Air France and Airbus to stand trial 2009 crash
Agree entirely with vilas.
Imho the use of the term 'deep stall' is a dishonest distraction in this case.
The term 'deep stall' was introduced, iirc, for aircraft whose configuration ( usually T tail) allowed them to enter configurations where the tail plane was rendered ineffective because it was washed by the wing turbulence.
In the AF 447 case, the airplane was stalled by the PF and then held in the stall configuration. As has been pointed out by others, just letting go of the controls might have save the day.
So no sign of a 'deep stall', except perhaps in the mind of the PF.
The legal case really should focus on AF CRM, the PM who was senior recognized that the PF was mishandling the aircraft, yet failed to intervene. That points to a serious weakness, but it still was not a 'deep stall'.
Imho the use of the term 'deep stall' is a dishonest distraction in this case.
The term 'deep stall' was introduced, iirc, for aircraft whose configuration ( usually T tail) allowed them to enter configurations where the tail plane was rendered ineffective because it was washed by the wing turbulence.
In the AF 447 case, the airplane was stalled by the PF and then held in the stall configuration. As has been pointed out by others, just letting go of the controls might have save the day.
So no sign of a 'deep stall', except perhaps in the mind of the PF.
The legal case really should focus on AF CRM, the PM who was senior recognized that the PF was mishandling the aircraft, yet failed to intervene. That points to a serious weakness, but it still was not a 'deep stall'.
“… technique analysis has been done to death. The point now is the use of the law following an accident and the implications …” beardy #27
“This type of accident will almost certainly never happen again .. What we see now are legal issues about who has to pay money to who and how much...” ATC Watcher #38
A concern for the industry is if the findings set unwarranted precedents.
Whereas the 737 Max identified deficiencies in the design requirements and certification process - must be chnged, these aspects were not an issue with AF447.
AF447 involved assumptions about conditions outside of the requirements; the fault had been identified and was being addressed. The crew behaved as reasonably could be expected in conditions which were beyond regulatory assumtions, and thus any recovery would be classified as fortuitous, even if previous crews had succeeded. There are no reports of investigations into the previous successes, nor how the encounters differed environmentally; thus there is little or no justification to assume that subsequent crews would manage similarly.
Whist the legal process could have adverse outcomes, we should leave those battles to Airbus and AF until there is fact. The important aspect is to review what can be - should be learnt about aspects beyond the accident and thus what everyone should consider to improve safety.
Design, certification, regulatory, training, operation, and individually.
“This type of accident will almost certainly never happen again .. What we see now are legal issues about who has to pay money to who and how much...” ATC Watcher #38
A concern for the industry is if the findings set unwarranted precedents.
Whereas the 737 Max identified deficiencies in the design requirements and certification process - must be chnged, these aspects were not an issue with AF447.
AF447 involved assumptions about conditions outside of the requirements; the fault had been identified and was being addressed. The crew behaved as reasonably could be expected in conditions which were beyond regulatory assumtions, and thus any recovery would be classified as fortuitous, even if previous crews had succeeded. There are no reports of investigations into the previous successes, nor how the encounters differed environmentally; thus there is little or no justification to assume that subsequent crews would manage similarly.
Whist the legal process could have adverse outcomes, we should leave those battles to Airbus and AF until there is fact. The important aspect is to review what can be - should be learnt about aspects beyond the accident and thus what everyone should consider to improve safety.
Design, certification, regulatory, training, operation, and individually.
Pegase Driver
Some humor is being lost in the translation here 
But we seem to be only discussing the depth of stalls now which is not the subject of this thread . The AF447 court case is .
But we seem to be only discussing the depth of stalls now which is not the subject of this thread . The AF447 court case is .
Most of us are trained to recover a stall as soon as it is recognised, at the incipient stage. Or, if instructed to; at the first wing drop. We do so primarily by pitching down to unstall the wing.
As I understand it; AF447 was held in a stall for an extended period, with full back-stick, resulting in low forward IAS, and high downward V/S, during which time, the Stab trim wound NU as far as the FBW allowed.
Call that what you want, but it wasn't really a 'normal' stall situation that we are all used to recovering from.
For the court case: How was that pilot trained? Was he trained? What part of his training told him to hold full back-stick during a stall?
As I understand it; AF447 was held in a stall for an extended period, with full back-stick, resulting in low forward IAS, and high downward V/S, during which time, the Stab trim wound NU as far as the FBW allowed.
Call that what you want, but it wasn't really a 'normal' stall situation that we are all used to recovering from.
For the court case: How was that pilot trained? Was he trained? What part of his training told him to hold full back-stick during a stall?
Pegase Driver
That is the essence of the part of the current trial which is against AF : training . Reading the first (BEA) report one can see that they did not recognize the stall. Not only the PF but the 2 others as well, including the Captain at the beginning , only towards the end, he , and he alone , realized it but it was(far) too late.
One chapter in one of the reports, I forgot which one , goes in detail into the AF training syllabus, as far as I remember hands on training was concentrating on approach to stall, not on stall recovery. Those were the requirements of that time, although most airlines and AF in particular have changed that drastically since then. In addition against AF are their decision not to install /buy the BUSS, the late change of the Pitot sensors and some other small differences AF had compared to other airlines that were more pro-active in that respect. , That is what the Judges , lawyers and their experts are debating now.
One chapter in one of the reports, I forgot which one , goes in detail into the AF training syllabus, as far as I remember hands on training was concentrating on approach to stall, not on stall recovery. Those were the requirements of that time, although most airlines and AF in particular have changed that drastically since then. In addition against AF are their decision not to install /buy the BUSS, the late change of the Pitot sensors and some other small differences AF had compared to other airlines that were more pro-active in that respect. , That is what the Judges , lawyers and their experts are debating now.
