Abstract: An aircraft, has an airframe, a transmission, and a liquid inertia vibration elimination (LIVE) system disposed between the airframe and the transmission via spherical bearings of two legs and via a central spherical bearing.

Abstract: An example of a hub for a tail rotor includes a body configured to couple to a mast of a rotor system, a trunnion disposed within the body, first and second shafts disposed on opposite sides of the trunnion, first and second end plates secured to the body, and first and second end bearings, the first end bearing disposed between the first shaft and the first end plate and the second end bearing disposed between the second shaft and the second end plate.

Abstract: A method is provided in one example embodiment and may include positioning at least one nozzle within a hollow portion of a rotor blade at a distance associated with a span of the rotor blade and providing, via the at least one nozzle, a liquid foam mixture in the hollow portion, wherein the liquid foam expands and becomes a solid foam material that fills the hollow portion of the rotor blade. Another method is provided in another example embodiment and may include providing a plurality of openings for a rotor blade that are positioned proximate to a hollow portion of the rotor blade and providing a liquid foam mixture in the hollow portion of the rotor blade through at least one opening of the rotor blade, wherein the liquid foam mixture expands and becomes a solid foam material that fills the hollow portion of the rotor blade.

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: An example of a hub for a tail rotor includes a body configured to couple to a mast of a rotor system, a trunnion disposed within the body, first and second shafts disposed on opposite sides of the trunnion, first and second end plates secured to the body, and first and second end bearings, the first end bearing disposed between the first shaft and the first end plate and the second end bearing disposed between the second shaft and the second end plate.

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 a 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: An example of a hub for a tail rotor includes a body configured to couple to a mast of a rotor system, a trunnion disposed within the body, first and second shafts disposed on opposite sides of the trunnion, first and second end plates secured to the body, and first and second end bearings, the first end bearing disposed between the first shaft and the first end plate and the second end bearing disposed between the second shaft and the second end plate.

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: An exemplary rotorcraft includes a power train with an engine coupled to a gearbox, a main rotor blade having a mast coupled to the power train, a control input linkage in communication between a pilot input device and the main rotor blade configured to communicate a control input force from the pilot input device to the main rotor blade, and a counterweight system in connection with the control input linkage and the power train to apply a centrifugal force to the control input linkage.

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 example of a hub for a tail rotor includes a body configured to couple to a mast of a rotor system, a trunnion disposed within the body, first and second shafts disposed on opposite sides of the trunnion, first and second end plates secured to the body, and first and second end bearings, the first end bearing disposed between the first shaft and the first end plate and the second end bearing disposed between the second shaft and the second end plate.

Abstract: A duct configured with a fan to increase thrust. The duct includes an interior surface configured to surround a rotation axis of the fan. The interior surface includes a nozzle portion configured to be located upstream of the fan and a diffuser portion configured to be located downstream of the fan. The interior surface defines an opening configured to introduce additional airflow along the diffuser portion.

Abstract: An aircraft, has an airframe, a transmission, and a liquid inertia vibration elimination (LIVE) system disposed between the airframe and the transmission via spherical bearings of two legs and via a central spherical bearing.

Abstract: An exemplary rotorcraft includes a power train with an engine coupled to a gearbox, a main rotor blade having a mast coupled to the power train, a control input linkage in communication between a pilot input device and the main rotor blade configured to communicate a control input force from the pilot input device to the main rotor blade, and a counterweight system in connection with the control input linkage and the power train to apply a centrifugal force to the control input linkage.

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 method is provided in one example embodiment and may include positioning at least one nozzle within a hollow portion of a rotor blade at a distance associated with a span of the rotor blade and providing, via the at least one nozzle, a liquid foam mixture in the hollow portion, wherein the liquid foam expands and becomes a solid foam material that fills the hollow portion of the rotor blade. Another method is provided in another example embodiment and may include providing a plurality of openings for a rotor blade that are positioned proximate to a hollow portion of the rotor blade and providing a liquid foam mixture in the hollow portion of the rotor blade through at least one opening of the rotor blade, wherein the liquid foam mixture expands and becomes a solid foam material that fills the hollow portion of the rotor blade.

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: An abrasion strip and method of manufacturing the same. The abrasion strip being composed of INCONEL® alloy 718SPF™ and being shaped by superplastic forming.

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.

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.