An air intake unit for an engine of an aircraft; the intake unit has: a tubular housing; a first inlet opening which is obtained through an outer wall of the tubular housing and through which external air can be taken in; an air filter which engages the first inlet opening; a second inlet opening which is obtained through the outer wall of the tubular housing and through which external air can be taken in; a shutter device which is coupled to the second inlet opening and is movable between a closed position, in which it closes the second inlet opening, and an open position, in which it sets the passage through the second inlet opening free; and an actuator, which moves the shutter device.

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.

An air intake structure for a nacelle of an aircraft is disclosed having an air intake lip with a U-shaped section open towards the rear, an acoustic panel that extends the air intake lip towards the rear and on an inner side, an outer panel extending the air intake lip towards the rear and on an outer side, and a rear strengthening frame fixed between the outer panel and the acoustic panel, where the rear strengthening frame partly defines an inner volume that is immediately in front of the rear strengthening frame. The air intake structure comprises an impact absorber element positioned in the inner volume and the impact absorber element assumes the form of a structure that is deformable during an impact and that is at least partially filled with a fluid. The impact absorber element is a flexible shroud filled with a pressurized gas.

A nacelle may comprise an inlet cowling defining an inlet of the nacelle, wherein the inlet cowling comprises an inlet cowling maximum point and an inlet cowling aft edge, wherein the inlet cowling aft edge comprises an aft edge length; and a boat tail cowling disposed aft of the inlet cowling, wherein the boat tail cowling comprises a boat tail cowling forward edge having a forward edge length, and wherein the boat tail cowling forward edge is disposed adjacent to the inlet cowling aft edge. The forward edge length may be smaller than the aft edge length, forming a step, the step being defined by a portion of the inlet cowling aft edge that is radially outward of the boat tail cowling forward edge.

A propulsion system includes a main gas turbine engine adapted for generating propulsive thrust during subsonic and supersonic flight operations and a supplementary propulsion unit adapted for generating additional thrust. The supplementary propulsion unit has an air intake and an exhaust for gas accelerated by the supplementary propulsion unit to provide the additional thrust and is adapted to generate the additional thrust during a limited range of subsonic flight operations, and to be dormant during other flight operations. The propulsion system has housing for the supplementary propulsion unit, including intake and exhaust covers which are moveable between deployed and stowed configurations. During the limited range of subsonic flight operations the intake and exhaust cover are moved to the deployed configuration to open the intake and the exhaust. During other flight operations the intake and exhaust cover are moved to the stowed configuration to close the intake and the exhaust.

An air inlet for an aircraft nacelle, including a lip and a front frame, which together form a duct with D-shaped section receiving hot air. The front frame is arranged in an advanced position inside the lip. The lip has de-icing grooves, which communicate with the duct and extend essentially downstream of the front frame. Downstream of the front frame, outside of the de-icing grooves, the lip has perforated zones provided with sound absorption holes. The air inlet includes a foil, which hermetically seals the de-icing grooves and is provided with sound absorption holes facing the perforated zones. The air inlet comprises acoustic panels inside the lip downstream of the front frame. The advanced position of the front frame, due to the de-icing grooves which ensure the de-icing of the lip downstream of the front frame, allows the acoustic treatment surface of the air inlet to be increased.

An aircraft comprises a machine body. The machine body encloses a turbofan gas turbine engine and a plurality of ancillary systems. The turbofan gas turbine engine comprises, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, a turbine module, a combustor module, and an exhaust module.

The machine body comprises either one or two fluid inlet apertures. The or each fluid inlet aperture is configured to allow a fluid flow to enter the machine body and to pass through the heat exchanger module. The heat exchanger module is configured to transfer a waste heat load from the gas turbine engine and the ancillary systems to the fluid flow prior to an entry of the fluid flow into the fan module, and thence into the compressor module, the turbine module, the combustor module, and the exhaust module.

A turbofan gas turbine engine comprises, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, a turbine module, and an exhaust module. The fan assembly comprises a plurality of fan blades defining a fan diameter (D). The heat exchanger module is in fluid communication with the fan assembly by an inlet duct, and the heat exchanger module comprises a plurality of radially-extending hollow vanes arranged in a circumferential array with a channel extending axially between each pair of adjacent hollow vanes. The heat exchanger module has a square axial cross-sectional profile, where a side length of the square cross-section is D.

A nacelle assembly includes a fixed inlet segment and a translating inlet segment. The translating inlet segment includes a slider beam laterally between a pair of tracks of the fixed inlet segment. The slider beam is mated with and slidable longitudinally along the pair of tracks. The translating inlet segment is configured to translate longitudinally between a retracted position and an extended position. An aft end of the translating inlet segment is abutted against a forward end of the fixed inlet segment when the translating inlet segment is in the retracted position. An airflow inlet into an inlet passage of the nacelle assembly is opened longitudinally between the aft end of the translating inlet segment and the forward end of the fixed inlet segment when the translating inlet segment is in the extended position.

A nacelle for a gas turbine engine having a longitudinal centre line. The nacelle includes an air intake disposed at an upstream end of the nacelle. The air intake includes, in flow series, an intake lip, a throat and a diffuser. The diffuser further includes a diffuser angle (θ.sub.diff), indicating a degree of divergence of the diffuser relative to the longitudinal centre line. The diffuser angle (θ.sub.diff) is from about 0 degrees to about 12 degrees.