Abstract: A rotor blade assembly connectable to a rotor hub configured to rotate about a center axis includes a torsional pitch member coupled to the rotor hub, a torque tube coupled to the torsional pitch member, wherein the torsional pitch member extends away from the center axis through a portion of the torque tube, a blade coupled to the torque tube, and a pitch control member coupled to the torque tube and configured to control a pitch angle of the blade, wherein the torsional pitch member includes a first curvilinear channel and a second curvilinear channel each having a front side and a back side, wherein the first curvilinear channel and the second curvilinear channel are disposed adjacent to each other, such that the back side of the first curvilinear channel faces the back side of the second curvilinear channel.

Abstract: A rotor blade assembly of an aircraft having a rotor hub including a structural member having an inboard end and an outboard end, the structural member being connectable with the rotor hub. A spar surrounds the structural member and extends at least partially along a rotor blade axis. A pitch bearing assembly supports the spar relative to the structural member. The pitch bearing assembly includes an inboard pitch bearing mounted to the inboard end of the structural member and an outboard pitch bearing mounted to the outboard end of the structural member. The rotor blade assembly additionally includes a centrifugal assembly including a centrifugal bearing disposed between the inboard pitch bearing and the outboard pitch bearing relative to the rotor blade axis.

Abstract: A rotor blade assembly connectable to a rotor hub configured to rotate about a center axis includes a torsional pitch member coupled to the rotor hub, a torque tube coupled to the torsional pitch member, wherein the torsional pitch member extends away from the center axis through a portion of the torque tube, a blade coupled to the torque tube, and a pitch control member coupled to the torque tube and configured to control a pitch angle of the blade, wherein the torsional pitch member includes a first curvilinear channel and a second curvilinear channel each having a front side and a back side, wherein the first curvilinear channel and the second curvilinear channel are disposed adjacent to each other, such that the back side of the first curvilinear channel faces the back side of the second curvilinear channel.

Abstract: A hub assembly for a rotary wing aircraft having a rotor shaft which rotates about a rotational axis includes: a hub extender arm coupled to the rotor shaft; a pitch bearing that is disposed within and connected to the hub extender arm; and a rotor blade assembly having an inboard section disposed within the hub extender arm and connected to the pitch bearing; wherein the hub extender arm has an inboard cross-sectional area where coupled to the rotor shaft that is greater than an outboard cross-sectional area where coupled to the pitch bearing.

Abstract: A rotor blade assembly of an aircraft having a rotor hub including a structural member having an inboard end and an outboard end, the structural member being connectable with the rotor hub. A spar surrounds the structural member and extends at least partially along a rotor blade axis. A pitch bearing assembly supports the spar relative to the structural member. The pitch bearing assembly includes an inboard pitch bearing mounted to the inboard end of the structural member and an outboard pitch bearing mounted to the outboard end of the structural member. The rotor blade assembly additionally includes a centrifugal assembly including a centrifugal bearing disposed between the inboard pitch bearing and the outboard pitch bearing relative to the rotor blade axis.

Abstract: A hub assembly for a rotary wing aircraft having a rotor shaft which rotates about a rotational axis includes: a hub extender arm coupled to the rotor shaft; a pitch bearing that is disposed within and connected to the hub extender arm; and a rotor blade assembly having an inboard section disposed within the hub extender arm and connected to the pitch bearing; wherein the hub extender arm has an inboard cross-sectional area where coupled to the rotor shaft that is greater than an outboard cross-sectional area where coupled to the pitch bearing.

Abstract: A rotary wing aircraft yoke is provided including an arcuate medial portion. A pair of arms extends from the medial portion and each terminates in a distal end. The yoke is made from multiple plies of glass and graphite fibers of varying orientations. The number of graphite plies increases along each arm from adjacent the medial portion to the distal end.

Abstract: An actuator assembly including a resilient substrate having one or more shape memory alloys secured to the substrate. The shape memory alloys are configured to move a portion or all of the actuator assembly between an at-rest configuration and an actuated configuration. The shape memory alloys are elastically bendable and can be contracted from an elongated length to a contracted length in response to transmission of an electrical current therethrough. The electrical current is of a magnitude sufficient to heat the shape memory alloys from a first temperature to a second temperature so that a portion of or the entire actuator assembly can move from the at-rest configuration to the actuated configuration. Termination or reduction of the electrical current allows the shape memory alloy to cool and thereby elongate from the contracted length to the elongated length.

Abstract: A rotary wing aircraft yoke is provided including an arcuate medial portion. A pair of arms extends from the medial portion and each terminates in a distal end. The yoke is made from multiple plies of glass and graphite fibers of varying orientations. The number of graphite plies increases along each arm from adjacent the medial portion to the distal end.

Abstract: An anti-torque mechanism which permits a full range of swashplate assembly motion. The anti-torque mechanism generally includes an anti-torque shaft and a compound bearing mounted thereto to provide five-degrees-of-freedom (spherical-linear-elastomeric) so as to permit a swashplate attachment point to move axially in response to pitch input; pivot in response to swashplate tilt; and move in/out in the radial direction.

