First, the Der Spiegel article still fits into the category of rumor at this point, so this is comment assuming the rumor has a basis in truth.
This is beginning to look like the
X-31 scenario. Once actual airspeed is far enough from system accepted airspeed, the control system gains become set inappropriately and the control system becomes unstable.
The Captain might have had a clue from deck angle when the carts started to roll, or he may just have heard the "Cavalry Charge" through the cockpit door. And I suppose that if I was in the seat, trying to sort out this scenario and my "boss" came in on the middle of it, you can bet I'd mentally pass the situation to him to sort out and then do what he said, whether or not he really understood the situation yet. In this case, the arrival of the Captain in the middle might have worked against this crew.
The swept wing pitch up characteristic works against recovery if a deep stall is achieved from the outset.
My question of a few days ago regarding whether activation of manual THS trim (as during a stall) while in Alternate law, would subsequently be overridden by the system was not fully answered by TAKATA.
Quote:
Originally Posted by Machinbird
Doesn't it run back to where the computer wants to put it?
Not really, manual-trim mode is activated:
"microswitches, actuated by the override mechanism, ensure that the computers remain synchronized with the manually-selected postion."
Unless manual trim mode involves physically moving the THS trim wheel in some ?Oubtoard? position to achieve manual trim, the more likely method of operation is a force override detection switch to let the computer know that it has been overriden. But then the question is "
How does the system know that the crew is done making manual changes?"
If it is a force override detection system, and the system no longer detects a manual override, wouldn't the system return to putting the THS where it "thought" it belonged? Then the next question would be, "Where would the system want to move the THS trim?"
Once in a deep stall, an A330 would likely behave in a manner similar to the F-16 deep stall. The deeper into the stall you get, the more wings behave like flat plates, and less like finely designed airfoils.
Many have assumed that the aircraft would begin to autorotate after a stall, but this general assumption may not prove correct with a FBW aircraft provided sufficient control authority exists to prevent it.
The final question is, whether or not a variation of the F-16 deep stall recovery would work on the Airbus?