and oil heat exchanger 56 fohe a second fuel and oil heat exchanger 46 and a fuel accumulator 48 the recirculated fuel circuit 42 is situated on the main fuel line 50 between the main aircraft fuel tank 52 usually housed within the aircraft 39 s fuselage or wing and a fuel injector or the combustion equipment 16 note that the recirculation fuel circuit 42 is part of the engine 10 and not the aircraft inclusion of certain engine units in the fuel circuit is to increase the thermal capacity e g the addition of a second fohe 46 and filter 60 the second fohe 46 is fluidly connected to an engine oil circuit 54 and the first fohe 56 is fluidly connected to a starter generator 34 the oil in the starter circuit is self contained it is not connected to the engine oil system a small oil sump not shown is provided in the starter generator 34 a filter 60 is positioned between the second fohe 46 and the combustor 16 a shut off valve 62 is positioned downstream of the fuel accumulator 48 to stop fuel return flow during normal engine running in use the circuit 42 re circulates fuel via the pump 44 through the variable frequency starter generator fohe 56 the fohe 56 dissipates heat from the vfsg 34 which is in contrast to the conventional practice of sending the fuel back to aircraft fuel tank 52 the accumulator 48 situated on a fuel return line 58 is used to control the volume of fuel in the circuit 42 and increases the fuel 39 s thermal capacity to remove the limitations of the conventional static thermal sink i e the main fuel tank 52 in a conventional engine aircraft the accumulator 48 will be filled.