Originally Posted by Machinbird
There was only a small trim change in THS position leading up to the stall, but if that trim change had not occurred, the aircraft would have sought to fly at its original trimmed speed and PF would have had to work mighty hard to slow it down to a stall.
I don't think that is a correct description of how the system functions. A sidestick input commands a change of flight path. The flight control system moves the control surface to satisfy that demand. If the THS had not moved, the FCS would have commanded more elevator to achieve the demanded response from the airplane, 1.5° for 1° of THS estimated by Owain Glyndwr. The elevator would have reached its maximum deflection of 30° 5 seconds earlier
(see chart below). At that time the AoA was 33° and perhaps it would not have increased beyond that with the THS remaining at 3° and the sidestick held on the back stop.
I'm going to offer the opinion that if AF447 dropped to Direct Law on loss of speeds, even with the crew she had on that night, the odds of arrival at the other end would have dramatically improved.
I doubt that also. It would not have made longitudinal control any easier, and the PF would probably have over-controlled. And what were his targets? Would they have been different in direct law?
