A320 stall recovery
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@ Vilas
Maybe I misunderstand your post, but if you do stall recovery in a simulator, you must remember what you experience might not represent what the aircraft would do in real life, as the "stall" data for the sim is not available. You just "fly" a computer, and this computer does not have the actual stall behaviour of the real aircraft.
From a Airbus testpilot, I have the following : "both A321 and A330 have nice stall characteristics. If deeply stalled, it requires a very distinct nosedown for quite some time, so not to enter a second stall"
Maybe I misunderstand your post, but if you do stall recovery in a simulator, you must remember what you experience might not represent what the aircraft would do in real life, as the "stall" data for the sim is not available. You just "fly" a computer, and this computer does not have the actual stall behaviour of the real aircraft.
From a Airbus testpilot, I have the following : "both A321 and A330 have nice stall characteristics. If deeply stalled, it requires a very distinct nosedown for quite some time, so not to enter a second stall"
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What you say is not true anymore. Airbus has provided authentic data package to Sim manufacturers and what the sim behaviour in a stall is very authentic and not merely a computer idiosyncrasy. Except it cannot create any g loading.
Yes, further to what Vilas is saying is the UPRT training which all pilots will start to get over the next couple of years. UPRT Training on non Extended Envelope Training sims should have ceased by now as it's negative transfer of training.
Last edited by compressor stall; 7th Apr 2021 at 12:48. Reason: Added "UPRT" to remove ambiguity
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OK Vilas, then I stand corrected. I have always appreciated your in depth knowledge of the Airbus 
2 years ago, this was not available. When have Airbus started to provide these authentic data packages ?
What do you ask the sim center about, if you want to check if they have this installed ? is it Extended Envelope Training sim ?
2 years ago, this was not available. When have Airbus started to provide these authentic data packages ?
What do you ask the sim center about, if you want to check if they have this installed ? is it Extended Envelope Training sim ?
N4790P
compressor stall
Within EASA, details on FFS approved UPRT capabilities can be found on the Qualification Certificate section "J Additional Capabilities".
This Qualification Certificate must be displayed near to the FSTD by regulation. You can also view these certificates on the EASA website.
Within EASA, details on FFS approved UPRT capabilities can be found on the Qualification Certificate section "J Additional Capabilities".
This Qualification Certificate must be displayed near to the FSTD by regulation. You can also view these certificates on the EASA website.
With FBW failures we must remember to fly Airbus FBW like a B737. Go back to basics:
Look at primary flight display - pitch and bank and speed.
Pitch/power couple - actively control the pitch.
The vertical speed readout is your performance.
Things like this that we never normally do should be practised a lot in the SIM, which hopefully will be coming in soon. Flying skills and reactions will only be fully maintained with actual physical practise. Even if the SIM dynamics are not quite correct, it is useful to see the instrumentation readouts, and practise one's raw data scan and coordination of the controls without the full FBW assisting.
Look at primary flight display - pitch and bank and speed.
Pitch/power couple - actively control the pitch.
The vertical speed readout is your performance.
Things like this that we never normally do should be practised a lot in the SIM, which hopefully will be coming in soon. Flying skills and reactions will only be fully maintained with actual physical practise. Even if the SIM dynamics are not quite correct, it is useful to see the instrumentation readouts, and practise one's raw data scan and coordination of the controls without the full FBW assisting.
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Done this in an fully certified for UPRT A320 NEO Sim:
As a stall is only dependent of AoA first and most important thing is to lower pitch. Well below the horizon. Then roll wings level, check speed brakes retracted, because these reduce your critical AoA. Thereafter deploy FLPAS 1, as they significantly increase your AoA crit. If you see a good positive speed trend add a little bit power and when slats are half way out and speed is above Vls start releasing the forward stick input to smoothly let the nose rise. If terrain is no factor, altitude loss is secondary. It will be approximately 4000'.
