PPRuNe Forums - View Single Post - MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Old 24th Sep 2019, 14:17
  #2584 (permalink)  
Peter H
 
Join Date: Jun 2008
Location: Cambridge UK
Posts: 164
Originally Posted by Tomaski View Post
Real life does not go by script, nor is there any prohibition against multiple or ambiguous malfunctions.
Nice thoughtful post.

Not only is there no prohibition against multiple or ambiguous malfunctions, but in some case
their occurrence is by-design (intentional or not). Naively as SLF I assumed that this would
be identified by some sort of dependency-tree analysis at design-time, and their occurrence
identified and prevented if possible, or at least allowed for in operating procedures.

AoA-high failure seems to be a perfect example, leading to the triggering of things like UAS,
autopilot drop-out, stall-warnings, and inappropriate MCAS activation (in the absence of flaps
and other blocking states).
Peter H is offline