Abstract: A method of controlling a rotor tip clearance in a gas turbine engine (10). The method comprises determining an engine or component remaining useful life Tr, and controlling a tip clearance control arrangement (38) to maintain a rotor tip clearance (36) at a target tip clearance Dtarget. The target tip clearance Dtarget is determined in accordance with a function of remaining engine life Tr.

Abstract: An aircraft comprises at least first and second gas turbine engines arranged in a line extending generally normally to an aircraft longitudinal axis (A), each engine comprising at least one compressor or turbine rotor disc defining a respective rotational plane (D32-D42). The rotational plane (D32-D42) of at least one of the rotors of at least one of the engines is angled relative to the aircraft longitudinal line (A) such that a burst disc plane of the respective engine is nonintersecting with another engine.

Abstract: A turbomachinery control system for controlling supercritical working fluid turbomachinery. The control system includes a light emitter to project light through working fluid of the turbomachinery toward a primary light detector provided within a line of sight to the emitter. The system further includes one or more secondary light detectors spaced from the line of sight, and a controller determining one or both of an intensity of light detected by the primary detector relative to the detected light intensity by the secondary detector, and wavelength of light detected by the primary detector relative to wavelength of light detected by the secondary detector. The controller determines the working fluid proximity of the critical point based on one or both of the determined relative intensity and determined relative wavelength, and controlling an actuator to control turbomachinery inlet or outlet conditions in accordance with the working fluid determined proximity of the critical point.

Abstract: An aircraft (2) comprises at least first and second gas turbine engines (10a, 10b) arranged in a line extending generally normally to an aircraft longitudinal axis (A), each engine (10a, 10b) comprising at least one compressor or turbine rotor disc (32-42) defining a respective rotational plane (D32-D42). The rotational plane (D32-D42) of at least one of the rotors (32-42) of at least one of the engines (10a, 10b) is angled relative to the aircraft longitudinal line (A) such that a burst disc plane of the respective engine (10a, 10b) is nonintersecting with another engine (10a, 10b).

Abstract: An aircraft has an internal combustion engine and a wing including a hollow structural member. The aircraft has an electrical network including: at least one alternating current electrical generator configured to be driven by the internal combustion engine; an electrical motor configured to drive an aircraft propulsor; at least one conductor configured to electrically couple the electrical motor and the electrical generator; wherein the electrical conductor is formed of the hollow structural member of the aircraft wing.

Abstract: An aircraft (10) comprising a fuselage (12), the fuselage (10) comprising at least first and second inwardly tapering portions (20, 22) extending in a generally rearward direction from an aft end of the fuselage (12), each inwardly tapering portion (20, 22) comprising a boundary layer ingesting propulsor (36) mounted thereon.

Abstract: An aircraft propulsion system includes at least first and second propulsor arrangements. Each propulsor arrangement includes an internal combustion engine configured to mechanically drive a plurality of propulsors. At least one of the propulsors of each propulsor arrangement is driveable via a shaft and at least one reduction gearbox. Each internal combustion engine is coupled to a motor generator arrangement configured to drive at least one of the mechanically driven propulsors when in a motor mode, and to generate electrical power when in a generating mode. The system further includes an electrical interconnector configured to transfer electrical power between the first and second propulsor arrangements.

Abstract: An aircraft including trailing edge flaps, a wing mounted propulsor positioned such that the flaps are located in a slipstream of the first propulsor in use when deployed. The aircraft further including a thrust vectorable propulsor configured to selectively vary the exhaust efflux vector of the propulsor in at least one plane. The thrust vectorable propulsor includes a ducted fan configurable between a first mode, in which the fan provides net forward thrust to the aircraft, and a second mode in which the fan provides net drag to the aircraft. The fan is positioned to ingest a boundary layer airflow in use when operating in the first mode.

