Originally Posted by
OldnGrounded
Yes. In the discussions of both crashes, it has been striking that there has been so much confusion and disagreement about the operation of MCAS, much of it on the part of transport-experienced professional aviators. And no matter how much relevant material I've read, or how often I've re-read it, some things still aren't clear. For instance, some descriptions of the "system" (software patch) suggest that it is necessary for the MAX to be in a high bank for it to be activated. That doesn't make sense and it doesn't seem to have been the case in the Lion Air or the ET crashes (if the ET incident was MCAS-related), but it pops up repeatedly in lists and graphics.
Common sense and basic principles of human engineering dictate that a system or application that creates this much uncertainty and confusion, even among experts in a discipline, is begging for redesign.
The Lion Air crash happened presumably because of a faulty AOA indicator. I guess the Boeing statement about needing high bank is related to needing a high AOA (so low speed and high bank) to activate MCAS as opposed to a separate AOB input into MCAS. This further proves you are totally right about the confusion and disagreement.