Originally Posted by
DaveReidUK
True, there is very little that we can be absolutely sure about.
But your proposition requires that
a) the trim motor was stalled due to aerodynamic forces; and
b) simultaneously there was an unrelated software/processor issue that prevented the pilots' trim inputs from being recorded on the FDR
As opposed to the stab not moving simply because the pilots hadn't commanded it to.
Occam again ...
Or a trim motor overheat, due to incessant use.
For this reason full stab trim exercising in pre flight checks has in the past on another aircraft type been discontinued. Subsequently only a short stab run in each direction was practised.