Abstract: A propeller pitch control actuation system includes a relatively lightweight, relatively inexpensive means for selectively preventing the propeller pitch control actuator from commanding reverse pitch positions.

Abstract: A propeller pitch control actuation system includes a relatively lightweight, relatively inexpensive means for selectively preventing the propeller pitch control actuator from commanding reverse pitch positions.

Abstract: A flow divider valve for a gas turbine engine fuel supply system is provided. The flow divider valve is configured, whenever fuel pressure at its inlet port is between a first predetermined pressure and a second predetermined pressure, to supply the fuel to a start nozzle manifold outlet port at a substantially constant flow rate, and to direct any fuel flow in excess of the substantially constant flow rate to a run nozzle manifold outlet port.

Abstract: A system provides “fail fixed” functionality and allows a user to manually manipulate fuel flow to a gas turbine engine in the unlikely event the primary control means is unavailable. The fuel metering unit includes a fuel metering valve, a flow increase valve, and a flow decrease valve. The flow increase valve and flow decrease valves are both in fluid communication with the fuel metering valve and are each adapted to selectively receive fuel flow commands from a primary fuel flow command source and from a secondary fuel flow command source. The flow increase and decrease valves are responsive to the fuel flow commands to selectively control the position of the fuel metering valve.

Abstract: A system provides “fail fixed” functionality and allows a user to manually manipulate fuel flow to a gas turbine engine in the unlikely event the primary control means is unavailable. The fuel metering unit includes a fuel metering valve, a flow increase valve, and a flow decrease valve. The flow increase valve and flow decrease valves are both in fluid communication with the fuel metering valve and are each adapted to selectively receive fuel flow commands from a primary fuel flow command source and from a secondary fuel flow command source. The flow increase and decrease valves are responsive to the fuel flow commands to selectively control the position of the fuel metering valve.

Abstract: A flow divider valve for a gas turbine engine fuel supply system is provided. The flow divider valve is configured, whenever fuel pressure at its inlet port is between a first predetermined pressure and a second predetermined pressure, to supply the fuel to a start nozzle manifold outlet port at a substantially constant flow rate, and to direct any fuel flow in excess of the substantially constant flow rate to a run nozzle manifold outlet port.

Abstract: A system and method is provided for controlling a variable displacement piston pump that supplies fluid to one or more loads. If fluid is being supplied through a metering valve to a load, then the variable displacement piston pump is controlled to operate in accordance with a variable flow/variable discharge pressure scheme. However, if fluid is not being supplied through the metering valve to the load, then the variable displacement piston pump is controlled to operate in accordance with a variable flow/constant discharge pressure scheme.

Abstract: A system and method is provided for controlling a variable displacement piston pump that supplies fluid to one or more loads. If fluid is being supplied through a metering valve to a load, then the variable displacement piston pump is controlled to operate in accordance with a variable flow/variable discharge pressure scheme. However, if fluid is not being supplied through the metering valve to the load, then the variable displacement piston pump is controlled to operate in accordance with a variable flow/constant discharge pressure scheme.