A320 - Eng out in crz + Emer desc

[nj314]

If the incident of Southwest happened in an Airbus 320, I am wondering what engine setting we set for the descend? MCT (eng out) or Iddle (Emer desc)?

I would appreciate if someone can spread a light, thanks

[KingAir1978]

??? Are we talking about the actual thrust, or the thrust LEVER position and Autothrust function?

The Authothrust is active between the IDLE and CLB detent (n engines) and between IDLE and MCT detent (n-1 engines). That is of course, when the autothrust isn't switched off/disconnected.

If you disconnect the autothrust, the actual thrust is dependant on the thrust lever position.

In the given incident and provided terrain is not an issue, I would expect the THRUST LEVER to be in the MCT detent, because of the engine out, but the ACTUAL thrust to be IDLE, because of the emergency descent.

[nj314]

thanks for your input, but I am not clear.

Imagine we have Ecam Eng fire, we shut down the Eng and proceed to N-1 during cruise: Thrust Lever to MCT, and then disconnect A/THR. I descend with Fma: Thrst MCT/Op Desc.

And then I have Ecam Cabin Excess Press, now I do my actions for Emergency Descend: Mask on and Initiate the descend. Now, how can I descend with thrust Idle when lever is MCT with A/THR offf?

The question is, do I keep Thr MCT/Op Desc or Reduce thrust lever to Idle to descend with Thr Idle/Op Desc.

[Roj approved]

Do the ECAM for Engine Fire,
Thrust LVR - IDLE (you might set MCT A/THR OFF at this point)
MASTER SW - OFF
FIRE PB - PUSH
AGENT 1 - DISCHARGE

once secure go for your companies OEI descent strategy. This will be say .78/300 for best windmilling, or Green dot for best Obstacle clearance.

Normally this would have you do the following:
MCT -Set
A/THR - off, (already done as part of the fire drill above maybe)
ALT - Turn- pull,
HDG - Turn - pull,
SPD -Turn - pull
But this will give you a descent at MCT (about 1700FPM maybe) which isn’t going to get you down to 10,000/safe alt very quickly.

SO

Follow the Emerg Descent procedure:
O2 masks on
Comms establish
Emergency Descent announce
Turn pull x 3
CHECK IDLE
- At this point, leaving the A/THR on (with the Thrust lever in MCT) will give you IDLE, which is what you want because the most important thing now is to get down to a safe Altitude, and when you go to level out you will get MCT again.

If you don’t get IDLE - close the thrust lever and turn A/THR OFF
SPEED BRAKES
Etc
...
...

It’s a very out of the box situation, I imagine things happened in very quick succession, so some practical thinking is required.

If you already had the A/THR off, then the EMERG DESC procedure would have you setting the thrust lever to idle (As it was in MCT A/THR off, it would be giving you MCT, LVR MCT on the FMA)
If you hadn’t got to turning the A/THR OFF, then it should have gone to Idle when you pulled OPEN DES. (THR IDLE OP DES on the FMA)

The most important thing is to get the aircraft going down, probably no faster that the speed it decompressed at, so you need to get the Thrust to IDLE. If you left it in MCT and pulled OPEN DES, it would pitch for the speed and then as it accelerates the ROD will reduce due to the MCT thrust on the good engine.

Either way, back to Golden rules,
Fly the aircraft,
Use appropriate automation,
Understand the FMA,
Take action if things don’t go as expected.

Good question, it really got me thinking, mainly, that I don’t ever want this to happen to me:ok:

[akindofmagic]

The question is, do I keep Thr MCT/Op Desc or Reduce thrust lever to Idle to descend with Thr Idle/Op Desc.

Re-engage the ATHR and descend in THR IDLE/ OP DES (thrust lever to idle will obviously work as well but it's one more thing to forget in the excitement later on, and this is one situation where maximum use of automation wouldn't be a bad plan).

But this will give you a descent at MCT (about 1700FPM maybe)

Obviously depends on a few factors, but RoD will be significantly lower than 1000fpm with the remaining engine at MCT.

[swissmen]

Imagine we have Ecam Eng fire, we shut down the Eng and proceed to N-1 during cruise: Thrust Lever to MCT, and then disconnect A/THR. I descend with Fma: Thrst MCT/Op Desc.

Your FMA will be MAN MCT|OP DES|NAV or HDG. If THR MCT is shown, the A/THR is still active...

[nj314]

Your FMA will be MAN MCT|OP DES|NAV or HDG. If THR MCT is shown, the A/THR is still active...

thank for the remarks

[KingAir1978]

Your FMA will be MAN MCT|OP DES|NAV or HDG. If THR MCT is shown, the A/THR is still active...