Abstract: A computer-implemented method of controlling an aircraft including, determining whether a change in altitude at a predetermined thrust-setting can be performed, the determination including: determining a climb-requirement including initial and final altitudes and a required range of airspeeds at the final altitude; determining aircraft performance data including a thrust at the final altitude at the thrust-setting, an initial airspeed at the initial altitude and an aircraft total mass at the initial altitude; using the aircraft performance data to determine a final airspeed and drag at the final altitude if a change in altitude at the predetermined setting were performed; determining whether thrust at the final altitude at the thrust-settings and airspeed is greater than drag; and providing a signal indicating whether the calculated final airspeed falls within the required range of airspeeds, and whether the thrust at the final altitude and airspeed at the cruise thrust-setting is greater than drag.

Abstract: A computerised aircraft engine maintenance planning system for maintaining an aircraft engine fleet comprising a plurality of aircraft engines, each engine in the fleet comprising an engine health monitoring system configured to provide data indicative of an incipient fault for a respective engine. The planning system comprises: a fault forwarding sub-system configured to receive indications of incipient faults from respective engine health monitoring systems, the fault forwarding system being configured to identify two or more engines having linked incipient faults; and a queuing sub-system configured to assign each engine identified as having an incipient fault to a virtual maintenance queue position; wherein the queuing sub-system is configured to group engines having linked incipient faults to adjacent queue positions.

Abstract: An aircraft (2) comprises at least first and second gas turbine engines (10a, 10b) arranged in a line extending generally normally to an aircraft longitudinal axis (A), each engine (10a, 10b) comprising at least one compressor or turbine rotor disc (32-42) defining a respective rotational plane (D32-D42). The rotational plane (D32-D42) of at least one of the rotors (32-42) of at least one of the engines (10a, 10b) is angled relative to the aircraft longitudinal line (A) such that a burst disc plane of the respective engine (10a, 10b) is nonintersecting with another engine (10a, 10b).

Abstract: An aircraft (40). The aircraft comprises a plurality of propellers (46) mounted to wings (44). Each propeller comprises at least one blade (72, 74) coupled to a respective propeller cyclic actuator (78) configured to cyclically alter the pitch of the respective blade (72, 74) as the propeller rotates. The aircraft (40) is configured such that provision of cyclic pitch to the propeller (46) twists at least a portion of the wing (44) about a span of the wing (46) relative to the fuselage (42), to thereby adjust the local angle of incidence of the wing (46).

Abstract: A computer-implemented method of controlling an aircraft including, determining whether a change in altitude at a predetermined thrust-setting can be performed, the determination including: determining a climb-requirement including initial and final altitudes and a required range of airspeeds at the final altitude; determining aircraft performance data including a thrust at the final altitude at the thrust-setting, an initial airspeed at the initial altitude and an aircraft total mass at the initial altitude; using the aircraft performance data to determine a final airspeed and drag at the final altitude if a change in altitude at the predetermined setting were performed; determining whether thrust at the final altitude at the thrust-settings and airspeed is greater than drag; and providing a signal indicating whether the calculated final airspeed falls within the required range of airspeeds, and whether the thrust at the final altitude and airspeed at the cruise thrust-setting is greater than drag.

Abstract: An aircraft (40). The aircraft (40) comprises a propulsion system comprising a pair of internal combustion engines (10) each driving an electrical power generator (56), each electrical power generator (56) being electrically coupled to a plurality of electrically driven propulsors (46). The propulsors (46) are located forward of a leading edge (45) of the wings (44) such that an airstream generated by the propulsors flows over the wings (44) in use. Each internal combustion engine (10) and electrical generator (56) is mounted on a respective wing (44) outboard of a center of thrust (70) of the propulsors (46) on that wing (44).

Abstract: An aircraft (40). The aircraft (40) comprises a propulsion system comprising a pair of internal combustion engines (10) each driving an electrical power generator (56), each electrical power generator (56) being electrically coupled to a plurality of electrically driven propulsors (46). The propulsors (46) are located forward of a leading edge (45) of the wings (44) such that an airstream generated by the propulsors flows over the wings (44) in use. Each internal combustion engine (10) and electrical generator (56) is mounted on a respective wing (44) outboard of a centre of thrust (70) of the propulsors (46) on that wing (44).