Abstract: A propeller oil control system for a turboprop engine of an aircraft includes an engine control unit and a propeller oil controller. The engine control unit is operable to determine a flight phase of the aircraft and is configured to supply control commands. The propeller oil controller is coupled to receive a supply of oil and to discharge the oil at a discharge oil pressure. The propeller oil controller includes an electrohydraulic servo valve that receives the control commands moves to a plurality of positions between a first position and a mid-position, and a plurality of positions between the mid-position and a second position. The engine control unit only commands the electrohydraulic servo valve to move out of the first position when the engine control unit determines the aircraft is conducting a take-off roll or the aircraft is in flight.

Abstract: 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.

Abstract: A propeller oil control system for a turboprop engine of an aircraft includes an engine control unit and a propeller oil controller. The engine control unit is operable to determine a flight phase of the aircraft and is configured to supply control commands. The propeller oil controller is coupled to receive a supply of oil and to discharge the oil at a discharge oil pressure. The propeller oil controller includes an electrohydraulic servo valve that receives the control commands moves to a plurality of positions between a first position and a mid-position, and a plurality of positions between the mid-position and a second position. The engine control unit only commands the electrohydraulic servo valve to move out of the first position when the engine control unit determines the aircraft is conducting a take-off roll or the aircraft is in flight.

Abstract: 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.

Abstract: Systems and methods for icing resistant total air temperature probes are provided. In one embodiment, a total air temperature data probe comprises: a probe base; a probe body comprising: a first interior airflow passage comprising a first annulus; a temperature sensor positioned within the first annulus; a heating element; a notched intake port positioned at a distal end, wherein the probe body provides a conductive thermal path from the heating element to the intake port, the intake port including an open channel extending inward into an intake aperture of the probe body, and a cutaway region that defines a recessed second face inset from the first face and exposes the open channel at least partially from the leading edge. The notched intake port further comprises a slot inset from the recessed second face that traverses across at least a portion of the intake aperture perpendicularly to the open channel.

Abstract: Systems and methods for icing resistant total air temperature probes are provided. In one embodiment, a total air temperature data probe comprises: a probe base; a probe body comprising: a first interior airflow passage comprising a first annulus; a temperature sensor positioned within the first annulus; a heating element; a notched intake port positioned at a distal end, wherein the probe body provides a conductive thermal path from the heating element to the intake port, the intake port including an open channel extending inward into an intake aperture of the probe body, and a cutaway region that defines a recessed second face inset from the first face and exposes the open channel at least partially from the leading edge. The notched intake port further comprises a slot inset from the recessed second face that traverses across at least a portion of the intake aperture perpendicularly to the open channel.