Originally Posted by
Brosa
It appears he tried to engage the left autopilot a fourth time, near the end at 05:43:30.
That's the only explanation to the AP Warning they got there.
It appears they
- restored the stab trim cutout switches
- made two quick manual ANU imputs
- hit the autopilot engange button, hoping the autopilot would solve the situation for them
Instead MCAS kicked in again...
The pilot may have recalled that MCAS is disabled when AP is enabled. Perhaps engaging AP seemed like a good idea at that point?