Originally Posted by
Lost in Saigon
It is pretty basic. An aircraft has to fly like an aircraft. If you pull the nose up, and then release back pressure, the nose must return to somewhere near the original attitude and speed.
All indications are that the MAX does this.
What MCAS does is insure that the pilot must keep pulling on the control column harder and harder to continue pitching the nose up further as AoA rises. It was added because the regulations do not allow the resisting force of the column to decrease as elevator input increases and AoA rises.
The Lion Air and Ethiopian crashes seem to have occurred because the aircraft was unable to accurately judge if it was in this flight regime, and in the short, distracting time available to them, it did not occur to the pilots to perpetually counter AND trim from MCAS with ANU trim of their own or to trim the aircraft to neutral and then disable electric trim completly.