Greetings,
737 and 727 200 , if , using a spoon you hit (not hard of course) the control colum the auto pilot would trip, this was more than 20 years ago and we still dont know why
Aircraft pitch down and autopilot trip could be a transcient from ADRU altitude increase to which the autopilot will respond to a pitch down to maintain the demand, and then disconnect, investigation will; as one colleague wrote close the matter with NFF.
Auto pilots are certified using DO 178B level A, this Design Order is highly constraining for hardware and software, specifically when it comes to CAT III.
Level A means NO FAILURES hardware, or software within MTBUR, to the exception of fail passive and fail operational for CAT II/III B.
The component of the board processing the signal are different from the board monitoring, the power supply is different, and the software is different on the boards, and all boards are physically segregated from one another
