AF447 wreckage found

[bearfoil]

Lonewolf50

Offered only insofar as to what could explain a Pilot pulling back when Confronted with STALL warn or actual Stall.

The elevators change the Pitch of the A/C acting through the Horizontal Stabiliser. This would not happen if the HS was free to move where the elevators put it. 'eg'. the elevators would change the AoA of the HS rather than the a/c.

So IF the Horizontal Stabiliser was not connected to its jackscrew (which "Positions it internally"), it would deflect to whichever angle the elevators put it. This would in turn change the Pitch of the a/c, but opposite to ss input. Down elevator pushes the trailing edge of the HS UP, climbing the a/c.

I don't wish to make any claim re:447. AGAIN, I think it is worth a look, if only to better understand the way the a/c functions.

The PF WAS making ND input, and the STALL WARN tripped. It is logical (though perhaps not correct in this case) to assume the effect of his command was counter to his expectation (And to ours).

So, in the failure case (separated jackscrew), the a/c is reacting to the THS' position, which is commanded by "trimming" elevators, rather than "commanding" elevators. Simply drop a step in the arrangement of conventional trim tab, elevator, and HS. Eliminate the HS, and what is left, is the arrangement on all THS flying a/c!

Aside.... BEA say "..and remained in that position to impact..." They are speaking of the THS, planted at 13. What holds it there? Perhaps not the Pilot's NU, perhaps not Hydraulics, active or lock. Perhaps airflow.

sebaska. I believe the two motors are positioned on the same jack. Perhaps not.