Abstract: A transmission tilt control device includes a transmission rotatably coupled to an airframe of a helicopter, a rotor mast coupled to the transmission, and an actuator coupled between the transmission and the airframe. The actuator being configured to rotate the transmission fore and aft about a tilt axis that is perpendicular to an axis of rotation of the rotor mast.

Abstract: A rotor system includes a yoke, a plurality of blade grip assemblies and a plurality of centrifugal force bearings coupling the blade grip assemblies with the yoke. A plurality of rotor blades are coupled to the blade grip assemblies such that each rotor blade has a coincident hinge and such that each rotor blade has three independent degrees of freedom including blade pitch about a pitch change axis, blade flap about a flapping axis and lead-lag about a lead-lag axis. A blade-to-blade damping ring includes a plurality of damper anchors each coupled to one of the blade grip assemblies along the respective pitch change axis and a plurality of lead-lag dampers each coupled between adjacent damper anchors. During blade pitch operations, each blade grip assembly is operable to rotate relative to the respective damper anchor, such that the blade-to-blade damping ring is operable to provide pitch independent lead-lag damping.

Abstract: Systems and methods include providing an aircraft with a tail rotor system having a tail rotor housing that forms a cambered airfoil between an upper cambered surface and an lower cambered surface of the tail rotor housing. The cambered airfoil design of the tail rotor housing is capable of providing sufficient lifting force of an aircraft to offload the tail rotor during forward flight, thereby eliminating the need for a traditional vertical stabilizer or fin. The tail rotor blades of the tail rotor system are disposed within an aperture in the tail rotor housing, which minimizes or preferably eliminates exposure of the tail rotor blades to edgewise airflow typically encountered during forward flight, thereby allowing rigid rotor hubs, both in-plane and out-of-plane, to be used in the tail rotor system while also reducing noise output of the tail rotor system.

Abstract: A standpipe assembly for a rotorcraft includes a slip ring positioned within the mast of the rotorcraft. The slip ring includes a stator rotationally connected to a rotor. A flexible coupling is connected to the stator and a standpipe tube is connected to the flexible coupling. The flexible coupling is capable of angular, axial, and torsional displacement.

Abstract: Systems and methods of operating a test apparatus to simulate testing a production aircraft component include assembling a test assembly having a test specimen and a wear protection material disposed on opposing sides of the test specimen, an outer plate disposed on each side of the test specimen in contact with the wear protection material, and a bolt disposed through the test specimen and the outer plates and applying a preload against the wear protection material. The test assembly is secured in a test machine, and the test machine is operated to provide a predetermined displacement of the test specimen relative to the outer plates at a predetermined frequency at a determined frequency of displacement cycles. The preload, the predetermined displacement, and the predetermined frequency of displacement cycles are determined through finite element analysis of an analytical model of the production component.

Abstract: A rotor assembly has a composite driveshaft extending between a transmission and a yoke for providing torque from the transmission to the yoke to cause rotation of the yoke and a plurality of rotor blade assemblies attached thereto. The rotor hub also has a composite static mast coupled to the yoke and a frame. The static mast being configured to carry the lift and thrust forces from the yoke to the frame.

Abstract: Systems and methods of operating a test apparatus to simulate testing a production aircraft component include assembling a test assembly having a test specimen and a wear protection material disposed on opposing sides of the test specimen, an outer plate disposed on each side of the test specimen in contact with the wear protection material, and a bolt disposed through the test specimen and the outer plates and applying a preload against the wear protection material. The test assembly is secured in a test machine, and the test machine is operated to provide a predetermined displacement of the test specimen relative to the outer plates at a predetermined frequency at a determined frequency of displacement cycles. The preload, the predetermined displacement, and the predetermined frequency of displacement cycles are determined through finite element analysis of an analytical model of the production component.

Abstract: An aircraft rotor assembly has a yoke and a plurality of rotor blade assemblies coupled thereto. Each of the rotor blade assemblies include a rotor blade, a bearing, and a blade grip coupling the rotor blade to the bearing. Each of the rotor blades is rotatable about a lead-lag axis, flap axis, and a pitch change axis, wherein all the axes intersect within the bearing. Adjacent pairs of rotor blade assemblies are coupled together via a damper assembly that is coupled to the pitch change axis of each of the rotor blade assemblies.

Abstract: In one embodiment, a rotor hub comprises a hub plate, a yoke for attaching a plurality of rotor blades, a plurality of yoke support bearings, and a plurality of cushioned damper bearings for attaching a plurality of dampers.

Abstract: In one embodiment, a rotor hub comprises a hub body, and a plurality of blade grips configured for attaching a plurality of rotor blades. The rotor hub further comprises a plurality of centrifugal force bearings coupled to the plurality of blade grips, wherein a focus of the plurality of centrifugal force bearings is aligned with a centerline of a rotor mast. The rotor hub further comprises a plurality of drive links configured to transfer torque to the plurality of rotor blades, wherein the plurality of drive links is positioned to correspond with a leading edge side of the plurality of rotor blades. The rotor hub further comprises a plurality of pitch horns configured to adjust a pitch of the plurality of rotor blades.

Abstract: In one embodiment, a method may comprise coupling a plurality of reinforcement fibers to a plurality of spherical components; inserting the plurality of spherical components into an enclosure; and heating the enclosure to cause the plurality of spherical components to expand, wherein the plurality of spherical components expands to form a geodesic structure, wherein the geodesic structure comprises a plurality of polyhedron components configured in a geodesic arrangement.

Abstract: An adjustable balance module for the balancing of rotatable blades. The adjustable blade balance module includes a frame that retains and covers an adjustment screw with a mass that translates along a threaded shaft of the adjustment screw. The adjustment screw is incrementally controlled by an adjustment dial that is accessible from an exterior surface of the blade.

Abstract: In one embodiment, a rotorcraft can include a teetering tail rotor assembly. The teetering tail rotor assembly can include one or more multi-bearing yokes. Each yoke can include three or more spherical bearings evenly spaced apart from each other. The teetering tail rotor assembly can include a tail rotor blade affixed to each yoke arm through the three or more spherical bearings. The physical dimensions of the three-bearing yoke can be 10% smaller than a two bearing yoke that can support an equivalent load. For example, the length of each three bearing yoke can be 28 inches, the thickness can be 0.85 inches, and the width can be 3.250 inches.