Abstract: A gas turbine engine (30) comprising a rear cowl (38) defining an exhaust aperture (40) and a motive system. The rear cowl (38) comprises at least one panel (42) and the motive system is operable to selectively move the panel (42) between deployed and stowed configurations by rotation of the panel (42) about an axis substantially parallel to the main rotational axis of the engine (30). This alters the area of the exhaust aperture (40).

Abstract: A gas turbine engine (30) comprising a rear cowl (38) defining an exhaust aperture (40) and a motive system. The rear cowl (38) comprises at least one panel (42) and the motive system is operable to selectively move the panel (42) between deployed and stowed configurations by rotation of the panel (42) about an axis substantially parallel to the main rotational axis of the engine (30). This alters the area of the exhaust aperture (40).

Abstract: A compressor variable stator vane arrangement comprises at least one stage of variable stator vanes. A speed sensor measures the rotational speed of the compressor rotor. A pressure sensor measures the outlet pressure of the compressor. A second pressure sensor, a temperature sensor and a third pressure sensor measure the total inlet pressure, the temperature and the ambient pressure at the inlet of the gas turbine engine. A processor determines a target operating line as a function of ambient pressure and total inlet pressure. The target operating line is defined to ensure the gas turbine engine operates simultaneously at both the minimum required compressor speed and the minimum required compressor outlet pressure when commanded to idle to minimize idle thrust and fuel burn. The processor determines if the operating point of the compressor, defined in terms of corrected outlet pressure and corrected rotational speed of the compressor rotor is above or below the target operating line of the compressor.

Abstract: A method and associated system for managing power within an aircraft electrical system, the aircraft having a generator driven by a gas turbine engine for the supply of electrical power to the system, wherein the generator and electrical system are connected to a common energy store. The method includes determining predicted electrical energy demands of the system and predicted thrust demands for the gas turbine engine over at least a portion of a flight. A plurality of time periods within at least a portion of the flight are defined and a desired rate of charge of the energy store for each time period is determined based upon the predicted thrust and electrical energy demands over the time period. The rate of charge of the energy store is controlled during the flight in accordance with the determined desired rate of charge for each time period.

Abstract: A method and associated system for managing power within an aircraft electrical system, the aircraft comprising a generator driven by a gas turbine engine for the supply of electrical power to the system, wherein the generator and electrical system are connected to a common energy store. The method comprises determining predicted electrical energy demands of the system and predicted thrust demands for the gas turbine engine over at least a portion of a flight. A plurality of time periods within at least said portion of the flight are defined and a desired rate of charge of the energy store for each time period is determined based upon the predicted thrust and electrical energy demands over said time period. The rate of charge of the energy store is controlled during the flight in accordance with the determined desired rate of charge for each time period.

Abstract: A compressor variable stator vane arrangement comprises at least one stage of variable stator vanes. A speed sensor measures the rotational speed of the compressor rotor. A pressure sensor measures the outlet pressure of the compressor. A second pressure sensor, a temperature sensor and a third pressure sensor measure the total inlet pressure, the temperature and the ambient pressure at the inlet of the gas turbine engine. A processor determines a target operating line as a function of ambient pressure and total inlet pressure. The target operating line is defined to ensure the gas turbine engine operates simultaneously at both the minimum required compressor speed and the minimum required compressor outlet pressure when commanded to idle to minimise idle thrust and fuel burn. The processor determines if the operating point of the compressor, defined in terms of corrected outlet pressure and corrected rotational speed of the compressor rotor is above or below the target operating line of the compressor.