Originally Posted by
737 Driver
MCAS does not “unwind” any of the nose down trim it has inputted. The expectation is that the pilots will put in the correct trim as they recover from the impending stall. We do stall recovery training regularly in the sim, and there is always a lot of retrimming involved.
MCAS absolutely should unwind the nose down trim once the AOA drops below 10 degrees (as long as no pilot trim input occurs). I don't have the detailed reference, but this was the whole point of MCAS. It would operate silently in the background, provide a simulated yoke force feedback (or longitudinal stability), and then disengage once the maneuver is completed.
Any automated (and previously undocumented) system that left an aircraft out of trim after a "simple" maneuver, could never possibly be certified. Stall escape implementated by the pilots is an entirely different matter, as was the runaway behaviour of MCAS due to a stuck AOA sensor.
This discussion is around a not previously considered human/machine feedback process, driven by a delayed trim unwinding process, and subject to interruption by pilot trim inputs. This point seems not to have been covered in any other forum, other than the brief hint, and useful chart, referenced earlier in this thread.
This may turn out to be a non-issue, if properly implemented and documented. It is definitely the kind of concern to be discussed by the Joint Authorities Technical Review.