A vertical take-off and landing (VTOL) unmanned aerial vehicle having a foldable fixed wing and a twin-ducted fan power system (7) arranged at a tail portion of a fuselage in a transverse and tail propulsion arrangement provides lift for vertical take-off and landing and propulsion for horizontal flight. By means of deflection of a control servo plane arranged at a duct exit, a vectored thrust is provided to enable a fast attitude change. When the aerial vehicle takes off and lands vertically/flies at a low speed, the wing is folded to reduce the frontal area exposure to crosswind. When the aerial vehicle is flying horizontally, the wing is expanded to obtain larger lift. A Coanda effect is created at a trailing edge of the wing by suction of the duct to improve performance.

A duct for a ducted-rotor aircraft includes a hub, a duct ring, and a plurality of stators that extend outward from the hub. The hub may be configured to support a motor. The duct ring defines a trailing edge. The duct ring is coupled to each of the plurality of stators such that all or substantially all of each of the plurality of stators is located aft of the trailing edge of the duct ring.

A method for optimizing the operation of at least one first propeller and of at least one second propeller of a hybrid helicopter. The method comprises the following step during a control phase: deflection, with an autopilot system, of at least one aerodynamic stabilizer member into a setpoint position having, with respect to a reference position, a target deflection angle that is a function of a setpoint deflection angle, the setpoint deflection angle being calculated by the autopilot system in order to compensate for a torque exerted by the lift rotor at zero sideslip.

A method for optimizing the operation of at least one first propeller and of at least one second propeller of a hybrid helicopter. The method comprises the following step during a control phase: deflection, with an autopilot system, of at least one aerodynamic stabilizer member into a setpoint position having, with respect to a reference position, a target deflection angle that is a function of a setpoint deflection angle, the setpoint deflection angle being calculated by the autopilot system in order to compensate for a torque exerted by the lift rotor at zero sideslip.

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 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.

In an embodiment, a ducted fan assembly includes a housing that further includes a rotor. The ducted fan assembly also includes a plurality of stators that extend outward from the housing. The ducted fan assembly also includes a control vane pivotally attached to at least one of the plurality of stators. The ducted fan assembly also includes a rim that extends around at least a portion of a perimeter of the ducted fan assembly and is supported by the plurality of stators and the control vane, where the rim defines an opening surrounding at least a portion of the housing.

A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.