Re:Ethiopian Airlines 737 MAX Investigation Preliminary Report
by msbarnett on Thursday April 04, 2019 @03:55PM
(#19576441)
I don't think they were concerned about snapping the cable, but based on a simulation run last week by a Swedish pilot (who needed both arms locked around the column to keep it held back, towards the end), and the reports' notes of the pilot repeatedly instructing the co-pilot to help him trim up, the forces on the column were such that the pilot couldn't assist in cranking AND continue to pull back on the column at the same time.
Releasing the stick to assist with the wheel would have meant allowing the plane to nose-dive. This might have allowed them to crank in the stabilizer in time to recover, but they only had 7,000 feet above the ground to work with.
I don't see in the report that the pilots attempted to both operate the manual trim wheel at the same time. I'm not sure if its explicit in the training, but in the manual its made clear that pilots may need to work together to move the trim out of extreme positions when the electric system is not available, and that doing so will not break the manual trim system.