Re: Pull Breakers
There is a procedure for "runaway elevator trim" in the flight manual. However the situation calling for this was when the original STS (speed trim system) was installed only, where it would trim nose-up at constant rate.
MCAS does a nose-down trim, and switches off for 5 seconds after the pilots counter trim from the yoke, and then repeats.
The pilots were not familiar with this behaviour, so it didn't trigger the action to turn off the two switches.
On the flight preceding JT610, a Batik air captain (typically the grey-beards coming out of long service from sister company Lionair), who was also 737-max8 rated and sitting in the observer seat, did conclude it had to do with auto-trim (he wasn't in control, so had a bit more room to evaluate the situation), and advised the flight crew to turn the switches to off position, which recovered the situation.
Biting the hand that feeds IT
