Re the elevator crank and difficulty in turning, I've posted this link before but worth reposting
Shutdown caused Boeing crash. - Page 4 - International Skeptics Forum
Quote..
"I agree it's a flawed design. And I used to work there. I'm glad I don't now.
Regarding the trim wheels: When the NG was being introduced, I happened to be the Lead Engineer in charge of them and a whole lot of other stuff. There were some issues. The new display system created a pinch point between the dash and the wheel. We had to make the wheel smaller. And the new trim motor resulted in the wheel, which is directly connected to the stabilizer by a long cable, springing back when electric trim was used. It was an undamped mass on the end of a spring. We had to add a damper. Result: Depending on the flight conditions, the force to manually trim can be extremely high. We set up a test rig and a very fit female pilot could barely move it.
As I said, I'm glad I'm no longer there."
Alchad
Last edited by Alchad; 19th Jun 2019 at 13:41.