... The normal control
is an electrical system which actuates the jackscrew through the main electrical actuator. The main
electric actuator and autopilot actuator, autopilot control is provided by the autopilot actuator on the
gearbox. A manual control system drives through cables to the cable drum on the jackscrew
gearbox. ...
Normal electric trimming of the stabilizer is done at one of two rates as controlled by flap position.
Trim rate with flaps retracted is 1/3 the trim rate with flaps extended. High speed autopilot rate is
equal to the normal electric low speed rate. The low speed autopilot rate is 1/2 the rate of the high
speed autopilot rate.
From this excerpt it seems that there were two discrete actuators for autopilot and for electric manual (hence the need for two cut out switches).
This would also suggest that there could be two electric motors fighting each other when AP and manual el. trim are applied the same time?
Which one would succeed? I would also expect the rate switch to have some impact on available torque. So the outcome may be dependent on AC coniguration.
From what has been posted here it seems very likely, that this has been changend on the MAX.
So unfortuneately this actually raises more questions to me.