Abstract: An example airfoil assembly includes an airfoil body extending between a leading edge, a trailing edge, a suction side, and a pressure side. The assembly further includes a first protective sheath, an indicator sheath, and a second protective sheath. The first protective sheath has an outer side and an inner side that forms a cavity for receiving at least a portion of the airfoil body. The inner side being bonded to the leading edge of the airfoil body. A portion of the indicator sheath is positioned forward the first sheath relative to the leading edge of the airfoil. A portion of the second protective sheath is positioned forward the indicator sheath relative to the leading edge of the airfoil.

Abstract: An airfoil assembly includes an airfoil body extending between a leading edge, a trailing edge, a suction side, and a pressure side. A first sheath having an outer side and an inner side forms a cavity for receiving at least a portion of the airfoil body and is bonded on the inner side to the leading edge of the airfoil body. The first sheath is formed of a titanium-based metallic material. A second sheath is bonded to the outer side of the first sheath.

Abstract: A propeller blade mounted with a preload adjacent a propeller blade root retention which increases the moment capacity of the retention for a given pitch diameter, yet permits pitching of the propeller blade about a blade axis in response to a propeller pitch change actuation system. The propeller blade retention assembly includes a tapered roller bearing set having a multiple of tapered roller bearing cartridge assemblies. Each tapered roller bearing cartridge assembly includes a retention cartridge and at least one tapered roller bearing element to facilitate installation and retention during assembly.

Abstract: A fan blade for a turbine engine includes an exterior surface defining an airfoil that is provided by leading and trailing edges, opposing generally chord-wise surfaces interconnecting the leading and trailing edges, and a tip. The airfoil extends from a root. A fan rotor includes a slot that receives the root. A spar is constructed from a first material and includes opposing sides. The spar provides at least a portion of the exterior surface. A sheath is constructed from a second material different than the first material. The sheath is arranged on both of the opposing sides to provide at least a portion of the exterior surface at the opposing surfaces.

Abstract: A blade pitch actuation mechanism for a plurality of propeller blades supported in a blade hub comprises a plurality of bearing assemblies, a bearing support plate and a yoke. The plurality of bearing assemblies receives a plurality of actuation trunnion pins from the plurality of propeller blades. The bearing support plate is connected to the plurality of bearing assemblies and unifies the plurality of bearing assemblies in a ring-like configuration. The yoke is connected to the bearing support plate and translates within the hub to adjust the pitch of the plurality of propeller blades.

Abstract: A split slip ring assembly formed from first and second halves of a slip ring having a contact surface for rotational engagement with a stationary brush element for transferring electrical signals there between. The contact surface has a smooth surface at the junction of the first and second halves. A fastener locates the first and second halves to form a ring shape. An electrical contact on the ring carries electrical signals between the slip ring and the brush element. An alignment element aligns the first and second halves to form the smooth surface at their junction.

Abstract: A propeller system includes a propeller hub which supports a multiple of propeller blades. A tailshaft extends from a propeller hub portion of the propeller hub along an axis of rotation with a propeller pitch change yoke mounted within the propeller hub for movement along an axis of rotation to change a pitch of the multiple of propeller blades, the propeller pitch change yoke in sliding engagement with the tailshaft.

Abstract: A mounting assembly for a propeller assembly component includes a monolithic piece having a housing and a mounting pad. An auxiliary component is directly mounted to the mounting pad of the monolithic piece.

Abstract: A propeller blade mounted with a preload adjacent a propeller blade root retention which increases the moment capacity of the retention for a given pitch diameter, yet permits pitching of the propeller blade about a blade axis in response to a propeller pitch change actuation system. The propeller blade retention assembly includes a tapered roller bearing set having a multiple of tapered roller bearing cartridge assemblies. Each tapered roller bearing cartridge assembly includes a retention cartridge and at least one tapered roller bearing element to facilitate installation and retention during assembly.

Abstract: A balance system for a rotational airfoil assembly includes a bulkhead, an elongated member, a support member and at least one balance weight. The elongated member extends through the bulkhead along a bore toward a tip segment of the airfoil assembly. The balance weights are mounted to a tip segment of the elongated member positioned within the bore proximate to a mid-span segment of the airfoil assembly. A reduced quantity of weight is required to balance the airfoil assembly because of the location of the balance weights outside of the mid-span segment of the airfoil assembly.

Abstract: A pitch change system includes a yoke assembly which receives a pitch trunnion that extends from each propeller blade assembly. Each pitch trunnion is received within a respective bearing assembly mounted in the yoke assembly. The bearing assemblies are mounted between a forward yoke plate and an aft yoke plate. A spacer is mounted between each adjacent bearing assembly to position and restrain each bearing assembly. Each spacer includes an extension which retains the adjacent bearing assembly on a pitch trunnion pin in a direction generally parallel to axis. Each of the bearing assemblies includes a generally rectilinear outer race and a spherical inner race inside diameter to receive the pitch trunnion pin. The rectilinear outer race reduces contact stresses to acceptable levels for high load applications yet permits blade installation without actuator disassembly.

