Abstract: A landing arrangement for an aircraft comprises an aircraft support assembly (22) to support the aircraft (10) when the aircraft is on the ground. The aircraft support assembly (2) is movable between a first ground engaging condition (22b) in which the aircraft nose (24) is spaced above the ground by a first distance (X) and a second ground engaging condition (22C) in which the aircraft nose (24) is spaced above the ground by a second distance (Y). The second distance (Y) is less than the first distance (X).

Abstract: A cowl structure (18) for a gas turbine engine (10) comprises an outer skin (26) defining a first path for a load applied to the engine (10). The cowl structure (18) includes an inner skin (24) defining a second path for the load. The inner and outer skins (24, 26) are constructed such that a major proportion of the load is transmitted along the first path.

Abstract: A blade arrangement for a gas turbine engine includes a plurality of blades mounted for rotation on a disc so as to extend radially therefrom and a retention member, the retention member including an attachment portion which is attached to the disc and an abutment portion for resisting forward axial movement of at least one of the blades relative to the disc. The blade arrangement further comprises restraint means spaced from the attachment portion of the retention member, for substantially preventing radially outward movement of the abutment portion of the retention member when a forward axial force is applied by the blade to the abutment portion.

Abstract: A mounting arrangement (46) for mounting a turbofan gas turbine engine (10) on an aircraft pylon (44). The gas turbine engine (10) comprises a core engine (24) having a core engine casing (26). The mounting (46) comprises a first mounting (48) for mounting the core engine casing (26) on the pylon (44) and a second mounting (50) for mounting the core engine casing (26) on the pylon (44). The first mounting (48) comprises a first hinge adjacent (52) the core engine casing (26) and a second hinge adjacent (54) adjacent the pylon (44). The first hinge (52) is arranged parallel to the axis (S) of the gas turbine engine (10) to form a roll hinge. The second hinge (54) is arranged in a plane perpendicular to the axis (S) of the gas turbine engine (10) to form a pitch hinge. The second mounting (50) comprises a third hinge (56) adjacent the core engine casing (26) and a fourth hinge (58) adjacent the pylon (44).

Abstract: A cowl structure (18) for a gas turbine engine (10) comprises an outer skin (26) defining a first path for a load applied to the engine (10). The cowl structure (18) includes an inner skin (24) defining a second path for the load. The inner and outer skins (24, 26) are constructed such that a major proportion of the load is transmitted along the first path.

Abstract: A mounting arrangement (46) for mounting a turbofan gas turbine engine (10) on an aircraft pylon (44). The gas turbine engine (10) comprises a core engine (24) having a core engine casing (26). The mounting (46) comprises a first mounting (48) for mounting the core engine casing (26) on the pylon (44) and a second mounting (50) for mounting the core engine casing (26) on the pylon (44). The first mounting (48) comprises a first hinge adjacent (52) the core engine casing (26) and a second hinge adjacent (54) adjacent the pylon (44). The first hinge (52) is arranged parallel to the axis (S) of the gas turbine engine (10) to form a roll hinge. The second hinge (54) is arranged in a plane perpendicular to the axis (S) of the gas turbine engine (10) to form a pitch hinge. The second mounting (50) comprises a third hinge (56) adjacent the core engine casing (26) and a fourth hinge (58) adjacent the pylon (44).

Abstract: A gas turbine engine 10 includes an intermediate pressure compressor 14 connected to an intermediate pressure turbine 22 by a driveshaft 28. The driveshaft 28 comprises a downstream turbine shaft 34 attached to the intermediate pressure turbine 22 and an upstream compressor shaft 32 attached to the intermediate pressure compressor 14. The compressor shaft 32 and turbine shaft 34 are connected together by a splined connection 36 which allows the turbine shaft 34 to drive the compressor shaft 32. If the splined connected 36 should fail, so that it no longer transmits torque, a further splined connection 41 comes into operation to transmit torque between the turbine shaft 34 and compressor shaft 32. When this happens, torque is transmitted via a torsionally weakened, shear section 48 of the turbine shaft 34 which tends to break under certain engine conditions. The turbine shaft 34 is then released axially and turbine overspeed is restrained.

Abstract: A blade arrangement for a gas turbine engine includes a plurality of blades mounted for rotation on a disc so as to extend radially therefrom and a retention member, the retention member including an attachment portion which is attached to the disc and an abutment portion for resisting forward axial movement of at least one of the blades relative to the disc. The blade arrangement further comprises restraint means spaced from the attachment portion of the retention member, for substantially preventing radially outward movement of the abutment portion of the retention member when a forward axial force is applied by the blade to the abutment portion.

Abstract: A mounting arrangement (46) for mounting a turbofan gas turbine engine (10) on an aircraft pylon (44). The gas turbine engine (10) comprises a core engine (24) having a core engine casing (26). The mounting (46) comprises a first mounting (48) for mounting the core engine casing (26) on the pylon (44) and a second mounting (50) for mounting the core engine casing (26) on the pylon (44). The first mounting (48) comprises a first hinge adjacent (52) the core engine casing (26) and a second hinge adjacent (54) adjacent the pylon (44). The first hinge (52) is arranged parallel to the axis (S) of the gas turbine engine (10) to form a roll hinge. The second hinge (54) is arranged in a plane perpendicular to the axis (S) of the gas turbine engine (10) to form a pitch hinge. The second mounting (50) comprises a third hinge (56) adjacent the core engine casing (26) and a fourth hinge (58) adjacent the pylon (44).

