I wasn't aware, and seemed quite ridiculous that there was not enough torque to rotate the screw, but looking at it, the angel of the helical threading is pretty steep.
And it turns out this can/happens even with the electronic motorized way, and there is a maneuver to work around the load. But it got removed from the manual...
https://www.netairspace.com/photos/N37474/United_Airlines/Bo...
And it turns out this can/happens even with the electronic motorized way, and there is a maneuver to work around the load. But it got removed from the manual...
https://www.pprune.org/tech-log/619326-boeing-advice-aerodyn...