Originally Posted by
infrequentflyer789
based on the bits of AMMs I (unofficially) happen to have, the answer to that appears to be - no. Or more precisely "only some of it". - the not properly disengaged clutch would be the weakest point.
Very good, thank you for that information.
Originally Posted by
infrequentflyer789
Worth noting that this run-on issue on classics was only in high speed mode, and the trim motor is (should be) in high speed mode only when flaps are down. MCAS is (should be) on only with flaps up, therefore with low speed mode and much less loading on the whole actuator system.
My understanding of MCAS is that while it only operates in manual flight with flaps up, it runs the trim nose down at the (faster) flaps down rate of 0.27 units per second. You can see a rate of trim disparity between MCAS trimming down at 0.27 units per second and the slower flaps up commanded main electric trim rate in the FDR data. I think that that is one of the issues with trying to countermand MCAS ND trim with main electric NU trim. If you're not actually checking the resultant trim outcome and just retrimming nose up on an 'equal time' basis MCAS will win the slow war of attrition to get the stab trimmed further and further nose down.