> It's also surprising the MCAS was implemented at all, instead of an alarm.
Regulations are that "(1) The stick force vs. g curve must have a positive slope at any speed up to and including VFC/MFC; and......(a lot of other text)......During the approach to the stall, the longitudinal control pull force should increase continuously as speed is reduced from the trimmed speed to the onset of stall warning."
The Max's aerodynamics are such that as you approach a stall angle, at a certain point the force inverts and the aircraft "pitches nose up" reducing force against the stick close to the stall angle.
An alarm thus fails to meet the stick force requirement. The intention behind the MCAS is to push force against the stick throughout the approach to the stall angle to meet the requirement.
(Which obviously created a whole host of failure modes that everyone seems to have entirely missed).
> The Max's aerodynamics are such that as you approach a stall angle, at a certain point the force inverts and the aircraft "pitches nose up" reducing force against the stick close to the stall angle.
Which anybody who claims that MAX is safe without MCAS is ignoring: without properly working MCAS the plane effectively starts to misbehave exactly when it shouldn't (when it's harder to save it).
Unfortunately, with improperly working MCAS, the way it was designed (non redundant single sensor which is blindly trusted by MCAS and which is in effect stronger than the pilots fighting against it) there were already two crashes.
>Which anybody who claims that MAX is safe without MCAS is ignoring: without properly working MCAS the plane effectively starts to misbehave exactly when it shouldn't (when it's harder to save it).
MCAS is there to prevent stalls at high thrust and AoA. It's also disabled when flaps are down. Meaning that it's turned off for take offs and landings where you'd most expect high thrust and AoA as well as the worst times to stall. It's hard to square that with MCAS being necessary for safe operation.
Regulations are that "(1) The stick force vs. g curve must have a positive slope at any speed up to and including VFC/MFC; and......(a lot of other text)......During the approach to the stall, the longitudinal control pull force should increase continuously as speed is reduced from the trimmed speed to the onset of stall warning."
The Max's aerodynamics are such that as you approach a stall angle, at a certain point the force inverts and the aircraft "pitches nose up" reducing force against the stick close to the stall angle.
An alarm thus fails to meet the stick force requirement. The intention behind the MCAS is to push force against the stick throughout the approach to the stall angle to meet the requirement.
(Which obviously created a whole host of failure modes that everyone seems to have entirely missed).