Abstract: A fuel circuit of an aircraft engine including a fuel tank; an engine fuel system including a low-pressure pump and a high-pressure pump, and a fuel recirculating pipeline connected to the engine fuel system; and a fuel recirculating valve arranged so as to switch between an open position and a closed position according to the pressure differential of the low-pressure pump, the valve being able to obstruct the fuel recirculating pipeline in the closed position, and to bring the fuel recirculating pipeline into communication with the fuel tank in the open position.

Abstract: A method for detecting a failure in a fuel return valve of an aircraft engine fuel circuit, the fuel circuit including a fuel tank, an engine fuel system connected to the fuel tank capable of delivering a flow of fuel to the engine depending on a speed of the engine, a fuel return pipe connected between the engine fuel system and the fuel tank, a fuel return valve arranged to switch between an open and closed position, the valve being capable of blocking the fuel return pipe in the closed position, and of bringing the fuel return pipe into communication with the fuel tank in the open position, the method including measuring a pressure of the flow of fuel from the fuel tank, and if the measured pressure is lower than a predefined threshold, measuring the engine speed.

Abstract: A method detects a failure in a fuel return valve of an aircraft engine fuel circuit. A fuel system is connected to a fuel tank of the circuit and includes a high-pressure pump delivering a flow rate to an actuating cylinder, a cutoff valve capable of feeding the actuating cylinder disposed in a feed pipe of the engine; a fuel return pipe; a fuel return valve arranged to switch between an open position and a closed position. The method includes starting the engine at an engine speed; increasing the engine speed until a flow rate reaches a predefined value sufficient for opening the cutoff valve; measuring the position of the actuating cylinder and an engine speed corresponding to the opening of said cutoff valve.

Abstract: A method detects a failure in a fuel return valve of an aircraft engine fuel circuit. A fuel system is connected to a fuel tank of the circuit and includes a high-pressure pump delivering a flow rate to an actuating cylinder, a cutoff valve capable of feeding the actuating cylinder disposed in a feed pipe of the engine; a fuel return pipe; a fuel return valve arranged to switch between an open position and a closed position. The method includes starting the engine at an engine speed; increasing the engine speed until a flow rate reaches a predefined value sufficient for opening the cutoff valve; measuring the position of the actuating cylinder and an engine speed corresponding to the opening of said cutoff valve.

Abstract: A method for detecting a failure in a fuel return valve of an aircraft engine fuel circuit, the fuel circuit including a fuel tank, an engine fuel system connected to the fuel tank capable of delivering a flow of fuel to the engine depending on a speed of the engine, a fuel return pipe connected between the engine fuel system and the fuel tank, a fuel return valve arranged to switch between an open and closed position, the valve being capable of blocking the fuel return pipe in the closed position, and of bringing the fuel return pipe into communication with the fuel tank in the open position, the method including measuring a pressure of the flow of fuel from the fuel tank, and if the measured pressure is lower than a predefined threshold, measuring the engine speed.

Abstract: A fuel circuit of an aircraft engine including a fuel tank; an engine fuel system including a low-pressure pump and a high-pressure pump, and a fuel recirculating pipeline connected to the engine fuel system; and a fuel recirculating valve arranged so as to switch between an open position and a closed position according to the pressure differential of the low-pressure pump, the valve being able to obstruct the fuel recirculating pipeline in the closed position, and to bring the fuel recirculating pipeline into communication with the fuel tank in the open position.

Abstract: A method tracking positive displacement efficiency of a high pressure positive displacement pump in a hydraulic regulator system of a turbomachine delivering a flow rate based on an engine speed of the turbomachine, the flow rate delivered to an actuator actuating variable geometry vanes of the turbomachine and to a bypass valve feeding engines of the turbomachine, the method including: starting engines of the turbomachine at a low engine speed, the valve being closed; using a computer to order a movement of the actuator; progressively increasing the engine speed until the flow rate reaches a predetermined value sufficient for opening the valve; storing in the computer a position of the actuator and the engine speed corresponding to opening of the valve; repeating the preceding operations at successive instants during a lifetime of the engines; and replacing the high pressure positive displacement pump when the engine speed exceeds a predetermined value.

Abstract: A method tracking positive displacement efficiency of a high pressure positive displacement pump in a hydraulic regulator system of a turbomachine delivering a flow rate based on an engine speed of the turbomachine, the flow rate delivered to an actuator actuating variable geometry vanes of the turbomachine and to a bypass valve feeding engines of the turbomachine, the method including: starting engines of the turbomachine at a low engine speed, the valve being closed; using a computer to order a movement of the actuator; progressively increasing the engine speed until the flow rate reaches a predetermined value sufficient for opening the valve; storing in the computer a position of the actuator and the engine speed corresponding to opening of the valve; repeating the preceding operations at successive instants during a lifetime of the engines; and replacing the high pressure positive displacement pump when the engine speed exceeds a predetermined value.