People here seem to be missing a few things. 1: The 737 family, including the 737 MAX, still use manual/hydraulic controls, not fly-by-wire. A computer failure

People here seem to be missing a few things. 1: The 737 family, including the 737 MAX, still use manual/hydraulic controls, not fly-by-wire. A computer failure isn't supposed to be as catastrophic as it would in a fully fly-by-wire system. 737 pilots are already trained on other automatic system failures, such as a pitch trim motor runaway. 2: The original design of MCAS had a limited scope - stop pitch instabilities from causing an uncontrolled pitch-up into a stall in high AoA and high power regimes, such as just after takeoff. It read from both a G-sensor and the AoA vane and both sensors had to be reading excessive values for the system to trigger. This was probably the justification for not requiring higher levels of reliability. 3: The plane was found to have handling issues in slow flight regimes. In order to improve the handling, Boeing engineers modified MCAS to be active in more of the flight regime, removing one of the sensor readings. Now it would trigger if it detected the plane was near a stall, even in level flight without a high G loading. It is unclear whether MCAS was recertified within Boeing for continuous use. Wikipedia states "The FAA did not conduct a safety analysis on the changes. It had already approved the previous version of MCAS, and the agency's rules did not require it to take a second look because the changes did not affect how the plane operated in extreme situations." 4: Pilots could not disable MCAS without disabling electric trim control. In at least the LionAir case, the pilots did disable the electric trim, but were unable to re-trim the plane manually against the aerodynamic forces of their dive. They re-enabled the electric trim to re-trim the aircraft, and MCAS re-triggered and put them back in the same situation. Remember, these aircraft use manual controls. The pilots need to put a serious amount of force into the control column when the plane is out of trim and at a high airspeed. This greatly diminishes their ability to do anything else. 5: Both accident aircraft were missing an optional safety feature - the AoA disagree warning. Both aircraft experienced a failure of one of their AoA vanes. I don't recall whether these failures happened in flight or before the flight, but such a warning would have likely stopped the pilots from taking off. 6: The single computer issue was not uncovered until simulator testing after the crashes. It is not directly related to the MCAS problems. Wikipedia is your friend, as usual. https://en.wikipedia.org/wiki/Maneuvering_Characteristics_Augmentation_System https://en.wikipedia.org/wiki/Maneuvering_Characteristics_Au... Here's even more detailed information: http://www.b737.org.uk/mcas.htm http://www.b737.org.uk/mcas.htm