Abstract: A propeller blade retention arrangement having a propeller blade comprising in radial sequence an aerofoil portion, a shank portion and a root portion. The root portion having first cross-sectional area close to the shank portion and second cross-sectional area at the end distal to the aerofoil portion, wherein the second cross-sectional area is greater than the first cross-sectional area. At least two cheeks each having an inner surface arranged to abut the root portion, an outer surface that is threaded and edge surfaces that abut another of the at least two cheeks; wherein the at least two cheeks are arranged to surround the root portion in circumferential abutment. A collar having a threaded inner surface arranged to threadingly engage the outer surfaces of the at least two cheeks.

Abstract: An aircraft including a pylon attached to a gas turbine engine and a mounting system attaching the engine to the pylon. The mounting system including a first and a second frame each of three elongate members arranged in a triangle, each frame respectively arranged such that a core of the engine is positioned extending through an area defined between the three elongate members of each frame. Each frame forming at least part of a load bearing connection between the pylon and the engine. Each frame consisting of two portions, each portion corresponding to each side of the engine as attached to the pylon. The triangle formed by each frame being symmetrical about a plane separating the two portions. The engine is attached to the mounting system such that both frames are positioned axially forward of a radially extending projection of a first turbine stage in the core.

Abstract: An engine mount, for mounting the casing of an aircraft engine to the fuselage or wing of an aircraft, e.g. via a pylon, including first and second links having connector formations for connection to respective mounting and support formations on the engine casing and aircraft mounting structure. Each of the first and second links is typically connected by a pin between the mounting and support formations. Each link has a further connector formation arranged such that the connector formation of the first link is offset from the connector formation of the second link. The connector formations are joined by an intermediate link. The mount allows lateral forces and torque to be resolved in such a way as to substantially avoid lateral displacement of the engine away from a central plane. The intermediate link may also provide a failsafe catcher arrangement in the event that the first or second link fail.

Abstract: This invention relates to a blade assembly comprising: a hub which is rotatable about an axis; at least one blade having an aerofoil portion and a root, wherein the root is coupled to the hub using a primary retention device which prevents radial separation of the root and hub in normal use; and, a secondary retention device which comprises an annular catcher having a restriction through which the root portion cannot radially pass, the restriction being located radially outwardly and radially spaced from the root part during use.

Abstract: A mounting system is arranged in use for attaching a gas turbine engine to a pylon of an aircraft. The mounting system comprises a first frame of three elongate members arranged in a triangle. The first frame is arranged in use such that a core of the gas turbine engine is positioned extending through the area defined between the three elongate members. The first frame forms at least part of a load bearing connection between the pylon and gas turbine engine. The first frame consists of two portions, one corresponding to each side of the gas turbine engine when attached to the pylon. The triangle is symmetrical about a plane separating the two portions of the first frame.

Abstract: A support ring for a rotary assembly such as a propeller assembly includes support cups for receiving blade roots of propeller blades. The support cups are interconnected by bridging structures. Each bridging structure includes bridging walls which extend radially from a bridging web. The bridging structures thus have a channel-shaped cross-section. The bridging walls have a scalloped configuration at their radially outer edges. As a result of this configuration, the neutral axes of the bridging structures are straight, so that the support ring behaves, in structural terms, as a polygon.

Abstract: An engine mount, for mounting the casing of an aircraft engine to the fuselage or wing of an aircraft, e.g. via a pylon, including first and second links having connector formations for connection to respective mounting and support formations on the engine casing and aircraft mounting structure. Each of the first and second links is typically connected by a pin between the mounting and support formations. Each link has a further connector formation arranged such that the connector formation of the first link is offset from the connector formation of the second link. The connector formations are joined by an intermediate link. The mount allows lateral forces and torque to be resolved in such a way as to substantially avoid lateral displacement of the engine away from a central plane. The intermediate link may also provide a failsafe catcher arrangement in the event that the first or second link fail.

Abstract: A propeller blade retention arrangement having a propeller blade comprising in radial sequence an aerofoil portion, a shank portion and a root portion. The root portion having first cross-sectional area close to the shank portion and second cross-sectional area at the end distal to the aerofoil portion, wherein the second cross-sectional area is greater than the first cross-sectional area. At least two cheeks each having an inner surface arranged to abut the root portion, an outer surface that is threaded and edge surfaces that abut another of the at least two cheeks; wherein the at least two cheeks are arranged to surround the root portion in circumferential abutment. A collar having a threaded inner surface arranged to threadingly engage the outer surfaces of the at least two cheeks.

Abstract: This invention relates to a blade assembly comprising: a hub which is rotatable about an axis; at least one blade having an aerofoil portion and a root, wherein the root is coupled to the hub using a primary retention device which prevents radial separation of the root and hub in normal use; and, a secondary retention device which comprises an annular catcher having a restriction through which the root portion cannot radially pass, the restriction being located radially outwardly and radially spaced from the root part during use.

Abstract: In a turbofan gas turbine engine, a fan shaft is rotatably mounted and radially supported by a bearing in a bearing support structure-supported from a fixed engine structure by radially frangible bolts and radially extending spokes. The radially inner ends of the radially extending spokes are mounted on a common member that engages the bearing support structure. The radially outer ends of the radially extending spokes are mounted on fixed structure of the engine located radially outwardly of the bearing support structure. The radially extending spokes are held in tension and include a super elastic material to exert a radially inward restoring force on the bearing support structure, subsequent to any radial excursion of at least part of the fan shaft relative to an engine rotational axis (X) following any fracture of the frangible bolts.

Abstract: In a turbofan gas turbine engine, a fan shaft is rotatably mounted and radially supported by a bearing in a bearing support structure supported from a fixed engine structure by radially frangible bolts and radially extending spokes. The radially inner ends of the radially extending spokes are mounted on a common member that engages the bearing support structure. The radially outer ends of the radially extending spokes are mounted on a fixed engine structure located radially outwardly of the bearing support structure. The radially extending spokes are held in tension and include a super elastic material to exert a radially inward restoring force on the bearing support structure, subsequent to any radial excursion of at least part of the fan shaft relative to an engine rotational axis (X) following any fracture of the frangible bolts.

Abstract: A disc arrangement for a gas turbine engine, the disc arrangement including a rotational axis, a disc, a coverplate, and a retainer to retain association between the disc and the coverplate by interference. The retainer is displaceable in a recess of the disc or the coverplate to allow release of the interference. The recess presents the retainer at an inclined angle to the rotational axis for the disc and/or the coverplate.

Abstract: In a turbofan gas turbine engine, a fan shaft is rotatably mounted and radially supported by a bearing in a bearing support structure supported from a fixed engine structure by radially frangible bolts and radially extending spokes. The radially inner ends of the radially extending spokes are mounted on a common member that engages the bearing support structure. The radially outer ends of the radially extending spokes are mounted on a fixed engine structure located radially outwardly of the bearing support structure. The radially extending spokes are held in tension and include a super elastic material to exert a radially inward restoring force on the bearing support structure, subsequent to any radial excursion of at least part of the fan shaft relative to an engine rotational axis (X) following any fracture of the frangible bolts.