Originally Posted by
Ian W
It doesn't seem a particularly difficult task although the avionics architecture separation may make it less simple.
Or, simply require
both MCAS inputs to indicate nose down trim before trimming.
That way you need similar failures both sides to trigger it incorrectly (in which case you are probably already in big trouble). And if it doesn't trigger when it should, it is because of a failure condition somewhere.
The problem is probably with the certification not the engineering, at some point I suspect someone decided that if MCAS failed to trigger when one side fails it wasn't reliable enough, so it triggers on
either side (as does the stick shaker in effect, and the elevator feel system). Trying to unpick that decision may open a whole can of certification worms.