Abstract: A quiet landing gear door and methods are presented. A landing gear door comprises a trailing edge and a leading edge and is operable to deploy to a landing gear door deployed position. A door flap comprises the trailing edge and is hinged to the landing gear door. The door flap deflects toward a landing gear strut to a door flap deployed position in response to deployment of the landing gear door. A leading edge section comprises the leading edge and is coupled to the door flap. The leading edge section deflects toward the landing gear strut to a leading edge deployed position in response to deployment of the landing gear door.

Abstract: A quiet landing gear door and methods are presented. A landing gear door comprises a trailing edge and a leading edge and is operable to deploy to a landing gear door deployed position. A door flap comprises the trailing edge and is hinged to the landing gear door. The door flap deflects toward a landing gear strut to a door flap deployed position in response to deployment of the landing gear door. A leading edge section comprises the leading edge and is coupled to the door flap. The leading edge section deflects toward the landing gear strut to a leading edge deployed position in response to deployment of the landing gear door.

Abstract: A quiet landing gear door and methods are presented. A landing gear door comprises a trailing edge and a leading edge and is operable to deploy to a landing gear door deployed position. A door flap comprises the trailing edge and is hinged to the landing gear door. The door flap deflects toward a landing gear strut to a door flap deployed position in response to deployment of the landing gear door. A leading edge section comprises the leading edge and is coupled to the door flap. The leading edge section deflects toward the landing gear strut to a leading edge deployed position in response to deployment of the landing gear door.

Abstract: A method and apparatus for controlling a propeller of a contra-rotation open fan (CROF) engine of an aircraft. A diameter of the propeller is set to be at a first diameter during at least a portion of a first flight condition of the aircraft. The diameter of the propeller is set to be at a second diameter, different from the first diameter, during at least a portion of a second flight condition of the aircraft.

Abstract: A quiet landing gear door and methods are presented. A landing gear door comprises a trailing edge and a leading edge and is operable to deploy to a landing gear door deployed position. A door flap comprises the trailing edge and is hinged to the landing gear door. The door flap deflects toward a landing gear strut to a door flap deployed position in response to deployment of the landing gear door. A leading edge section comprises the leading edge and is coupled to the door flap. The leading edge section deflects toward the landing gear strut to a leading edge deployed position in response to deployment of the landing gear door.

Abstract: An air vehicle propulsion system incorporates an engine core with a power shaft to drive an outer blade row. The power shaft extends through and is supported by a counter rotation transmission unit which drives an inner blade row in counter rotational motion to the outer blade row. The counter rotation transmission unit exchanges power from the engine core with the shaft. An actuator engages the shaft for translation from a first retracted position to a second extended position.

Abstract: A method and apparatus for controlling a propeller of a contra-rotation open fan (CROF) engine of an aircraft. A diameter of the propeller is set to be at a first diameter during at least a portion of a first flight condition of the aircraft. The diameter of the propeller is set to be at a second diameter, different from the first diameter, during at least a portion of a second flight condition of the aircraft.

Abstract: An air vehicle propulsion system incorporates an engine core with a power shaft to drive an outer blade row. The power shaft is extends through and is supported by a counter rotation transmission unit which drives an inner blade row in counter rotational motion to the outer blade row. The counter rotation transmission unit exchanges power from the engine core with the shaft. An actuator engages the shaft for translation from a first retracted position to a second extended position.