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THREAD: If people learn anything useful from the 737MAX tragedy, it should be this: Organizations can make decisions (to ship an unsafe product) that no one inside wants.
The organization is an organism. It has motivations that none of its members do. One cell of this organism may cut a small corner but is assured that due to the safety culture, it will be compensated for in another way.
That works, mostly, until the pressure to deliver and to cut corners pervades the organization on a critical project, and everyone is expecting everyone else to be their backstop. If you understand:
1: The commercial imperative Boeing was under. They had to deliver the MAX on time and without significant changes to the flight manual. Changes to the flight manual would have meant extra pilot training, which they promised the airlines there wouldn't be.
2: The “brick wall” sensor/computer system in the 737. Each of the two redundant computers has its own, completely isolated set of sensors. If there is any failure on one "side", the other side will still work.
If both sides are even looking at both AoA sensors as a cross-check, you don't have that isolation. This creates pressure to show that MCAS is safe with just one sensor, otherwise, a redesign would be required.
3: The last minute surprise in flight testing. After they built the plane, Boeing was ready to start production after flight testing. Flight testing found unfortunately that MCAS needed to be 4x more powerful to maintain stability.
Engineers probably assumed that although MCAS wasn't redundant, the pilots could simply overpower it in a mistaken activation. At the higher setting though, they couldn't, but the train was already leaving the station with no time left for a redesign.
4: The fact that much of the regulatory verification was performed by Boeing employees subject to the same pressures (fast schedule, no flight manual/training changes) as the rest of engineering.
It’s really not a big surprise that it turned out the way it did. It’s not that the engineers or anyone else at Boeing didn’t want to build a safe aircraft. For the organization itself though, perhaps without anyone inside realizing it, safety became a lower priority.
