# US 10,864,980 B2 · System and method for feathering an aircraft propeller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,864,980 B2 - Document ID: US10864980B2 - Status: Granted - Kind: B2 - Application number: 16/031,361 - Filed: 2018-07-10 - Published: 2020-01-16 - Granted: 2020-12-15 - Earliest claimed: 2018-07-10 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Jasraj Chahal; Carmine Lisio; Darragh McGrath; Giancarlo Zingaro - Web page: https://patentgrep.com/patent/US10864980B2 ## CPC - B64C 11/385: {comprising feathering, braking or stopping systems} - B64C 11/303: {characterised by comprising a governor} - B64C 11/40: automatic - B64C 11/42: non-automatic - B64C: AEROPLANES; HELICOPTERS ## Abstract A system and method for feathering an aircraft propeller are provided. The aircraft propeller is coupled to an actuator for setting a blade pitch of the propeller. The blade pitch is controlled by modulating a supply of hydraulic fluid to the actuator. At least one feather solenoid is provided that comprises a first solenoid coil, a second solenoid coil, and a solenoid valve coupled to the actuator and to the first and the second solenoid coil. At least one controller is configured to selectively energize and de-energize the first and the second solenoid coil. The solenoid valve is configured to be activated when the first solenoid coil and the second solenoid coil are de-energized and to, when activated, modulate the supply of hydraulic fluid to the actuator for adjusting the blade pitch of the propeller towards a feather position. ## Claims ### Claim 1 A system for feathering an aircraft propeller having coupled thereto an actuator for setting a blade pitch of the propeller, the blade pitch controlled by modulating a supply of hydraulic fluid to the actuator, the system comprising: at least one feather solenoid comprising a first solenoid coil, a second solenoid coil, and a solenoid valve coupled to the actuator and to the first and the second solenoid coil; and at least one controller configured to selectively energize and de-energize the first and the second solenoid coil, the solenoid valve configured to be activated when the first solenoid coil and the second solenoid coil are de-energized and to, when activated, modulate the supply of hydraulic fluid to the actuator for adjusting the blade pitch of the propeller towards a feather position. ### Claim 2 (depends on 1) The system of claim 1, wherein the at least one controller comprises a first solenoid driver configured to selectively energize and de-energize the first solenoid coil and a second solenoid driver configured to selectively energize and de-energize the second solenoid coil, the at least one controller comprising a first channel for controlling the first solenoid driver and a second channel for controlling the second solenoid driver. ### Claim 3 (depends on 2) The system of claim 2, wherein the first solenoid driver and the second solenoid driver are configured to respectively de-energize the first solenoid coil and the second solenoid coil in response to receiving a feather command. ### Claim 4 (depends on 2) The system of claim 2, wherein each of the first solenoid driver and the second solenoid driver comprises a first electrical switch connected to a corresponding one of the first solenoid coil and the second solenoid coil, the first electrical switch controllable between an open position and a closed position and configured to, when in the closed position, connect the corresponding solenoid coil to ground and to, when in the open position, disconnect the corresponding solenoid coil from ground. ### Claim 5 (depends on 4) The system of claim 4, wherein the first electrical switch of the first solenoid driver is configured to default to the open position when the first channel is unpowered and the first electrical switch of the second solenoid driver is configured to default to the open position when the second channel is unpowered. ### Claim 6 (depends on 4) The system of claim 4, wherein the first electrical switch of the first solenoid driver is configured to default to the open position when the first channel is non-functioning and the first electrical switch of the second solenoid driver is configured to default to the open position when the second channel is non-functioning. ### Claim 7 (depends on 4) The system of claim 4, wherein each of the first solenoid driver and the second solenoid driver comprises a second electrical switch connected to a corresponding one of the first solenoid coil and the second solenoid coil, the second electrical switch controllable between the open position and the closed position and configured to, when in the closed position, connect the corresponding solenoid coil to a power source and to, when in the open position, disconnect the corresponding solenoid coil from the power source. ### Claim 8 (depends on 7) The system of claim 7, wherein the corresponding solenoid coil is de-energized when at least one of the first electrical switch and the second electrical switch is in the open position. ### Claim 9 (depends on 7) The system of claim 7, wherein the second electrical switch of the first solenoid driver is configured to default to the open position when the first channel is unpowered and the second electrical switch of the second solenoid driver is configured to default to the open position when the second channel is unpowered. ### Claim 10 (depends on 7) The system of claim 7, wherein the first electrical switch and the second electrical switch of the first solenoid driver are configured to default to the open position when the first channel is unpowered and the first electrical switch and the second electrical switch of the second solenoid driver is configured to default to the open position when the second channel is unpowered. ### Claim 11 (depends on 2) The system of claim 2, wherein the at least one controller is a full authority digital engine control (FADEC) and the first channel and the second channel are redundant channels. ### Claim 12 A method for feathering an aircraft propeller having coupled thereto an actuator for setting a blade pitch of the propeller, the blade pitch controlled by modulating a supply of hydraulic fluid to the actuator, the method comprising: receiving a command to feather the propeller; in response to receiving the command, commanding at least one controller to de-energize a first feather solenoid coil and a second feather solenoid coil, the first and second solenoid coil coupled to a solenoid valve coupled to the actuator; and activating the solenoid valve when the first solenoid coil and the second solenoid coil are de-energized, the solenoid valve, when activated, modulating the supply of hydraulic fluid to the actuator for adjusting the blade pitch of the propeller towards a feather position. ### Claim 13 (depends on 12) The method of claim 12, wherein commanding the at least one controller to de-energize the first solenoid coil and the second solenoid coil comprises commanding a first solenoid driver to de-energize the first solenoid coil and commanding a second solenoid driver to de-energize the second solenoid coil. ### Claim 14 (depends on 13) The method of claim 13, wherein commanding the first solenoid driver to de-energize the first solenoid coil comprises commanding a first electrical switch of the first solenoid driver to an open position for disconnecting the first solenoid coil from ground; and wherein commanding the second solenoid driver to de-energize the second solenoid coil comprises commanding a first electrical switch of the second solenoid driver to an open position for disconnecting the second solenoid coil from ground. ### Claim 15 (depends on 14) The method of claim 14 wherein the first electrical switch of the first solenoid driver is configured to default to the open position when a first channel of the at least one controller is unpowered and the first electrical switch of the second solenoid driver is configured to default to the open position when a second channel of the at least one controller is unpowered, the first channel is for controlling the first solenoid driver and the second channel is for controlling the second solenoid driver. ### Claim 16 (depends on 13) The method of claim 13, wherein commanding the first solenoid driver to de-energize the first solenoid coil comprises commanding a second electrical switch of the first solenoid driver to an open position for disconnecting the first solenoid coil from a power source; and wherein commanding the second solenoid driver to de-energize the second solenoid coil comprises commanding a second electrical switch of the second solenoid driver to an open position for disconnecting the second solenoid coil from the power source. ### Claim 17 (depends on 16) The method of claim 16 wherein the second electrical switch of the first solenoid driver is configured to default to the open position when the first channel is unpowered and the second electrical switch of the second solenoid driver is configured to default to the open position when the second channel is unpowered. ### Claim 18 (depends on 16) The method of claim 16, wherein the first electrical switch and the second electrical switch of the first solenoid driver are configured to default to the open position when the first channel is unpowered and the first electrical switch and the second electrical switch of the second solenoid driver is configured to default to the open position when the second channel is unpowered.