Abstract: A method of manufacturing an aircraft blade is provided. The method includes attaching a fluid communicator to a plug tool connected to a blade plug, opening a passage in the blade plug using the plug tool, communicating fluid to or from a blade cavity through the passage using the fluid communicator, and sealing the passage in the blade plug using the plug tool.

Abstract: A blade plug for an aircraft blade is provided. The blade plug includes a first body having a boss extending therefrom and an aperture passing through the boss, the first body configured to sealingly engage with an opening of a blade, a plug cap configured to releasably engage with the boss and move between a first position and a second position, and a passage passing through the first body configured to allow fluid communication through the first body. When the plug cap is in the first position, fluid may not pass through the passage and, when the plug cap is in the second position, fluid may pass through the passage, and the first body has an outer diameter of 4.15 inches (105.37 mm).

Abstract: A method of controlling a Counter-Rotating Open-Rotor (CROR) includes mechanically linking a pitch change system of a first rotor with a pitch change system of a second rotor and commanding a Blade Angle (Beta1 commanded) of the first rotor such that a Blade Angle (Beta2 Actual) of the second rotor is a function of the commanded Blade Angle (Beta1 commanded) to provide a linear relationship between an actual Blade angle (Beta1 Actual) and Beta1 commanded of the first rotor and a non-linear relationship between Beta2 Actual and Beta1 commanded.

Abstract: A propeller system includes at least one propeller hub having a plurality of hub arms formed therein. The plurality of hub arms are arranged circumferentially on the at least one propeller hub and are spaced apart from one another by a hub distance. The propeller system further includes a plurality of propeller blades. Each propeller blade includes a base portion rotatably disposed in a respective hub. At least one counterweight is coupled to the base portion of a respective propeller blade. The counterweight includes a hinge configured to pivot a portion of the at least one counterweight.

Abstract: A method of manufacturing an aircraft blade is provided. The method includes attaching a fluid communicator to a plug tool connected to a blade plug, opening a passage in the blade plug using the plug tool, communicating fluid to or from a blade cavity through the passage using the fluid communicator, and sealing the passage in the blade plug using the plug tool.

Abstract: A blade plug for an aircraft blade is provided. The blade plug includes a first body having a boss extending therefrom and an aperture passing through the boss, the first body configured to sealingly engage with an opening of a blade, a plug cap configured to releasably engage with the boss and move between a first position and a second position, and a passage passing through the first body configured to allow fluid communication through the first body. When the plug cap is in the first position, fluid may not pass through the passage and, when the plug cap is in the second position, fluid may pass through the passage, and the first body has an outer diameter of 4.15 inches (105.37 mm).

Abstract: A propeller rotor has a hub mounting a plurality of blades. A counterweight is movably mounted on the blade. A pitch change mechanism for changing an angle of incidence of an airfoil is associated with each of the blades. The counterweight twists the blades toward an increased pitch direction should the pitch change mechanism fail. A stop member stops rotation of the counterweight as the blade moves to a feather position.

Abstract: A fluid pressure regulating system includes an auxiliary fluid circuit having a high pressure region and a low pressure region, a pump connected to the auxiliary fluid circuit and configured to discharge fluid into the high pressure region of the auxiliary fluid circuit, and a check valve connecting the high pressure region of the auxiliary fluid circuit to a main fluid interface line. The fluid pressure regulating system also includes a pressure regulating valve connecting the high pressure region of the auxiliary fluid circuit and the low pressure region of the auxiliary fluid circuit. The pressure regulating valve includes an aperture defining a fluid path from the high pressure region of the auxiliary fluid circuit to the low pressure region of the auxiliary fluid circuit. The aperture has a variable area as a function of fluid pressure within the main fluid interface line.

Abstract: A propeller blade includes a foam core and a structural layer that surrounds at least a portion of the foam core and includes a face side and a camber side is disclosed. The propeller blade also includes an insert disposed in the foam core in operable contact with the face side and the camber side of the structural layer.

Abstract: A propeller rotor has a hub mounting a plurality of blades and a drive shaft for driving the hub and the blades about a central axis. A motor to change its position is operably connected to drive at least one counterweight. A sensor senses vibration on the propeller rotor and communicates with a controller. The controller controls the motor to change a position of the counterweight in response to a sensed imbalance. A method of operating a propeller rotor is also disclosed.

