Originally Posted by
megan
It would be interesting to know just how much of the envelope requires MCAS type input, given that it has been said the MCAS is only required to address shortcomings at light weight and CoG at the aft limit.
Megan, many years ago after the loss, overseas, of a couple of T tailed aircraft in deep stall accidents OZ DCA sent a team overseas to examine the stall requirements then applied to transport category aircraft. A result was amendment to ANO's 101.5 and 101.6 to include, amongst many other things, a requirement for accelerated stalls at a deceleration rate of 5kts per second. BCAR, FAA requirements were less, so I ended up flying a variety of transport category aircraft to show compliance with the ANO requirements.
My experience was that light weight, aft CG, turning flight stalls, power on, at high deceleration rates were most likely to indicate any tendency toward longitudinal stick force lightening or pitch up.
So, with absolutely no evidence, my guess is this would be where the MAX 8 was found non-compliant. I posted my thoughts many months ago on at least one MAX 8 thread.
It should be noted that 1lbf stick force reduction below the requirement is just as non-compliant as, say, some pitch up - they both require a fix.
Plenty of posters here make assumptions about the pitching moment curves and how bad the MAX 8 is - I am in no position to make any assumptions.
A turning flight accelerated stall programme can be a very exciting exercise, even at the current FAA requirement of about 3kts/sec deceleration.
During these test it is pretty well inevitable that you will find yourself at about 40 degress nose up, 30 degrees of bank and a speed well below the 1g stall speed.
Not sure if many airline pilots would want to go there to witness the operation of a SAS system which should be transparent anyway.
For what it is worth......