Fuel control system for a gas turbine engine.

摘要

A fuel control system includes a flow line (16) along which fuel flows to an engine. A relief valve (20) is responsive to an increase in pressure in the flow line (16) to spill fuel to a return line (24). The relief valve (20) is also responsive to a servo pressure in a chamber (22). A control valve communicates with the chamber (22) through a line (25) and a port (26), and is responsive to an increase in engine speed above a predetermined level to reduce the servo pressure in the chamber (22) and thereby to increase spill flow. Spill flow is limited by closure of the port (26) when the relief valve (20) is partly open. A further valve (27) is electrically operable to vent the servo pressure to the return line (24) to effect shut-down of the engine.