Originally Posted by
Concours77
When the Commandant du Bord entered the cockpit,
With respect, sir, their names are:
David Robert, Pierre-Cedric Bonin, Marc Dubois (the captain)
As most experienced pilot in 2b, Bonin may have gained sufficient mastery to understand the jet was comfortable in Stall. The "sweet spot" as it were.
Bonin, also a glider pilot, was experienced enough to know that He Does Not Want To Be Stalled and that Being Stalled Means That You Aren't Flying, You Are Falling. My provisional conclusion was that Bonin was never aware -- in the cognitive sense -- that the aircraft was stalled. (until perhaps some seconds before impact). I have seen nothing to make me revise that conclusion. We discussed at length, in previous threads, the issue of the trained maneuvers, which is stall prevention focused with the cue of a stall warning. Stall recovery was not a training maneuver for the A320 type. Please note that, when you are stalled, your stall prevention procedures most often are not going to solve your problem but your stall recovery procedure usually will. (I spent a few years teaching spins and stalls, half of a lifetime ago).
Attempts to lower the nose caused the Stall Warn to activate and may have actually re introduced "buffet", a signal that lowering the nose was the "wrong" thing to do. ... Whatever buffet there was was likely encountered when the aircraft "began a recovery", iow, there was buffet on either side of the Stall, entry, and escape. ... Did Bonin purposely defeat the Stall Warn (by pulling back the stick) to demonstrate to the Captain they were not as bad off as might be surmised? Thinking they were on the "right side" of the Stall?
What brand are you smoking? I'd like a taste.
Based on the feedback/cueing Robert was providing to Bonin as the latter tried to get his hand flying up to scratch, Bonin's instrument scan was somewhere between slow and non existent, and it is difficult to ascertain whether or not he was trying to follow the flight director or to try and keep the AH level ... go back and read the reminders/feedback Robert is providing. Bonin is Behind The Aircraft from a few seconds after he announces that he's go the controls, and as I read the timeline, something like six seconds after he starts to manipulate the side stick the first stall warning voice message is logged in the CVR.
2 h 10 min 06,4 Bonin | I have the controls
2 h 10 min 11,0 SV | stall
Have you read the full report and all of the appendices?
Have you read the tech log forum discussions (here at PPRuNE) that began with the release of the first CVR, and the subsequent FDR, information that came out in one of BEA's interim reports. While there's a bit of noise, there is some superb exposition on how that system works, and where some of the "gotcha" bits are.
I think none of these three experienced aviators had ever actually flown in Roll Direct before this flight.
That was discussed at length, and speculated over, during the series of threads on this crash. One more opinion is now offered. The discussions on training took up a lot of space in the PPRuNe threads.
As to the THS: There seems to be no discussion in the report of the logic that produces Automatic trim into and through the Stall, which also served to make recovery difficult, if not impossible.
If you keep pulling the stick back, and the flight control surfaces keep trying to do what your control inputs call for, the THS isn't going to change its orientation since it keeps trying to trim to account for the latest commands to the elevators.
The extended discussion in the PPRuNe threads arrived at a number of very sharp folks concluding that you'd need to make a nose down command -- and hold it for a while -- so that the THS would move (albeit slowly) in the other direction away from a trimmed position that was "pro stall."
In the record, on the CVR, Robert is quoted: "loss of Protections," or similar. That is sufficient to satisfy the duty Airbus has to inform pilots of a particular design feature. There is no liability to provide a Protection if it is known that none are available in this flight Law? Inhibiting AutoTrim would IMO qualify as a protection...
In what flight regime? Inhibiting auto trim might also
create handling problems.