Abstract: A gas turbine engine fuel control system includes a metering device responsive to an electrical signal for regulating fuel flow from a pump to the engine, a shut-off valve downstream of the metering device and operable by a first servo pressure, a spill valve operable by a second servo pressure for spilling fuel from upstream of the metering device, an electrically operable valve for controlling the first and second servo pressures, and a circuit for supplying electrical signals to the metering device and the electrically operable valve so that during shut down of the system the spill valve and the shut off valve are maintained respectively open and shut before the metering device shuts.

Abstract: A gas turbine engine fuel control system has a metering device which is controlled by the delivery pressure of the engine compressor, and an arrangement for modifying flow through the metering device in accordance with the difference between a calculated value of the pressure rise across the compressor, and a measured value of this pressure rise. The calculated value is obtained from a compound cam which is positioned in accordance with desired engine thrust and with one of the compressor pressures and is profiled in accordance with desired values of the other pressure. Movement of a cam follower is compared with a sensed value of the other pressure and used to modify fuel flow.

Abstract: A gas flow control system has a variable metering device, a circuit for generating a first electrical signal which is a function of a desired gas flow through the metering device, a circuit for generating a second electrical signal which is a function of the gas pressure upstream of the metering device, and control means, responsive to the first and second electrical signals, for varying the effective flow area of the metering device.