18 October 2019

Boeing Boeing - part the eighth

Well, David Gelles, et al are at it again. More perfidy from Boeing. What a surprise!

But I didn't come here to bury Caesar. I came here to remind folks that MCAS continues to be misrepresented with regard to the two climb-out crashes. It's important to understand this.
Boeing CEO Dennis Muilenburg said "[MCAS] has been reported or described as an anti-stall system, which it is not. It's a system that's designed to provide handling qualities for the pilot that meet pilot preferences."[4] The wiki. This is the ref.

IOW, MCAS was originally designed to provide a 'backstop' to AoA issues in normal flight at 30,000+ feet. It was only later that MCAS was modified to activate at climb out.

Some more
[MCAS] would trim the airplane in modest increments for up to nine seconds at a time until it detected that the airplane had returned to a normal AoA and ended its steep climb. It seems simple enough — on paper, that is.

And, do you like aggression?
On paper, MCAS was only supposed to move the horizontal stabilizer 0.6 degrees at a time. In reality, it could move the stabilizer as much as 2.5 degrees at a time, making it significantly more powerful when forcing the nose of the airplane down.

Not all of the reporting makes clear that MCAS's initial task was to compensate the MAX's handling during cruise flight back to 'classic' 737 behavior. This one does
MCAS is "activated without pilot input" and "commands nose down stabilizer to enhance pitch characteristics during step turns with elevated load factors and during flaps up flight at airspeeds approaching stall."
[my emphasis]

No comments: