Hi
Answering here to A-FLOOR, from the thread "Humbling sim experience", in an effort not to hijack it for too long
Re:
Overspeed and
understanding of stall situation in AF447
Originally Posted by
A-FLOOR
Have you read the CVR transcipt?
Yes I did, thank you. En français dans le texte, qui plus est.
1/ At one time, the PF though the aircraft was (too?) speedy ("J’ai l’impression qu’on a une vitesse de fou non qu’est-ce que vous en pensez ?") but the aircraft was not. As the overspeed protection listen to its sensor inputs, and not to the PF mind, I maintain: no overspeed detected, hence no activation of overspeed protection.
2/ I fail to see where the transcript shows the crew was aware of the stall. OTOH, there are parts which show they weren't ("comment ça se fait qu’on continue à descendre à fond là ?")
Originally Posted by
A-FLOOR
My point was that with elevators alone the aircraft will drop the nose again when the elevator backpressure is released, but this may no longer be the case when the THS is trimmed fully aft.
Releasing the back pressure on the stick may be not enough, as the FBW will then try to maintain path/g load. If the stick is placed and held nose down, the nose will drop. It takes more time as long as the THS full nose-up, but it works, and if maintained the THS will come back from its "full nose-up" position.
NB: I do however agree that it's not a good idea for the auto-trim to go full nose-up when the SW is on (point discussed at lengh in one of AF447's dedicated thread).
Originally Posted by
A-FLOOR
I know of no Boeing type which has an Airbus type autotrim system that automatically trims the THS to relieve pitch input. In manual flight, even the 777 and 787 have to be trimmed manually for airspeed using the trim switches. This does not take into account some functions where the trim is adjusted automatically with flap and speedbrake deployment (...)
OK, wasn't aware of that. Thx.