Abstract: An aircraft designed to prevent foreign object damage to the aircraft. The aircraft includes an engine coupled aft of the aircraft's landing gear, and a deflecting member is coupled to the aircraft between the landing gear and an inlet of the engine so that when the deflecting member is extended, it intersects with a portion of lines of sight between the landing gear and an inlet of the engine.

Abstract: An aircraft designed to prevent foreign object damage to the aircraft. The aircraft includes an engine coupled aft of the aircraft's landing gear, and a deflecting member is coupled to the aircraft between the landing gear and an inlet of the engine so that when the deflecting member is extended, it intersects with a portion of lines of sight between the landing gear and an inlet of the engine.

Abstract: A supersonic external-compression inlet comprises a generally scoop-shaped supersonic compression section for diffusing a supersonic free stream flow. The supersonic compression section includes a main wall having a leading edge and a throat portion downstream of the leading edge, and side portions joined to opposite side edges of the main wall so as to form a generally scoop-shaped structure. The side portions advantageously extend into the supersonic flow stream far enough to encompass the initial oblique shock wave that is attached to the leading edge of the main wall. The main wall has an inner surface formed generally as an angular sector of a surface of revolution, the inner surface of the main wall coacting with inner surfaces of the side portions to define a three-dimensional external-compression surface. The supersonic external-compression inlet also includes a subsonic diffuser section arranged to receive flow from the supersonic compression section and to diffuse the flow to a subsonic condition.

Abstract: Methods and apparatus for controlling aircraft inlet air flow. The apparatus can include an external flow surface having a forward portion, and an engine inlet positioned at least proximate to the external flow surface and aft of the forward portion. The engine inlet can have an aperture and can be coupled with an engine inlet duct to an engine location. An auxiliary flow duct can be positioned at least proximate to the external flow surface and can include a first opening and a second opening spaced apart from the first opening. The first opening can be positioned to receive flow from the external flow surface during at least a first portion of an operating schedule of the propulsion system. The auxiliary flow duct can be configured to direct air to the engine location during at least a second portion of the operating schedule of the propulsion system.

Abstract: Methods and apparatus for controlling aircraft inlet air flow. The apparatus can include an external flow surface having a forward portion, and an engine inlet positioned at least proximate to the external flow surface and aft of the forward portion. The engine inlet can have an aperture and can be coupled with an engine inlet duct to an engine location. An auxiliary flow duct can be positioned at least proximate to the external flow surface and can include a first opening and a second opening spaced apart from the first opening. The first opening can be positioned to receive flow from the external flow surface during at least a first portion of an operating schedule of the propulsion system. The auxiliary flow duct can be configured to direct air to the engine location during at least a second portion of the operating schedule of the propulsion system.

Abstract: An internal compression engine inlet (39) including a flexible external cowl with leading edge cowl lips (72); a duct comprising a supersonic diffuser (44) defined by upper and lower forward ramps (50), (52), a subsonic diffuser (46) defined by upper and lower aft ramps (54), (56), and a throat region (48); a first slot (58) formed between adjacent ends of the upper forward and upper aft ramps; and a second slot (60) formed between adjacent ends of the lower forward and lower aft ramps, is provided. Each slot (58), (60) opens to a plenum (120), (122) having a vent door (126) covering a vent (124) that opens to a low pressure volume.

Abstract: An internal compression engine inlet (39) including a flexible external cowl with leading edge cowl lips (72); a duct comprising a supersonic diffuser (44) defined by upper and lower forward ramps (50), (52), a subsonic diffuser (46) defined by upper and lower aft ramps (54), (56), and a throat region (48); a first slot (58) formed between adjacent ends of the upper forward and upper aft ramps; and a second slot (60) formed between adjacent ends of the lower forward and lower aft ramps, is provided. Each slot (58), (60) opens to a plenum (120), (122) having a vent door (126) covering a vent (124) that opens to a low pressure volume.

Abstract: Boundary layer control apparatus is provided (22). The boundary layer control apparatus (22) is for use with an aircraft propulsion nacelle (12) positioned such that the air inlet (14) of the propulsion nacelle is located proximate an aircraft surface (10), wherein a boundary layer is established on the surface when the aircraft is propelled through an atmosphere, causing air to flow over the surface. The boundary layer control apparatus (22) includes a duct having an entrance (24) positioned between the aircraft surface (10) and the inlet (14) of the propulsion nacelle (12) for capturing the boundary layer air passing over the aircraft surface and diverting the boundary layer air away from the inlet.

Abstract: A mixed compression inlet having a forward ramp, an aft ramp, and a slot therebetween is disclosed. The aft ramp is coupled to the inlet to permit both fore-aft movement and rotational movement. The geometric throat of the inlet is located at the leading edge of the aft ramp. The slot opens into a plenum chamber. A vent permits air to exit from the plenum chamber. The pressure in the plenum chamber is maintained approximately equal to the pressure on the aft portion of the forward ramp. A servocontroller receiving input from pressure sensors of the forward ramp and in the plenum chamber controls the position of a vent door to ensure that the proper pressure is maintained within the plenum chamber.