PPRuNe Forums - View Single Post - MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Old 5th Sep 2019, 11:09
  #2182 (permalink)  
Join Date: Jul 2013
Location: Norway
Age: 53
Posts: 124
Originally Posted by Fly Aiprt View Post
Not sure whether I got it correctlyn but if the stick force goes to zero and the yoke has to be brought to neutral when approaching say 14 degrees AOA, then the aircraft can't be qualified as stable.

If so the public will never be willing to board the airplane again.
As i said, I had to make several assumptions, the most major assumption was at what AOA the MCAS starts, and at what AOA MCAS reaches its full travel. If MCAS starts putting in AND at 10 degrees AOA and reaches full 2,4 units of travel at 14 degrees AOA, then I would argue that the aircraft pitch behaviour would be in the neighbourhood of what you stated.

However if MCAS starts at say 8 degrees AOA and dont reach full travel until say 16 degrees AOA then the stick force lightening without MCAS would be much less, but I am convinced it still would be ligthening, not just flat.

Anyway, what this boils down to is that it would have been extremely interesting to have a stick force and stick position graph with inoperable MCAS all the way well into stall region, both at 1G/decaying speed and at a higher constant speed wind up turn.
So I fully support EASA's requirement of flight testing this part of the flight envelope, with inoperable MCAS.
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