Abstract: A variable area fan nozzle for a turbofan aircraft engine includes a first structure defining a forward portion of a bypass duct of the turbofan aircraft engine and a second structure defining an aft portion of the bypass duct. The second structure is movable relative to the first structure between a deployed position where a porting flow passage defined between the forward portion of the bypass duct and the aft portion of the bypass duct is open, and a stowed portion where the porting flow passage is closed. The movable second structure comprises a vane and a slat attached to the vane and disposed forward of the vane. The porting flow passage extends between the slat and the vane when the second structure is in the deployed position.

Abstract: A variable area fan nozzle for a turbofan aircraft engine includes a first structure defining a forward portion of a bypass duct of the turbofan aircraft engine and a second structure defining an aft portion of the bypass duct. The second structure is movable relative to the first structure between a deployed position where a porting flow passage defined between the forward portion of the bypass duct and the aft portion of the bypass duct is open, and a stowed portion where the porting flow passage is closed. The movable second structure comprises a vane and a slat attached to the vane and disposed forward of the vane. The porting flow passage extends between the slat and the vane when the second structure is in the deployed position.

Abstract: An aircraft having a propulsive power unit supported in a fuselage mounted configuration and including an engine and a nacelle structure housing the engine. The nacelle structure is provided with upper and lower displaceable nacelle portions, such as thrust reverser cowls and fan cowl doors which are displaceable between closed dispositions which they occupy during operational conditions of the aircraft and open dispositions which they take up to provide access to engine components. The upper and lower nacelle portions are so mounted as to be displaceable to their open and closed dispositions in movements in which one is assisted by gravitational force and the other is displaced against gravitational force. A force transfer mechanism is provided for transfer during opening and closing movements of the nacelle portions of gravitational force assisting displacement of one of the nacelle portions to assist in displacement of the other nacelle portion being displaced against gravitational force.

Abstract: A thrust reversing arrangement for an aircraft turbofan propulsive power unit includes a flow redirecting structure which has reverse flow enhancing sub-structures comprising: (i) a cavity which is so dimensioned as to generate a back pressure which supports redirection of flow; (ii) a cascade assembly which provides a flow control slot so dimensioned as to optimize reverse thrust for predetermined fan duct flow conditions; (iii) an obstructing duct wall portion having a leading edge so positioned as to form a leakage slot providing controlled leakage of forward flow; (iv) a box structure, the dimensions of which are such as to optimize back pressure in the cavity; and (v) provision for gaseous fluid under static pressure from the fan duct to load the redirecting structure to the inoperative position.

Abstract: An aircraft having a propulsive power unit supported in a fuselage mounted configuration and including an engine and a nacelle structure housing the engine. The nacelle structure is provided with upper and lower displaceable nacelle portions, such as thrust reverser cowls and fan cowl doors which are displaceable between closed dispositions which they occupy during operational conditions of the aircraft and open dispositions which they take up to provide access to engine components. The upper and lower nacelle portions are so mounted as to be displaceable to their open and closed dispositions in movements in which one is assisted by gravitational force and the other is displaced against gravitational force. A force transfer mechanism is provided for transfer during opening and closing movements of the nacelle portions of gravitational force assisting displacement of one of the nacelle portions to assist in displacement of the other nacelle portion being displaced against gravitational force.

Abstract: A thrust reversing arrangement for an aircraft turbofan propulsive power unit includes a flow redirecting structure which has reverse flow enhancing sub-structures comprising: (i) a cavity which is so dimensioned as to generate a back pressure which supports redirection of flow; (ii) a cascade assembly which provides a flow control slot so dimensioned as to optimize reverse thrust for predetermined fan duct flow conditions; (iii) an obstructing duct wall portion having a leading edge so positioned as to form a leakage slot providing controlled leakage of forward flow; (iv) a box structure, the dimensions of which are such as to optimize back pressure in the cavity; and (v) provision for gaseous fluid under static pressure from the fan duct to load the redirecting structure to the inoperative position.

Abstract: In an aircraft propulsive power unit a thrust reversing arrangement includes a flow redirecting structure having a flow redirecting downstream wall against which gaseous fluid flow in a first flow direction impinges to turn the flow into a second flow direction to produce reverse thrust and an upstream wall round which the fluid flow turns and which has a boundary surface so formed as to support adherence of a boundary layer of the redirected fluid flow at the boundary surface. The upstream wall is provided with projecting elements to generate vortices which prevent or delay separation of the boundary layer from the boundary surface of the upstream wall. Alternatively, the upstream wall is formed with a plurality of flow apertures which are connected by a duct to a pressure differential region or source to cause gaseous fluid to flow through the boundary surface of the upstream wall to prevent or delay separation of the boundary layer.