Hi guys, but here lies the problem. The 777 autopilot CAN be engaged while the aircraft is static on the ground; the T/O inhibit is only active above 80 KTS up to 50'RA, if engaged before the T/O roll commences, the A/P will remain engaged. Unlike all previous Boeings, there are no autopilot servos, but commands are directed to the Primary Flight Computers, which also send the backdrive commands. With the A/P engaged, the backdrives will make it appear, as was rightly stated, that there is a control jam. (Of course pilot direct input can over-ride and disengage the A/P). The presence of two symetrical A/P engage buttons each side of the MCP does not help the scenario either, but the BIG clue here is of course the PFD master mode annunciation. Shorting of Korry switches is extremely unlikely, as there are dual contacts feeding dual processor channels within the MCP. I don't think that you will find any recorded history of this occuring. Another major difference over previous designs, is that you do not engage the L, C or R autopilots individually, the press of the one engage switch selects and engages all available autopilots (all three unless there is a problem in one A/P).
I hope my blurb is of some help.
