Far being for me to debate a certified test pilot with all the degrees and actual diplomas from the "schools".
I cannot find the "#13" ref document.... I gave up looking for technical, non-political, non-management and so forth once pPrune closed discussion here on the Tech Log. Whatever document had "#13" ? It must have been buried in all the "return to service or certification" threads that were not worth the time to look at due to legal and non-pilot posts. I tried to get tech stuff on Tech Log to no avail.
I do not take completely agree with:
The design concept of MCAS was fine. It met the objectives - as misguided as they appear to be with hindsight.
I agree that moving the stab would change the control input gradient in order to require more aft stick for more AoA or whatever. It would not necessarily require more pounds per stick movement unless it influenced other systems in the control implementation. I do not agree that it was an acceptable concept to make the plane "feel" like the NG model. So meeting the "objective" of the Part "x" that FAA required seems to me to be the biggest bone of contention I have. How would moving the stab angle of incidence and then remain there at other parts of the envelope? "Oh, Gums, we just return to some other angle when ?" What angle?
I appreciate the implementation of moving the stab "gradually" to help with "elevator" pitch authority/movement. But my experience was with three jets that did not have "elevators" (and one that was a delta with elevators/elevons). We moved the stab for pitch control! In the "neutral" position, we followed basic FAA stability and control requirements. On autopilot, they trimmed the slab very slightly to maintain either mach hold or altitude. When we pulled hard it got harder approaching higher AoA, except for the last few degrees in the VooDoo. In the VooDoo we definitely got a "light stick" in the end game, and I wish you could have flown one to see what I mean.
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and then I completely agree with:
However, it was the engineering implementation that was flawed, together with weak and failed processes in testing, airworthiness, and certification; all of the holes in the Swiss Cheese lined up - they were already there just waiting for MCAS (it could have been something else).
You nailed it there, PEI. And do not forget some management issues that Big B is now paying for.