Originally Posted by CONF iture
Stall warning 2 came just after the FD reappeared. IMO the PF took what he thought to be the correct action by following that reappearing FD, and applied TOGA in response to the stall warning.
The final report, HF part, section 2.1.3.3.1 is not quite so positive:
Moreover, the flight director displays could have prompted him to command a positive pitch angle, of about 12.5°. This value appears in the stall warning procedure for the take-off phase. It is possible that, even though he did not call it out, the PF had recalled this memorised value and then had clung to this reference without remembering that it was intended for a different flight phase. The conjunction of this remembered value and the flight director displays may have constituted one of the few (and maybe even the only) points of consistency in his general incomprehension of the situation. Thus, it seems likely that the flight director exerted an influence.
Originally Posted by CONF iture
The autotrim helped him to believe that the mix of those 2 actions was appropriate as it gave him the temporary illusion of control.
The motion of the THS does not change the response of the airplane to the PF's inputs. He could not have perceived it except by monitoring the trim wheel or the EIS, which seems unlikely. Until about 02:11:40 autotrim had no effect on the airplane's motion nor on the pilot's perception of it.
Originally Posted by CONF iture
I'm not to sure about that equation or how to interpret it, would it mean that a full deflection of the THS at minus 14 deg could be anihiled by 21 deg down of elevators ?
Yes, that's what it means. Owain Glyndwr explained and applied it in
his post. Let's not quibble about the exact value of the exchange rate. The important point is that THS and elevator are interchangeable, until either one reaches its limit.