A method of managing a gas turbine engine includes the steps of detecting an airspeed and detecting a fan speed. A parameter relationship is referenced related to a desired variable area fan nozzle position based upon at least airspeed and fan speed. The detected airspeed and detected fan speed is compared to the parameter relationship to determine a target variable area fan nozzle position. An actual variable area fan nozzle position is adjusted in response to the determination of the target area fan nozzle position and at least one threshold.

A fan nacelle, a gas turbine engine cell assembly, and an aircraft are provided. The fan nacelle includes a fan duct skin arranged in a fan duct to direct airflow from the fan of a Turbofan engine toward a fan nozzle. An exterior skin of the fan nacelle directs air flow around an exterior of the engine. The fan duct skin and the exterior skin terminate at a trailing edge, and a trailing edge portion of the exterior skin is one of parallel to and diverging from a trailing edge portion of the fan duct skin in an aft direction. In certain aspects, the trailing edge portion of the exterior skin is actuatable or inflatable to selectively divert from the trailing edge portion of the fan duct skin.

A fan nacelle, a gas turbine engine cell assembly, and an aircraft are provided. The fan nacelle includes a fan duct skin arranged in a fan duct to direct airflow from the fan of a Turbofan engine toward a fan nozzle. An exterior skin of the fan nacelle directs air flow around an exterior of the engine. The fan duct skin and the exterior skin terminate at a trailing edge, and a trailing edge portion of the exterior skin is one of parallel to and diverging from a trailing edge portion of the fan duct skin in an aft direction. In certain aspects, the trailing edge portion of the exterior skin is actuatable or inflatable to selectively divert from the trailing edge portion of the fan duct skin.

A method of managing a gas turbine engine includes the steps of detecting an airspeed and detecting a fan speed. A parameter relationship is referenced related to a desired variable area fan nozzle position based upon at least airspeed and fan speed. The detected airspeed and detected fan speed is compared to the parameter relationship to determine a target variable area fan nozzle position. An actual variable area fan nozzle position is adjusted in response to the determination of the target area fan nozzle position and at least one threshold.

A method of managing a gas turbine engine includes the steps of detecting an airspeed and detecting a fan speed. A parameter relationship is referenced related to a desired variable area fan nozzle position based upon at least airspeed and fan speed. The detected airspeed and detected fan speed is compared to the parameter relationship to determine a target variable area fan nozzle position. An actual variable area fan nozzle position is adjusted in response to the determination of the target area fan nozzle position and at least one threshold.

A method for operating an electric fan of an aircraft propulsion system includes driving a plurality of fan blades of the electric fan with an electric machine to generate thrust for the aircraft; and driving the electric machine with the plurality of fan blades of the electric fan to generate electrical power subsequent to driving the plurality of fan blades of the electric fan with the electric machine to generate thrust for the aircraft.

A method for operating an electric fan of an aircraft propulsion system includes driving a plurality of fan blades of the electric fan with an electric machine to generate thrust for the aircraft; and driving the electric machine with the plurality of fan blades of the electric fan to generate electrical power subsequent to driving the plurality of fan blades of the electric fan with the electric machine to generate thrust for the aircraft.

An actuation system for a gas turbine engine oriented about a centerline includes a translating ring, at least one hydraulic actuator, and at least one electric actuator. The translating ring is oriented about the centerline and configured to move axially along the centerline. The at least one hydraulic actuator is configured to provide a first mechanical force to move the translating ring along the centerline. The at least one electric actuator is configured to provide a second mechanical force to move the translating ring in the axial direction. The at least one electric actuator is controlled to provide the second mechanical force upon determination of an operating condition.

An actuation system for a gas turbine engine oriented about a centerline includes a translating ring, at least one hydraulic actuator, and at least one electric actuator. The translating ring is oriented about the centerline and configured to move axially along the centerline. The at least one hydraulic actuator is configured to provide a first mechanical force to move the translating ring along the centerline. The at least one electric actuator is configured to provide a second mechanical force to move the translating ring in the axial direction. The at least one electric actuator is controlled to provide the second mechanical force upon determination of an operating condition.

A convergent-divergent nozzle arranged to convey fluid from an upstream zone to a downstream zone via a throat aperture, wherein the nozzle includes an assembly movable to vary the size of the throat aperture of the nozzle, thereby regulating the flow of fluid to the downstream zone.