What I find interesting, is whenever MCAS is being discussed (re the Lion Air crash and possibly this one as more data comes to light), there are a lot of posts saying that if they’d just done the trim runaway checklist, everything would have been OK. Yes, probably. But what would have led them to that checklist? If you took off in a 737 MAX on a flight where nothing went wrong and you didn’t crash (rare, I know
) and manually flew the cleanup, would you get a bit of trim from MCAS as the last of the flap went in, making it something “normal” and “expected"?
If you had read all the manuals, then got a stall warning shortly after clean, you’d expect the MCAS to do a bit of trimming, yes? So “normal” behaviour? It’s also intermittent and you can trim back and forth yourself, so hardly a “runaway” in the traditional sense; in fact not in the sense of the QRH either, which describes a runaway stab as “continuous”.
So, unless you are prepared to do the runaway stabiliser drill every time you see the trim wheel moving and it wasn’t initiated by you (which would lead to lots of very short flights), how do you tell in a limited timeframe whether MCAS is trying to save your life or trying to kill you...?