Abstract: A gearbox system includes a first drive gear rotatable about an axis of rotation and a second drive gear disposed coaxial with the first drive gear and rotatable about the axis of rotation. An input shaft provides a first torque and includes an input gear. Driving pinions are operably connected to the input gear and positioned between the first drive gear and the second drive gear compliantly along a direction parallel to the axis of rotation. Each driving pinion drives the first drive gear in a first direction about the axis of rotation and drives the second drive gear in a second direction opposite the first direction about the axis of rotation. Each driving pinion transfers an equal second torque to the first drive gear and the second drive gear.

Abstract: A device for testing a rotor blade of an aircraft. The device is configured to receive and secure a shaft of the rotor blade. Once secured, the device is configured to allow for inputting combined loads and bending moments into the rotor blade to simulate the rotor blade behavior in flight. A testing assembly is also disclosed that includes the device and the rotor blade and methods of use that provide for testing the rotor blade.

Abstract: A propulsor hub is provided and includes a casing including an inner annular part and blade-connection parts extending outwardly from the inner annular part, a liner having inner and outer opposed radial ends, the liner being disposed about a corresponding one of the blade-connection parts with the inner radial end thereof at a distance from the inner annular part and a weighted element securely disposed about the corresponding one of the blade-connection parts to abut the outer radial end of the liner.

Abstract: A composite spar having an upper and lower wall region connected by leading and trailing edge regions is provided including a plurality of first laminates and a plurality of second laminates. The plurality of first laminates includes one or more intermediate modulus graphite plies having an intermediate modulus. The plurality of first laminates is arranged in one or more intermediate modulus layers to form at least a portion of the upper wall region, lower wall region, leading edge region and trailing edge region. The plurality of second laminates includes one or more high modulus graphite plies having a high modulus. The plurality of second laminates is arranged in one or more high modulus layers. The high modulus layers are generally interposed between intermediate modulus layers.

Abstract: A tension torsion strap by which a blade is connectable with a hub of a propulsor is provided. The tension torsion strap includes an elongate body formed to define attachment features at opposite ends thereof, the attachment features being connectable to the blade at one of the opposite ends and to the hub at the other of the opposite ends, fibrous materials extending along the elongate body and around the attachment features and pretension flanges elastically interposable between the hub and the elongate body. The pretension flanges are configured to maintain pretension in the fibrous materials above a predefined pretension level when the attachment features are connected to the blade and the hub.

Abstract: A rotor blade configured to fold about a blade fold axis includes a first section and a second section. The first section is configured to mount to a rotor hub and includes a first connector having at least one first opening. The second section includes a second connector having at least one second opening. The second section is rotatably coupled to the first section and is configured to rotate about the blade fold axis between an aligned position and a rotated position. A linkage is operably coupled to the first section and the second section. The linkage includes a plurality of links loosely connected such that the linkage is configured to support the second section of the rotor blade only when the second section is in the rotated position.

Abstract: A device for testing a rotor blade of an aircraft. The device is configured to receive and secure a shaft of the rotor blade. Once secured, the device is configured to allow for inputting combined loads and bending moments into the rotor blade to simulate the rotor blade behavior in flight. A testing assembly is also disclosed that includes the device and the rotor blade and methods of use that provide for testing the rotor blade.

Abstract: An aircraft is provided and includes an airframe, a blade disk, which is rotatable relative to the airframe, including a plurality of rotor blades, a rotor shaft disposed to drive rotation of the blade disk relative to the airframe and a pitching of each of the rotor blades about corresponding pitch axes and a rotor assembly configured to form couplings by which each of the rotor blades is coupled to the rotor shaft. The rotor assembly includes a composite laminate arranged to resolve loading associated with the couplings in-plane of the composite laminate.

Abstract: A rotor includes a blade retention cuff configured to receive a rotor blade; a yoke coupled to the blade retention cuff; and a rigid propeller shaped hub configured to enclose at least a portion of the blade retention cuff and at least a portion of the yoke.

Abstract: A rotor hub assembly for a rotary-winged aircraft includes a spool portion and a plurality of hub arms extending radially outwardly from the spool portion. A rotor blade is connectable to each hub arm. Each hub arm includes a spine portion and at least two leg portions extending from the spine portion. The spine portion and the at least two leg portions defining an I-shaped cross-section of each hub arm. A rotor assembly includes a rotor hub assembly including a spool portion and a plurality of hub arms extending radially outwardly from the spool portion. Each hub arm includes a spine portion and at least two leg portions extending from the spine portion. The spine portion and the at least two leg portions define an I-shaped cross-section of each hub arm. A rotor blade is secured to each hub arm.

Abstract: A pin configured for use in a rotor blade movable between an aligned position and a folded position and having a rotor blade airfoil contour is provided including a cylindrical body configured to couple a first section and a second section of the rotor blade when the rotor blade is in the aligned position. A handle is mounted to an end of the cylindrical body and has an airfoil contour complementary to the rotor blade airfoil contour. The handle is movable between an open position and a closed position. When the handle is in the closed position, the handle is flush with an adjacent portion of the rotor blade. When the handle is in the open position, the handle is accessible to pull the cylindrical body from the first and second section s of the rotor blade.

