still displayed on the PFD. I can't reproduce your observation.

Could you save a situ?


Cheers,

|-|ardy

744

Hi l-lardy

Thanks for the reply, being a bit new to the forum I'm not quite sure how to attach screen shots + I'm going to be away for a few days so perhaps we could revisit this after Christmas.

Compliments of the season, speak soon.

ATB - Steve

macOS BigSur V11.4

Hardy Heinlin

Sure, after Christmas. No hurry :-)


Cheers,

|-|ardy