Abstract: Jet propulsion nozzle comprises a pair of mutually confronting side walls 11, a pair of mutually confronting first panels 14 extending transversely between the walls and being supported thereon for pivotal movement about a first axis 18. A pair of mutually confronting second panels 20 situated downstream of the first panels are pivotally supported on the respective first panels by pivots 21. Actuators 19,24 are adapted to pivot the panels 14,20 so that the panels can be moved between a convergent position (as shown) and a convergent-divergent position. Further, the second panels can be pivoted into a position in which they divert the flow obliquely away from the normal flow axis 15 of the nozzle, and the first panels can be pivoted into a position in which they reverse the flow through openings 34 normally closed by these panels.

Abstract: The invention relates to an alloy suitable for making single-crystal castings and to a casting made thereof. The alloy comprises, by weight percent, Chromium 10-16%, Cobalt 4-16%, Molybdenum 2-4%, Tungsten 0-2%, Tantalum 2-8%, the sum of ##EQU1## lying between 5 and 7%, Aluminium 4-6%, Titanium 1-4% the sum of ##EQU2## lying between 5 and 7%. Carbon 0.015-0.05%, Boron 0-0.01%, Zirconium 0-0.01%, the balance being nickel plus incidental impurities.

Abstract: A method of molding a composite material comprising reinforcing fibres enclosed in a resin matrix. Layers of the resin impregnated fibres are laid-up in a suitably shaped die whereupon the laid-up layers are overlaid by a silicone rubber member which generally corresponds in shape with the die. Hydraulic pressure is exerted upon the silicone rubber member so that it urges the laid-up fibres into the configuration of the die. The whole molding apparatus is placed in an oven and its temperature is raised to that at which consolidation of the laid-up fibres occurs and the resin cures. The exerted hydraulic pressure is progressively reduced during heating as the silicone rubber member thermally expands so as to ensure that the pressure exerted by the silicone rubber member upon the laid-up fibres remains substantially constant.

Abstract: A gas turbine engine which is used for aircraft propulsion, is provided with a pair of thrust deflecting doors which, when deployed, deflect the exhaust gases onto some path other than axially of the engine, so as to spoil the thrust. The doors are waisted in profile. To prevent some of the exhaust gases from missing the doors, when deployed, and thus reducing their functional efficiency, plane flaps are provided on the jet pipe, which can be moved into the gas stream when the doors are deployed. The gas stream is thus constricted and so remains within the bounds of the deployed doors.

Abstract: Gas turbine engine compressor blades tend to untwist and decamber when subjected to working loads. Previous methods of observing the phenomenum and recording the magnitude of distortion have been restricted to the blade outer extremity, and to delayed display of the results. The invention provides a laser beam which is movable lengthwise of the blades and which effectively traverses each blade in a chordal direction. Photo devices pick up the light spot on each blade in turn and the signals produced are combined with signals representative of the speed of revolution of the blades and passed to an oscilloscope e.g. which immediately displays the shape of the blades.

Abstract: A cooled vane or blade for a gas turbine engine has a cooling arrangement for its trailing region which can be accommodated in the relatively thin section available. In this arrangement the trailing region of the hollow interior of the blade is divided off from the remainder by a partition which may be apertured to allow cooling air to enter the compartment thus formed. The concave, pressure flank of the compartment is cooled by arrays of film cooling holes while the convex, suction flank has a perforated plate spaced therefrom to provide impingement cooling. The suction flank is therefore unapertured and there is no disturbance of the high speed airflow in this region. The spent impingement air leaves the aerofoil via a slot and may pass over pedestals en route to cool the entire trailing edge.

Abstract: Combustion equipment for a gas turbine engine operating on the pre-mix lean combustion bases comprises a flame tube having a plurality of alternately arranged main and pilot air ducts each having a respective fuel injector and receiving axially directed air from downstream of part span outlet guide vanes. The fuel and air in each duct are substantially pre-mixed before entry into the flame tube and the outlets of the pilot ducts direct the fuel and air mixture into the recirculation zone in a single vortex. At engine idle the air fuel ratio (AFR) is substantially stoichiometric to prevent the formation of unburnt hydrocarbons (UHC) and carbon monoxide (CO). As the engine accelerates the fuel flow to the pilot air ducts remains near constant so that the AFR in the re-circulation zone progressively weakens, and fuel is introduced into the main air ducts, the outlets of which direct the air fuel mixture into the flame tube with a substantial downstream component.