Abstract: A vane for a duct, such as an exit guide vane for an exhaust duct of a gas turbine engine, includes a vane plate, an interior strut and an internal wall disposed between the vane plate and the strut. The vane further includes a fluid inlet in the form of a scoop arranged to direct bypass fluid from outside the duct into a gap between the vane plate and the internal wall.

Abstract: A nozzle arrangement for a VTOL or STOVL aircraft having an airframe mounted lift system comprises a hinged deflector door pivotally mounted on the underside of the airframe for exhaust efflux deflection. The door is movable about its axis to vector impinging exhaust gases rearwards during the transition between vertical and horizontal flight, and in addition comprises a pair of lateral sidewalls which are movable in the plane of the door to direct the exhaust efflux sideways for improved aircraft yaw control.

Abstract: A vane for a duct, such as an exit guide vane for an exhaust duct of a gas turbine engine, comprises a vane plate, an interior strut and an internal wall disposed between the vane plate and the strut. The vane further comprises a fluid inlet in the form of a scoop arranged to direct bypass fluid from outside the duct into a gap between the vane plate and the internal wall.

Abstract: A variable area exit for a gas turbine engine discharge nozzle having a generally rectangular outlet includes a pair of rotatable flaps which extend between opposing sidewalls of the nozzle. Each of the flaps are provided with a profiled cam track which cooperates with a cam roller mounted on an axially moveable shroud ring. The shroud ring is coaxially disposed about the nozzle axis so that translation of the shroud causes the flaps to rotate and the nozzle exit area to alter.

Abstract: A changeover valve for a tandem fan type of engine is located in a duct between fan stages at either end. The valve arrangement has a butterfly flap valve to selectively obstruct flow along the cut, a drop-down chute to eject front fan flow and secondary inlet means to induct air to the second fan stage to supply the core engine. The secondary inlet means comprises drop-in doors hinged to pivot into the duct behind the flap valve. A tertiary airflow in a space defined by the duct and an engine nacelle is admitted to the region at the second fan entry face which is shadowed by the secondary inlet doors.

Abstract: In a tandem fan gas turbine engine two fan compressor stages are provided connected by a flow duct housing a diverter valve which can be used to admit the flow from the first fan to the second fan or to divert it to exhaust through an auxiliary outlet in which case the second fan draws ambient air in through an auxiliary inlet. The connecting duct is annular in cross section because an inner cylindrical wall surrounds the shaft driving the front fan. The diverter valve which therefore has to operate in the annular duct comprises a pair of flat side lobes connected by curved plates which straddle the inner wall. The valve is operated by a rotary actuator in synchronism with closure means which obstruct or open the auxiliary outlet and inlet.

Abstract: A nozzle guidevane for a gase turbine engine 10 comprising a first fixed upstream portion 24, a movable downstream portion 26 and a seal situated therebetween. The seal comprises two pairs of ridges 56, 58 on the upstream portion and two ridges 60 on the downstream portion 26 which co-operate with each other to form a flow restrictor which maintains the flow of escaping air within acceptable limits. The air which does escape is used to advantage by maintaining the mainflow of air over the outside of the vane 22.