A propulsion system for an aircraft, comprising at least one rotor and a nacelle fairing extending around the at least one rotor with respect to an axis of rotation of the rotor, the nacelle fairing comprising: an upstream section forming an inlet section of the nacelle fairing; a downstream section, a downstream end of which forms an outlet section of the nacelle fairing; and an intermediate section connecting the upstream and downstream sections, wherein the downstream section comprises a radially inner wall and a radially outer wall made of a deformable shape memory material, and wherein the downstream end forming the outlet section has a pneumatic or hydraulic annular actuator extending around the axis of rotation and configured to deform radially under a predetermined control pressure so as to vary an outer diameter of the outlet section between a minimum diameter and a maximum diameter.

A propulsion system for an aircraft, comprising at least one rotor and a nacelle fairing extending around the at least one rotor with respect to an axis of rotation of the rotor, the nacelle fairing comprising: an upstream section forming an inlet section of the nacelle fairing; a downstream section, a downstream end of which forms an outlet section of the nacelle fairing; and an intermediate section connecting the upstream and downstream sections, wherein the downstream section comprises a radially inner wall and a radially outer wall made of a deformable shape memory material, and wherein the downstream end forming the outlet section has a pneumatic or hydraulic annular actuator extending around the axis of rotation and configured to deform radially under a predetermined control pressure so as to vary an outer diameter of the outlet section between a minimum diameter and a maximum diameter.

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 turbofan gas turbine engine includes a core engine within a core nacelle, a fan nacelle at least partially surrounding the core nacelle to define a bypass flow path and a variable fan nozzle exit area for bypass flow, and a pylon variable area flow system which operates to effect the bypass flow. A method of operating a turbofan gas turbine engine is also disclosed.

A turbofan gas turbine engine includes a core engine within a core nacelle, a fan nacelle at least partially surrounding the core nacelle to define a bypass flow path and a variable fan nozzle exit area for bypass flow, and a pylon variable area flow system which operates to effect the bypass flow. A method of operating a turbofan gas turbine engine is also disclosed.

A turbofan engine has an engine core including in flow series a compressor, a combustor and a turbine. The engine further has a fan located upstream of the engine core, has a supersonic intake for slowing down incoming air to subsonic velocities at an inlet to the fan formed by the intake, has a bypass duct surrounding the engine core, wherein the fan generates a core airflow to the engine core and a bypass airflow through the bypass duct, and has a mixer for mixing an exhaust gas flow exiting the engine core and bypass airflow exiting bypass duct. The engine further has a thrust nozzle rearwards of the mixer for discharging mixed flows, the thrust nozzle having a variable area throat. The engine further has a controller controlling the thrust produced by the engine over a range of flight operations including on-the-ground subsonic take-off and subsequent off-the-ground subsonic climb.

Fairing installations disclosed herein may include a damper for mitigating vibration of a cantilevered fairing disposed in a bypass duct of a gas turbine engine. The bypass duct may include a first shroud radially spaced apart from a second shroud to define a bypass passage between the first and second shrouds. The fairing may be disposed in the bypass passage and cantilevered from the first shroud. The fairing may have a secured end secured to the first shroud and a free end proximate the second shroud. The damper may be engaged with the free end of the fairing to damp movement of the free end of the fairing.

Fairing installations disclosed herein may include a damper for mitigating vibration of a cantilevered fairing disposed in a bypass duct of a gas turbine engine. The bypass duct may include a first shroud radially spaced apart from a second shroud to define a bypass passage between the first and second shrouds. The fairing may be disposed in the bypass passage and cantilevered from the first shroud. The fairing may have a secured end secured to the first shroud and a free end proximate the second shroud. The damper may be engaged with the free end of the fairing to damp movement of the free end of the fairing.

A gas turbine engine according to the present disclosure includes, among other things, a fan section having a plurality of fan blades, the plurality of fan blades having a peak tip radius Rt and an inboard leading edge radius Rh at a first inboard boundary of a first flowpath, and a core engine including a first turbine configured to drive a first compressor, and a fan drive turbine configured to drive the fan section.