Abstract: A rotor assembly for generating thrust for a vehicle. The rotor assembly includes a rotor hub and a plurality of rotor blade assemblies coupled to the rotor hub. Each rotor blade assembly includes a metallic bearing race, a composite rotor blade and a metallic coupling assembly. The composite rotor blade has a root section with a radially outwardly tapered outer surface. The metallic coupling assembly has a radially inwardly tapered inner surface that receives the radially outwardly tapered outer surface of the root section of the rotor blade therein to provide a centrifugal force seat for the rotor blade. The coupling assembly includes at least two circumferentially distributed coupling members. The coupling assembly is configured to couple the rotor blade to the bearing race and to provide a centrifugal force load path therebetween.

Abstract: A rotor assembly for generating thrust for a vehicle. The rotor assembly includes a rotor hub and a plurality of rotor blade assemblies coupled to the rotor hub. Each rotor blade assembly includes a metallic bearing race, a composite rotor blade and a metallic coupling assembly. The composite rotor blade has a root section with a radially outwardly tapered outer surface. The metallic coupling assembly has a radially inwardly tapered inner surface that receives the radially outwardly tapered outer surface of the root section of the rotor blade therein to provide a centrifugal force seat for the rotor blade. The coupling assembly includes at least two circumferentially distributed coupling members. The coupling assembly is configured to couple the rotor blade to the bearing race and to provide a centrifugal force load path therebetween.

Abstract: An airfoil component assembly for an aircraft includes an additively manufactured flyaway tool including an infill support core and an interface sheet surrounding the infill support core, a spar formed from one or more layers of composite material disposed on the interface sheet of the flyaway tool and a skin formed from one or more layers of composite material disposed on the spar and the interface sheet of the flyaway tool. The flyaway tool, the spar and the skin form the airfoil component assembly for use by the aircraft in flight.

Abstract: A yaw control system for a rotorcraft featuring a floor mounted pair of pedals configured to measure an up and down motion of a pair of pedals and utilize that up and down motion as a yaw moment control input. The pair of pedals can rock laterally, fore and aft, or vertically. The pair of pedals can be mechanically interconnected to other pairs of pedals or electrically interconnected to duplicate motion across pairs of pedals.

Abstract: An airfoil component assembly for an aircraft includes an additively manufactured flyaway tool including an infill support core and an interface sheet surrounding the infill support core, a spar formed from one or more layers of composite material disposed on the interface sheet of the flyaway tool and a skin formed from one or more layers of composite material disposed on the spar and the interface sheet of the flyaway tool. The flyaway tool, the spar and the skin form the airfoil component assembly for use by the aircraft in flight.

Abstract: In an implementation, a rotor blade for a helicopter may include an outer layer. The outer layer may have a leading edge region and a trailing edge region and may define a cavity. The leading edge region may include a first shape at least partially corresponding with an airfoil, e.g., a wing. An insert may be included within the cavity and be encompassed thereby. The insert may include a shape that substantially corresponds with the first shape, e.g., the insert may substantially correspond with a leading edge of an airfoil. The insert may have a plurality of weight shot each of which may be surrounded by a binding agent.

Abstract: A yaw control system for a rotorcraft featuring a floor mounted pair of pedals configured to measure an up and down motion of a pair of pedals and utilize that up and down motion as a yaw moment control input. The pair of pedals can rock laterally, fore and aft, or vertically. The pair of pedals can be mechanically interconnected to other pairs of pedals or electrically interconnected to duplicate motion across pairs of pedals.

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 proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. Hub bolts couple each of the bearing cages to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assemblies and the yoke inboard of the inboard pockets.

Abstract: A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket with an outboard surface. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a shear bearing and a centrifugal force bearing having an integral shoe with an outboard surface. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. The integral shoes are coupled to the yoke such that there is a spaced apart relationship between the outboard surfaces of the integral shoes and the outboard surfaces of the pockets to prevent centrifugal force load transfer therebetween.

Abstract: A method for determining a shear property of a sample includes supporting a sample at three or more separate support locations about a periphery of a first surface of the sample in a testing fixture, the sample including a second surface separated from the first surface by a thickness, wherein the sample is axisymmetric about an axis that is orthogonal to the first surface. The method includes applying a load on the second surface of the sample with a load applicator in a direction substantially parallel with the axis, measuring, with a controller, shear testing data of the sample in response to applying the load, and determining, with the controller, a shear property of the sample from the measured shear testing data.

Abstract: A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. Hub bolts couple each of the bearing cages to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assemblies and the yoke inboard of the inboard pockets.

Abstract: A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket with an outboard surface. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a shear bearing and a centrifugal force bearing having an integral shoe with an outboard surface. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. The integral shoes are coupled to the yoke such that there is a spaced apart relationship between the outboard surfaces of the integral shoes and the outboard surfaces of the pockets to prevent centrifugal force load transfer therebetween.

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 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 method for determining a shear property of a sample includes supporting a sample at three or more separate support locations about a periphery of a first surface of the sample in a testing fixture, the sample including a second surface separated from the first surface by a thickness, wherein the sample is axisymmetric about an axis that is orthogonal to the first surface. The method includes applying a load on the second surface of the sample with a load applicator in a direction substantially parallel with the axis, measuring, with a controller, shear testing data of the sample in response to applying the load, and determining, with the controller, a shear property of the sample from the measured shear testing data.

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.