Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) which has an inner surface (62), an outer surface (64), an upstream flange (42) and a downstream flange (52). The outer surface (62) of the metal casing (40) is provided with a pattern of blind apertures (66) which extend radially inwardly from the outer surface (62) of the metal casing (40) between the flanges (42,52). The fan blade containment has reduced weight of the metal casing (40) of the fan blade containment assembly (38) for a large diameter turbofan gas turbine engine (10) but has unimpaired stiffness and penetration resistance.

Abstract: A three-stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36,40,44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (54,70,92). The fuel and air mixing ducts (54,70,92) have a plurality of air injections apertures (62,64,76,98) spaced apart in the direction of flow through the fuel and air mixing ducts (54,70,92). The apertures (62,64,76,98) reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone (36,40,44). This reduces the generation of harmful vibrations in the combustion chamber (28).

Abstract: A gas turbine engine fan blade (26) comprises a root portion (36) and an aerofoil portion (32). The aerofoil portion (32) has a convex surface (44), a concave surface (42), a leading edge (38) and a trailing edge (40). The leading edge (38) of the aerofoil portion (32) is formed from a harder material than the regions of the concave surface (42) and convex surface (44) immediately adjacent the leading edge (38) such that the leading edge (38) of the aerofoil portion (32) remains pointed. This improves the efficiency of the fan blade (26) and hence the gas turbine engine (10) and reduces flutter of the fan blade (10).

Abstract: A component for a gas turbine engine having at least one surface, that has been treated by ultrasonic hammer peening so as to provide a region of deep compressive residual stress in the treated region.

Abstract: Use of an optical fiber for the direct receipt of heat radiation for transmission to a remote pyrometer is enabled by the provision of an apertured, contaminant free compartment in the component being heated, and aligning the heat receiving end of the optical fiber with the aperture so as to receive radiated heat from within the compartment.

Abstract: A breather outlet 10 for discharging a liquid dispersion therefrom comprising an outlet pipe 12 wherein the breather outlet 10 further comprises an electromagnetic wave generator 14 so that, in use, electromagnetic waves produced by the wave generator 14 impart sufficient electromagnetic energy to the liquid dispersion to evaporate at least a portion thereof.

Abstract: A three stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36, 40, 44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (76, 78, 80, 92). Secondary fuel injectors (106) and two secondary fuel manifolds (105A, 105B) supply fuel into different circumferential sectors, halves, of the secondary fuel and air mixing duct (80). The secondary fuel manifolds (105A, 105B) have secondary fuel valves (107A, 107B) which supply a greater proportion of fuel to the secondary fuel manifold (105A) than the secondary fuel manifold (105B) so that there is circumferential biasing of fuel in the secondary combustion zone (40). This circumferential biasing of fuel in the secondary combustion zone (40) reduces the generation of harmful pressure oscillations in the combustion chamber (28).

Abstract: Two stages of relatively rotatable guide vanes (22,24) are arranged in tandem. Shroud portions (42,46) on the vanes overlap in loose engagement, until an associated gas turbine engine starts operating. Gas loads then act on the downstream vane stage (24) and move it in a downstream direction until the opposing flanks of radially opposing lands (44,48) on respective shrouds (42,46) engage, whereupon, gas leakage via the overlap onto the turbine casing (40) is at least substantially reduced.

Abstract: A coupling between a drive and a driven shaft includes a rigid tube to which are attached in axially spaced apart relation at least two flexible rings of elastomeric material; the outer periphery of each ring is attached to a flange of a connecting hub with each hub mounted or connected to one the shafts; in one form the tube is split axially and is adjustably attachable to the periphery of the rings.

Abstract: A turbine assembly for a gas turbine engine includes a plurality of turbine blades (32) mounted on a rotatable support means in the form of a turbine disc so as to extend radially therefrom. The turbine blades include circumferentially extending blade platforms (40) spaced from the turbine disc and means are provided for allowing the passage of air between an internal region of the blades (32) and a space located between the blade platforms (40) and the turbine disc. The air may flow out of and back into the same turbine blade, or may flow into an adjacent blade. This flow of air results in the cooling of the blade platforms (40).

Abstract: A method of manufacturing a ceramic matrix composite comprises forming a slurry comprising a ceramic sol, filler particles and a solvent and forming laminates of fibres (12). The laminates of fibres (12) are impregnated with the slurry and are stacked (14) on a mould (10). The stack (14) of laminates of fibres (12) is covered by a porous membrane (16), a breather fabric (18) and a vacuum bag (20). The vacuum bag (20) is evacuated and is heated to a temperature of 60° C. for 10 hours to produce a ceramic matrix composite. The ceramic matrix composite is then heated to a temperature of 1200° C. at atmospheric pressure to sinter the ceramic matrix composite.

