Originally Posted by
737 Driver
All that “troubleshooting” takes less than 5 seconds.
Actually it can take longer than 40 seconds. For just the 2 first steps out of 3. From one of my previous posts:
17:59 - F/O - "auto pilot - disengage"
18:01 - Mentour - "autopilot is disengaged"
18:04 - F/O - "auto throttle - disengage"
18:07 - Mentour - "if you can do that for me please"
18:09 - F/O - "disengaged"
18:11 - F/O - "if it continues, I will go with the stab trim cutout switches"
18:13 - Mentour - "ok, let's evaluate this to see if it's moving"
18:20 - F/O - "memory items for the runaway stabilizer complete"
18:21 - Mentour - "yeah, let's evaluate"
18:25 - Mentour - "I have no authority of the trim at the moment"
18:29 - F/O - "roger"
18:32 - Mentour - "I can't control it manually, so it doesn't really work, so if you can continue with the memory items please"
18:37 - F/O - "memory items - stab trim cutout switches to cutout"
18:40 - Mentour - "Continue"
18:41 - F/O moves the switches to the cutout position
18:42 - F/O: "Cutout"
You could do all 3 steps in 5 seconds if you had no communication with the other pilot and didn't wait at all between the steps. But that doesn't sound very wise.
Later edit, actually I think that's one of the mistakes of the Ethiopian crew. They executed this checklist too hastily and they skipped the step about disabling the auto-throttles. If they did that, they probably would have payed more attention to their speed and adjusted it manually as needed. Instead, the engines remained at 94% until VMO, when from the FDR trace it seems the A/T lowered that to around 90%.