Abstract: A cowl structure (18) for a gas turbine engine (10) comprises an outer skin (26) defining a first path for a load applied to the engine (10). The cowl structure (18) includes an inner skin (24) defining a second path for the load The inner and outer skins (24, 26) are constructed such that a major proportion of the load is transmitted along the first path.

Abstract: A gas turbine engine 10 includes an intermediate pressure compressor 14 connected to an intermediate pressure turbine 22 by a driveshaft 28. The driveshaft 28 comprises a downstream turbine shaft 34 attached to the intermediate pressure turbine 22 and an upstream compressor shaft 32 attached to the intermediate pressure compressor 14. The compressor shaft 32 and turbine shaft 34 are connected together by a splined connection 36 which allows the turbine shaft 34 to drive the compressor shaft 32. If the splined connected 36 should fail, so that it no longer transmits torque, a further splined connection 41 comes into operation to transmit torque between the turbine shaft 34 and compressor shaft 32. When this happens, torque is transmitted via a torsionally weakened, shear section 48 of the turbine shaft 34 which tends to break under certain engine conditions. The turbine shaft 34 is then released axially and turbine overspeed is restrained.

Abstract: A turbofan gas turbine engine (10) comprises a fan rotor (32) carrying a plurality of radially extending fan blades (34). A fan blade containment assembly (38) surrounds the fan blades (34) and the fan blade containment assembly (34) comprises a generally annular, or frustoconical, cross-section casing (52). At least one corrugated sheet metal ring surrounds the casing (52) wherein the corrugations extend with axial and/or circumferential components.

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 mounting arrangement (46) for mounting a turbofan gas turbine engine (10) on an aircraft pylon (44). The gas turbine engine (10) comprises a core engine (24) having a core engine casing (26). The mounting (46) comprises a first mounting (48) for mounting the core engine casing (26) on the pylon (44) and a second mounting (50) for mounting the core engine casing (26) on the pylon (44). The first mounting (48) comprises a first hinge adjacent (52) the core engine casing (26) and a second hinge adjacent (54) adjacent the pylon (44). The first hinge (52) is arranged parallel to the axis (S) of the gas turbine engine (10) to form a roll hinge. The second hinge (54) is arranged in a plane perpendicular to the axis (S) of the gas turbine engine (10) to form a pitch hinge. The second mounting (50) comprises a third hinge (56) adjacent the core engine casing (26) and a fourth hinge (58) adjacent the pylon (44).

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 ducted fan gas turbine engine (10) is provided with a fan (12) which is carried by a shaft (16). A frangible support member (27) maintains a coaxial relationship between the shaft (16) and the longitudinal axis (15) of the engine (10). In the event of severe damage to the fan (12), the frangible member (27) fractures, allowing the shaft (16) carrying the fan (12) to orbit about the engine longitudinal axis (15). A resilient support member (33,45) exerts a radially inward restoration force on the shaft (16) carrying the fan (12) to reduce vibration.

Abstract: A ducted fan gas turbine has a fan shaft which is supported at its upstream end by a bearing. In the event of damage to the engine's fan, frangible bolts fracture to permit radial movement of the shaft. That movement is limited by the sequential engagement of the outer race of the bearing with first and second movement limiting portions on fixed structure of the engine. This alters the natural frequency of vibration of the fan, so permitting the fan to windmill without excessive vibration.

Abstract: A ducted fan gas turbine engine is provided with a fan which is carried by a shaft. Frangible fuse pins maintain the shaft carrying the fan coaxial with the engine longitudinal axis. In the event of severe fan damage, the fuse pins fracture and the fan shaft orbits about the engine longitudinal axis. An annular resilient member is provided to exert a radially inward restoration force upon the fan shaft following such an event in order to reduce vibration.

Abstract: A ducted fan gas turbine engine is provided with a fan which is carried by a shaft. A frangible fuse ring maintains the shaft carrying the fan coaxial with the engine longitudinal axis. In the event of severe fan damage, the fuse ring (28) fractures and the fan shaft orbits about the engine longitudinal axis. A pair of threaded members (39, 41), one of which is of generally frusto-conical configuration, cooperate as a result of the orbiting motion to restore the coaxial relationship between the fan shaft and the engine longitudinal axis.

Abstract: A mounting for connecting a turbofan gas turbine engine to an aircraft structure comprises three mounting points at the vertices of a triangle on the aircraft structure and three mounting points on the fan casing of the turbofan gas turbine engine. The first mounting point on the aircraft structure is connected to all of the three mounting points on the fan casing by three links. The second mounting point on the aircraft structure is connected to the second mounting point and the third mounting point on the fan casing by two links. The third mounting point on the aircraft structure is connected to the second mounting point and the third mounting point by two links. The links provide an open spaceframe which defines the structure of a pylon. The mounting has reduced weight compared to conventional mountings and is cheaper to manufacture.