Originally Posted by
FGD135
I can see what Boeing were trying to do. From their point of view, the pilots are already trained (supposedly) to deal with the situation the MCAS may bring up, so why complicate things?
If the pilots had followed the prescribed procedure for inadvertent/inappropriate/runaway stabiliser trim (a procedure which has existed for decades, across all Boeing models) then these crashes would not have occurred and the pilots would be none the wiser about MCAS.
If you take that literally, then yes but we are looking at this a bit post hoc. The question is how do you define the trigger(s) for applying the runaway stabiliser trim drill? STS, MCAS and the AP will (and do) adjust the trim without pilot input, so what exactly are you looking for? Also, this is not on a low workload flight deck level at 20,000’, this is shortly after takeoff in a critical flight phase where all margins are much smaller and spare cognitive bandwidth is much reduced. It needs to be simple logic, not a large branching flowchart.
I guess what I’m trying to say is that suppose the trim starts moving after takeoff: is that a runaway or is it normal operation? I can’t see a quick and easy way to figure it out, so in the interests of safety you’d be better assuming it’s a runaway but that means on virtually every flight you’re disconnecting the trim on the climb-out, not ideal.
Add a UAS event to the mix and I can absolutely see why things go wrong. There is as much, maybe more, to the Human Factors side of these accidents than the technical, IMO.