@gums
4) If the crew is holding or moving the manual trim wheel and the "system" keeps applying trim, as the traces show, then can the trim motor overheat and jam fighting the manual command?
The traces for manual trim only show the manual inputs for the ELECTRIC trim via the switches on the yoke.
If you move the trim wheel manually it is only shown via the Trim position. (You can see that on the FDR readout from the previous flight where they apparently used the CUTOUT switches)
So manual trim basically has two very distinct meanings. Maybe the nomenclature is a little awkward. One would probably call the trim inputs on the yoke the electric trim. But as they are manual inputs into the electric trim system that's how the FDR trace is labeled.
As far as i understand moving the trim wheel moves a drum with steel cable on it. That steel cable runs all the way back to the tail and turns the jackscrew.
So when the electric trim is used the trim wheel is backdriven via the steel cable.
The electric trim motor is located at the jackscrew.
I'm scared, and do not unnerstan why giving "hints" to the crew that trim is required cannot be done with the exising "feel" inplementation versus moving the largest, most effective pitch control surface without notice. And then not making the new system well-known and maybe demonstrated to the crews before their first flight with the new doofer. GASP!
If an electric system was fighting for trim commands how long would you have counteracted it with switches on your yoke before using the CUTOUT switches?
My bet would be you would have gotten annoyed after less than 30 seconds and asked the copilot to trim for you with the wheel.
As someone probably also wrote when the stick shaker started going off they extended the flaps to 5 while the speed was around 300 knots.