PDA

View Full Version : A320 Dual FMGC Failure


Flyman35
4th Jun 2015, 10:57
scenario :

A320-You are in the climb phase on an SID from Geneva to Beirut, then you got a dual FMGC failure, now would you continue the long flight if fuel is sufficient to fly a non RVSM altitude or no,because some pilots say you should continue and others say you should go back or do a technical landing in other airports, the point is you donít have any amber or red LAND ASAP,I would appreciate if any company policies are there regarding that failure.

Gryphon
4th Jun 2015, 11:54
MEL 22-83-01A FMGC (1 must be operative). To be taken into account.

When talking about FMGC is not only a Flight Management problem (FMS), a lot more functions are affected.

Personally I would divert to an appropriated airport.

Citation2
4th Jun 2015, 13:43
It's a raw data aicraft with CAT 1 capability it's not an emergency although automation has gone. There is a reset in the QRH and some aircrafts are equipped with back up nav which could help. Still you would have to descend to non RVSM flight level until at least one FMGC is recovered. There is a long reset in the QRH which takes 15 minutes

If you were doing a RNAV SID ask radar vectoring or a direct to VOR , reduce your speed , climb above MSA , notify ATC "unable RNAV , Unable RVSM".
Then you would have to check your fuel status , whether it can bring you to destination , provided that weather is good enough.

Do not interrupt your flight , holding somewhere might bring your fuel status below minimum fuel to continue and even if both FMGC are recovered you would be unable to reach your destination because you burnt fuel during hold. And now you have to tell your company that you came back because you were short of fuel!

Consider calling your company , MCC via stockholm radio or ACARs , SATCOm if fitted , maybe they want you to come back to departure airport instead of grounding aircraft at destination? This is a sharing decision.

But in my opinion there is no rush, it's not a LAND ASAP , you would still have plenty of fuel at that stage, gather information as much as you can regarding weather , maintenance availability, make up your mind wisely.

It will depend on so many factors , are you departing from home base ? How is the weather at departure , destination etc.. ? Maybe the company will ask you to divert enroute wehere they can fix the aircraft.

Feather44
5th Jun 2015, 09:42
Since you are a few miles from your dep airport (sid), and assuming an unsuccessful reset, I don't consider that continue to Beirut is the best option.

Microburst2002
12th Jun 2015, 15:14
Citation 2 has explained brilliantly.

That kind of situation where there is several safe possible decisions is a situation where you want to find the optimum decision. To achieve it, it is good to resort to one of those mnemotechnics, like DODAR of FORDEC, get all the facts, consider several options, evaluate them in terms of safety, legality and efficiency, get input from your company and your FO, and make a decision. The outcome should be the best possible given the particular circumstances. This circumstances could be radically different the next day, mind you.

A quick "let's return" or a "let's go on, the airplane flies nicely" decision is not advisable. You have all the time in the world to think about it.

dream747
9th May 2016, 05:30
Does anyone know where I can find guidance on what to expect in the event of a go-around for dual fmgc failure?

Capt Scribble
9th May 2016, 08:37
Tea without biscuits. The aircraft does not fall from the sky without the FMGCs.

BEL1000
9th May 2016, 10:38
Should a dual FMGC failure occur, the AP/FD and A/THR will disconnect. The crew
will try to recover both AP and A/THR by selecting them back ON (The AP and
A/THR can be recovered if the FG parts of the FMGS are still available).
If both AP and A/THR cannot be recovered, the thrust levers will be moved to
recover manual thrust. The pilot will switch off the FDs and select TRK / FPA to
allow the blue track index and the bird to be displayed. The RMPs will be used to
tune the NAVAIDs

BEL1000
9th May 2016, 10:46
With an FMGC failure you would not find your destination as there will no longer be any route on the PFD which causes it to be almost impossible to find your Destination as the route is programmed with the MCDU/FMGC and the V Speeds, etc..

Ollie Onion
9th May 2016, 11:00
BEL1000, you still have a Flightplan with the route and you will have access to an airways chart, why can't you follow the route 'old school'?

