Originally Posted by
OldnGrounded
Right. We knew about the proposal to redesign MCAS to use both FCCs, but I don't think the sim "near-crash" has been discussed.
Edit: Re-reading . . . actually, maybe it was, sort of.
We knew about the change to MCAS to use both AOA sensors, but that was only the tip of the iceberg.
More thorough simulator testing uncovered the potential for runaway trim on the MAX, caused by the inclusion of additional relays to override the yoke cutoff switches, which were only included on the MAX to satisfy the MCAS design criteria.
This fault condition led to the requirement for dual-channel FCC monitoring on the MAX (not the NG), which has turned out more complicated and time-consuming than expected.
This story is almost a textbook example of hubris and nemesis. If MCAS had not been included on the MAX, none of this would be happening. The MAX would never have been grounded, and would be flying today with the same 'relative' level of safety as the NG series.