Abstract: A rotor blade has a spanwise axis, a root comprising an anchor having an anchor surface configured to form at least one of a normal angle relative to the spanwise axis and an acute angle relative to the spanwise axis, and a selectively removable tip comprising a connector having a connector surface configured to complement the anchor surface.

Abstract: A rotorcraft rotor blade assembly includes a stub spar extending less than a full span of the rotor blade assembly. An upper skin portion extends substantially the full span of the rotor blade assembly. A lower skin portion extends substantially the full span of the rotor blade assembly. The stub spar is positioned between the upper skin portion and the lower skin portion.

Abstract: A rotor blade assembly includes a rotor blade comprising an inboard end and an outboard end. A composite yoke fitting made from a composite material is attached to the rotor blade. The composite yoke fitting includes an outboard portion inserted into the inboard end of the rotor blade, an inboard portion, and a flexure region about which the rotor blade is configured to flex. The inboard portion and the flexure region are outside the rotor blade.

Abstract: A rotorcraft rotor blade assembly includes an upper skin portion extending substantially a full span of the rotor blade assembly and a lower skin portion extending substantially the full span of the rotor blade assembly. Each of the upper skin portion and the lower skin portion is configured to carry at least substantially 30% of rotor blade assembly loads.

Abstract: A rotorcraft rotor blade assembly includes a stub spar extending less than a full span of the rotor blade assembly. An upper skin portion extends substantially the full span of the rotor blade assembly. A lower skin portion extends substantially the full span of the rotor blade assembly. The stub spar is positioned between the upper skin portion and the lower skin portion.

Abstract: A rotorcraft rotor blade assembly includes a stub spar extending less than a full span of the rotor blade assembly. An upper skin portion extends substantially the full span of the rotor blade assembly. A lower skin portion extends substantially the full span of the rotor blade assembly. The stub spar is positioned between the upper skin portion and the lower skin portion.

Abstract: A rotor hub can include a yoke, a mast, and one or more radially oriented actuators. The first radial actuator and the second radial actuator each have a piston configured to impart a translation of the yoke relative to the mast. The radial actuators are configured to attenuate in-plane whirling vibrations. The rotor hub can also have actuators coupled between the mast and the yoke for attenuating flapping and vertical vibrations.

Abstract: According to one embodiment, a constant velocity (CV) joint includes a first yoke, a second yoke, and three bearings. The first yoke is configured to be rotatably coupled to an input device about a first axis and configured to receive the input device through a first opening. The second yoke is rotatably coupled to the first yoke about a second axis and rotatably coupled to an output device about a third axis. The first bearing is disposed about the first axis adjacent to the first yoke, the second bearing is disposed about the second axis adjacent to the first yoke or the second yoke, and the third bearing disposed about the third axis adjacent to the second yoke. The first and third bearings torsionally constrain movement the first yoke and the second yoke so as to achieve a substantially CV characteristic between the input device and the output device.

Abstract: According to one embodiment, a bearing features an elastomeric portion having an opening therethrough, a member disposed within the opening of the elastomeric portion, and a separation feature disposed between the member and the elastomeric portion. The member comprises a conical body portion arranged such that an interior diameter of the conical body portion is smaller than an exterior diameter of the conical body portion. The separation feature prevents contact between the member and the elastomeric portion.

Abstract: According to one embodiment, a bearing is situated between a pitch link and a swashplate or a hub. The bearing comprises an outer housing having a first opening therethrough, an intermediate housing adjacent the housing inside the first opening and having a second opening therethrough, and an inner housing adjacent the intermediate housing inside the second opening and having a third opening therethrough. The inner housing comprising a first inner surface and a second inner surface defining the third opening. A first member is adjacent the first inner surface inside the third opening having a fourth opening therethrough. A second member is adjacent the second inner surface inside the third opening having a fifth opening therethrough coaxial with the fourth opening.

Abstract: A rotor hub comprises a gimbal assembly and an elastomeric centrifugal force bearing. The gimbal assembly is configured to transfer rotational movement of a mast to the rotor hub and to enable the rotor hub to flap relative to the mast. The elastomeric centrifugal force bearing is configured to withstand centrifugal force of a rotor blade when the mast is rotated and is configured to accommodate pitch changes of the rotor blade. A method comprises designing a gimbal assembly that enables a tail rotor hub to flap relative to a tail rotor mast. A centrifugal force bearing is selected that enables tail rotor blades to withstand centrifugal force and that allows for tail rotor blade pitch change articulation. Then, instructions are provided to use the gimbal assembly and the centrifugal force bearing in an in-plane tail rotor assembly.

