Originally Posted by
Just This Once...
All we have is a statement from EASA noting that the electric trimmers don't work in part of the performance envelop, complete with a reply from Boeing to say it is 'feature' and that manual trim remains available throughout the envelope. Of course, we now know that Boeing's statement to EASA was a falsehood known to Boeing for decades. If Boeing had answered the question correctly then, just maybe, these accidents may never have occurred.
As previously discussed, the manual electric trim does not have the capability to trim to the "full limit" of the stab. This is claimed as a "safety benefit" to prevent unintentional mis-trimming.
MCAS, and the manual trim wheels, do have the ability to move the stab all the way to its mechanical limit. The manual electric trim
can be used to move the stab in the opposite direction if it has been manually cranked (or moved by MCAS, or runaway, etc) past the aforementioned limit.