BEL1000
9th May 2016, 12:38
Yes the flight dispatch paper which you have with routes, cost index, etc.. but still you must have a functioning MCDU/FMGC to enter the WP's for the route in order to navigate there. A pilot enters route, etc.. (Usually entered automatically with CO-RTE (Company Route) or just manually) in the F-PLN (Flight Plan) page. With no route entered you will not be able to navigate unless as what you said navigate "old school".

Metro man
9th May 2016, 17:39
The route may be RNAV rather than the old fashioned beacon to beacon method. It's a long time since I did plotting or used a sextant. I would want my navigation in the Middle East to be pretty accurate given the situation on the ground.

Domestic UK or USA flight with good beacon and radar coverage would be a different matter.

tubby linton
9th May 2016, 17:57
Use the back up nav function.DSC22_10-30

Denti
9th May 2016, 18:51
Back up nav is an option, not everyone buys it.

Mooneyboy
28th Apr 2019, 09:00
Just a quick question regarding this failure.

I believed if you have double FMGC failure you canít get a DME on the ILS when selecting NAV on RMP. You should get DME on a VOR.

Before the aircraft was fully shut down I tried selecting NAV on RMP and selecting the ILS for the airport. I was surprised to see a DME indicating on the PFD when LS pb on and it seemed to be accurate. When selecting a nearby VOR it was the opposite to what I thought. Tried different VORs but none came up with DME.

Which navigation aid should you get a DME and which one shouldnít you get a DME?

D-OCHO
28th Apr 2019, 09:54
Which navigation aid should you get a DME and which one shouldnít you get a DME?
Excuse me but are you really asking this question?

Mooneyboy
28th Apr 2019, 10:17
Excuse me but are you really asking this question?


Sorry you lost me a bit.

In in the FCOM it says ĎWhen flight crew uses RMP to tune an ILS/DME the PFDís do not display a DMEí. However when I did this on the aircraft for real ( both RMP on NAV) I did get a DME reading associated with an ILS. The VOR/DME didnít have a DME distance. I didnít expect to see this.

BluSdUp
28th Apr 2019, 14:32
Flyman 35
I am not A320 qualified anymore, did SFI stuff only in 2001 for a few years.
So I am wondering why no FMC leads to no RVSM.
If that is correct I would bet a few on You never making Beirut at FL270 instead of say FL370.
Second thing is once on ground, assuming You made it to Beirut, the aircraft is now grounded.
How about right turn 270 to FL 280 , " Vectors for Toulouse "
Fix it and off You go to Beirut.
At destination 3 hrs late max.
Bon Voyage
Cpt B 738

Mooneyboy
28th Apr 2019, 15:59
Flyman 35
I am not A320 qualified anymore, did SFI stuff only in 2001 for a few years.
So I am wondering why no FMC leads to no RVSM.
If that is correct I would bet a few on You never making Beirut at FL270 instead of say FL370.
Second thing is once on ground, assuming You made it to Beirut, the aircraft is now grounded.
How about right turn 270 to FL 280 , " Vectors for Toulouse "
Fix it and off You go to Beirut.
At destination 3 hrs late max.
Bon Voyage
Cpt B 738

When you have a loss of both FMGCís you lose
both Autopilots. RVSM regulation requires Ď1 autopilot functioní.

BluSdUp
28th Apr 2019, 17:20
No ****!
Well that will do it.
My old 737-800 trucks along in HDG ALT or VOR/LOC ALT all the way to Beirut at FL410! FMC or not!
AP AT on!
Cool

Banana Joe
28th Apr 2019, 17:43
Well, the 60 year old aircraft wins this one:}

sonicbum
28th Apr 2019, 18:01
No ****!
Well that will do it.
My old 737-800 trucks along in HDG ALT or VOR/LOC ALT all the way to Beirut at FL410! FMC or not!
AP AT on!
Cool

Oh Your 737-800 is RNAV 5 with HDG ALT and VOR/LOC ?

