Abstract: Automatic flight control apparatus, preferably for use in a helicopter, comprises a parallel connected servosystem which allows the apparatus to discern manual input forces and to respond naturally to them. The manual forces are sensed internal the parallel servosystem by monitoring the corrective error drive signal to the parallel servomotor. A signal indicative of excess manual force is used to develop other signals, one of which aids in temporarily defeating the command signal generated by the autopilot in trying to do its job, and another of which temporarily contributes positive feedback within the parallel servosystem so as to cause the servomotor to aid the pilot's manual input force. Another preferred embodiment includes a series connected servosystem.

Abstract: A flight control system increases the automatic control authority over, preferably, a helicopter yaw axis. A limited authority series servo is complemented with a full authority parallel servo. The parallel servo is driven by a combination of a trim command signal and a signal representing the excess of the yaw command signal over the amplitude limited drive signal to the series servo.

Abstract: A gyro system employing the pickoff synchros as erection sensors and as torquers to erect the gyro.

Abstract: A redundant channel control system includes one or more voters having a high-pass filter connected between a pair of voter inputs.

Abstract: In a helicopter a servo system connected to operate in parallel with the rotor blade pitch controlling linkages and also to receive autopilot generated signals directing maneuvers. The system limits the autopilot control over the blade pitch or position in the short term and permits full control over the long term.

Abstract: Method and apparatus for limiting the authority of a position servo system over an aircraft control surface. The amplitude of the energizing signal delivered to the actuator portion of the servo system is limited in accordance with a non-constant function of time.