Abstract: A retractable gun for mounting within the fuselage of an aircraft, typically a helicopter, is disposed in a firing position and aimed by rotation of a turret which is coupled to and parallel to the longitudinal axis of the aircraft. The gun is aimed by simultaneous and independent rotation of the gun about an elevation pivot axis through which the gun is coupled to the turret. The turret axis and turret is disposed within an enclosure or within the fuselage of the airplane to allow withdrawal of the gun and turret from their exposed position. However, even in the enclosed position the gun can be fired. The elevation pivot axis is approximately perpendicular to the turret axis and permits two independent degrees of rotational freedom with which the gun may be aimed. Thus, the gun may be aimed at any point within at least a hemispherical range beneath the fuselage of an aircraft.

Abstract: A low drag, bearingless coupling is provided between a blade and hub of a helicopter rotor system by coupling the hub and blade together by means of a planar, elastic flexure or element which extends between the blade and the hub in a generally azimuthal direction in the rotor plane. The thickness of the flexure is such so that it is smaller than the adjacent blade or hub thicknesses so that the aerodynamic cross section presented by the flexure to air flow is negligible. The flexure is particularly characterized by having a bend in the coupling between the hub and blade. In the illustrated embodiment the flexure is integral and "W"-shaped with a "U"-shaped segment of the "W"-shaped flexure extending between each side of the adjacent blade and hub arms. The flexure may be made of rod having a circular cross section or of flat plate formed in a shape to have the desired elastic and resilient characteristics.

Abstract: A low drag, bearingless coupling is provided between a blade and hub of a helicopter rotor system by coupling the hub and blade together by means of a planar, elastic flexure or element which extends between the blade and the hub in a generally azimuthal direction in the rotor plane. The thickness of the flexure is such so that it is smaller than the adjacent blade or hub thicknesses so that the aerodynamic cross section presented by the flexure to air flow is negligible. The flexure is particularly characterized by having a bend in the coupling between the hub and blade. In the illustrated embodiment the flexure is integral and "W"-shaped with a "U"-shaped segment of the "W"-shaped flexure extending between each side of the adjacent blade and hub arms. The flexure may be made of rod having a circular cross section or of flat plate formed in a shape to have the desired elastic and resilient characteristics.