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Jimmy Hoffa Rocks
23rd Nov 2009, 15:02
Got a FAC1+2 fault in descent today, local reset ok, then all normal

Is seems Airbus prefers not to admit that it does not happen ?

What could cause a FAC1+2 Fault ?

Wiring from FAC 1/2 ?

any ideas how to decifer this stuff ?
cheers

CURRENT LEG REP 23NOV +
<GMTl100 PH06 ATA22663~
AFS:FACl
<GMTl100 PH06 ATA22663~
AFS:FAC2
<GMTl100 PH06 ATA22663~
A<FGSM:TFlA1C021/RPTHL06ACATTRA22~6C6C31
AFS:FACl/RTL ACTR 1CC
<GMTl100 PH06 ATA27933~
ELACl OR WIRING FROM FACl/2
<GMTl101 PH06 ATA22663~
A<FGSM:TFlA1C0l1 PH06 ATA22663~
AFS:FAC2
<GMTl102 PH06 ATA226631

Microburst2002
24th Nov 2009, 05:58
Just guessing

I think it might have to do with the rudder travel limiter, if it affected both FACs at the same time, but we need engineers to decipher the report.

Let us now what they find out when they troubleshoot and all.

cheers

Torque2
24th Nov 2009, 10:10
The ATA's are MEL references associated withe the FAC failures (22.66.3) and ELAC (27.93.3) I believe, the rudder travel limiter actuator comes up because both FAC 1 and 2 failed?

IFixPlanes
24th Nov 2009, 17:07
Sorry, but if you expect detailed answers you should provide correct data.
It look like you use a poor OCR program. :ugh:

TURIN
24th Nov 2009, 19:59
The ATA codes are TSM Maint message references. Those numbers are used in the AirNav* electronic trouble shooting manual. Enter the code and associated data such as source, class of fault (1,2,3 ) in the right place and the PC comes up with the most likely faults and the AMM/TSM procedures to follow.

Sounds easy. It ain't. Most ATA codes will bring up several possibilities, one has to wade through the chaff and red herrings to find the actual fault.

The above looks like a brief electrical spike somewhere or other. If it's a one off with no history, move on if not, make sure it's logged....


*Other Electronic programs are available :)

Microburst2002
24th Nov 2009, 20:58
Simultaneous electrical spikes in different electrical subsystems?
Maybe.
Probably the cause is in the software, the conditions for FAC "healthy", etc...
I mentioned the RTL because both systems 1 and 2 are physically contained in the same unit, so something failing in that unit might affect both systems and for some reason render FACs invalid. But this is just a guess.

Either a dual non related simultaneous failure occurred, which is unlikely but not impossible, or the system is not as redundant as it should be. Computerized systems dissimilar redundancy is not as easy to achieve as it seems, I deem. Unforeseen problems are not only possible but they occur quite often. This might be the case.