Abstract: An actuator assembly including a resilient substrate having one or more shape memory alloys secured to the substrate. The shape memory alloys are configured to move a portion or all of the actuator assembly between an at-rest configuration and an actuated configuration. The shape memory alloys are elastically bendable and can be contracted from an elongated length to a contracted length in response to transmission of an electrical current therethrough. The electrical current is of a magnitude sufficient to heat the shape memory alloys from a first temperature to a second temperature so that a portion of or the entire actuator assembly can move from the at-rest configuration to the actuated configuration. Termination or reduction of the electrical current allows the shape memory alloy to cool and thereby elongate from the contracted length to the elongated length.

Abstract: An articulated rotor system with a servo-flap rotor control system locates the focal point of a blade retention spherical elastomeric bearing inboard of a joint in the servo-flap pitch control tube which separates the flap hinge and supports the servo-flap pitch control tube on a single pivot bearing within a blade retention spindle. Rotor blade flapping produces relative movements between the servo-flap pitch control tube and the blade retention spindle which is converted through a servo-flap drive linkage into servo-flap pitch motions to provide flap/pitch coupling which reduces steady and transient blade flapping.

Abstract: A bearingless rotor system includes a flexbeam assembly having a first beam and a second beam arranged in a back-to-back orientation with a pitch shaft channeled therebetween. The beams morph into a rotor blade spar at an outboard rotor blade station. The outboard section of the flexbeam assembly receives the full pitch input from the pitch shaft while the most inboard section of the flexbeam assembly is essentially fixed in pitch by a blade attachment to a rotor hub assembly. The flexbeam assembly twist versus span is essentially linear from the most inboard to the most outboard rotor blade stations. The outboard rotor blade station, being attached to the outboard section of the flexbeam assembly, thereby also defines the pitch input equivalent from the outboard rotor blade station to the rotor blade tip.

Abstract: An upper rotor control system is contained within an upper rotor shaft and upper hub assembly of a contra-rotating rigid rotor system. A collective servo assembly includes a hydraulic actuator that provides collective pitch to all blades through axial extension/retraction of the control rod relative the upper rotor shaft for collective pitch control of the rotor blades. The collective servo assembly includes a spherical bearing for attachment of the control rod to aircraft structure. An X-Y positioner assembly includes a bearing arrangement which allows the shaft to rotate, while the X-Y positioner assembly remains non-rotational therein. The X-Y positioner assembly includes a multitude of hydraulic actuators, orthogonally positioned, to tilt the control rod about the spherical bearing off the axis of rotation of the upper rotor shaft for cyclic pitch control of the rotor blades.

Abstract: An upper rotor control system is contained within an upper rotor shaft and upper hub assembly of a contra-rotating rigid rotor system. A collective servo assembly includes a hydraulic actuator that provides collective pitch to all blades through axial extension/retraction of the control rod relative the upper rotor shaft for collective pitch control of the rotor blades. The collective servo assembly includes a spherical bearing for attachment of the control rod to aircraft structure. An X-Y positioner assembly includes a bearing arrangement which allows the shaft to rotate, while the X-Y positioner assembly remains non-rotational therein. The X-Y positioner assembly includes a multitude of hydraulic actuators, orthogonally positioned, to tilt the control rod about the spherical bearing off the axis of rotation of the upper rotor shaft for cyclic pitch control of the rotor blades.

Abstract: A rotor blade folding system includes a bearing housing which supports a bearing and rotor blade spindle which folds relative the rotor hub assembly about a fold axis. The rotor blade folding system essentially collapses the rotor hub to facilitate compatibility with a fairing system. By rotating the entire pitch bearing assembly, pitch lock systems are also minimized as the pitch lock system need only react a blade-feathering moment.

Abstract: A rotor blade folding system includes a bearing housing which supports a bearing and rotor blade spindle which folds relative the rotor hub assembly about a fold axis. The rotor blade folding system essentially collapses the rotor hub to facilitate compatibility with a fairing system. By rotating the entire pitch bearing assembly, pitch lock systems are also minimized as the pitch lock system need only react a blade-feathering moment.

Abstract: An anti-torque mechanism which permits a full range of swashplate assembly motion. The anti-torque mechanism generally includes an anti-torque shaft and a compound bearing mounted thereto to provide five-degrees-of-freedom (spherical-linear-elastomeric) so as to permit a swashplate attachment point to move axially in response to pitch input; pivot in response to swashplate tilt; and move in/out in the radial direction.

Abstract: A bearingless rotor system includes a flexbeam assembly having a first beam and a second beam arranged in a back-to-back orientation with a pitch shaft channeled therebetween. The beams morph into a rotor blade spar at an outboard rotor blade station. The outboard section of the flexbeam assembly receives the full pitch input from the pitch shaft while the most inboard section of the flexbeam assembly is essentially fixed in pitch by a blade attachment to a rotor hub assembly. The flexbeam assembly twist versus span is essentially linear from the most inboard to the most outboard rotor blade stations. The outboard rotor blade station, being attached to the outboard section of the flexbeam assembly, thereby also defines the pitch input equivalent from the outboard rotor blade station to the rotor blade tip.

Abstract: An articulated rotor system with a servo-flap rotor control system locates the focal point of a blade retention spherical elastomeric bearing inboard of a joint in the servo-flap pitch control tube which separates the flap hinge and supports the servo-flap pitch control tube on a single pivot bearing within a blade retention spindle. Rotor blade flapping produces relative movements between the servo-flap pitch control tube and the blade retention spindle which is converted through a servo-flap drive linkage into servo-flap pitch motions to provide flap/pitch coupling which reduces steady and transient blade flapping.