A system and method for feathering an aircraft propeller are provided. A first feather solenoid and a second feather solenoid each comprising at least one solenoid coil and a solenoid valve coupled to the actuator and to the at least one solenoid coil are provided. At least one controller is configured to selectively energize and de-energize the at least one solenoid coil. The solenoid valve of the first feather solenoid is configured to be activated when the at least one solenoid coil of the first feather solenoid is energized and the solenoid valve of the second feather solenoid is configured to be activated when the at least one solenoid coil of the second feather solenoid is de-energized. The solenoid valve is configured to, when activated, modulate the supply of hydraulic fluid to an actuator for adjusting a blade pitch of the propeller towards a feather position.

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.

A propeller pitch control system for a turboprop engine of an aircraft includes an engine control unit and a pitch control unit. The engine control unit is operable to determine a phase of flight of the aircraft and is configured to supply control commands. The pitch control unit is coupled to receive the control commands from the engine control unit and includes a housing, a beta piston, a position sensor, a beta tube, and an electrohydraulic valve. The engine control unit only commands the electrohydraulic valve to move the beta piston from the fully retracted position when the engine control unit determines the aircraft is conducting pre-takeoff roll taxiing operations or is conducting post landing touchdown operations.

A propeller pitch control system for a turboprop engine of an aircraft includes an engine control unit and a pitch control unit. The engine control unit is operable to determine a phase of flight of the aircraft and is configured to supply control commands. The pitch control unit is coupled to receive the control commands from the engine control unit and includes a housing, a beta piston, a position sensor, a beta tube, and an electrohydraulic valve. The engine control unit only commands the electrohydraulic valve to move the beta piston from the fully retracted position when the engine control unit determines the aircraft is conducting pre-takeoff roll taxiing operations or is conducting post landing touchdown operations.

A method for controlling an aircraft propeller is provided that comprises obtaining a measurement of a speed of the propeller, comparing the propeller speed to a first threshold, responsive to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening a two-position solenoid valve coupled to the propeller, the two-position solenoid valve configured for controlling fluid flow to and from the propeller to control propeller blade angle, computing a rate of change of the propeller speed, comparing the rate of change of the propeller speed to a second threshold, and responsive to determining that the rate of change of the propeller speed is below the second threshold, outputting the valve control signal for closing the two-position solenoid valve. A system for controlling an aircraft propeller and an aircraft propeller control assembly are also provided.

A method for controlling an aircraft propeller is provided that comprises obtaining a measurement of a speed of the propeller, comparing the propeller speed to a first threshold, responsive to determining that the propeller speed exceeds the speed threshold, outputting a valve control signal for opening a two-position solenoid valve coupled to the propeller, the two-position solenoid valve configured for controlling fluid flow to and from the propeller to control propeller blade angle, computing a rate of change of the propeller speed, comparing the rate of change of the propeller speed to a second threshold, and responsive to determining that the rate of change of the propeller speed is below the second threshold, outputting the valve control signal for closing the two-position solenoid valve. A system for controlling an aircraft propeller and an aircraft propeller control assembly are also provided.

There is described herein methods and system for correcting steady state errors in propeller speed by calculating a leakage flow rate as a function of engine and propeller parameters.

There is described herein methods and system for correcting steady state errors in propeller speed by calculating a leakage flow rate as a function of engine and propeller parameters.

A propeller pitch control system for a turboprop engine of an aircraft includes a negative torque sensor, a full feather control valve assembly, and a feather valve assembly. The feather valve assembly is responsive to fluid pressures from the negative torque sensor and the control valve assembly to move between a plurality of positions. An engine control unit or a manual user interface can also be used to control the position of the feather.

Systems and methods are disclosed for controlling the pitch angle of a propeller and rotor assembly that minimizes circumferential loads and stresses to a pitch angle control system. The system may generally include an annular actuator, load transfer bearing (LTB), and a guide shaft is pivotally attached to the LTB to direct the LTB along an arcuate path relative to a rotor frame.