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Old 29th Nov 2018, 02:59
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Mad (Flt) Scientist
 
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Originally Posted by OldnGrounded
Right. But the reason MCAS was implemented on the MAX is that the aircraft has a tendency to pitch up in conditions where that would not be the case with earlier 737 versions, correct?
From the peanut gallery, sort-of, not totally 100%.

MCAS appears designed to give assistance to using the elevator to recover from a high AoA condition. Likely the scenario for which it is implemented also includes some combination of high thrust (causes nose-up moment) and stab trimmed to abnormally nose-up position. Both 737NG and, I think, at least one AB variant have had high pitch angle upsets in very similar conditions, and the concern for such a scenario has been the subject of more general discussions. Thus Boeing, perhaps prodded by FAA, seem to have implemented a "helper" to trim the stab a bit nose-down for such a case. While the MAX has more thrust than NG and thus more nose-up possibly in the scenario I don't think it's a black-and-white "problem on MAX not on NG" - I suspect it's shades of grey.
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