https://www.seattletimes.com/busines...ion-air-crash/
...Three former Boeing flight control experts were startled by the FAA’s description last week of the new MAX system. In an airworthiness directive, the FAA cited an analysis by Boeing that “if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands” that will swivel the plane’s horizontal tail to pitch the nose downward.
The fact that the plane’s nose could be automatically and repeatedly pushed down due to one false signal shocked Peter Lemme, a former Boeing flight controls engineer, who said it looks like a design flaw.
“To contemplate commanding the (horizontal tail to pitch the jet) nose down clearly is a major concern. For it to have been triggered by something as small as a sensor error is staggering,” Lemme said. “It means somebody didn’t do their job. There’s going to be hell to pay for that.”