No it will not, because you DISCONNECT the Autothrust.

Please read my earlier reply again.

If you have an engine failure in cruise, the procedure calls for the thrust levers to be put in MCT and to disconnect the autothrust. The reason is that you want to keep MCT as a fixed thrust on your working engine.

When you put one thrust lever in idle, the ACTIVE range of the autothrust will increase. It will now be active from IDLE to MCT (instead of IDLE to CLB).

If you continue the procedure and initiate the descent, the FMA reading will be:
blank | OP DES | NAV or HDG. The actual thrust will be MCT.

If you want to change your descent to an emergency descent from here, the simplest way is to just re-engage the autothrust. The autothrust will become active and thus give you idle thrust:

THR IDLE | OP DES | NAV or HDG.

[Roj approved]

If you continue the procedure and initiate the descent, the FMA reading will be:
blank | OP DES | NAV or HDG. The actual thrust will be MCT.

KingAir1978 is correct, the first column will be blank. I stand corrected

[sierra_mike]

if i had any clues that there is a decompression involved on top of the engine fire, i'd definitely don the masks first before me brain is toast at high alt

[Icelanta]

Decompression recall items get priority over anything else.
Common-sense:
1)Secure yourself ( get your oxygen flowing)
2)Secure the fire/engine ( severe damage/fire engine recall items)
3)Emergency descend recall procedures and NNC
4)Engine severe damage NNC

[Verbal Kint]

Ask yourself: "Which is going to kill me first? Engine failure, or depressurization?". The answer is (should be) obvious. Get masks on, & get descending.

Once settled in an emergency descent, then deal with the engine failure. No need to rush eng failure (& risk mismanagement of thrust) at the expense of descending to a safe level.

Your time of useful consciousness at altitude might only be in the order of 10 secs - same for your pax/crew. We commonly see this scenario in the sim on command course. Well worth thinking about.

[vilas]

Hypoxic pilots are not great help to tackle engine fire. If it is Airbus then what is ECAM priority may or may not help. If it's fire then you will have to overrule and do the memory items of EMER DES and pull both THR levers to idle, fire can wait. Once established in descent switch over to fire drill. There is no need to waste time setting MCT in initial descent. Once the engine is secured then select ATHR and move the live thrust lever to MCT. Surely you wouldn't like do descend on OEI profile and run out of oxygen.

[FullWings]

Ask yourself: "Which is going to kill me first? Engine failure, or depressurization?". The answer is (should be) obvious. Get masks on, & get descending.

Once settled in an emergency descent, then deal with the engine failure. No need to rush eng failure (& risk mismanagement of thrust) at the expense of descending to a safe level.

Your time of useful consciousness at altitude might only be in the order of 10 secs - same for your pax/crew. We commonly see this scenario in the sim on command course. Well worth thinking about.
Can’t argue with that. Simple prioritisation.

As above I would recommend against trying to do the drills at the same time - inevitably one or both get messed up.

There are many scenarios where getting that mask on may be what saves the day: decompression, smoke/fire/fumes and that subtle one where your colleague starts acting strangely or loses consciousness for no obvious (at the time) reason...

[swissmen]

No it will not, because you DISCONNECT the Autothrust.

Yes, it will. (My reply was to nj314 statement in his second post about the eng shutdown, has nothing to do with the emergency descent yet). And it is like this BECAUSE you disconnect the A/THR.



If you have an engine failure in cruise, the procedure calls for the thrust levers to be put in MCT and to disconnect the autothrust. The reason is that you want to keep MCT as a fixed thrust on your working engine.

When you put one thrust lever in idle, the ACTIVE range of the autothrust will increase. It will now be active from IDLE to MCT (instead of IDLE to CLB).

That's correct. So the first column your FMA will show is MAN MCT (in white). With A/THR active (not the case in this scenario), it would be THR MCT (in green).

If you continue the procedure and initiate the descent, the FMA reading will be:
blank | OP DES | NAV or HDG. The actual thrust will be MCT.

This however is clearly wrong. It is THR MCT or MAN MCT. It can never be blank with at least one thrust lever in MCT.

FCOM DSC-22-30-100

If you want to change your descent to an emergency descent from here, the simplest way is to just re-engage the autothrust. The autothrust will become active and thus give you idle thrust:

THR IDLE | OP DES | NAV or HDG.

Correct.

