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.

Abstract: A fuel control system (10) for a gas turbine engine includes a main fuel inlet line (18), an auxiliary fuel inlet line (20) and an engine fuel outlet line (16). A first flow path extends from the main fuel inlet line (18) to the engine fuel outlet line (16) and a second flow path extends from the auxiliary fuel inlet line (20) to the engine fuel outlet line (16). A check valve (22) in the first flow path allows fuel flow through the first flow path in a direction from the main fuel inlet line (18) to the engine fuel outlet line (16) and substantially prevents fuel flow through the first flow path in a direction from the engine fuel outlet line (16) to the main fuel inlet line (18). The check valve (22) is shiftable between a first position connecting the auxiliary fuel inlet (20) to the engine fuel outlet (16) and a second position blocking the second flow path. Also a method of controlling fuel flow in a fuel control system of a gas turbine engine.

Abstract: A controlled piston (20, 62, 102) having a first end (24, 64, 104) mounted in a controlled piston sleeve (22) and a spool (16) movably mounted in a spool sleeve (18), a first fluid passage (40, 66, 108) from the spool (16) to the controlled piston first end (24, 64, 104), the position of the spool (16) affecting a position of the controlled piston (20, 62, 102), an FFV (42, 68, 110) in an FFV sleeve (44, 70, 112) in the first fluid passage (40, 66, 108) having a first end section (46, 74, 116), a second end section (48, 78, 120) and a central section (50, 82, 126) having a third diameter less than the diameters of the first and second sections, the FFV (42, 68, 110) being shiftable between a first position blocking the first fluid passage (40, 66, 108) and a second position allowing fluid flow past the central section (50, 82, 126) to the controlled piston (20, 62, 102), and a second fluid passage (56, 88, 134) from the spool (16) to the FFV first end section (46, 74, 116).

Abstract: A modular reed switch assembly and method for making the same are provided. A switch assembly (101) includes a reed switch (206, 106) that is enclosed between a primary reed switch cover (208) and a reed switch base (104) wherein the reed switch cover and reed switch base are recessed to accommodate the reed switch. A secondary reed switch cover (102) further covers the primary reed switch cover (208) and the secondary reed switch cover (102) connects with the reed switch base (104). A protrusion (106) provides access to the electrical contacts (302) of the reed switch (206, 106) through the primary reed switch cover (208) and secondary reed switch covers (102).

Abstract: A thermal recirculation throttle valve (1) for an aircraft fuel system includes a housing (11) having a throttling valve chamber; a cover (5) operatively engaging a first side of the housing (11); a power piston (6) within a power piston sleeve (7), the power piston (6) having a first (21) and second face (22) for control pressure to act upon, the power piston (6) and power piston sleeve (7) operatively engaged with the housing (11) within the throttling valve chamber; a Linear Variable Differential Transformer (15) for measuring a linear position of the power piston (6) within the housing (11); a throttling valve (8) within a throttling valve sleeve (9), the throttling valve (8) operatively engaged with the power piston (60) to transfer the linear movement of the piston (6) between a fully extended and a fully retracted operating position; and a flow deflector (10) engaged with the throttling valve (8) for protecting the housing (11) from flow erosion from fuel exiting flow windows (37).

Abstract: A fuel control system, battle override valve and a method of controlling bypass fuel in a fuel system are disclosed. A battle override valve 30 for an engine fuel system 10 includes a metering valve 50 having a rate limiting function providing for control of a slew rate during an operation of the battle override valve 30. A transfer valve 70 having a manual fuel control operating position and a normal fuel control operating position permits a flow of fuel between the metering valve 50 and the transfer valve 70. The transfer valve 70 is controlled between the normal fuel control operating position and the manual fuel control operating position in order to regulate a flow of fuel during a manual or bypass fuel system 10 operation.