Originally Posted by
capngrog
In my limited understanding of the B-737 MAX MCAS/trim workings, I believe that once the trim Cut Out switches are opened, the only way to trim the stabilizer is via the manual trim wheels. My friends with Boeing experience say that this is a slow and physically taxing operation. To re-trim the horizontal stabilizer quickly would require closing of the trim Cut Out switches, but, of course, that would allow the MCAS to re-initiate the nose down trim action. The pilots would have had a very small window of opportunity (maybe 5 seconds) in which to close the Cut Out Switches, trim ANU, and open the Cut Out switches before MCAS could resume commanding AND.
Just as a matter of interest, I quote from the Boeing 707 Stratoliner Flight Manual, Revision 11-8-60, entitled "Stabilizer Trim Emergency Operation":
"If the stabilizer electric trim becomes inoperative, the manual trim can be used. Due to the flight loads imposed in an out of trim condition, it may be necessary to release the control column to a low force position and retrim while in an "unloaded" condition. If the airplane is much out of trim , this action will have to be repeated until correct trim is obtained."
The manual also stated that the procedure to "Raise Nose" if the stabilizer was jammed nose down was to deactivate the inboard spoilers and raise the outboard spoilers by operating the speed brake lever.
I don't remember where or how I obtained this manual, but I've had it for 30 years or so.
Cheers,
Grog
that’s exactly what you did on 707. for jammed STAB AND. you opened left spoiler cutoffs =INBOARD spoilers which raised outboard only. Then you split the flaps and lowered only the inboard flaps. Both gave nose up trim.