As a stall is only dependent of AoA first and most important thing is to lower pitch. Well below the horizon. Then roll wings level, check speed brakes retracted, because these reduce your critical AoA. Thereafter deploy FLPAS 1, as they significantly increase your AoA crit. If you see a good positive speed trend add a little bit power and when slats are half way out and speed is above Vls start releasing the forward stick input to smoothly let the nose rise. If terrain is no factor, altitude loss is secondary. It will be approximately 4000'.
Are you sure ?
The last SIM stalling I remember before Covid was A330 and I am pretty sure we kept well within 1,000'. Obviously we knew it was coming, so we were prepared. Don't lower the nose too much.
The last SIM stalling I remember before Covid was A330 and I am pretty sure we kept well within 1,000'. Obviously we knew it was coming, so we were prepared. Don't lower the nose too much.
Just like AF447...
Height loss is secondary. Getting out of the stall is all about lowering the angle of attack.
Height loss is secondary. Getting out of the stall is all about lowering the angle of attack.
Last edited by compressor stall; 7th Apr 2021 at 12:45.
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LW20
When you pitch well below the horizon and add thrust to recover the flight path you need to change the attitude quiet a bit it either triggers a secondary stall or VFE exceedance.
When you pitch well below the horizon and add thrust to recover the flight path you need to change the attitude quiet a bit it either triggers a secondary stall or VFE exceedance.
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During the initial recovery you have to keep the thrust at idle to avoid a pitch up force created through the engines. You wait with your recovery until you are above Vls. Then you start smoothly pitching up again and later smoothly adding some thrust. You will come close to VFE, but not above. During the "procedure" thrust will not exceed the numbers for straight and level flight.
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This is true according to the memory Items: adding thrust comes before path recovery.
From my experience in the sim I think I instinctively pitch up first and add thrust gently after or maybe at the same time to avoid the pitch up moment like LW20 mentionned above.
From my experience in the sim I think I instinctively pitch up first and add thrust gently after or maybe at the same time to avoid the pitch up moment like LW20 mentionned above.
Last edited by pineteam; 12th Apr 2021 at 08:18. Reason: Added one sentence
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The "practice stall and recovery' that we teach in the Simulator will definitely be different from a stall that one may encounter on line. But an easy method to teach it is as follows:
1) Do not use the Bird as it is unreliable in a dynamic situation.
2) When entering the stall condition tell the trainee not to apply any backpressure on the sidestick till the speed reaches VLS. Then enough backpressure to maintain V/S 0.
3) When aircraft stalls tell the Trainee to just take hands off the stick. The nose will drop. Once the nose drops the PF asks for Flaps 1.
4) The nose will drop to the extent that the 'black box' on the PFD will just reach below the horizon line and it will pitch up again. If it pitches up you will get a secondary stall. So the idea is to hold enough forward pressure to prevent the 'black box' rising again (i.e. hold it just below the horizon).
5) The PM has only moved the Flap Lever to F 1. But it will take a while for the Slats to extend. The PF can glance at the Upper ECAM and once the Slats are fully extended raise the nose smoothly to get a V/S of 0 on the PFD (No need to open thrust)
6) Once the V/S reaches 0 on the PFD open enough power to kill the 'trend arrow'
The trick in preventing a secondary stall is:
a) Do NOT allow the box to pitch up once it comes below the horizon.
b) Wait for the Slat to fully extend on the Upper ECAM
1) Do not use the Bird as it is unreliable in a dynamic situation.
2) When entering the stall condition tell the trainee not to apply any backpressure on the sidestick till the speed reaches VLS. Then enough backpressure to maintain V/S 0.
3) When aircraft stalls tell the Trainee to just take hands off the stick. The nose will drop. Once the nose drops the PF asks for Flaps 1.
4) The nose will drop to the extent that the 'black box' on the PFD will just reach below the horizon line and it will pitch up again. If it pitches up you will get a secondary stall. So the idea is to hold enough forward pressure to prevent the 'black box' rising again (i.e. hold it just below the horizon).
