A320 - Eng out in crz + Emer desc
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A320 - Eng out in crz + Emer desc
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
I would appreciate if someone can spread a light, thanks
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??? 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.
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.
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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.
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.
Great question
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
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
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The question is, do I keep Thr MCT/Op Desc or Reduce thrust lever to Idle to descend with Thr Idle/Op Desc.
But this will give you a descent at MCT (about 1700FPM maybe)
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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.
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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
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
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.
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.
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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.
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.
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.
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...
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
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).
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).
FCOM DSC-22-30-100
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
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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
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
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?
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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.