AF447 final crew conversation - Thread No. 1
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"Again, somewhere on the Tech Log threads at least one Airbus FBW pilot stated that F/Os train on both sides of the flight deck, so left/right-hand orientation should not have been a problem. "
"Sorry. Once again : prior to june 1st 2009 Air France F/Os did NOT get any, on purpose, left-seat flight training.
Some sim sessions ("true" captain not compulsory) just happenned to be with a two F/O crew but the purpose was not to train F/Os in the left seat."
I believe the PF was in the right seat in which case left/right hand orientation should not have been an issue for him.
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Razoray.
..what also doesn't sit well is the fact that the plane just fell out of the sky in a deep stall. The tail didn't tear off, the engines didn't fail, there was no "act of God"...
..what also doesn't sit well is the fact that the plane just fell out of the sky in a deep stall. The tail didn't tear off, the engines didn't fail, there was no "act of God"...
There was no b*oody deep stall, man.
The pilot held the stick hard back. THAT is what kept the aeroplane stalled.
Whenever he got tired and released the back-pressure, the poor aeroplane started to recover. Then, he pulled it back again!
Can people read the definition of 'deep stall' or 'super-stall' before using those phrases?
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BOAC,
Indeed not. Which is why I have been hinting that this was a manually induced and prolonged deep stall.
Clandestino,
You said it yourself. BASIC aerodynamics. ATPL Principles of Flight leaves a lot to be desired. I suggest that you ferret a bit deeper into advanced aerodynamics.
A deep stall is NOT irrecoverable. A deep stall maybe harder to recover in a T-Tail aircraft because of reduced elevator effectiveness. It is the combination of both swept wings AND T-Tail configurations in aircraft such as the 727 that makes a deep stall more of a problem. Elevator/pitch rocking and induced roll are two ways to recover but these may take a lot of time and height.
Swept wing aircraft can all be made to deep stall if you have enough elevator authority.
Of course, pitch up may only be a problem if it's excessive or it's exacerbated by poor handling! I congratulate you. It is possible that the A330 lost elevator effectiveness because of vortex buffeting during the pre stall regime stall which caused excessive pitch up exacerbated by the full NU command led to deep stall entry.
Aileron Drag,
There was no bloody locked in deep stall.
If adequate control authority is not available to recover you are in a deep stall. Usually because of vortex buffeting on T-Tails or, on other types, anything else that reduces elevator control margins.
You are all ignoring the nose down pitch change that occurred each time nose down elevator was applied?
Clandestino,
References contrary to your claim can be found in "Handling the big jets". third edition, page 119. Or any decent basic aerodynamics textbook, e.g. Atlantic Flight Training ltd JAA ATPL training handbook, Principles of flight, pages 8-14 to 8-16 in 2006. edition. Those were first that I dug out of my bookshelf and I can't publish excerpts due to copyright issues but if you really want to know what's written in them, i don't think you'll have problem finding out.
A deep stall is NOT irrecoverable. A deep stall maybe harder to recover in a T-Tail aircraft because of reduced elevator effectiveness. It is the combination of both swept wings AND T-Tail configurations in aircraft such as the 727 that makes a deep stall more of a problem. Elevator/pitch rocking and induced roll are two ways to recover but these may take a lot of time and height.
Swept wing aircraft can all be made to deep stall if you have enough elevator authority.
But it doesn't follow that moving the Cp in stall forward results in pitch-up! If it were so in the real world, we would be in deep trouble and I certainly would not be writing this post but pushing daisies at certain quiet village graveyard.
Aileron Drag,
There was no bloody locked in deep stall.
If adequate control authority is not available to recover you are in a deep stall. Usually because of vortex buffeting on T-Tails or, on other types, anything else that reduces elevator control margins.
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Lord Spandex Masher
I was taught aerodynamics here - on Planet Earth.
I really am not sure where you were taught.
This is in English......................
There.....was......no......DEEP.......stall.....in.....this. ...case.
Lord Spandex Masher, I urge you to take your own advice.
Oh YES IT IS, mate; and I have one dead friend to prove it.
This is utter garbage.
That's what I've been trying to get into your head for days. There WAS NO DEEP STALL.
The PILOT held the aircraft in a stalled condition until it hit the sea.
Let me summarize....
1. AF 447 DID NOT DEEP-STALL.
2. AF 447 was held in a stalled condition by the PF, for reasons known only to him.
I was taught aerodynamics here - on Planet Earth.
I really am not sure where you were taught.
Which is why I have been hinting that this was a manually induced and prolonged deep stall.
There.....was......no......DEEP.......stall.....in.....this. ...case.
I suggest that you ferret a bit deeper into advanced aerodynamics.
A deep stall is NOT irrecoverable.
Swept wing aircraft can all be made to deep stall if you have enough elevator authority.
There was no bloody locked in deep stall.
The PILOT held the aircraft in a stalled condition until it hit the sea.
Let me summarize....
1. AF 447 DID NOT DEEP-STALL.
2. AF 447 was held in a stalled condition by the PF, for reasons known only to him.
Last edited by Aileron Drag; 27th Oct 2011 at 03:37.
Which is presumably why there is no evidence of persistent ND inputs with a voice commentary along the lines of 'I am trying to reduce pitch but the aircraft isn't responding', or did I miss that bit ?
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No, Mr Optimistic, you didn't miss that bit.
