US Patent 12110827 Fuel systems for aircraft engines

A turbo engine for an aircraft includes a gas turbine engine having a combustion section and a fuel system to provide pressurized fuel to the combustion section. The fuel system includes a fuel tank and a boost pump and a main pump driven by an accessory gearbox that is powered by a shaft of the turbo engine. The boost pump and the main pump are arranged in series. The fuel system also includes an auxiliary pump and a controller to operate the fuel system in (1) a first mode in which the boost pump and the main pump produce pressurized fuel for the turbo engine and the auxiliary pump is deactivated, and (2) a second mode in which the auxiliary pump is activated and produces the pressurized fuel for the turbo engine while bypassing the boost pump and the main pump.