Originally Posted by
gums
Had to go back to the Alaska Airline crash with the " jackscrew nut. Wanted to see if there had been a squak on a preceding flight. Couldn't tell, but it would seem to me with all the damage that jackscrew had and the metal trapped in the big nut, that there would have been some slight indication to the PF. OTOH, with the use of the AP, the jammed stab was overcome by basic elevator trim. Finally, aero forces and commands by the PF caused the frst failure.
The longitudinal trim control system had been working up to and including the initial phase of the accident flight.