This guy sat there with the stick held fully back, presumably wondering why the pitch attitude was so high, the airspeed so low, and the RoD so high.
It's so sad. You wish you could have been there, as though in a simulator session, and say to them, "What are you doing? Why are you holding the nose up like this?
This guy sat there with the stick held fully back, presumably wondering why the pitch attitude was so high, the airspeed so low, and the RoD so high.
It's so sad. You wish you could have been there, as though in a simulator session, and say to them, "What are you doing? Why are you holding the nose up like this?
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"A deep stall is NOT irrecoverable."
You might want to tell the bloke who flew the NASA Schweizer in the deep stall regime over twenty times. That's right, at least twenty entries into and recoveries from deep stalls. Irrecoverable...NO, IT ISN'T.
AF447 was put into and held in a stable deep stall. If they had recognised this fact they may have had enough time to recover. The sad thing is they did not recognise it and held it in a deep stall for over three minutes.
You understand the difference between a deep stall and locked in deep stall?
Oh YES IT IS, mate; and I have one dead friend to prove it.
AF447 was put into and held in a stable deep stall. If they had recognised this fact they may have had enough time to recover. The sad thing is they did not recognise it and held it in a deep stall for over three minutes.
You understand the difference between a deep stall and locked in deep stall?
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"I don't really want to be dragged in to the SS/yoke battle except to say that if I had been dragged out of my pit in my silk pyjamas and arrived in a cockpit at 35,000' with 15 degrees nose up, 10,000fpm+ and a co-pilot with the yoke back in his groin, I might have had a clue as to why the nose was up that high - I hope so."
Very interesting point. There has been a lot mentioned about the lack of SS feedback to the pilot but very little about the lack of feedback to the rest of the crew compared to the old fashioned yoke, feedback that in this case may have been vital.
I also wonder about the constant noises bells and whistles going off. There has been a lot of research showing that constant loud noises are an accelerant to panic (as anyone having to deal with a runaway smoke alarm at 2 in the morning can attest) which appears to have been a factor in this accident. By all means aural messages are good but constant repetitive noises will simply dramatically increase stress and degrade performance. The pilots knew there was a problem, and the constant alarms did not help them find a solution.
Very interesting point. There has been a lot mentioned about the lack of SS feedback to the pilot but very little about the lack of feedback to the rest of the crew compared to the old fashioned yoke, feedback that in this case may have been vital.
I also wonder about the constant noises bells and whistles going off. There has been a lot of research showing that constant loud noises are an accelerant to panic (as anyone having to deal with a runaway smoke alarm at 2 in the morning can attest) which appears to have been a factor in this accident. By all means aural messages are good but constant repetitive noises will simply dramatically increase stress and degrade performance. The pilots knew there was a problem, and the constant alarms did not help them find a solution.
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No pilots who hold back pressure on the yoke or SS in a stall live very long if they ever stall. I thought it was instinctive to release any back pressure if it ever occured. I know, for some reason they didn't know they were in a stall even with their attitude and descent rate. Strange.
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They knew their descent rate, in the end. Originally "I have no Vertical Speed". You think they knew Attitude? Betcha a buck they did not."
The Captain came in...."What are you doing?" "I don't know, but we are descending".
How do we know? Because with an attitude cue, one of these worthies would suggest Nose Down. Occam, again. Slightly less likely is that the two NF pilots were unaware PF was holding back stick, and assumed he was pushing the stick forward. Poor display, poor cockpit design, poor training, poor CRM, shortsighted SW design, inexplicable Autotrim...... all down to Occam? Hardworking fella, this Occam.....
Repeating the same rhetorical "How could three pilots...bla, bla, bla......."
does not suggest, let alone confirm, there was a reliable attitude display.
How many times did PF correct the ship's Nose Down proclivity? Sufficient to climb to Stall? What attitude was he reading? What was the exact source of the disagreement between the PNF/PF re: altitude?
CVR please.......
The Captain came in...."What are you doing?" "I don't know, but we are descending".
How do we know? Because with an attitude cue, one of these worthies would suggest Nose Down. Occam, again. Slightly less likely is that the two NF pilots were unaware PF was holding back stick, and assumed he was pushing the stick forward. Poor display, poor cockpit design, poor training, poor CRM, shortsighted SW design, inexplicable Autotrim...... all down to Occam? Hardworking fella, this Occam.....
Repeating the same rhetorical "How could three pilots...bla, bla, bla......."
does not suggest, let alone confirm, there was a reliable attitude display.
How many times did PF correct the ship's Nose Down proclivity? Sufficient to climb to Stall? What attitude was he reading? What was the exact source of the disagreement between the PNF/PF re: altitude?
CVR please.......
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BEA have replaced what was an unimaginably dynamic cockpit with parsed and misleading bits of data. Drawing conclusions from these is premature. Not even BEA have made conclusions. And they get paid for them.
I know you do not accuse, and that is the sad part, for condemnation prior to investigation is absurd.
I know you do not accuse, and that is the sad part, for condemnation prior to investigation is absurd.
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No pilots who hold back pressure on the yoke or SS in a stall live very long if they ever stall. I thought it was instinctive to release any back pressure if it ever occured. I know, for some reason they didn't know they were in a stall even with their attitude and descent rate. Strange.
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What would 1g vertical acceleration have felt like in the cockpit during the descent?
It's as though a total lack of instinct prevailed.
As bubbers said, "strange."