Abstract: A program-controlled heat management system for an aircraft's bypass gas turbine (turbofan) engine installation, in which the engine's fuel system is put into direct heat exchange relationship with the engine's own oil system, and with an engine-driven electrical generator's oil system, by means of respective fuel/oil heat exchangers and also into selective indirect heat exchange relationship with a variable proportion of the engine's bypass air means of an engine oil/air heat exchanger. The fuel system is switchable between four different fuel flow configurations in order to vary the heat flows between the fuel system and the oil systems, two of the fuel flow configurations also involving recirculation of fuel from the engine's fuel system to a fuel tank in the aircraft wing in order to put the fuel system into selective heat exchange relationship with the tank and hence with the airstream passing over the wing.

Abstract: A program-controlled heat management system for an aircraft's bypass gas turbine (turbofan) engine installation, in which the engine's fuel system is put into direct heat exchange relationship with the engine's own oil system, and with an engine-driven electrical generator's oil system, by means of respective fuel/oil heat exchangers and also into selective indirect heat exchange relationship with a variable proportion of the engine's bypass air means of an engine oil/air heat exchanger. The fuel system is switchable between four different fuel flow configurations in order to vary the heat flows between the fuel system and the oil systems, two of the fuel flow configurations also involving recirculation of fuel from the engine's fuel system to a fuel tank in the aircraft wing in order to put the fuel system into selective heat exchange relationship with the tank and hence with the airstream passing over the wing.

Abstract: A fuel control valve arrangement is provided, which when connected to a number of fuel flow paths in the fuel system of a turbofan aeroengine, is capable of interconnecting them in several different fuel flow configurations as necessary to vary transport of heat around the fuel system. The valve arrangement has fuel ports as necessary to connect it to the fuel flow paths and transfer fuel between a diverter valve component and a fuel spill control valve component, each of which has independently translatable valve elements which are positionable to selectively prevent communication between the fuel ports. The spill control valve element is controllable to move progressively over a range of positions to throttle fuel flow to one of the ports and the connected fuel flow path which spills fuel back to a fuel supply tank.

Abstract: A program-controlled heat management system for an aircraft's bypass gas turbine (turbofan) engine installation, in which the engine's fuel system is put into direct heat exchange relationship with the engine's own oil system, and with an engine-driven electrical generators's oil system, by means of respective fuel/oil heat exchangers and also into selective indirect heat exchanger relationship with a variable proportion of the engine's bypass air means of an engine oil/air heat exchanger. The fuel system is switchable between four different fuel flow configurations in order to vary the heat flows between the fuel system and the oil systems, two of the fuel flow configurations also involving recirculation of fuel from the engine's fuel system to a fuel tank in the aircraft wing in order to put the fuel system into selective heat exchange relationship with the tank and hence with the airstream passing over the wing.

Abstract: A fuel control unit forms part of a control system of a gas turbine aeroengine. The control unit is in communication with a main fuel line leading to the aeroengine and comprises a fuel accumulator, i.e. volume varied by free piston, which is controllable by the control system to take fuel from the fuel line to reduce temporarily but substantially the mass flow of fuel to the aeroengine. This is helpful in combating surge conditions in the aeroengine caused by temporary overfueling of the aeroengine by the fuel control system.