Patent ID: 8166765

Claim:
A fuel delivery and control system for a gas turbine engine having a maximum engine fuel flow requirement and a fuel metering unit, an actuation system requiring a minimum operating fuel flow and minimum operating pressure, the fuel control system comprising: a variable displacement actuation pump of a size capable of providing a first portion of the maximum fuel flow requirement of the engine, the actuation pump having an outlet and a discharge pressure; and a fixed displacement main pump of a size configured to provide a second portion of the maximum fuel flow requirement of the engine, the main pump having an outlet and a discharge pressure, the outlet of the main pump in fluid communication with the fuel metering unit and in selective fluid communication with the outlet of the actuation pump, wherein the fuel delivery and control system is configurable between an isolated pumps mode wherein the outlets of each of the actuation pump and the main pump are separated from each other and a shared pumps mode wherein the outlets of each of the actuation pump and the main pump are in fluid communication with each other to combine the first portion of the maximum fuel flow of the engine with the second portion of the maximum fuel flow of the engine and wherein the combined flow is supplied to the fuel metering unit of the engine.