Abstract: A propeller control system for controlling a blade pitch angle including: a propeller blade extending from a blade base, the propeller blade being configured to rotate around a longitudinal axis to generate thrust for the propeller blade and rotate around a pitch change axis to adjust the blade pitch angle, wherein the pitch change axis extends through a center point of the blade base; a trunnion pin operably connected to the blade base at a location offset from the center point; a yoke plate operably connected to the trunnion pin; an actuator configured to move the yoke plate linearly along the longitudinal axis to rotate the trunnion pin and the propeller blade around the pitch change axis; and a transfer tube operably connected to the yoke plate, the transfer tube being free to rotate around the longitudinal axis as the actuator moves the yoke plate linearly along the longitudinal axis.

Abstract: Provided are embodiments for deicing an aircraft propeller having a plurality of blades of an aircraft. An example method includes performing a first heating, by a first plurality of heating elements connected to a first portion of each of the plurality of blades, for a first period of time, the first portion of each of the plurality of blades of the propeller defining a first deicing zone. The method further includes, subsequent to expiration of the first period of time, performing a second heating, by a second plurality of heating elements connected to a second portion of each of the plurality of blades, for a second period of time, the second portion of each of the plurality of blades of the propeller defining a second deicing zone.

Abstract: A propeller control system for controlling a blade pitch angle including: a propeller blade extending from a blade base, the propeller blade being configured to rotate around a longitudinal axis to generate thrust for the propeller blade and rotate around a pitch change axis to adjust the blade pitch angle, wherein the pitch change axis extends through a center point of the blade base; a trunnion pin operably connected to the blade base at a location offset from the center point; a yoke plate operably connected to the trunnion pin; an actuator configured to move the yoke plate linearly along the longitudinal axis to rotate the trunnion pin and the propeller blade around the pitch change axis; and a transfer tube operably connected to the yoke plate, the transfer tube being free to rotate around the longitudinal axis as the actuator moves the yoke plate linearly along the longitudinal axis.

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 balancing device includes at least one stationary outer disc and a drive wheel arranged adjacent to the outer disc. The drive wheel includes magnets arranged at the periphery. A balancing weight is arranged in a groove formed in one of the outer disc or the drive wheel. A propeller including the propeller balancing device and a method of balancing a propeller are also disclosed.

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 retractable contact assembly includes an outer casing having a first opening and a piston located in the first opening of the outer casing and moveable axially within the opening. The piston has a second opening. The assembly further includes an inelastic force generating device configured to control an axial movement of the piston and a contact located in the second opening of the piston and movable axially in the second opening of the piston. The assembly further includes an elastic force biasing device configured to provide an elastic force to the contact in an axial direction outward from the second opening.

Abstract: A propeller balancing device includes at least one stationary outer disc and a drive wheel arranged adjacent to the outer disc. The drive wheel includes magnets arranged at the periphery. A balancing weight is arranged in a groove formed in one of the outer disc or the drive wheel. A propeller including the propeller balancing device and a method of balancing a propeller are also disclosed.

Abstract: A retractable contact assembly includes an outer casing having a first opening and a piston located in the first opening of the outer casing and moveable axially within the opening. The piston has a second opening. The assembly further includes an inelastic force generating device configured to control an axial movement of the piston and a contact located in the second opening of the piston and movable axially in the second opening of the piston. The assembly further includes an elastic force biasing device configured to provide an elastic force to the contact in an axial direction outward from the second opening.

Abstract: A propeller control system includes a propeller control logic subsystem in conjunction with an engine control logic subsystem to provide an optimized transition from forward to reverse speed governing under all operating conditions. By creating a Propeller control Mode (PCM) map relative the blade angle and Power Lever Angle (PLA), the minimum blade angle allowed for forward speed governing and the maximum blade angle allowed for reverse speed governing is determined. By combining the actual propeller blade angle, the min and max angles for speed governing, and the PLA signal, the state of the propeller speed governor is determined.

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 system adjusts the pitch of a variable pitch propeller having a non-rotating side and a rotating side. The rotating side of the propeller has a hub, a propeller blade mounted to the hub, a propeller shaft that rotates the hub and propeller blade, and an actuation system. The actuation system has a screw and a piston. A motor has a non-rotating component in communication with the non-rotating side of the propeller and a rotating component in communication with the actuation system. When the motor increases speed, the screw rotates and the piston moves laterally in a first axial direction to decrease the pitch of the propeller and, when the motor decreases speed, the screw rotates and the piston moves laterally in a second axial direction to increase the pitch of the propeller.

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 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 system adjusts the pitch of a variable pitch propeller having a non-rotating side and a rotating side. The rotating side of the propeller has a hub, a propeller blade mounted to the hub, a propeller shaft that rotates the hub and propeller blade, and an actuation system. The actuation system has a screw and a piston. A motor has a non-rotating component in communication with the non-rotating side of the propeller and a rotating component in communication with the actuation system. When the motor increases speed, the screw rotates and the piston moves laterally in a first axial direction to decrease the pitch of the propeller and, when the motor decreases speed, the screw rotates and the piston moves laterally in a second axial direction to increase the pitch of the propeller.

Abstract: Maintenance requirements on a variable pitch propeller control system are minimized by eliminating the need for mechanical elements, such as a flyweight, mechanism in a secondary control for the variable pitch propeller. The system includes a secondary control (40) operating a pitch change mechanism (24) in response to the existence of at least one undesirable propeller condition and includes a target (34), (38) along with a target pickup (32), (36) for sensing the target (34), (38) and providing information to a function generator (76) which in turn provides information to a logic device (78), (80), (82), (84), (86), (88), (94) which in turn is connected to the pitch change mechanism (24) for operating the same.