摘要 |
A system allows a user to manually manipulate fuel flow to a gas turbine engine during a loss of power to the fuel supply system fuel metering unit. The fuel metering unit includes a fuel metering valve, a metering valve actuator, a fail-fixed valve, a flow increase valve, and a flow decrease valve. The fuel metering unit is configured such that, upon electrical power interruption to the metering valve actuator, the fail-fixed valve shifts and provides a hydraulic lock on the fuel metering valve, to thereby maintain its position. The flow increase and flow decrease valves are powered from a power source that is independent of that used to power the fuel metering unit and, when appropriately energized will allow movement of the fuel metering valve.
|