Originally Posted by
Lake1952
How could MCAS (which is just software code) be on the MEL. if it wasn't even mentioned in the manual?
Boeing considered MCAS to be a subset of the Speed Trim System, thus it's functionality would be tied to the availability of the STS. In the original design (and similar to the 737NG today), STS was operated by two independent controllers that alternated every flight. The MEL allowed one STS channel to be inoperative as long as the other one was verified to be working. You could not dispatch with both STS channels inop. With the proposed MCAS revision, I'm expecting that the both FCC's and both STS (and thus both MCAS) controllers must be operative for dispatch.