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 rotor hub assembly for a rotorcraft includes a yoke forming a bearing bore. The yoke has a teetering axis extending through the bearing bore. The rotor hub assembly includes a flapping bearing disposed in the bearing bore. The flapping bearing is operable to regulate teetering of the yoke about the teetering axis. The rotor hub assembly includes an axial spring abutting the flapping, thereby reducing movement of the flapping bearing along the teetering axis.

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: 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 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: A rotor hub assembly for a rotorcraft includes a yoke forming a bearing bore. The yoke has a teetering axis extending through the bearing bore. The rotor hub assembly includes a flapping bearing disposed in the bearing bore. The flapping bearing is operable to regulate teetering of the yoke about the teetering axis. The rotor hub assembly includes an axial spring abutting the flapping, thereby reducing movement of the flapping bearing along the teetering axis.

Abstract: A liquid inertia vibration elimination (LIVE) system having an upper end cap, a lower end cap, a spindle located between the upper end cap and the lower end cap, and an external tube connected between the upper end cap and the lower end cap.