This is my understanding too, though Boeing hasn't really come out and said it definitively. Specifically: > MCAS was devised to fulfill an airworthiness cert

This is my understanding too, though Boeing hasn't really come out and said it definitively. Specifically: > MCAS was devised to fulfill an airworthiness certification condition in 14 CFR 25.173 and 14 CFR 25.175. In high angle-of-attack (AoA) flight configuration, it is required that stick force/g (the stick force necessary to produce (hold) an incremental normal acceleration of 1g) and stick movement/g (ditto mutatis mutandis) must increase (or at least not decrease) with an increase in AoA (thanks to Clive Leyman for this formulation). I understand that in flight test, in which “wind-up turns” were conducted (a turn with increasing angle of bank; an increasing angle of bank means ceteris paribus increasing AoA), this condition was not fulfilled. -- https://abnormaldistribution.org/index.php/2019/04/30/ieee-spectrum-on-possible-software-involvement-in-two-recent-airliner-crashes/ https://abnormaldistribution.org/index.php/2019/04/30/ieee-s...