The advent of the high altitude supersonic aircraft has brought in its train a whole host of complex control problems. As far as the engine manufacture is concerned, these are perhaps best indicated in the diagrammatic layout shown in Fig. 1

It is not my intention however, to go into the question of multiplicity of controls and their proper co-ordination, nor will I venture into the abstruse province of stability. I should like instead to concentrate on the fuel system itself, i.e. the supply and control of fuel to the main engine combustion chamber.