Originally Posted by
Luc Lion
if I am not mistaken, in one of the multiple previous MCAS threads, a Boeing engineer has explained that MCAS had been designed to comply with 14 CFR Part 25.175.
https://www.ecfr.gov/cgi-bin/text-id...se14.1.25_1145
This requirement is definitely about stick force gradient (or stick force stable slope) and its title is "§25.175 Demonstration of static longitudinal stability."
So the difference between a "longitudinal stability system" and a "stick-force gradient correction system" might be just pedantic.
Yes, the reference has been cited multiple times. When it has, it's almost always in the context of someone claiming that MCAS isn't an anti-stall/stability-enhancement system -- because the MAX allegedly doesn't need one -- but is "only" to address the stick force requirement.
From now on, I think I'm going to save BDAttitude's post, just above, and paste it in as a response to repeated assertions that "it's not anti-stall."