BluSdUp
28th Apr 2019, 20:26
No it is not, but it still is RVSM and I have yet to follow a flightplan from start to finish in Europe.
Direct a VOR or follow a radial will work fine , if not vectors are provided for 5nm + separation.
Par Problem

BluSdUp
28th Apr 2019, 20:30
Remember Sonic
Once air -borne MEL and all that jazz is history
We actually got to destination in the old days as well.

sonicbum
28th Apr 2019, 20:41
Remember Sonic
Once air -borne MEL and all that jazz is history
We actually got to destination in the old days as well.

Oh great, so if I lose my RNAV capability I just shut up and go to destination without advising ATC I have lost my RNAV capability. Thanks for the tip.

sonicbum
28th Apr 2019, 20:48
No it is not, but it still is RVSM and I have yet to follow a flightplan from start to finish in Europe.
Direct a VOR or follow a radial will work fine , if not vectors are provided for 5nm + separation.
Par Problem

ICAO : "When an aircraft cannot meet the requirements for either P-RNAV or B-RNAV, as required by the RNAV ATS route or procedure, as a result of a failure or degradation of the RNAV system, a revised clearance shall be requested by the pilot."

It's a complex world we live in my friend.

BluSdUp
28th Apr 2019, 21:08
Indeed
It is indeed. I have had total FMC fail on the 738 3 times and once HDG is selected and my friend in the RH seat is deeply and intimately engaged with the QRH and I have concocted a plan B for the next few FIR boundarys , Murphy has let the old Boeing reset itself and we order some coffee.
And for the rest of the trip we pay a bit more attention to which country we happen to be in.
PS
Still not so keen on Beirut raw data, not quite the place for large navigation errors!
I will practice in Europe
Thanks

neilki
29th Apr 2019, 01:39
MEL 22-83-01A FMGC (1 must be operative). To be taken into account.

When talking about FMGC is not only a Flight Management problem (FMS), a lot more functions are affected.

Personally I would divert to an appropriated airport.

Applying MELs' airborne? Pretty sure you mean 'Apply QRH procedure...'

Feather44
29th Apr 2019, 14:05
Applying MELs' airborne?

No, just gathering info. Can it be repair at destination if that's a No Go??

sonicbum
29th Apr 2019, 15:15
Applying MELs' airborne?

No, just gathering info. Can it be repair at destination if that's a No Go??

And also if the item is a no dispatch, there could be one or more good reasons behind it. Always worth a bit of brainstorming, especially if that happens during taxi out... 5 mins before we would have been stuck at the gate waiting for a repair, now we are going to fly 10 hours with it ?

autoflight
30th Apr 2019, 12:11
MEL surely would leave the aircraft u/s in Beirut

metro301
30th Apr 2019, 23:13
What if BEY was home base? This was never stated by the OP.

Lew747
27th May 2019, 11:49
If youíve hard tuned in the RAD NAV page a couple of VORís/ NDB and then experience dual FMGC failure will these beacons be dropped out and lost from your ND until you recover nav back up? (And have to insert manually again).

I ask because a couple captains always like to tune something into the rad nav page to follow raw data in case of a dual FMGC...

sonicbum
27th May 2019, 16:55
If youíve hard tuned in the RAD NAV page a couple of VORís/ NDB and then experience dual FMGC failure will these beacons be dropped out and lost from your ND until you recover nav back up? (And have to insert manually again).

I ask because a couple captains always like to tune something into the rad nav page to follow raw data in case of a dual FMGC...

If You have preset some navaids via back-up tuning and then deselect the NAV key You can subsequently have them ready for use once the NAV key is selected again (dual FMGC fail). About 20+ years ago that used to be the procedure in my airline in case of dispatch with 1 FMGC INOP, but that was mainly due to the fact that the airline was relatively new to the Airbus 320 family and coming from conventional liners there was still this "I don't trust You" mentality that luckily quickly disappeared with some Airbus expertise. I believe that the guys You mention are either low experienced on type coming from 737s-like aircrafts or just simply over zealous. Aside of not being an Airbus procedure, statistically speaking it is more likely to have an engine failure on takeoff than a dual fmgc failure.

sierra_mike
29th May 2019, 10:27
I ask because a couple captains always like to tune something into the rad nav page to follow raw data in case of a dual FMGC...

raw data as backup from hard tuned stations can be helpful for other situations/malfunctions. maybe that's the their reasoning behind that?