gas turbine engine fuel control system schematic as in fig3 with the exception that the other embodiment of the inventive rapid shutdown and ecology system 10 is now shown in its second position at engine shut down it is at this phase that it accomplishes its intended dual function of rapid shutoff or turn on of fuel flow as well as ecology fuel management when the gas turbine engine is shut down either by manual command from the control system for instance by the pilot for aircraft applications or automatically through an overspeed overtemperature or other fault detection system the ecu opens solenoid valve 74 and shortly thereafter when p2 falls below a predetermined level pressure rising valve 21 closes closure of pressure rising valve 21 terminates fuel delivery to the combustor atomizers and opening of solenoid valve 74 immediately establishes a communication path between the upstream and downstream sides of high pressure pump 14 via line 73 solenoid valve 74 and lines 78 and 79 fuel pressure in fuel cavity u201c a u201d 57 px thus drops to po causing spring 55 to shift large piston member u201c b u201d 51 to the extreme of its stroke in the direction of lower end 53 this action increases the volume of fuel cavity u201c b u201d 54 thereby collecting all the fuel in the fuel control system 10 downstream of pressure rising valve 21 and preventing it from draining into the engine creating atmospheric pollution and or puddling causing hot starts upon subsequent engine operation simultaneously at rapid shutdown subsystem 48 b with the reduction of px to po small piston 71 moves toward.