A method (600) for testing control logic for a propeller driven by a gas turbine engine of an aircraft includes overriding (602) a signal indicating the aircraft is operating in a ground mode. The method can further include testing (604) minimum pitch protection logic when the signal is overridden; determining (606) the gas turbine engine is operating at a ground fine setting; restoring (608) the signal to an original state in which the signal indicates the aircraft is operating in the ground mode; modifying (610) pitch protection logic; determining (614) the propeller is operating at an overspeed condition; and testing (616) the propeller overspeed protection logic. In addition, the method can also determine (612) the propeller is operating at a low pitch condition when the gas turbine engine is operating at the ground fine setting.

A flight control computer (FCC) for a rotorcraft includes a processor and a non-transitory computer-readable storage medium storing a program to be executed by the processor, with the program including instructions for providing main rotor overspeed protection. The instructions for providing the main rotor overspeed protection include instructions for monitoring sensor signals indicating a main rotor RPM, determining a target operating parameter, determining one or more flight parameters in response to a relationship between the main rotor RPM and the target operating parameter indicating a main rotor overspeed condition. Determining the one or more flight parameters includes determining a setting for a flight control device of the rotorcraft that changes the main rotor RPM, controlling positioning of a pilot control according to the flight parameters, and controlling the flight control device of the rotorcraft according to positioning of the pilot control.

A flight control computer (FCC) for a rotorcraft includes a processor and a non-transitory computer-readable storage medium storing a program to be executed by the processor, with the program including instructions for providing main rotor overspeed protection. The instructions for providing the main rotor overspeed protection include instructions for monitoring sensor signals indicating a main rotor RPM, determining a target operating parameter, determining one or more flight parameters in response to a relationship between the main rotor RPM and the target operating parameter indicating a main rotor overspeed condition. Determining the one or more flight parameters includes determining a setting for a flight control device of the rotorcraft that changes the main rotor RPM, controlling positioning of a pilot control according to the flight parameters, and controlling the flight control device of the rotorcraft according to positioning of the pilot control.

Systems and methods are described for governing the speed of a propeller on a propeller-based engine in an aircraft. The method comprises obtaining a synthesized or estimated blade angle for the propeller of the engine, determining one or more gain for a controller of the propeller based on the synthesized or estimated blade angle and one or more engine or aircraft parameter, determining a difference between a reference propeller speed and an actual propeller speed, applying the one or more gain to the difference via the controller in order to generate a command signal for controlling the propeller, and governing the propeller of the engine using the command signal.

Systems and methods are described for governing the speed of a propeller on a propeller-based engine in an aircraft. The method comprises obtaining a synthesized or estimated blade angle for the propeller of the engine, determining one or more gain for a controller of the propeller based on the synthesized or estimated blade angle and one or more engine or aircraft parameter, determining a difference between a reference propeller speed and an actual propeller speed, applying the one or more gain to the difference via the controller in order to generate a command signal for controlling the propeller, and governing the propeller of the engine using the command signal.

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

A control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4), is provided with: a control unit (12) to control a forward operating mode or a reverse operating mode of the gas turbine engine (1); and a supervising unit (14), operatively coupled to the control unit (12), to receive an input signal (PLA) indicative of a forward, or reverse, power request and to cause the control unit (12) to control the forward, or reverse, operating mode based on the input signal (PLA). The supervising unit (14) has an enabling stage (20) to enable a transition between the forward and reverse operating modes based on a check that a safety condition is satisfied.

A control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4), is provided with: a control unit (12) to control a forward operating mode or a reverse operating mode of the gas turbine engine (1); and a supervising unit (14), operatively coupled to the control unit (12), to receive an input signal (PLA) indicative of a forward, or reverse, power request and to cause the control unit (12) to control the forward, or reverse, operating mode based on the input signal (PLA). The supervising unit (14) has an enabling stage (20) to enable a transition between the forward and reverse operating modes based on a check that a safety condition is satisfied.

A system includes a thermal engine operatively connected to drive a propeller. An electric motor is operatively connected to the thermal engine to drive the propeller together with the thermal engine. An external input system is configured to accept input and output a thrust command. A protection function module is configured to enforce limits on the thermal engine, electric motor, and propeller. A low select module is operatively connected to receive input from the external input system and form the protection function module and to output the lower of input from the protection function module and external input system to the thermal engine, the electric motor, and the propeller.

A system includes a thermal engine operatively connected to drive a propeller. An electric motor is operatively connected to the thermal engine to drive the propeller together with the thermal engine. An external input system is configured to accept input and output a thrust command. A protection function module is configured to enforce limits on the thermal engine, electric motor, and propeller. A low select module is operatively connected to receive input from the external input system and form the protection function module and to output the lower of input from the protection function module and external input system to the thermal engine, the electric motor, and the propeller.