Abstract: An aircraft is provided and includes a gearbox housing through which a drive shaft configured to drive propeller rotation extends and a pitch control apparatus. The pitch control apparatus includes a drive element coupled to an exterior of the gearbox housing and an annular electro-mechanical actuator (EMA) configured to convert rotational energy generated by the drive element to thereby control a pitching of propeller blades about corresponding pitch axes.

Abstract: A mounting assembly for connecting a first surface to a second surface and for holding a first servo which moves an adjacent first component is provided including a leg. A first end of the leg is attachable to the first surface and a second end of the leg is attachable to the second surface. The leg is generally bent such that the first end of each leg is arranged at an angle to the second end of each leg so as to transmit forces between the first and second surface. A bracket connected to the leg includes a notch configured to receive the first servo. When the first servo is positioned within the first notch, a free end of the first servo is operably coupled to the adjacent first component and the leg reacts forces generated by the first servo into the first and second surfaces.

Abstract: An aircraft is provided and includes an airframe, a main rotor assembly operably disposed at an upper portion of the airframe to provide lift, a propulsor assembly operably disposed at a tail portion of the airframe to provide thrust and a control system. The control system includes a mono-cyclic swashplate assembly that is translatable in a translation direction to execute collective control of the propulsor assembly and rotatable about an axis defined transversely with respect to the translation direction to execute cyclic control of the propulsor assembly.

Abstract: A gearbox system includes a first drive gear rotatable about an axis of rotation and a second drive gear disposed coaxial with the first drive gear and rotatable about the axis of rotation. An input shaft provides a first torque and includes an input gear. Driving pinions are operably connected to the input gear and positioned between the first drive gear and the second drive gear compliantly along a direction parallel to the axis of rotation. Each driving pinion drives the first drive gear in a first direction about the axis of rotation and drives the second drive gear in a second direction opposite the first direction about the axis of rotation. Each driving pinion transfers an equal second torque to the first drive gear and the second drive gear.

Abstract: A tension torsion strap by which a blade is connectable with a hub of a propulsor is provided. The tension torsion strap includes an elongate body formed to define attachment features at opposite ends thereof, the attachment features being connectable to the blade at one of the opposite ends and to the hub at the other of the opposite ends, fibrous materials extending along the elongate body and around the attachment features and pretension flanges elastically interposable between the hub and the elongate body. The pretension flanges are configured to maintain pretension in the fibrous materials above a predefined pretension level when the attachment features are connected to the blade and the hub.

Abstract: A propulsor hub is provided and includes a casing including an inner annular part and blade-connection parts extending outwardly from the inner annular part, a liner having inner and outer opposed radial ends, the liner being disposed about a corresponding one of the blade-connection parts with the inner radial end thereof at a distance from the inner annular part and a weighted element securely disposed about the corresponding one of the blade-connection parts to abut the outer radial end of the liner.

Abstract: A propeller system includes a propeller located at a tail section and a drive shaft operably connected to the propeller to drive the propeller about a propeller axis. A propeller gearbox connects the propeller to the drive shaft and a propeller gearbox lubricant cooler is operably connected to the propeller gearbox and disposed circumferentially about the drive shaft. The propeller gearbox lubricant cooler transfers thermal energy from a flow of lubricant flowing therethrough to a flow of air flowing through the tail section across the propeller gearbox lubricant cooler. A method of cooling a gearbox for a propeller includes circulating a volume of lubricant through a propeller gearbox and flowing the lubricant into a propeller gearbox cooler. Thermal energy is transferred from the lubricant to a flow of air flowing across the propeller gearbox cooler and the flow of air is vented from the tail section of the rotorcraft.

Abstract: A swashplate apparatus is provided and includes a first swashplate including outer and inner bodies and an intermediate portion defining a major groove between the outer and inner bodies, a second swashplate disposable in the major groove to be rotatable relative to the first swashplate, the second swashplate including an interior facing surface radially separated from the inner body to define a minor groove and defining a recess in which the rod end is disposable, a connector disposable in the recess to pivotably couple the rod end to the second swashplate and a plate element disposable in the minor groove and affixable to the interior facing surface of the second swashplate and the connector.

Abstract: A constant velocity drive includes a drive ring and a driven ring positioned around the drive ring. Drive links extend from the drive ring to the driven ring to transfer torque applied at the drive ring to the driven ring. Elastomeric bearings are positioned at the driven ring to transfer torque from a drive link of the plurality of drive links to the driven ring. Each elastomeric bearing includes both spherical bearing elements and planar bearing elements to allow for tilt of an axis of rotation of the driven ring with respect to an axis of rotation of the drive ring while ensuring a constant rotational velocity of the driven ring with respect to the rotational velocity of the drive ring.