Abstract: A two stage fuel delivery system for an aircraft includes a first stage pump including an inlet connected to a source of fuel and an outlet connected to a combustor assembly, and a second stage pump including an inlet portion connected to the source of fuel and an outlet portion connected to the combustor assembly. A bypass valve is connected between the source of fuel, the inlet, and the inlet portion. The bypass valve selectively disconnects the second stage pump from the source of fuel. A metering valve is connected to the inlet and the inlet portion. The metering valve includes a metering valve inlet and a metering valve outlet. A pressure regulating valve is connected to the metering valve. A stage monitoring system is configured to detect a change in operation of the second stage and control the bypass valve.

Abstract: A system includes a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line. A bypass valve (BPV) includes a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP. An actuator is operatively connected to control the BPV to vary flow from the BPV inlet to the bypass line. A flow sensing valve (FSV) is connected in the outlet line. The FSV includes a sensor configured to generate sensor data indicative of flow out of the outlet line. A controller operatively connected to the actuator to control recirculation flow passed through the BPV based on the sensor data and based on a predetermined low threshold of flow through the VDP.

Abstract: A system includes a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line. The VDP includes a variable displacement mechanism configured to vary pressure to the outlet line. A bypass valve (BPV) includes a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP. A minimum pressure shutoff valve (MPSOV) is connected in fluid communication with the outlet line, configured to block flow through the outlet line for shutoff. The MPSOV is connected in fluid communication with the BPV for triggering recirculation through the BPV.

Abstract: A system includes a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line. The VDP includes a variable displacement mechanism configured to vary pressure to the outlet line. A bypass valve (BPV) includes a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP. An actuator is operatively connected to control the BPV to vary flow from the BPV inlet to the bypass line. A controller is operatively connected to the actuator to control recirculation flow passed through the BPV based on requested flow from a downstream system supplied by the outlet line and based on a predetermined low threshold of flow through the VDP.

Abstract: A fuel system can include a main fuel pump (MFP) configured to output main flow to a main line, an augmentor fuel pump (AFP) configured to output an augmenter flow to an augmenter line, and a variable displacement pump assembly (VDPP) in fluid communication with the AFP via the augmentor line to receive the augmentor flow. The VDPP can include a variable displacement pump (VDP) configured to output a VDP flow to a VDP output line. The system can include a main fuel throttle valve assembly (MFTV) in fluid communication with the main fuel pump via the main line to receive the main flow and in fluid communication with the VDPP via a backup line. The MFTV can be in fluid communication with an engine line, an actuation assembly in fluid communication with the VDPP via an actuation line to receive an actuation flow.

Abstract: In accordance with at least one aspect of this disclosure, a system includes an in-tank fuel pump configured to be disposed in a fuel tank to supply fuel from the fuel tank to a fuel line at a first pressure. A boost pump is configured to be disposed in the fuel line to receive fuel from the in-tank fuel pump and supply the fuel to one or more downstream components at a boost pressure. An augmentation pump system is configured to be disposed in the fuel line to receive fuel from the boost pump and to supply fuel at a second pressure to one of, at least one fuel consuming component downstream of the augmentation pump system, or an in-tank ejector pump, based on an operational state of the in-tank fuel pump.

Abstract: A system includes a variable displacement pump (VDP) with a pump inlet and a pump outlet. The VDP is configured to receive a flow at the pump inlet at a first pressure and to outlet a flow from the pump outlet at a second pressure elevated relative to the first pressure. A second pump is in fluid communication to receive flow at the pump inlet at the first pressure and to outlet flow from an auxiliary outlet. A backup selector is in fluid communication with the pump outlet and with the auxiliary outlet. The backup selector is configured to operate in a normal mode to supply the pump outlet from the VDP and to supply the auxiliary outlet from the second pump. The backup selector is configured to switch to a backup mode to supply the pump outlet from the second pump upon failure of the VDP.

Abstract: A system includes a variable displacement pump (VDP) with a pump inlet and a pump outlet. The VDP is configured to receive a flow at the pump inlet at a first pressure and to outlet a flow from the pump outlet at a second pressure elevated relative to the first pressure. The VDP includes a variable displacement mechanism configured to vary the second pressure. A controller is operatively connected to a pressure sensor and to the variable displacement mechanism for control of the VDP. An output splitter is configured to split flow from the pump outlet to a first outlet branch and to a second outlet branch for supplying two different systems each having a different pressure schedule. The output splitter is operatively connected to the controller, which is configured to control the output splitter to regulate pressure in both of the first and second outlet branches.

Abstract: A system includes a variable displacement pump (VDP) having a pump inlet, a pump outlet, and a pump control line configured to receive a control pressure to actuate a variable displacement mechanism of the VDP. A controller is operatively connected to the pump control line to actively control actuation of the variable displacement mechanism in a first mode for variable displacement pumping and in a second mode for fixed displacement pumping.

Abstract: A system includes a variable displacement pump (VDP) with a pump inlet and a pump outlet. The VDP is configured to receive a flow at the pump inlet at a first pressure and to outlet a flow from the pump outlet at a second pressure elevated relative to the first pressure. The VDP includes a variable displacement mechanism configured to vary the second pressure. A controller is operatively connected to a pressure sensor and to the variable displacement mechanism for control of the VDP. An output splitter is configured to split flow from the pump outlet to a first outlet branch and to a second outlet branch for supplying two different systems each having a different pressure schedule. The output splitter is operatively connected to the controller, which is configured to control the output splitter to regulate pressure in both of the first and second outlet branches.