5) The PM has only moved the Flap Lever to F 1. But it will take a while for the Slats to extend. The PF can glance at the Upper ECAM and once the Slats are fully extended raise the nose smoothly to get a V/S of 0 on the PFD (No need to open thrust)
6) Once the V/S reaches 0 on the PFD open enough power to kill the 'trend arrow'
The trick in preventing a secondary stall is:
a) Do NOT allow the box to pitch up once it comes below the horizon.
b) Wait for the Slat to fully extend on the Upper ECAM
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Vilas,
What I have found works fairly consistently in the low altitude clean stall recovery (and I emphasize this is technique), is after the initial pitch down to wait until the speed trend is trending up and then bring in thrust to about 50% N1 (PW1100). Once the speed is out of Vls, begin gently pitching up at about 2 degrees per second while slowly feeding in thrust with the intent to eventually reach about 10 degrees up and CLB detent.
For the slat extension, sometimes people do that too early and it causes pitch instability. I have seen people call for flaps 1 while still in the initial pitch down, only to have that pop the nose up again and start a PIO. Best to get the nose down first, then call for the flaps.
If the bird is on, one technique one of our instructors uses that I like is to watch the relationship between the bird and the nose. If that distance starts to increase you are nearly guaranteed a secondary stall warning. It helps to learn the proper coordination of pitch and power.
For flap retraction, sometimes this needs to be done fairly quickly as the speed builds up. Over speeds usually happen when someone gets the power in too quickly, and the pitch back up too slow.
The secondary stall warning itself is not considered negatively for grading the maneuver, as long as the pilot makes the corrections.
What I have found works fairly consistently in the low altitude clean stall recovery (and I emphasize this is technique), is after the initial pitch down to wait until the speed trend is trending up and then bring in thrust to about 50% N1 (PW1100). Once the speed is out of Vls, begin gently pitching up at about 2 degrees per second while slowly feeding in thrust with the intent to eventually reach about 10 degrees up and CLB detent.
For the slat extension, sometimes people do that too early and it causes pitch instability. I have seen people call for flaps 1 while still in the initial pitch down, only to have that pop the nose up again and start a PIO. Best to get the nose down first, then call for the flaps.
If the bird is on, one technique one of our instructors uses that I like is to watch the relationship between the bird and the nose. If that distance starts to increase you are nearly guaranteed a secondary stall warning. It helps to learn the proper coordination of pitch and power.
For flap retraction, sometimes this needs to be done fairly quickly as the speed builds up. Over speeds usually happen when someone gets the power in too quickly, and the pitch back up too slow.
The secondary stall warning itself is not considered negatively for grading the maneuver, as long as the pilot makes the corrections.
You’re learning a stall recovery sequence here and to recover from that one and that one alone (assuming your sim has been certified beyond the stall and not many have yet)
Remember AF didn’t get a nose drop. They didn’t know they were stalled.
Stalls come in many shapes and sizes. Don’t rote learn a recovery.
Agree.
Remember AF didn’t get a nose drop. They didn’t know they were stalled.
Stalls come in many shapes and sizes. Don’t rote learn a recovery.
The secondary stall warning itself is not considered negatively for grading the maneuver, as long as the pilot makes the corrections.
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hikoushi
First para is correct. Second para if anyone calls for flaps before nose down then it's wrong as flaps are not part of stall recovery but flight path recovery. Once the thrust is increased only then flaps should be taken. And once beyond VLS as you said very gentle pitch up is applied but it has to be continuous till 10°. If done properly then slat overspeed doesn't occur. Slat overspeed happens when the pitch is less. Last para correct again as it's a stall warning and as long as it's stopped not an issue.
First para is correct. Second para if anyone calls for flaps before nose down then it's wrong as flaps are not part of stall recovery but flight path recovery. Once the thrust is increased only then flaps should be taken. And once beyond VLS as you said very gentle pitch up is applied but it has to be continuous till 10°. If done properly then slat overspeed doesn't occur. Slat overspeed happens when the pitch is less. Last para correct again as it's a stall warning and as long as it's stopped not an issue.