I should note that I'm not an expert on this subject. According to the below, Airbus cockpit sidesticks have a red button on them. Pressing it disengages the a

I should note that I'm not an expert on this subject. According to the below, Airbus cockpit sidesticks have a red button on them. Pressing it disengages the autopilot if it's engaged, which is probably the more normal use. Pressing it when the autopilot is already disengaged engages sidestick priority for as long as it's held down. It latches if held continuously for 40 seconds. http://aviation.stackexchange.com/questions/3455/why-is-the-priority-takeover-button-used http://aviation.stackexchange.com/questions/3455/why-is-the-... If they were on the ceiling perhaps it could be difficult to hold the button down continuously for 40 seconds.