Originally Posted by
Luc Lion
The first point is about uncommanded stabiliser movements:
As this happens during the time the cutout switches were on the off position, I understand that this means that the stabiliser has moved under aerodynamic forces.
Could also be the result of attempt at using the manual trim wheel, as it was a relatively small movement. It is also possible that it was an anomaly in the data.
Keep in mind that, during all this sequence, the stick shaker is active and the EFS feedback force against aft command is multiplied by 4.
I think this may be an incorrect understanding. The four times reference comes from the maintenance manual, but our FCOM says the force is doubled. I asked our fleet guys who supposedly asked Boeing and the answer was that the pressure delivered to the elevator feel system is approximately four times (increase from 200 psi to 800 psi) but the force actual felt at the control column is approximately doubled to around 40-50 lbs.