Originally Posted by
Dave Therhino
MCAS can be interrupted with the electric trim switches on the yoke each time it activates, and trim can be returned to a low/zero column force state each time if the pilot puts in adequate opposite trim inputs. That is what the Lion Air crew did for approximately 2 dozen cycles of MCAS before the final few cycles, where the pilot flying at that point failed to put in an adequate amount of opposite trim in those final cycles, allowing the out of trim condition to increase to the point where they couldn't recover in the altitude available.
That is the assumption that is at question (my emphasis). If your suggestion is correct then the crew did not apply sufficient opposite trim inputs. It remains in doubt as to whether it is possible to apply sufficient opposite trim inputs. If Boeing is to be believed the Lion Air pilots casually flew the aircraft into the sea and did not attempt to apply sufficient opposite trim inputs. I do not buy into this theory. I suspect that the only solution is to use the cutout switches at an early stage. There may be multiple reasons that sufficient opposite trim is not possible. What is raising doubt is that the Lion Air pilots were trying to do just what you suggest and did not succeed. Granted, that they should have taken a different path, but it remains they were trying to trim nose-up and apparently were unable. There is a lot more to this story, I suspect that many assumptions being made are not entirely correct. People are trying to reverse engineer from Boeing publications that may not be entirely accurate and are too brief to give a full explanation of the systems. So far it does not seem to make sense. I could be wrong, but my bull**** meter is quivering.