A shut-off valve includes a float and a negative G control component. The float is configured to occlude a tank outlet at a first fluid level and 1 G and unocclude the tank outlet at a second fluid level and 1 G. The negative G control component is operatively connected to the float to limit fluid, e.g. liquid or gas, communication between a tank outlet and an ejector pump during negative G events. An ecology fuel return system includes a tank, an ejector pump, a float, and a negative G control component, as described above. The tank has an inlet and an outlet. The inlet is configured to be in fluid communication with components of an engine. The ejector pump is in fluid communication with the tank outlet and is configured to pump fuel from the tank to a fuel pump inlet of an engine.

A fuel management system may include a first fuel tank and a second fuel tank. The fuel management system may also include an intelligent crossfeed valve positioned between the first fuel tank and the second fuel tank and configured to allow fuel to flow between the first fuel tank and the second fuel tank. The fuel management system may also include a sensor configured to detect an amount to which the intelligent crossfeed valve is open. The fuel management system may also include an engine controller connected to the sensor and configured to cause the intelligent crossfeed valve to close in response to the intelligent crossfeed valve being open a third predetermined amount.

A pump system is disclosed including a first pump having a first inlet and a first outlet, and a second pump having a second inlet and a second outlet. The second pump is arranged in parallel with the first pump, and the first inlet and the second inlet are for fluidically coupling to one or more fluid reservoirs. A control system is coupled to the first pump and the second pump for controlling the operation of the first pump and the second pump simultaneously. The control system is configured to measure a value of a first pressure head at the first outlet, measure a value of a second pressure head at the second outlet, control the first pump to achieve a required output and control the second pump by providing a demand for the second pump to achieve a measured value of the second pressure head which equals the measured value of the first pressure head.

A pump system is disclosed including a first pump having a first inlet and a first outlet, and a second pump having a second inlet and a second outlet. The second pump is arranged in parallel with the first pump, and the first inlet and the second inlet are for fluidically coupling to one or more fluid reservoirs. A control system is coupled to the first pump and the second pump for controlling the operation of the first pump and the second pump simultaneously. The control system is configured to measure a value of a first pressure head at the first outlet, measure a value of a second pressure head at the second outlet, control the first pump to achieve a required output and control the second pump by providing a demand for the second pump to achieve a measured value of the second pressure head which equals the measured value of the first pressure head.

An apparatus contains a dihydrogen tank and/or a dihydrogen circuit, and a device for regulating a concentration of dihydrogen located outside the tank and/or the circuit. The device includes at least one pair of electrical conductors including a first electrical conductor supplied with a first voltage and a second electrical conductor supplied with a second voltage which is different from the first voltage. At least one controller repeatedly commands the application of a predetermined voltage difference between the first electrical conductor and the second electrical conductor so that an electric arc of controlled power is formed in order to burn dihydrogen possibly coming from the tank and/or from the circuit. Thus, dihydrogen does not accumulate in undesired places in the apparatus.

An apparatus contains a dihydrogen tank and/or a dihydrogen circuit, and a device for regulating a concentration of dihydrogen located outside the tank and/or the circuit. The device includes at least one pair of electrical conductors including a first electrical conductor supplied with a first voltage and a second electrical conductor supplied with a second voltage which is different from the first voltage. At least one controller repeatedly commands the application of a predetermined voltage difference between the first electrical conductor and the second electrical conductor so that an electric arc of controlled power is formed in order to burn dihydrogen possibly coming from the tank and/or from the circuit. Thus, dihydrogen does not accumulate in undesired places in the apparatus.

A deployable drains mast for draining fluids from a propulsion system is provided. The deployable drains mast includes a bordered structure. The bordered structure includes a plurality of exterior walls forming a cavity. The bordered structure further includes at least one drain opening to the cavity located at a first end of the bordered structure. The at least one drain opening configured to receive a drain line from a component of a core compartment of the propulsion system. The bordered structure further includes at least one drain exit from the cavity located at a second end of the bordered structure opposite the first end. The drain exit configured to expel the fluid.

A deployable drains mast for draining fluids from a propulsion system is provided. The deployable drains mast includes a bordered structure. The bordered structure includes a plurality of exterior walls forming a cavity. The bordered structure further includes at least one drain opening to the cavity located at a first end of the bordered structure. The at least one drain opening configured to receive a drain line from a component of a core compartment of the propulsion system. The bordered structure further includes at least one drain exit from the cavity located at a second end of the bordered structure opposite the first end. The drain exit configured to expel the fluid.

A valve state detection system for directly determining and confirming the existing valve state in an aircraft fuel control valve in real time, with an aircraft fuel control valve incorporating a electromagnetic energy beam transmitter and receiver for emitting and receiving an electromagnetic energy beam across an aircraft fuel control valve assembly chamber.

An aircraft includes a cabin in which an occupant rides, and a driving source driven by using fuel supplied thereto, the aircraft further including a tank unit which is disposed between the cabin and the driving source and in which a plurality of fuel tanks for storing the fuel are stacked.