> MCAS is there mostly because of certification requirements for hands-off stability I don’t believe this is correct. During testing the MAX was discovered to

> MCAS is there mostly because of certification requirements for hands-off stability I don’t believe this is correct. During testing the MAX was discovered to have an inverted force curve on the stick approaching a stall — as the aircraft approaches stall angle, forces flip around and it becomes easier to pull the stick back (into the stall) than forward (out of the stall angle). This violates a fundamental airworthiness requirement — commercial aircraft cannot be certified as airworthy if the stick forces invert. MCAS “solves” this by commanding the stabilizers down as the airplane approaches stall — effectively using the stabilizer to put the forces on the stick that are “missing” due to the MAX’s aerodynamics, ensuring the force curve never inverts. MCAS is entirely about generating force on the stick to meet airworthiness regs, not hands-off stability. It actually can’t disengage when the pilot pulls back on the stick, as that would defeat its entire purpose re: the airworthiness force-on-stick requirement. The WSJ kind of muddled things here. The KC-46A does mid-air refueling, and its semi-similar MCAS system is about hands-off stability — compensating automatically as the weight and balance of the plane dynamically changes as fuel is offloaded. The pilot can override it with the stick because its purpose isn’t to provide stick force.