Abstract: A variable pitch propulsor system with a propeller pitchlock system having a pitchlock solenoid valve located in communication with a pitchlock pressure circuit to selectively actuate pitchlocking in response to a controller. The pitchlock solenoid valve includes an electro-mechanical device which is normally closed but may be commanded to electrically open and dump the pitchlock pressure which causes actuation of the pitchlock system. The pitchlock solenoid provides a mechanism which will selectively pitchlock the propulsor system; permits a built in test routine to determine the condition of the pitchlock system through a commanded propeller pitchlock sequence; requires no mechanical link between the rotating and non-rotating propeller components to initiate pitchlock; is independent of engine and gearbox configurations; and can initiate pitchlock remotely with a signal from a remote location.

Abstract: A variable pitch propulsor system with a propeller pitchlock system which utilizes a follower style pitchlock ballscrew screw which tracks the actuator axial stroke. The pitchlock system transfers the propeller yoke loads, from the ballscrew ballnut to the pitchlock nut allowing the propeller to pitchlock; utilizes the same screw thread lead angle for normal ballscrew back driving operation as well as pitch locking capabilities; provides a single ballscrew which is capable of both being back driven by the ballnut and structurally adequate for reacting the blade loads resulting from any flight condition; and minimizes the requirement of additional rotation and torque transferring interfaces between the ballscrew and pitchlock nut.

Abstract: A pitch change system includes a yoke assembly which receives a pitch trunnion that extends from each propeller blade assembly. Each pitch trunnion is received within a respective bearing assembly mounted in the yoke assembly. The bearing assemblies are mounted between a forward yoke plate and an aft yoke plate. A spacer is mounted between each adjacent bearing assembly to position and restrain each bearing assembly. Each spacer includes an extension which retains the adjacent bearing assembly on a pitch trunnion pin in a direction generally parallel to axis. Each of the bearing assemblies includes a generally rectilinear outer race and a spherical inner race inside diameter to receive the pitch trunnion pin. The rectilinear outer race reduces contact stresses to acceptable levels for high load applications yet permits blade installation without actuator disassembly.

Abstract: A propeller blade mounted with a preload adjacent a propeller blade root retention that increases the moment capacity of the retention for a given pitch diameter, yet permits pitching of the propeller blade about a blade axis in response to a propeller pitch change actuation system. During assembly, the preload condition is established by preload springs which apply a load on the end of a tapered roller bearing set as a floating race is rotated which allows the tapered roller bearing set to progressively push the propeller blade root outboard and the floating race inboard to generate the preloaded condition.

Abstract: An auxiliary tank is filled by a pitch control system, which enables the size of the auxiliary tank to be reduced.

Abstract: A propeller control generates a once per revolution (1P) blade thrust variation through cyclic pitch of rigidly mounted non-flapping propeller blades. The resultant shaft bending moment is used to provide aircraft attitude control. Axial translation of a pitch change assembly including a pitch change yoke along an axis of rotation drives a pitch link attached to each propeller blade to collectively change the propeller blade pitch angle. The pitch change yoke includes a translating pitch change yoke portion and an articulatable pitch change yoke portion. Deflection of the articulatable pitch change yoke portion changes the pitch change effect of each pitch link as a function of its angular position such that a sinusoidal pitch angle is superimposed on normal pitch angle. Cyclic pitch change actuators deflect the articulatable pitch change yoke portion in any angular direction while the linear deflection of the cyclic pitch change actuators generate the magnitude of the cyclic pitch.

Abstract: A propeller control generates a once per revolution (1P) blade thrust variation through cyclic pitch of rigidly mounted non-flapping propeller blades. The resultant shaft bending moment is used to provide aircraft attitude control. Axial translation of a pitch change assembly including a pitch change yoke along an axis of rotation drives a pitch link attached to each propeller blade to collectively change the propeller blade pitch angle. The pitch change yoke includes a translating pitch change yoke portion and an articulatable pitch change yoke portion. Deflection of the articulatable pitch change yoke portion changes the pitch change effect of each pitch link as a function of its angular position such that a sinusoidal pitch angle is superimposed on normal pitch angle. Cyclic pitch change actuators deflect the articulatable pitch change yoke portion in any angular direction while the linear deflection of the cyclic pitch change actuators generate the magnitude of the cyclic pitch.

Abstract: The expense of a bearing employed at the interface of a yoke (22) and a propeller blade pin (14) in a variable pitch propeller assembly is reduced in a bearing construction (16) wherein a bearing race (48) includes a crowned surface (50) adapted to engage a slot (20) in the yoke (22) and having a profile (Pi) wherein the diameter at one side (88, 90) of the race (48) is less than the diameter at the opposite side (90, 88) of the race (48).

Abstract: The expense of a bearing employed at the interface of a yoke (22) and a propeller blade pin (14) in a variable pitch propeller assembly is reduced in a bearing construction (16) wherein a bearing race (48) includes a crowned surface (50) adapted to engage a slot (20) in the yoke (22) and having a profile (P1) wherein the diameter at one side (88, 90) of the race (48) is less than the diameter at the opposite side (90, 88) of the race (48).