Abstract: A system for backdriving the flight deck controllers of a fly-by-wire aircraft that is under autopilot control to provide a pilot with tactile and visual feedback of autopilot activity. The system, distributed between the aircraft primary flight computers and the autopilot flight computer, uses actuators mechanically coupled to each flight deck controller to position the flight deck controller to mimic manual operation of the flight control surfaces. Additionally, the system allows smooth disengagement of the autopilot and transfer of the aircraft to pilot control when the pilot takes control of any flight deck controller by moving it from a backdrive system-commanded position by a predetermined displacement for a predetermined time.

Abstract: A system for backdriving the flight deck controllers of a fly-by-wire aircraft that is under autopilot control to provide a pilot with tactile and visual feedback of autopilot activity. The system, distributed between the aircraft primary flight computers and the autopilot flight computer, uses actuators mechanically coupled to each flight deck controller to position the flight deck controller to mimic manual operation of the flight control surfaces. Additionally, the system allows smooth disengagement of the autopilot and transfer of the aircraft to pilot control when the pilot takes control of any flight deck controller by moving it from a backdrive system-commanded position by a predetermined displacement for a predetermined time.

Abstract: A method and apparatus for producing a dynamic thrust asymmetry airplane rudder compensation command with no direct thrust measurement is disclosed. An excess thrust estimate based on measured acceleration along the flight path of the airplane and measured vertical speed of the airplane is low pass filtered (11) to attenuate noise from the inertially derived data. The low pass filtered data is further filtered by a washout filter (15) to produce data that is sensitive only to changes in the excess thrust estimate. The input to the washout filter is frozen (13) and the output of the washout filter reduced to zero if the go-around or flare modes of the control system of the airplane are active or if the thrust asymmetry compensation feature of the primary flight computer is armed. The output of the washout filter is also zeroed when both engines are running, or multiplied by either -1 or +1 when one engine is out. Whether the multiplication is by -1 or +1 depends upon which engine is out.