Flight Control Query (Real aircraft)

[John H Watson]

A YouTuber has claimed that if the Captain's yoke is held in neutral, that the F/O cannot override him/her. His credentials are unknown, but he seems to have access to an aircraft or 747-400 commercal flight sim. He's not disputing that there is a system to help overcome jammed controls on one side, but he seems to be saying that  holding the captain's yoke is not the equivalent of jammed controls.

The Maintenance Manual has procedures for checking the control column "breakout" mechanisms. One check includes clamping the captain's yoke in the fully clockwise position and then rotating the F/O's yoke counter-clockwise 185 degrees (normal limit is 100 for the F/O). There is no mention of flight control positions. Further on in the ground check procedures, however,  the captain's yoke is held in the neutral position, the speedbrakes raised fully and the F/O's yoke turned 95 degrees counter-clockwise and the RH outboard spoilers (11 and 12) noted to be fully down. This suggests that the F/O can override the captain in some way, at least on the ground.

Expert opinions welcome.

Thanks.