In normal operation, the input cranks to both the MPCU and standby rudder actuator will rotate to provide the servo valve command to the units, and the rudder will be hydraulically moved by the MPCU. The rudder movement is in turn fed back mechanically to both the MPCU and standby actuator systems so that when the rudder surface deflects to the position commanded by the pilot, the input cranks on both of the units will be returned to their null positions. Thus, there is a geometric relationship between the rudder position, the input crank of the MPCU, the torque tube, and the input crank of the standby rudder actuator that is retained during normal operation.