Abstract: A propeller system for an aircraft includes a propeller assembly rotatable about a central axis and a reduction gearbox operably connected to the propeller assembly via a propeller shaft. An electrical power transfer system is positioned such that the gearbox is located axially between the electrical power transfer system and the propeller assembly. The electrical power transfer system includes a slip ring assembly secured to an oil transfer tube extending to the propeller assembly and a brush block interactive with the slip ring assembly to transfer electrical power to a plurality of lead wires extending from the slip ring assembly to the propeller assembly. The brush block is positioned such that brush block tips of the brush block extend toward the slip ring assembly in a substantially radial direction relative to the central axis of the propeller assembly.

Abstract: A propeller system for an aircraft includes a propeller assembly rotatable about a central axis and a reduction gearbox operably connected to the propeller assembly via a propeller shaft. An electrical power transfer system is positioned such that the gearbox is located axially between the electrical power transfer system and the propeller assembly. The electrical power transfer system includes a slip ring assembly operably connected to an oil transfer tube extending to the propeller assembly and a brush block interactive with the slip ring assembly to transfer electrical power to a plurality of lead wires extending from the slip ring assembly to the propeller assembly. The brush block is positioned such that brush block tips of the brush block extend toward the slip ring assembly in a substantially axial direction relative to the central axis.

Abstract: A propeller blade includes a foam core having a slot formed through it from a camber side to a face side, an internal stiffener disposed through the slot and including flanges in contact with both the camber and face sides and a structural layer that surrounds at least a portion of the foam core and in contact with the flanges on both the camber and face sides.

Abstract: A propeller blade pitch actuation system includes a propeller control module (PCM), a PCM drain line, a first drain line, a drain line restriction, a second drain line, and a valve. The PCM drain line connects to the PCM to drain hydraulic fluid. The first drain line is downstream of the PCM drain line and the drain line restriction is downstream of the first drain line. The second drain line is downstream of the PCM drain line. The valve includes a first valve position and a second valve position. The first valve position connects the PCM drain line to the first drain line and the second valve position connects the PCM drain line to the second drain line. Hydraulic pressure of the first drain line between the valve and the drain line restriction is greater than hydraulic pressure of the second drain line.

Abstract: A method of controlling a Counter-Rotating Open-Rotor (CROR) includes measuring a speed of a first rotor and deriving a speed of a second rotor and controlling a pitch of the first rotor and the second rotor.

Abstract: A propeller system includes at least one propeller hub having a plurality of hub arms formed therein. The plurality of hub arms are arranged circumferentially on the at least one propeller hub and are spaced apart from one another by a hub distance. The propeller system further includes a plurality of propeller blades. Each propeller blade includes a base portion rotatably disposed in a respective hub. At least one counterweight is coupled to the base portion of a respective propeller blade. The counterweight includes a hinge configured to pivot a portion of the at least one counterweight.

Abstract: A dowel element is provided and includes a shank portion including first and second mating parts. One of the first and second mating parts includes a first exterior surface and is formed to define an anti-fretting relief including a second exterior surface recessed from the first exterior surface in a radial dimension.

Abstract: A retention assembly for a propeller blade includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade; a base that is configured to be immediately adjacent the annular loop; an annular outer ring including a bearing race interface that is conical in shape and includes a radially inner surface that conforms to a radially outer surface of the annular loop; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop. Also, a propeller blade assembly includes a propeller blade having a blade portion and a root portion; and the retention assembly that is configured to attach to the propeller blade.

Abstract: A retention assembly for a propeller blade includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade; a base that is configured to be immediately adjacent the annular loop; an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop. Also, a propeller blade assembly includes a propeller blade having a blade portion and a root portion and the retention assembly configured to be attached to the propeller blade.

Abstract: A rotating assembly includes a shaft having a driven end and a driving end. At least one rotating member coupled to the driven end. A support member is operatively connected to the at least one rotating member. A dynamic balancing system is operatively coupled to the support member. The dynamic balancing system includes a first balancing weight rotatably mounted to the support member. The first balancing weight is operatively connected to a first motor. A second balancing weight is rotatably mounted to the support member. The second balancing weight is operatively connected to a second motor. A controller is operatively connected to the first and second motors. The controller is configured and disposed to signal each of the first and second motors to rotate and to establish a desired position of the first balancing weight and the second balancing weight relative to at least one rotating member.