Autopilot automatic disconnect system for fly-by-wire aircraft

An autopilot automatic disconnect system of an aircraft having a fly-by-wire control system, the disconnect system comprising:

• (a) predicting a position of a flight deck controller by:
• filtering a back drive command signal to eliminate noise, applying a gain factor relating to aircraft speed to the filtered command, and delaying the gain factor-applied back drive command signal to produce a predicted position of the flight deck controller;
• (b) sensing an actual position of the flight deck controller;
• (c) comparing the predicted position and the actual position of the flight deck controller to determine a difference in the positions;
• (d) comparing the difference with a predetermined threshold value;
• and
• (e) disengaging the autopilot when the difference exceeds the threshold value.

An autopilot automatic disconnect system of an aircraft having a fly-by-wire control system, the disconnect system comprising:

• (a) predicting a position of a flight deck controller;
• (b) sensing an actual position of the flight deck controller;
• (c) comparing the predicted position and the actual position of the flight deck controller to determine a difference in the positions;
• (d) comparing the difference with a predetermined threshold value, said comparing including converting the difference between the prediced and actual postion of the flight deck controller to a signal proportional to g-forces;
• and
• (e) disengaging the autopilot when the difference exceeds the threshold value.