Headlines about the recent NTSB Safety Recommendation Report on the 737 MAX design are focusing all attention on the report’s cover page. But is the report really about pilots reacting to emergencies in unexpected ways?
I found the most relevant part of the report on page 5. This is where the NTSB described Boeing’s use of an engineering simulator in testing the severity of MCAS malfunctions.
Failure modes that could lead to uncommanded MCAS activation (such as an erroneous high AOA input to the MCAS) were not simulated.
In other words, Boeing never simulated MCAS sensor failures while evaluating pilot responses to MCAS malfunctions. If you thought this report was about bad assumptions on pilot behavior, you missed the fact that Boeing only used a scenario where the MCAS sensors were working just fine, and the MCAS silently went mad.
So the NTSB isn’t just telling Boeing and the FAA to adjust their metrics for pilot behavior. They are asking for a top-down review of pilot reactions to all realistic problems, such as sensor damage, when approving any new design as airworthy.