Iceman wrote:... Believe in one AoA sensor and when that goes faulty, indicating an unsafe AoA, believe it, MCAS then does what it’s supposed to and catastrophe ensues. With just a single sensor, there is no means of determining if the data it is giving is correct.
Iceman
ISTR reading that all Max's were equipped with 2 AoA sensors, but by default the output of only 1 was fed to MCAS. Airlines could specify that both should be fed, and that discrepancies could both warn the crew and disable MCAS, and that this was merely a software change; but
a. this would have cost the airline, and
b. it would also have required training the crew about the very existence of MCAS, the role of MCAS, and action to be taken in event of a discrepancy warning. As the major selling point by Boeing to the airline customers of the Max was that 737 Type-Rated crew would need no extra training, this option was either not explained or not pushed to the airline customers' purchasing decisionmakers.
Happy to be corrected, of course.
(mere guide at) Jet Age Museum, Gloucestershire Airport
http://www.jetagemuseum.org/TripAdvisor Excellence Award 2015
http://www.tripadvisor.co.uk/Attraction ... gland.html