Originally Posted by
GlobalNav
Regardless of the presence of a AOA disagree alert, the system had the data with which to disarm MCAS. Boeing’s recent statements that nothing was wrong with the design has already twice been disproven. And it’s wrong for at least two reasons, use of a single AOA sensor, the second, that when AOA sensors disagree, the MCAS is not disarmed.
The wiring diagram of the MCAS/STS is very eloquent. The pilots have no way to disarm the MCAS/STS. Is either both ON or CUT OFF, which means also thumb switches are disabled if in CUT OFF position. NG wiring diagram shows that STS could have been disarmed by one of the switches, keeping operative the thumb switches.