If you keep the A/THR off for the descent, YOU have to put the thrust lever to IDLE yourself and your FMA will be BLANK | OP DES | NAV or HDG

That's the reason why the EMER DESCENT says:

- if A/THR not active: THR LEVER.............IDLE

[Kipp]

Hi Swissmen,

The only way you will have a White (boxed) MAN TOGA/MAN MCT in the first column of your FMAs is if the Autothrust is armed - which in this case it wouldn’t be.

[KingAir1978]

Yes, it will. (My reply was to nj314 statement in his second post about the eng shutdown, has nothing to do with the emergency descent yet). And it is like this BECAUSE you disconnect the A/THR.





That's correct. So the first column your FMA will show is MAN MCT (in white). With A/THR active (not the case in this scenario), it would be THR MCT (in green).



This however is clearly wrong. It is THR MCT or MAN MCT. It can never be blank with at least one thrust lever in MCT.

FCOM DSC-22-30-100



Correct.

If you keep the A/THR off for the descent, YOU have to put the thrust lever to IDLE yourself and your FMA will be BLANK | OP DES | NAV or HDG

That's the reason why the EMER DESCENT says:

- if A/THR not active: THR LEVER.............IDLE

Dear Swissmen,

Assuming that I am clearly wrong, can you please explain the following two questions, please?

So to be clear, we'll completely ignore the decompression. We have a simple engine failure in cruise.
1) How would you go about it?
2) If you decide to follow the FCTM guidance, WHY would you switch the autothrust off?

[vilas]

OP's question shows lack of understanding of the purpose of abnormal procedures. Loss of pressurisation and loss of thrust on one engine has opposite aims to achieve. OEI in cruise you don't want to descent but have to because of insufficient thrust to maintain level flight so we do it with least ROD by locking thrust at MCT. In loss of pressurisation you want to descent as quickly as possible to ten thousand feet where oxygen is not required. So it can only be done at thrust idle, speed at MMO/VMO with speed brakes extended. Once the aircraft is settled in descent you can deal with engine fire to secure the engine and then complete EMER DES ECAM. After that switch back to engine fire items. It's unusual but not that complicated.

[Killaroo]

Ahhh....Airbus....

[vilas]

Ahhh....Airbus....
It has nothing to do with type of aircraft. You would do the same even in 737 or any aircraft.

[Killaroo]

I'm not talking about the procedure - I'm referring to the epic CONFUSION over basic modes of the Airbus Auto thrust system!

I just caught a recording of the 'Aircrash Investigation' program about the Habsheim crash. You remember - the one where the Top Training Captain in Air France flew a 2 day old A320 into a forest during a low flypast. He was fooled by - the Airbus AutoThrust system and its interface with the control laws.

Seems to me confusion still reigns out there 30 years later.

[vilas]

Forget Habshiem. The world has moved on. No there is no confusion whatsoever. It's a very popular aircraft. The best for low time pilot.

[Killaroo]

Forget?
So you don’t believe in learning lessons from past mistakes?
That’s not how it works in aviation.

Whatever your affinity to Airbus is, don’t let it cloud your judgement.

[iceman50]

Killaroo

It seems you are the one that does not learn from past mistakes, lessons have been learnt form Habsheim. Don't be stuck in the dark and fear an Airbus they are great aircraft, don't let your "affinity" cloud "your" judgement.

[Killaroo]

I read the discussion about what mode the Auto Thrust may or may not be in, and what the FMA may or may not say, and I find your faith in peoples knowledge and understanding of the AT to be plainly delusional. Nothing has changed since Habsheim. AF447 proved that again. How much more evidence is needed? The same 'accident' keeps happening.

[vilas]

Killaroo
You are obviously not an Airbus pilot if pilot at all. Your opinion about a system you know precious little is just that, an opinion. It has no professional merit. You should be asking questions and not giving answers. But don't expect full type rating on the forum.

[pineteam]

You can’t blame Airbus for these incidents. In both case it was lack of knowledge of the system and improper training.
In that logic we can mention the Kegworth accident where the crew switched off the wrong engine on the 737 or Emirates flight 521 crashed during a go around. Those 2 accidents would probably not have happened on Airbus as engine failure is clearly identified and the go around procedure is really instinctive; firewalling the levers forward just like on a Cessna. Does that means Boeing are bad aircraft? I don’t think so.

[Killaroo]

Killaroo
You are obviously not an Airbus pilot if pilot at all. Your opinion about a system you know precious little is just that, an opinion. It has no professional merit. You should be asking questions and not giving answers. But don't expect full type rating on the forum.
40 years on multiple types dear boy, and not a scratch to any of them.

[pineteam]

Apology accepted. That was funny tho. xD

=)

[Killaroo]

Cheap shot deleted.
Sorry.