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 system includes an inboard tiltrotor subsystem and an outboard tiltrotor subsystem. The inboard tiltrotor subsystem includes an inboard pylon, an inboard tiltrotor, and a single and non-redundant drivetrain. The outboard tiltrotor subsystem includes an outboard pylon that is coupled to a wing and an outboard tiltrotor. The outboard tiltrotor has a range of motion and is coupled to the wing via the outboard pylon, such that the outboard tiltrotor is aft of the wing. The outboard tiltrotor subsystem further includes a redundant drivetrain (which has a plurality of motors and a plurality of motor controllers) that drives one or more blades and the one or more blades.

A system includes an inboard tiltrotor subsystem and an outboard tiltrotor subsystem. The inboard tiltrotor subsystem includes an inboard pylon, an inboard tiltrotor, and a single and non-redundant drivetrain. The outboard tiltrotor subsystem includes an outboard pylon that is coupled to a wing and an outboard tiltrotor. The outboard tiltrotor has a range of motion and is coupled to the wing via the outboard pylon, such that the outboard tiltrotor is aft of the wing. The outboard tiltrotor subsystem further includes a redundant drivetrain (which has a plurality of motors and a plurality of motor controllers) that drives one or more blades and the one or more blades.

A control system for a hybrid electric powerplant of an aircraft can include a master controller configured to receive one or more power settings and to output a heat engine setting and an electric motor setting and a heat engine controller operatively connected to the master controller. The heat engine controller can be configured to receive the heat engine setting and to control a heat engine system as a function of the heat engine setting to control torque output by a heat engine. The system can include an electric motor controller operatively connected to the master controller. The electric motor controller configured to receive the electric motor engine setting and to control an electric motor system as a function of the electric motor setting to control torque output by an electric motor. The master controller can include a protection control module configured to provide one or more protection commands to directly control one or more heat engine protection systems and one or more electric motor protection systems.

A control system for a hybrid electric powerplant of an aircraft can include a master controller configured to receive one or more power settings and to output a heat engine setting and an electric motor setting and a heat engine controller operatively connected to the master controller. The heat engine controller can be configured to receive the heat engine setting and to control a heat engine system as a function of the heat engine setting to control torque output by a heat engine. The system can include an electric motor controller operatively connected to the master controller. The electric motor controller configured to receive the electric motor engine setting and to control an electric motor system as a function of the electric motor setting to control torque output by an electric motor. The master controller can include a protection control module configured to provide one or more protection commands to directly control one or more heat engine protection systems and one or more electric motor protection systems.

Unmanned aircraft have aligned forward and aft propulsion systems possessing different performance and/or noise characteristics. According to some embodiments, unmanned aircraft have a forward engine and a forward tractor propeller and an aft engine and an aft pusher propeller. Selected ones of forward and aft propulsion systems will thus be provided to have greater and lesser operational flight performance characteristics and greater and lesser noise signature characteristics, respectively, as compared to the other. For example, the forward propulsion system may be provided with the greater operational flight performance and higher signature characteristics as compared to the aft propulsion system, while conversely the aft propulsion system may be provided with a lesser flight performance and lower noise signature characteristics as compared to the forward propulsion system.

An autothrottle for an aircraft that includes a power-control input (PCL) manually movable by a pilot along a travel path to effect a throttle setting that controls engine power of the aircraft. The autothrottle determines a control-target setting for a throttle of the aircraft and dynamically adjusts the throttle according to the control-target setting, including moving the PCL to achieve the control-target setting. A virtual detent is set and dynamically adjusted at positions along a travel path of the PCL corresponding to the control-target setting. The virtual detent is operative, at least when the autothrottle is in a disengaged state for autothrottle control, to indicate the control-target setting to the pilot via a haptic effect that applies a detent force opposing motion of the PCL in response to the PCL achieving the position of the virtual detent.

An autothrottle for an aircraft that includes a power-control input (PCL) manually movable by a pilot along a travel path to effect a throttle setting that controls engine power of the aircraft. The autothrottle determines a control-target setting for a throttle of the aircraft and dynamically adjusts the throttle according to the control-target setting, including moving the PCL to achieve the control-target setting. A virtual detent is set and dynamically adjusted at positions along a travel path of the PCL corresponding to the control-target setting. The virtual detent is operative, at least when the autothrottle is in a disengaged state for autothrottle control, to indicate the control-target setting to the pilot via a haptic effect that applies a detent force opposing motion of the PCL in response to the PCL achieving the position of the virtual detent.

A method of operating an electrically powered rotorcraft of the type having a fuselage and a set of N rotors driven by a set of electric motors and coupled to the fuselage, N≥4, under a failure condition preventing ordinary operation of the rotorcraft. The method includes entering a failsafe mode of operation wherein autorotation of at least four of the rotors is enabled. The method also includes using electrical braking associated with a selected group of the rotors to control yaw of the rotorcraft.

A method of operating an electrically powered rotorcraft of the type having a fuselage and a set of N rotors driven by a set of electric motors and coupled to the fuselage, N≥4, under a failure condition preventing ordinary operation of the rotorcraft. The method includes entering a failsafe mode of operation wherein autorotation of at least four of the rotors is enabled. The method also includes using electrical braking associated with a selected group of the rotors to control yaw of the rotorcraft.