Abstract: A nacelle assembly of a gas turbine engine includes an annular structure defining a central axis, and having a radially inward surface and a radially outward surface, the radially inward surface at least partially defining a bypass duct. An aft portion of the radially inward surface at least partially defines an axially extending convergent-divergent exit nozzle. A secondary nozzle flap is radially spaced from the aft portion of the radially inward surface. The secondary nozzle flap and the aft portion of the radially inward surface define a secondary bypass duct therebetween. The secondary nozzle flap is operably connected to the annular structure such that the secondary nozzle flap is selectably movable relative to the aft portion of the radially inward surface, thereby changing a cross-sectional area of a secondary bypass duct exit.

Abstract: A nacelle may comprise an inlet cowling comprising an inlet cowling aft edge having an aft edge length; a boat tail cowling comprising a boat tail cowling forward edge having a forward edge length, wherein the boat tail cowling forward edge is disposed adjacent to the inlet cowling aft edge. The forward edge length may be shorter than the aft edge length, forming a step being defined by a portion of the inlet cowling aft edge that is radially outward of the boat tail cowling forward edge. The nacelle may further comprise a transition fairing coupled to the boat tail cowling, wherein the transition fairing comprises a fairing forward edge disposed adjacent to the inlet cowling aft edge and a fairing ramp surface spanning between the inlet cowling aft edge and a boat tail cowling external surface.

Abstract: A gas turbine engine includes a compressor section, a combustor, and a turbine section. A bleed tap taps air from the compressor section through a bleed valve. The bleed valve is selectively opened by a control to dump air from the compressor section to a dump outlet. A heat exchanger duct includes a duct air inlet to cool a fluid in a heat exchanger and a duct air outlet. The dump outlet is within the heat exchanger duct.

Abstract: 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.

Abstract: An environmental sampling system includes a passage in an aircraft component and a removable collector disposed in the passage. The passage has an inlet at a first region and an outlet at a second region. When the aircraft component is in operation the first region is at a greater pressure than the second region such that air flows through the passage from the inlet to the outlet. The removable collector is configured to retain constituents from the air and to react with the media designed to mimic corrosion effects seen at higher temperatures on engine parts. The constituents can then be characterized and correlated to engine deterioration to predict maintenance activity.

Abstract: A nacelle may comprise an inlet cowling comprising an inlet cowling aft edge having an aft edge length; a boat tail cowling comprising a boat tail cowling forward edge having a forward edge length, wherein the boat tail cowling forward edge is disposed adjacent to the inlet cowling aft edge. The forward edge length may be shorter than the aft edge length, forming a step being defined by a portion of the inlet cowling aft edge that is radially outward of the boat tail cowling forward edge. The nacelle may further comprise a transition fairing coupled to the boat tail cowling, wherein the transition fairing comprises a fairing forward edge disposed adjacent to the inlet cowling aft edge and a fairing ramp surface spanning between the inlet cowling aft edge and a boat tail cowling external surface.

Abstract: A nacelle for a gas turbine engine includes a ring shaped body defining a center axis and having a radially outward surface and a radially inward surface. An aft portion of the radially inward surface includes an axially extending convergent-divergent exit nozzle. An axially extending secondary duct passes through the nacelle in the convergent-divergent exit nozzle. The axially extending secondary duct includes an inlet at a convergent portion of the convergent-divergent exit nozzle and an outlet at a divergent portion of the convergent-divergent exit nozzle.

Abstract: A gas turbine engine includes a compressor section, a combustor, and a turbine section. A bleed tap taps air from the compressor section through a bleed valve. The bleed valve is selectively opened by a control to dump air from the compressor section to a dump outlet. A heat exchanger duct includes a duct air inlet to cool a fluid in a heat exchanger and a duct air outlet. The dump outlet is within the heat exchanger duct.

Abstract: A nacelle assembly of a gas turbine engine includes an annular structure defining a central axis, and having a radially inward surface and a radially outward surface, the radially inward surface at least partially defining a bypass duct. An aft portion of the radially inward surface at least partially defines an axially extending convergent-divergent exit nozzle. A secondary nozzle flap is radially spaced from the aft portion of the radially inward surface. The secondary nozzle flap and the aft portion of the radially inward surface define a secondary bypass duct therebetween. The secondary nozzle flap is operably connected to the annular structure such that the secondary nozzle flap is selectably movable relative to the aft portion of the radially inward surface, thereby changing a cross-sectional area of a secondary bypass duct exit.

