Originally Posted by
CurtainTwitcher
This is no beginners mistake. They apparently knew EXACTLY what they were doing. The only reason it was not classified as Critical is because in doing so would require a crew warning and thus more crew training. This allegedly would trigger penalties embedded in purchase contracts (the figure quoted was $1 million per aircraft for just one operator who had ordered 280 units).
Seattle Times:
Flawed analysis, failed oversight: How Boeing, FAA certified the suspect 737 MAX flight control system
This is much much darker than a rookie error, a Rubicon that has been crossed...
The reasoning was not 'a dark plot'. As with all automation in modern aircraft if things go awry as they will, it was thought that the flight crew would be able to counteract the problem. Just using the pickle trim stops MCAS, trimming up reverses MCAS. Repeated uncommanded down trim that becomes intrusive would be dealt with by the runaway trim NNC, but just trimming back to trim using normal trim would be sufficient as it was in the Lion Air cases except in the last the FO didn't trim back to normal trimmed flight and let MCAS take over. That in itself is a clue - Boeing thought that pilots would trim to trimmed flight as second nature as part of normal flying. In the same way that car manufacturers with lane keeping software assume that drivers want to stay in lane - only more so. As for professional pilots trimming so the controls can be lightly held is a natural part of flying. Boeing were wrong in this expectation.
It may be as discussed in several posts that the sheer human factors overload and automation surprise has been totally underestimated - in several posts the intrusive nature of the stick 'shaker' has been mentioned as completely over the top of what is required, a single minor fault has an FMEA that results in multiple systems all deciding to add to the cacophony instead of one calm report saying AOA disagree. This is a major human factors issue/failure in all modern aircraft.
Nevertheless, had autopilot, autothrottle and stab trim all been switched off; and control taken over manually all these aircraft would have been controllable and landed.
Aviate , Navigate, Communicate. is nice as a chant - but Boeing relied too much on pilots managing to aviate.
Be aware that this is logically pushing aircraft development toward full automation.