A question for 767 knowledgeable crew/engineers. If one of the (two?) autopilots is engaged, and the control columns are pulled fairly/very hard, does the AP disengage at some level of force or does it require positive selection of a button or switch?
I'm thinking of the Eastern Tristar that crashed in the Everglades, in that case gentle pressure on one column was enough to disengage altitude hold but I don't know if that caused the autopilot to release all control surfaces or if it was in one axis. I recall reading that there was a quiet chime that wasn't noticed when this happened whereas I thought that an AP disengaging is indicated in a louder and more attention-getting manner.
I saw up thread that an investigator commented that the Atlas crew "fought the automation" but logic suggests that significant control movement is clearly different from wanting the AP to keep doing what it was previously commanded to do.