Originally Posted by
kiwi grey
But that would put the aircraft into a known unsafe condition.
The MCAS was created solely because the B737MAX is sufficiently unstable without it (under some circumstances) to not be certifiable, and the stab trim switches are required to be on for MCAS to work.
Boeing have their "gentleman's parts" in a vice on this one
My understanding is not that the Max is unstable without MCAS but that the pull force on the control column is not linear close to stall AoA. This is why MCAS does not operate with AP engaged. So a regulatory 'protection' was put there for linear control forces. Or as in the case of the Max pilots with little feel for manual flying could to pull through into a stall as the column pull force got lighter. This is probably more likely in a high speed stall such as in a steep turn.