Abstract: A gas turbine engine includes a compressor section, a combustor, and a turbine section. A bleed tap taps air from the compressor section through a bleed valve. The bleed valve is selectively opened by a control to dump air from the compressor section to a dump outlet. A heat exchanger duct includes a duct air inlet to cool a fluid in a heat exchanger and a duct air outlet. The dump outlet is within the heat exchanger duct.

Abstract: A nacelle may comprise an inlet cowling comprising an inlet cowling aft edge having an aft edge length; a boat tail cowling comprising a boat tail cowling forward edge having a forward edge length, wherein the boat tail cowling forward edge is disposed adjacent to the inlet cowling aft edge. The forward edge length may be shorter than the aft edge length, forming a step being defined by a portion of the inlet cowling aft edge that is radially outward of the boat tail cowling forward edge. The nacelle may further comprise a transition fairing coupled to the boat tail cowling, wherein the transition fairing comprises a fairing forward edge disposed adjacent to the inlet cowling aft edge and a fairing ramp surface spanning between the inlet cowling aft edge and a boat tail cowling external surface.

Abstract: A face skin for an acoustic panel may comprise a sheet defining a first surface and a second surface. A plurality of slots may be formed through the face skin using abrasive blasting. Each slot of the plurality of slots may comprise a first semi-circular wall and a second semi-circular wall opposite the first semi-circular wall.

Abstract: A gas turbine engine has an inner housing surrounding a compressor, a combustor, and a turbine, with an inlet leading into the compressor, and a cooling sleeve defined radially outwardly of the inlet to the compressor for receiving cooling air radially outward of the compressor inlet. The cooling sleeve extends along a length of the engine, and radially outwardly of the inner housing, with the cooling air in the cooling sleeve being ejected at a downstream end to mix with products of combustion downstream of the turbine. An aircraft is also disclosed.

Abstract: An environmental sampling system includes a passage in an aircraft component and a removable collector disposed in the passage. The passage has an inlet at a first region and an outlet at a second region. When the aircraft component is in operation the first region is at a greater pressure than the second region such that air flows through the passage from the inlet to the outlet. The removable collector is configured to retain constituents from the air and to react with the media designed to mimic corrosion effects seen at higher temperatures on engine parts. The constituents can then be characterized and correlated to engine deterioration to predict maintenance activity.

Abstract: 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.

Abstract: 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.

Abstract: A gas turbine engine includes a compressor section, a combustor, and a turbine section. A bleed tap taps air from the compressor section through a bleed valve. The bleed valve is selectively opened by a control to dump air from the compressor section to a dump outlet. A heat exchanger duct includes a duct air inlet to cool a fluid in a heat exchanger and a duct air outlet. The dump outlet is within the heat exchanger duct.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, an engine wing. This disclosure also relates to an airplane including an engine wing.

Abstract: An exhaust section of a gas turbine engine includes an exhaust plug defining a plurality of exhaust plug apertures circumferentially spaced from each other. Also included is an exhaust nozzle radially offset from the exhaust plug defining an exhaust pathway between the exhaust plug and the exhaust nozzle. Further included is an exhaust plug liner having a non-uniform outer surface axially aligned with the exhaust plug apertures. The exhaust plug liner is rotatable relative to the exhaust plug between a first position and a second position to selectively change a cross-sectional area of the exhaust pathway during thrust reversal operation to reduce an amount of reverse thrust necessary.

Abstract: A gas turbine engine includes a fan, a compressor, a combustor, a turbine, a bypass duct downstream of the fan and outward of the compressor, and a cooling system. The cooling system includes an inlet for receiving air from the bypass duct, an outlet for returning air to the bypass duct, a cooling duct, and a heat exchanger and a modulator positioned in the cooling duct. The modulator includes dividers that extend parallel to each other and are arranged across the duct, and each divider includes two flaps that are rotatable about an axis in opposite directions.