Patent ID: 7587900

Claim:
A fuel control system for a gas turbine engine comprising: a metering valve for metering a flow of fuel; a throttling valve for maintaining a pressure drop across the metering valve, said throttling valve being shiftable between an open state and a shutoff state blocking an outlet of said metering valve; a primary control pressure supply for supplying a primary control pressure to said metering valve for controlling the position of said metering valve; a backup control pressure supply for supplying a backup control pressure to said metering valve for controlling the position of said metering valve; a transfer valve shiftable between a first position connecting said primary control pressure supply to said metering valve and a second position connecting said backup control pressure supply to said metering valve; and an electrohydraulic servovalve (EHSV) operably connected to said throttling valve and said transfer valve and controlling the state of said transfer valve and the position of said throttling valve.