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 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.

A propeller system includes a rotatable housing having at least one propeller blade mounted thereon and an electric pitch control motor within the rotatable housing. A pitch control member is coupled to the propeller blade and extends through a wall of the rotatable housing. The pitch control motor is configured to move the pitch control member and to thereby vary the pitch of the propeller blade.

A pitch control system configured to vary a pitch angle of at least one of a plurality of propeller blades of a propeller system is provided including a switch movable between a neutral position and a plurality of non-neutral positions. Movement of the switch to a first non-neutral position generates a command to move the propeller blades in a first direction. Movement of the switch to a second non-neutral position generates a command to move the propeller blades in a second direction. Movement of the switch to a third non-neutral position generates a command to move the propeller blades to a zero thrust position.

An electronic controller for an engine and a propeller, a control system and related methods are described herein. The control system comprises the controller having a first channel and a second channel independent from and redundant to the first channel. Each channel comprises a control processor configured to receive first engine and propeller parameters and to output, based on the first engine and propeller parameters, at least one engine control command and at least one propeller control command. Each channel also comprises a protection processor configured to receive second engine and propeller parameters and to output, based on the second engine and propeller parameters, at least one engine protection command and at least one propeller protection command. The control system comprises sensors for measuring the parameters of the engine and/or the propeller and effectors configured to control the engine and the propeller.

An electronic controller for an engine and a propeller, a control system and related methods are described herein. The controller comprises a first channel and a second channel independent from and redundant to the first channel. Each channel having a control processor configured to receive first engine and propeller parameters and to output, based on the first engine and propeller parameters, at least one engine control command comprising instructions for controlling an operation of the engine and at least one propeller control command comprising instructions for controlling an operation of the propeller. Each channel also comprises a protection processor configured to receive second engine and propeller parameters and to output, based on the second engine and propeller parameters, at least one engine protection command comprising instructions for protecting the engine from hazardous conditions and at least one propeller protection command comprising instructions for protecting the propeller from hazardous conditions.

Using a set of airflow sensors disposed on an airfoil of an aircraft, first airflow data including an amount of airflow experienced at each airflow sensor at a first time is measured. Using a trained neural network model, the first airflow data is analyzed to determine an airflow state of the aircraft. In response to determining that the aircraft is in the abnormal airflow state, a control surface and a power unit of the aircraft are adjusted. Responsive to the adjusting, the aircraft is returned to the normal airflow state.

A pitch control system configured to vary a pitch angle of at least one of a plurality of propeller blades of a propeller system is provided including a switch movable between a neutral position and a plurality of non-neutral positions. Movement of the switch to a first non-neutral position generates a command to move the propeller blades in a first direction. Movement of the switch to a second non-neutral position generates a command to move the propeller blades in a second direction. Movement of the switch to a third non-neutral position generates a command to move the propeller blades to a zero thrust position.

Methods and systems for slowing down an aircraft having a propeller. The method comprises operating the propeller at a reference speed with the propeller blades in a first position, applying a load to the propeller to slow down a rotational speed of the propeller when the propeller is in a windmilling state or just before the propeller enters the windmilling state, adjusting the propeller blades to a second position in response to the load being applied, to increase the rotational speed of the propeller back towards the reference speed, and operating the propeller at the reference speed with the propeller blades in the second position.

Systems and methods for controlling a gas turbine engine and a propeller are described herein. A target output power for the engine and a target speed for the propeller are received. A measurements of at least one engine parameter and a measurement of at least one propeller parameter are received. At least one engine control command is generated based on the target output power, the measurement of the at least one engine parameter and at least one model of the engine. At least one propeller control command is generated based on the target speed, the measurement of the at least one propeller parameter and the at least one model of the propeller. The at least one engine control command is output for controlling an operation of the engine accordingly and the at least one propeller control command is output for controlling an operation of the propeller accordingly.