Abstract: A ducted fan gas turbine engine comprises a fan 12 mounted on a first shaft 16 and a compressor mounted on a second shaft 43. The shafts are coaxial both with each other and with said engine longitudinal axis 15. The shafts are mounted in roller bearings 21, 40. The first bearing 21 carrying the upstream part of the first shaft and the second bearing 40 carrying the upstream part of the second shaft. Both bearings are attached to a structure 26 which comprises an axial sleeve and a front frustoconical portion and a rear radially stiff but axially flexible frustoconical portion and is attached to the engine casing 36. The front frustoconical portion is frangibly attached to the front part of the axial sleeve 28. In the event of damage to the fan the frangible connection breaks and the first shaft is allowed to orbit about the engine longitudinal axis 15. The rear member 32 is swashingly non-linear flexible and accommodates the out of balance radial loads transferred to it as couples during such an incident.

Abstract: A method of adding boron to a tungsten, or tantalum, containing titanium aluminide alloy to form a boride dispersion in the tungsten, or tantalum, containing titanium aluminide. A molten tungsten, or tantalum, containing titanium aluminide alloy is formed and tungsten, or tantalum, boride is added to the molten tungsten, or tantalum, containing titanium aluminide alloy to form a molten mixture. The molten mixture is cooled and solidified to form a tungsten, or tantalum, containing titanium aluminide alloy having a uniform dispersion of tungsten, or tantalum, boride particles substantially without the formation of clusters of tungsten, or tantalum, boride. The titanium aluminide alloy comprises between 0.5 at % and 2.0 at % boron.

Abstract: A gas turbine engine mounting arrangement (22) for attaching a gas turbine engine (10) to an aircraft via a pylon (18). The arrangement (22) comprising a main mounting means (23) which carries the engine loads under normal operating conditions, and an auxiliary mounting structure (25). The auxiliary mounting structure. (25) comprises a safety bracket (44), and auxiliary interconnection means (29) are arranged to connect the bracket (44) to the engine (10) independently of the main mounting means (23) and so that the auxiliary mounting structure (25) is substantially unloaded under normal operating conditions. The auxiliary interconnection means (29) and the safety bracket (44) engaging with the engine (10) and carrying substantial engine loads in the event of failure of the main mounting means (23). Preferably the safety bracket (44) is interposed and sandwiched between a main bracket (2), forming part of the main mounting structure (23), and the main bracket (2) and the pylon (18).

Abstract: A method of manufacturing a gas turbine engine fan blade (10) comprises forming three metal workpieces (30,32,34). The metal workpieces (30,32,34) are assembled into a stack (36) so that the flat surfaces (38,42,46,48) are in mating abutment. Heat and pressure is applied across the thickness of the metal workpieces (30,32,34) to diffusion bond the metal workpieces (30,32,34) together to form an integral structure (80). The integral structure (80) is upset forged at one end (58) to produce an increase in thickness (82) for forming the blade root (26). The upset forged integral structure (80) is then hot creep formed and superplastically formed to produce the required aerofoil shape and the thickened end (82) is machined to form the blade root (26). The method enables thinner metallic workpieces with better microstructure to be used and increases the yield of metallic workpieces.

Abstract: A hollow liner (14) for fitting in the interior of a aerofoil vane (10) is crimped prior to fitting within the vane (10). Following fitting, the liner (14) is expanded so as to fit snugly within the vane (10). The technique permits the insertion of liners (14) into vanes (10) that are so configured as to preclude the insertion of conventional liners.

Abstract: A locking device for a ball valve of the type having an operating stem includes a post attached to the valve body with the post extending parallel but spaced axially from the valve stem and formed to receive a locking pin between the post and valve stem to prevent rotation of the stem.

Abstract: An annular connector for connecting a rotor and shaft, has an axial cross sectional profile which approximates a serpentine form. The shape defines only obtuse angles and curves, so that during rotation of the assembly, stress variations in the connector are reduced, as are stress peaks.

Abstract: A nose cone assembly (30) for a gas turbine engine (10) comprising a spinner (34) having a generally conical forward portion (33) and a base portion (35). The base portion (35) of the spinner (34) is disposed radially inside an extended profile of the forward portion (33). Upon the base (35) there is a radially outwardly extending flange (41) through which mounting fasteners (40) are arranged to attach the spinner (34) to a fan hub (6) of the gas turbine engine (10). A fairing (36) is arranged to surround and cover the base portion (35) of the spinner (34) when the nose cone assembly (30) is fitted to the fan hub (6). The fairing (36) having a generally circumferentially and axially smooth continuous outer surface, the profile of which continues that of the forward portion 33 of the spinner 34. Fasteners (44) preferably extend from the fairing (36) in a substantially radially inwardly directed direction to attach the fairing (36).

Abstract: A metallic turbine blade (10) has a protective coating (22) applied to the shank (16) and the root (18) of the turbine blade (10). The protective coating (22) comprises a chromized coating (24) diffused into the surface of the metallic article (10) and a glass coating (26) on the chromized coating (24). The glass coating (26) comprises a silicate glass, preferably having a chromium oxide filler. The glass coating (26) preferably comprises a boron titanate silicate glass having a chromium oxide filler. The protective coating (22) provides oxidation and sulphidation resistance for the shank (16) and root (18) of the turbine blade (10).