Abstract: Apparatus and methods for eliminating back drive in a push pull type control system, are provided. An exemplary apparatus includes a control rod including a pair of spaced apart piston displacement members each configured to carry a check valve. The apparatus also includes a pair of opposite-face check valves each configured to seal against respective opposing face of a piston head to form a hydraulic lock, preventing back drive in the control system.

Abstract: Apparatus and methods for eliminating back drive in a push pull type control system, are provided. An exemplary apparatus includes a control rod including a pair of spaced apart piston displacement members each configured to carry a check valve. The apparatus also includes a pair of opposite-face check valves each configured to seal against respective opposing face of a piston head to form a hydraulic lock, preventing back drive in the control system.

Abstract: A rotor aircraft has an engine, a propeller, wings, and a rotor. An electric motor is coupled to the rotor drive shaft for applying torque to the rotor drive shaft. The electric motor is sized to supply all of the torque to pre-rotate the rotor to a selected speed prior to liftoff of the aircraft. The wings are capable of providing substantially all of the lift required during forward flight at a cruise speed. The rotor being is capable of being trimmed to provide substantially zero lift and auto-rotate at cruise speed. Sensors sense flight conditions of the aircraft and provide signals to a controller that selectively causes the electric motor to cease applying torque to the rotor drive shaft during autorotation at cruise speed. The controller also causes the electric motor to apply torque to the rotor drive shaft if the sensors indicate additional rotor speed is needed.

Abstract: A rotor aircraft has an engine having an output shaft. At least one propeller is driven by the engine to provide forward thrust to the aircraft. Wings provide lift while in forward flight. A rotor is driven by rotor drive mechanism, which selectively provides torque to the rotor drive shaft from the engine while in a first mode. The rotor drive mechanism selectively provides torque to the rotor drive shaft to rotate at a speed independent of a speed of the output shaft of the engine while in a second mode. In one embodiment, the rotor drive mechanism is a variable speed transmission powered by the engine. In another embodiment, the rotor drive mechanism is an electric motor.

Abstract: Apparatus and methods for eliminating back drive in a push pull type control system, are provided. An exemplary apparatus includes a control rod including a pair of spaced apart piston displacement members each configured to carry a check valve. The apparatus also includes a pair of opposite-face check valves each configured to seal against respective opposing face of a piston head to form a hydraulic lock, preventing back drive in the control system.