Originally Posted by
MurphyWasRight
A better explanation for the slight drift down while the electrical trim was disabled is that the pilots were attempting to move the wheel by rocking it but were not able to.
The deleted video clearly show how this might happen.
Just because the prelim report has no mention of activity during this time does not mean it was absent, we do not have a CVR transcript just a few excerpts.
The jackscrew cannot back drive the manual trim wheel for the same reason a screw jack holding a car will not slowly lower the car.
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That's called irreversibility. A screw Jack is irreversible. A ball recirculation screw Jack is reversible. The steering of a truck as an example of the latter.
And to the poster who suggested to stick to what happened and not to what may have happened, I think he is right and I would try to post only probable theories, not merely possible ones. The trim drift is bugging me inmensely but it is probably irrelevant and the rocking explanation also fits.