Abstract: A rotorcraft rotor blade assembly includes an upper skin portion extending substantially a full span of the rotor blade assembly and a lower skin portion extending substantially the full span of the rotor blade assembly. Each of the upper skin portion and the lower skin portion is configured to carry at least substantially 30% of rotor blade assembly loads.

Abstract: A rotorcraft rotor blade assembly includes a stub spar extending less than a full span of the rotor blade assembly. An upper skin portion extends substantially the full span of the rotor blade assembly. A lower skin portion extends substantially the full span of the rotor blade assembly. The stub spar is positioned between the upper skin portion and the lower skin portion.

Abstract: A hub system comprises at least one yoke, at least one shear bearing, and at least one mast adapter. The at least one mast adapter is configured to support the at least one yoke and the at least one shear bearing, and the at least one yoke has a flapping hinge that is non-coincident with a flapping hinge of the at least one shear bearing. Another hub system comprises a stacked yoke and a mast adapter. The mast adapter is configured to transfer rotation from a rotor mast to the hub system to rotate the hub system about a central axis of rotation. The mast adapter is further configured to support the stacked yoke such that each yoke in the stacked yoke is configured to accommodate at least some amount of rotation about an axis that is perpendicular to or about perpendicular to the central axis of rotation.

Abstract: A flexible joint assembly for providing flexure to a rotor blade comprising an upper hub plate and a lower hub plate configured to secure a rotor blade yoke via a bolted joint located radially outward of a mast; and an upper flexure assembly connected to the upper hub plate and a lower flexure assembly connected to the lower hub plate, wherein the upper flexure assembly and lower flexure assembly are configured to promote flapping of the rotor blade yoke about a flapping hinge located radially outward of the bolted joint.

Abstract: Some examples of techniques to cost-effectively embed fiber optic cables in laminate structures and to terminate the fiber optic cables on the surface of the laminate for robust and easily-repairable connections can be implemented in rotorcraft composites. To position a cable in the rotorcraft composite, a length of a fiber optic cable is embedded between layers of a composite rotorcraft material. The length of the fiber optic cable is oriented in a substantially S-shape between the layers. An end of the length of the substantially S-shaped fiber optic cable is extended to an edge of the composite rotorcraft material. The end of the length of the substantially S-shaped fiber optic cable is terminated at the edge of the composite rotorcraft material in either a storage area or easily machinable embedded connection.

Abstract: A rotor blade includes an active flap and an airflow disturber configured to selectively alter airflow across the active flap.

Abstract: A shear bearing for a rotor system has a four bar linkage and a grip configured to retain a flexural yoke and the grip is connected between a first set of opposing links of the four bar linkage. A rotor system has a flexural yoke and a shear bearing configured to perform at least one of transmitting forces to the yoke and receiving forces from the yoke, wherein the yoke is free of cavities for receiving the shear bearing. A rotational system has a flexural yoke and a damper disposed on a surface of the yoke.

Abstract: A rotor blade assembly includes a rotor blade comprising an inboard end and an outboard end. A composite yoke fitting made from a composite material is attached to the rotor blade. The composite yoke fitting includes an outboard portion inserted into the inboard end of the rotor blade, an inboard portion, and a flexure region about which the rotor blade is configured to flex. The inboard portion and the flexure region are outside the rotor blade.

Abstract: Some examples of techniques to cost-effectively embed fiber optic cables in laminate structures and to terminate the fiber optic cables on the surface of the laminate for robust and easily-repairable connections can be implemented in rotorcraft composites. To position a cable in the rotorcraft composite, a length of a fiber optic cable is embedded between layers of a composite rotorcraft material. The length of the fiber optic cable is oriented in a substantially S-shape between the layers. An end of the length of the substantially S-shaped fiber optic cable is extended to an edge of the composite rotorcraft material. The end of the length of the substantially S-shaped fiber optic cable is terminated at the edge of the composite rotorcraft material in either a storage area or easily machinable embedded connection.