Abstract: A flexbeam rotor blade assembly includes a flexbeam having a body that includes a first surface, a second, opposing surface, and an opening extending through the first and second surfaces. At least one snubber is mounted to one of the first and second surfaces spaced along the body from the opening. A snubber retainer is mounted to one of the first and second surfaces between the body and the at least one snubber. The snubber retainer includes a retainer plate having a snubber attachment member to which the snubber assembly is mounted and a mounting arm including a retainer plate opening spaced from the snubber attachment member. The retainer plate opening registers with the opening in the flexbeam. A mechanical fastener extends through the retainer plate opening and the opening in the flexbeam. The mechanical fastener joins the snubber retainer to the one of the first and second surfaces.

Abstract: The invention relates to a backing plate used for an elastomeric bearing system, the backing plate comprising a plate which defines an at least partial annulus about an axis, a motion limiter and a redundant pivot which extend from the plate so as to respond to a retainer plate disbond.

Abstract: An elastomeric bearing configured for use in a rotor blade assembly is provided including an inner race, and an outer race. An outer damper portion is arranged adjacent the outer race and an inner snubber portion is arranged adjacent the inner race. A rigid transition layer is disposed between the outer damper portion and the inner snubber portion. The rigid transition layer has a generally circular cross-section except at a segment which has been removed and which defines a generally planar surface at a chord of the segment. The generally planar surface is configured to contact a surface of an adjacent component.

Abstract: A trim tab for use in a blade housing includes a cavity connected to an opening extending from the cavity out a trailing edge of the blade housing, the cavity has a first dimension which is greater than a second dimension of the opening at a same spanwise location of the blade housing. The trim tab has a trim portion, a head portion having a head dimension substantially similar to the first dimension, and a tail portion connecting the trim portion and the head portion. The tail portion has a tail dimension substantially similar to the second dimension such that the trim tab is retainable by the blade housing when the head portion is disposed within the cavity and the tail portion is disposed within the opening.

Abstract: An aircraft rotor head is provided and includes a rotor hub including a central portion and radial arms extending outwardly from the central portion, blade retention yokes, each blade retention yoke being pivotably coupled to a corresponding one of the radial arms at one end and to a corresponding blade at another end and a lag restraint star rotatable about and translatable along the central portion. The lag restraint star is coupled to each of the blade retention yokes to facilitate uniform blade lead/lag and uniform blade coning.

Abstract: A retaining assembly for a tail rotor system is provided including a washer having a plurality of splines. The washer is configured to couple to an adjacent pitch change shaft. A retaining nut includes a self-locking feature and a flange arranged at a first end. The retaining nut is configured to threadably couple to the pitch change shaft such that the flange is in contact with the washer. The flange includes a plurality of first holes configured to at least partially align between the splines of the washer. A lock plate includes a body and a plurality of tabs extending generally perpendicularly from the body. The lock plate is slidably positioned about the pitch change shaft adjacent the flange. The lock plate is operably coupled to the retaining nut and the washer to limit rotational movement thereof relative to the pitch change shaft.

Abstract: An aircraft rotor head is provided and includes a rotor hub including a central portion and radial arms extending outwardly from the central portion, blade retention yokes, each blade retention poke being pivotably coupled to a corresponding one of the radial arms at one end and to a corresponding blade at another end and a lag restraint star rotatable about and translatable along the central portion. The lag restraint star is coupled to each of the blade retention yokes to facilitate uniform blade lead/lag and uniform blade coning.

Abstract: A rotor system includes a lead stop mounted to a spindle and a lead stop plate mounted to a rotor hub arm, the lead stop operable to contact the lead stop plate over a lead angle range.

Abstract: A retaining assembly for a tail rotor system is provided including a washer having a plurality of splines. The washer is configured to couple to an adjacent pitch change shaft. A retaining nut includes a self-locking feature and a flange arranged at a first end. The retaining nut is configured to threadably couple to the pitch change shaft such that the flange is in contact with the washer. The flange includes a plurality of first holes configured to at least partially align between the splines of the washer. A lock plate includes a body and a plurality of tabs extending generally perpendicularly from the body. The lock plate is slidably positioned about the pitch change shaft adjacent the flange. The lock plate is operably coupled to the retaining nut and the washer to limit rotational movement thereof relative to the pitch change shaft.

Abstract: A test apparatus for a rotor blade of a rotor includes at least one guide rail located in proximity to the rotor blade and at least one bearing secured to the rotor blade radially outboard of the at least one guide rail. The at least one bearing is in operable communication with a radially outboard surface of the at least one guide rail to be translatable thereon. At least one force applicator is in operable communication with the at least one guide rail and is configured to exert a force radially outwardly on the at least one guide rail. The force is transferred to the rotor blade via the at least one bearing and simulates a centrifugal force on the rotor blade. Further disclosed is a method for securing a rotor blade of a rotor in a test fixture.

Abstract: A swash plate assembly includes a rotationally stationary swash plate and rotational swash plate which rotates relative to the rotationally stationary swash plate through a bearing system. Each servo control rod is attached to the swash plate assembly to communicate control inputs thereto through a respective servo lug. Each servo lug defines a servo pivot point off an in-line plane inboard of the bearing system. As the servo lugs extend below the rotationally stationary swash plate, a relatively uncomplicated attachment arrangement is facilitated which provides for redundant locking features at a highly inspectable location which simplifies maintenance and increased safety. By locating the servo pivot point just inboard of the bearing system, an exceeding compact load path is defined thereby.

Abstract: A rotor system includes a lead stop mounted to a spindle and a lead stop plate mounted to a rotor hub arm, the lead stop operable to contact the lead stop plate over a lead angle range.

Abstract: The invention relates to a backing plate used for an elastomeric bearing system, the backing plate comprising a plate which defines an at least partial annulus about an axis, a motion limiter and a redundant pivot which extend from the plate so as to respond to a retainer plate disbond.

Abstract: A test apparatus for a rotor blade of a rotor includes at least one guide rail located in proximity to the rotor blade and at least one bearing secured to the rotor blade radially outboard of the at least one guide rail. The at least one bearing is in operable communication with a radially outboard surface of the at least one guide rail to be translatable thereon. At least one force applicator is in operable communication with the at least one guide rail and is configured to exert a force radially outwardly on the at least one guide rail. The force is transferred to the rotor blade via the at least one bearing and simulates a centrifugal force on the rotor blade. Further disclosed is a method for securing a rotor blade of a rotor in a test fixture.

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 rotor assembly having a rotor hub, a plurality of yokes, and a plurality of swing arms is provided. The yoke depending from the rotor hub. Each swing arm is movably positioned on the rotor hub for rotation between an unlocked position and a locked position. The yokes are freely movable about a pitch axis and a lead/lag axis when the swing arms are in the unlocked position and the yokes are locked in a predetermined pitch position and a predetermined lead/lag position when the swing arms are in the locked position.

Abstract: An electrically heatable elastomeric bearing provides a multiple of elastomeric material layers and a multiple of shim layers. At least one of the multiple of shim layers includes an electrically heatable shim layer.

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.