Abstract: A system includes a first pump connected to an inlet line and connected to a first outlet line for supplying a first sub-system over a first pressure schedule. A second pump is connected to the inlet line and connected to a second outlet line for supplying a second subsystem over a second pressure schedule. A backup selector is in fluid communication with the first and second outlet lines. The backup selector is configured to switch to a first backup mode to supply the first sub-system from the second pump upon failure of the first pump. The backup selector is configured to switch to a second backup mode to supply the second sup-system from the first pump upon failure of the second pump.

Abstract: A fuel system includes a main pump assembly. The main pump assembly has a main fuel pump connected to an input line, a recirculation pump connected to the input line, and a fuel recirculation system. A recirculation control includes a first selector valve in fluid communication with an outlet line of the recirculation pump, with a recirculation return line connected to return fuel to the input line, and with an inter-valve line. The recirculation control includes a second selector valve in fluid communication with the inter-valve line, with a back-up line connecting the second selector valve to a main fuel control, and with a cooler recirculation line connected to supply the one or more coolers.

Abstract: A fuel system of an aircraft engine, having: a boost pump having an input and an output; one or more selector valves; a first component pump having an input fluidly coupled to the output of the boost pump and an output of the first component pump is configured to direct fuel to a first component via the one or more selector valves; and a second component pump having an input that is selectively coupled to either the input or the output of the boost pump by the one or more selector valves, and an output of the second component pump is fluidly coupled to a second component and selectively coupled to the first component by the one or more selector valves.

Abstract: A two stage fuel delivery system for an aircraft includes a first stage pump including an inlet connected to a source of fuel and an outlet connected to a combustor assembly, and a second stage pump including an inlet portion connected to the source of fuel and an outlet portion connected to the combustor assembly. A bypass valve is connected between the source of fuel, the inlet, and the inlet portion. The bypass valve selectively disconnects the second stage pump from the source of fuel. A metering valve is connected to the inlet and the inlet portion. The metering valve includes a metering valve inlet and a metering valve outlet. A pressure regulating valve is connected to the metering valve. A stage monitoring system is configured to detect a change in operation of the second stage and control the bypass valve.

Abstract: A fuel system of an aircraft engine, having: a boost pump having an input and an output; one or more selector valves; a first component pump having an input fluidly coupled to the output of the boost pump and an output of the first component pump is configured to direct fuel to a first component via the one or more selector valves; and a second component pump having an input that is selectively coupled to either the input or the output of the boost pump by the one or more selector valves, and an output of the second component pump is fluidly coupled to a second component and selectively coupled to the first component by the one or more selector valves.

Abstract: According to an aspect, a dual fuel pump system includes a primary run-dry fuel pump having multiple stages, each of the stages configured to produce fuel pressure between a pump stage inlet and a pump stage outlet, and at least one of the stages operable in a run-dry mode. A secondary run-dry fuel pump is operable in run-dry mode, where the secondary run-dry fuel pump is mechanically driven by an accessory gearbox of an engine of the aircraft. An electric motor is operably coupled to the primary run-dry fuel pump and configured to drive rotation of the stages of the primary run-dry fuel pump. A controller is configured to pressurize fuel using a single stage of the primary run-dry fuel pump, pressurize fuel using at least two stages of the primary run-dry fuel pump, and pressurize fuel using the secondary run-dry fuel pump under various operating conditions.

Abstract: A hydraulic actuator system of an aircraft includes a hydraulic actuator having a housing with a piston having a piston shaft with a piston head attached thereto and arranged within the housing. The piston head divides in internal volume of the housing into an extend cavity and a retract cavity and the extend cavity is configured to be connected to low pressure fluid source. The system also includes a pressure selector unit fluidly connected to the retract cavity and configured to be connected to the low pressure fluid source and to a high pressure fluid source. The unit include three solenoids with the first and second connected in parallel to the fluid sources and the third solenoid having a third solenoid first input connected to the first solenoid output, a third solenoid second input connected to the second solenoid output, and a third solenoid output connected to the retract cavity.

Abstract: A dual pump fuel delivery system for an aircraft includes a fixed displacement fuel pump including an inlet and an outlet. The fixed displacement fuel pump is configured to supply a first portion of a fuel demand for the aircraft. A variable displacement fuel pump including an inlet portion and an outlet portion includes a selectively adjustable pump actuator configured to supply a second portion of the fuel demand. The second portion is variable. A fuel demand sensor operates to detect a selected fuel demand. A control member is operatively connected to the fuel demand sensor and the variable displacement fuel pump. The control member being configured to operate to adjust the variable displacement fuel pump to output the second portion of the fuel demand to satisfy the selected fuel demand.

Abstract: A fuel system includes a fuel metering unit having a fuel inlet and a fuel outlet defining a flow path therebetween. The fuel system includes a bleed valve in fluid communication with the flow path of the fuel metering unit. The fuel system includes a controller in communication with the fuel metering unit and the bleed valve to send data thereto and/or receive data therefrom. The bleed valve is configured and adapted to open or close depending on a command from the controller. The flow path is configured and adapted to be in selective fluid communication with a fuel system interstage through the bleed valve.