Originally Posted by
OldnGrounded
From the report:
Recommendation R3.4:
The FAA should review the natural (bare airframe) stalling characteristics of the B737 MAX to determine if unsafe characteristics exist. If unsafe characteristics exist, the design of the speed trim system (STS)/MCAS/elevator feel shift (EFS) should be reviewed for acceptability.
Emphasis added.
Yep, this all looks to be tied into the change to MCAS activation (and power) subsequent to first flight. It looks like JATR cannot determine whether or not this is the case because there is insufficient documentation around this change - as they complain about elsewhere (not only documentation not reaching FAA, as already reported elsewhere, but things like
safety analysis not updated).
Elsewhere I noticed they refer to "...reducing the
pitch-up tendency..." - now I don't think "pitch-up" is the same as "stick-lightening" (is it?), and I'd expect this report to make the distinction - if they really mean it pitches itself up into stall (at some point) then MCAS really
is stall prevention/protection and that will open a truckload of worm cans.