Originally Posted by
reamer
Didn't the ET crew leave it a long time before cutting off the stab trim switches.
So long in fact that the trim was so far out as to make manual trimming impossible.
This is not the procedure recomended. The equivalent of putting in rudder on a V1 cut when the aircraft has rolled on it's back.
The trim was the following;
9 sec MCAS, followed by
3 sec crew up, followed by
6 sec MCAS, followed by
9 sec crew up, followed by
cutout.
So, the crew put in a total of 12 sec manual trim up, MCAS put in a total of 15 sec trim down. But MCAS trims at about 50% larger speed than manual crew trim, so the end result was significantly out of trim at the time of cut out.
But for all those that say the crew hit cutout without trimming at all, they did in fact trim continuously for 9 sec before hitting cut out. Sadly they didnt trim all the way to zero yoke force. But it is neither stated in any training material that they should do that, it is merely a suggestion that they can do manual trim before cut out. Which they in fact did, for 9 consecutive seconds up until the moment of cutout, which in my opinion is quite a lot of manual trim.
In my opinion the failure here is squarely in Boeings hands as Boeing never in any training material made clear how difficult it is to trim with the trim wheel at such out of trim conditions and never ever made clear how important it is to trim to about zero yoke force before hitting cutout.