Originally Posted by
Tomaski
Current on the 737 but also used to fly other aircraft which did not have a "Boeing" trim wheel so let me throw out another consideration that seemingly is being overlooked. If a pilot was truly hand flying, hands on the controls and looking at his instruments, the obvious indication that something is wrong with the trim is that the control feel starts getting heavier for no apparent reason. You could cover up the trim wheel entirely and you should still be able to feel that the trim is doing something that it is not supposed to be doing. It really should not matter whether the pilot sees the trim wheel or not because he should be getting direct feedback through the controls. I think a big part of the problem with at least the Ethiopian accident is that it seems the pilot was highly automation dependent, trying to put on the A/P multiple times when he should have focused on hand flying through what was initially a simple case of a false stick shaker. This malfunction does happen on occasion and yes it is a bit confusing at first but many other crews have survived this just fine once they figure out the stick shaker warning is false. I suspect the Ethiopian pilot was not terribly familiar with how the 737 controls feel during the takeoff phase because he was always engaging the A/P right after takeoff. There are a lot of trim changes as you accelerate and retract flaps but you get used to it if you regular hand fly the maneuver. He was apparently uncomfortable with hand flying duties which would explain why he try to fight MCAS with elevator and not electric trim. That and leaving the throttles at takeoff thrust sealed their fate. Would have helped if he had a reasonably experienced FO to help him out. Very sad all way around.
At 08:39:45, Captain requested flaps up and First-Officer acknowledged. One second later, the flap handle moved from 5 to 0 degrees and flaps retraction began.
At 08:39:50, the selected heading started to change from 072 to 197 degrees and at the
same time the Captain asked the First-Officer to request to maintain runway heading.
The autopilot then disengaged and at 08:39:57,
the Captain advised again the First-Officer to request to maintain runway heading and that they are having flight control problems.
At 08:40:00 shortly after the autopilot disengaged, the FDR recorded an automatic aircraft nose down (AND) activated for 9.0 seconds and pitch trim moved from 4.60 to 2.1 units. The climb was arrested and the aircraft descended slightly.
This suggests something was wrong 3 or 10 seconds prior to the start of MCAS first activation. Would you check and initially disregard the elevator trim wheel (as it was not moving) in that first 3 or 10 seconds and start focusing on other things?