Abstract: An engine arrangement (14) comprises a gas turbine engine unit (16) and first and second support members (18, 20) extend from a structural component (24) of the engine casing (22) to support the engine unit in a position spaced from the body or airframe of the aircraft.

Abstract: An electrical machine, such as a generator or motor, is incorporated in a gas turbine engine. The engine has compressor blades which are shrouded at. Beyond the shroud, an electrical machine is provided by rotor projections which run in a channel in flux cores, with which excitor coils are associated. The result is an electrical machine which is external to the combustion gas paths of the engine, for ready access, and can have optimised magnetic flux paths for efficiency. High relative speeds within the electrical machine provide further advantages.

Abstract: An electrical machine, such as a generator or motor, is incorporated in a gas turbine engine. The engine has compressor blades which are shrouded at. Beyond the shroud, an electrical machine is provided by rotor projections which run in a channel in flux cores, with which excitor coils are associated. The result is an electrical machine which is external to the combustion gas paths of the engine, for ready access, and can have optimised magnetic flux paths for efficiency. High relative speeds within the electrical machine provide further advantages.

Abstract: An electrical machine, such as a generator or motor, is incorporated in a gas turbine engine. The engine has compressor blades which are shrouded at. Beyond the shroud, an electrical machine is provided by rotor projections which run in a channel in flux cores, with which excitor coils are associated. The result is an electrical machine which is external to the combustion gas paths of the engine, for ready access, and can have optimized magnetic flux paths for efficiency. High relative speeds within the electrical machine provide further advantages.

Abstract: An engine arrangement (14) comprises a gas turbine engine unit (16) and first and second support members (18, 20). The support members (18, 20) extend from a structural component (24) of the engine casing (22) to support the engine unit in a position spaced from the body or airframe of the aircraft.

Abstract: An electrical machine, such as a generator or motor, is incorporated in a gas turbine engine. The engine has compressor blades which are shrouded at. Beyond the shroud, an electrical machine is provided by rotor projections which run in a channel in flux cores, with which excitor coils are associated. The result is an electrical machine which is external to the combustion gas paths of the engine, for ready access, and can have optimised magnetic flux paths for efficiency. High relative speeds within the electrical machine provide further advantages.

Abstract: A gas turbine engine (10) is provided with a plurality of shafts (18, 19, 20) interconnecting its compressor portions (11, 12, 13) with its turbine portions (15, 16, 17). Each shaft (18, 19, 20) is supported in the hotter part of the engine by electromagnetic bearings (26, 28, 32) and by rolling element bearings (24, 27, 29, 31, 33) in the remainder of the engine (10). The arrangement provides a simplified liquid lubrication system for the rolling element bearings (24, 27, 29, 31, 33) which reduces the likelihood of lubricant thermal degradation of the lubricant.

Abstract: An aircraft gas turbine propulsion engine includes a compressor (10) and ancillary systems (cabin pressurizing pumps and other service) in a box 16. A fuel cell 18 powers electric motors (12) and (14) via a switch (20) for the purpose of either simultaneously driving the compressor (10) and ancillary systems, or the ancillary systems alone.

Abstract: A gas turbine engine is provided with a translatable cowl and a cascade structure which is nested within the translatable portion of the cowl. The cascade structure comprises a pair of C ducts which are exposed upon translation of a portion of the cowl. The C ducts are capable of rotation about an axis parallel to the longitudinal axis of the engine thus allowing access to the core of the engine.

Abstract: The fan duct of a ducted fan gas turbine engine is provided with a secondary duct at least partly within the downstream end of the primary duct. The secondary duct is provided with means such as flaps whereby the airflow therethrough may be varied to suit flight requirements of an associated aircraft, in a way which will control the maximum diameter of the free stream tube airflow at the intake of the engine, thus effectively reducing the frontal area of the fan duct, and therefor, drag.

Abstract: An aircraft mounted gas turbine engine system comprises a three shaft propulsive gas turbine engine having three electrical generators; each one respectively associated with one shaft of the engine. Two of the electrical generators are additionally configured so as to function as electric motors so as to facilitate power transfer between the engine shafts. One of the electric generators provides the primary source of electrical power for the aircraft, while the remaining electrical generators provide electrical power for the engine and back-up power for the aircraft.

Abstract: In a ducted fan gas turbine engine the fan module is connected rigidly to aircraft structure and flexibly to the core gas generator via flanged annular diaphragms (62,66) thus obviating the exertion of bending loads on the core gas generator casing when the fan intake experiences asymmetric aerodynamic loads.

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.

Abstract: A multispool gas turbine engine for an aircraft application includes a transmission system which is operative to transfer power between relatively rotatable engine spools. In a first mode the transmission system is operative to transfer power from the engine's low pressure spool to its high pressure spool and thereby improve the engine's in-flight relight characteristics; in a second mode it is operative to transfer power from the engine's intermediate pressure spool to its high pressure spool to improve engine part speed performance; and in a third mode to transfer power from the engine's high pressure spool to its intermediate pressure spool to assist in ground starting. With each shaft is an associated flow displacement machine (64,66,62) operable as a pump or motor. In other embodiments, a differential is employed for the power transfer between spools.

Abstract: A ducted fan gas turbine engine includes a fan which is driven by a low pressure turbine via a load transmitting shaft. The load transmitting shaft additionally drives the accessories of the engine and the aircraft upon which it is mounted. In the event of an engine failure, the power produced by the windmilling of the engine fan is sufficient to provide continuity of drive to the accessories.

Abstract: A ducted fan gas turbine engine is provided with a thrust reverser which comprises doors which deflect the fan exchaust efflux. Each door is pivotably attached at its downstream end to a common support member by a frangible coupling. In the event of an unintended in-flight deployment of the thrust reverser, the frangible couplings fracture to permit the doors to move to a non-thrust deflecting position.

Abstract: A ducted fan gas turbine engine nacelle assembly comprises an aerodynamic nacelle within which is enclosed a ducted fan gas turbine engine. The nacelle includes an annular containment structure which surrounds the engine fan and fan casing to contain any detached fan blade or blade parts.

Abstract: A gas turbine engine nacelle assembly (10) comprises a pylon (13) for mounting the assembly on an aircraft, a nacelle (11) and a gas turbine engine (12) enclosed within the nacelle (11). Part (15) of the nacelle (11) is structurally integral with the pylon (13) and has the remainder of the nacelle (11) attached to it. The nacelle part (15) additionally provides at least partial support for the gas turbine engine (12). The arrangement provides weight savings.

Abstract: A control mechanism for the thrust reverser of an aircraft comprises an open ended conduit, the open end of which operationally protrudes into the airflow over the surface of the aircraft. The airflow over the aircraft creates a partial vacuum within the conduit. A piston is translatable within a cylinder in accordance with the magnitude of the partial vacuum. The position of the piston within the cylinder determines whether the thrust reverser can or cannot be actuated, thereby preventing inadvertent in-flight thrust reverser actuation.

Abstract: A ducted fan gas turbine engine (10) is provided with an electric motor starter unit (16). The oil lubrication system of the engine (10) is so arranged that during engine starting, the heat generated by the starter unit (16) is used to heat up the oil in the system. This reduces the viscosity of the oil, thereby facilitating easy engine starting under very cold conditions.