I think the court should also look at what kind of 'rest' the captain had before this flight and what AF's instructions on the subject may have been. There is also the question of how the captain managed the flight. Would you, as the commander, decide to take your rest period when flying through the ITCZ? I know I would have wanted to be in my seat during that time and would have managed the crew rest accordingly.
Last edited by Bergerie1; 17th May 2021 at 15:02. Reason: spelling!!
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This it’ s difficult to understand for me too , first you decide not to avoid an area of cb topping FL530 and , instead to sit there and make tactical deviation with the two other pilot , you decide to go for rest probably for the most difficult or critical part of the flight .
Closing stable door when the Cheval has bolted and all that, but no, very few of us would have taken that action. Whatever - he and his (alleged) mistress died in the ensuing. Only his 'estate' remains liable in law for that decision, unless AF 'rules' at the time rigidly prescribed when rest MUST be taken by the Captain, in which case, lawyers................alert!
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They never realised they were in a stall, and the right-seater flying never acknowledged the PNF's quiet call out of Alternate mode, so he might well have believed he couldn't stall, being in normal mode. Of course all this was hashed out at the time, and it probably makes little sense to go over it again here, but I think questions about their training are indeed relevant to the judicial matters.
Pegase Driver
Bergerie1 :
This has been debated already during one of the trials, , and if I remember correctly the SNPL (AF union) had obtained earlier an injunction that actions during off-duty periods are private and should not be included in the BEA report . The gutter media reported wild stories but very few people if any know exactly what really happened during the rest period as all the direct witnesses perished in the accident , What remains as facts are only a 1h helicopter tour , one email to a friend that he slept badly prior the flight , and some wild rumours. .
I think the court should also look at what kind of 'rest' the captain had before this flight and what AF's instructions on the subject may have been.
vaneyck
Hence the comment I made (and criticized for) in one of the other AF447 threads - perhaps it's not such a good idea to teach pilots that they can't stall a particular aircraft.
Hence the comment I made (and criticized for) in one of the other AF447 threads - perhaps it's not such a good idea to teach pilots that they can't stall a particular aircraft.
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ATC Watcher
The court is not going to decide what the crew did was right or wrong even when to take rest. So many accidents SOPs are violated, mistakes are made. The only issue is did the manufacturer know unreliable speed can happen if so did they have an adequate procedure to deal with it. If yes, Airbus is off the hook. Did AF impart that training to this crew? If yes the case is closed.
The court is not going to decide what the crew did was right or wrong even when to take rest. So many accidents SOPs are violated, mistakes are made. The only issue is did the manufacturer know unreliable speed can happen if so did they have an adequate procedure to deal with it. If yes, Airbus is off the hook. Did AF impart that training to this crew? If yes the case is closed.
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Many of the complexities of the crew's decision making, and lack thereof, got addressed in the report from the California Training Institute: https://www.hptinstitute.com/wp-cont...rance-4472.pdf
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tdracer
Pilots need to know it doesn't stall in normal law because that affects GPWS terrain procedure. It only stalls once out of normal law. The pilots knew it they were taught stall recovery which can only be alternate law. Pilots were engulfed by fear because they didn't know what had happened and may be hyperventilating devoid of rational thought. Otherwise the Stall warning was blaring in the cockpit only a deaf couldn't hear that.
Pilots need to know it doesn't stall in normal law because that affects GPWS terrain procedure. It only stalls once out of normal law. The pilots knew it they were taught stall recovery which can only be alternate law. Pilots were engulfed by fear because they didn't know what had happened and may be hyperventilating devoid of rational thought. Otherwise the Stall warning was blaring in the cockpit only a deaf couldn't hear that.
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The 'Stall warning' was not 'blaring in the cockpit'. They had the angle of attack well beyond what Airbus had considered was likely and therefore beyond the angle where a stall warning was given. Therefore it was silent. At one stage they briefly lowered the angle of attack to a point where the stall warning was given. Their immediate response was to "undo what they had done that gave them the stall warning" and raised the nose again, silencing the stall warner. That does not sound like pilots who have been trained to understand the concept of a stall, let alone how to recover from one.
I will go back to the problem that I have mentioned of basic flying schools not even demonstrating fully developed stalls, let alone teaching their students to handle them correctly. The problem starts there...
But they end with Airbus 'designing out' stall warnings being given at extremely high angles of attack (stall warnings should be given whenever the aeroplane is stalled, without limits) and Air France having to answer questions about the stall recognition and recovery training.
I will go back to the problem that I have mentioned of basic flying schools not even demonstrating fully developed stalls, let alone teaching their students to handle them correctly. The problem starts there...
But they end with Airbus 'designing out' stall warnings being given at extremely high angles of attack (stall warnings should be given whenever the aeroplane is stalled, without limits) and Air France having to answer questions about the stall recognition and recovery training.
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When the stall warning sounded it kept sounding till the crew took the AoA beyond the warning design. The AoA probes are like aerofoils need certain forward speed to measure the AoA. When the aircraft speed dropped below 60kts it was beyond design and was taken as unreliable and treated as non computed data and rejected. Then the warning stopped. But during this time the only action the crew had taken was opposite of what was required. So they were already confused. AoA probes are manufactured by another agency. Does anyone has any idea about say Boeing 737/777/787 whether stall warning will sound at at all forward speeds?
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I have friends who joined Air France in 2015 and they told me flying raw data in daily line operations is a very common practice. They follow Airbus recommendations on that matter. I’m curious to know if that was the case before 2009?