Originally Posted by
Water pilot
This statement is exactly why I feel that we do not have the complete picture yet. When the trace shows that at least two different pilots did something completely counterintuitive (a few short bursts on the trim rather than holding it down) when they really, really wanted to make the plane go UP instead of DOWN, I think that there is a factor that we do not know about yet. I can't imagine anybody not continuously holding the "UP" switch when they see ground in the windshield, it is just not the way humans operate. You can see Formula 1 drivers adjusting the steering wheel while their car goes airborne, people try to turn on the lights when the power is out, the helmsman will pull on the throttles as the ship with dead engines inexorably heads to crush the wharf, etc. It defies reason that none of the four pilots held the button down to the last.
I don't know what it could be (can you break the switches by pressing too hard on them?)
Originally Posted by
RatherBeFlying
I am wondering how much negative g was produced in the cockpit with the final two MCAS excursions past Vmo.
I could be wrong but I thought it was clear that it was a full negative 2 Gs, partially due to the crew losing control of the yokes with the last nose down input. Additionally, to Water pilot's point I think that due to the fact that the aircraft was well past Vmo it would appear that the short bursts of nose up trim resulted in
very high momentary positive G forces. I firmly believe the crew stopped trimming nose up due to the momentarily high positive Gs on the aircraft...and 5 seconds later the unthinkable happened. Remember, the power is still set at TO, and is accelerating all this time, especially when pointing downward. A high speed nose-down trim input at Vmo+ can't be pretty...