Originally Posted by
KenV
That is correct. If for some reason the electric trim system runs away, it can be cut off. Once cut off one can use the manual trim wheels to manually trim the aircraft. The aircraft remains perfectly controllable. Further, even with a trim that has runaway to the mechanical limit of the system, the aircraft remains perfectly controllable. It's just that control column forces might be high and you might want the other pilot to assist you in overcoming the adverse column forces to lessen fatigue.
Probably unrelated to this accident but deserves a rebuttal:
There have been several instances where the stabilizer ended up at the stops and the elevator lacked authority to maintain attitude. At least one A320 crashed because the crew kept pushing to capture the glideslope from above and ran the trim all the way out. As far as I know the B737 manual states that during stall recovery with high engine power full nose down elevator might not be enough and reminds the crew to use aircraft nose down trim.