PPRuNe Forums - View Single Post - Boeing 737 Max Software Fixes Due to Lion Air Crash Delayed
Old 30th Mar 2019, 15:15
  #469 (permalink)  
Rob21
 
Join Date: Aug 2007
Location: Brazil
Age: 71
Posts: 131
Likes: 0
Received 0 Likes on 0 Posts
Disable MCAS with opposite pilot input

Originally Posted by QuagmireAirlines
They didn't need to turn it off. Not stalling. Pitch was high, yet with an empty aircraft, velocity vector was high too.
It does raise a related issue: What pitch angle and/or vertical speed should MCAS be safely disabled?
I might have implemented a disable for pitch angle < 6 degrees, and possibly add an AND condtion with vertical speed < 0 which would keep the nose from auto-trimming down when descending at a low or negative pitch angle.
What condition would you disable MCAS down-trim on? Boeing isn't buying any of that of course, yet doesn't keep us from suggesting something else.
As soon as the pilot input is in the opposite direction (Yoke, trim or both). If the pilot is trying to raise the nose, he is pretty much certain there is not a pre-stall situation.
Rob21 is offline