An aircraft fuel system including at least one fuel tank, a source of inerting gas, an inlet for introducing the inerting gas into the at least one fuel tank, and a vent system arranged to allow the inward and outward venting of air from the fuel tank. In embodiments, the vent system includes a vent, an inward vent pressure valve disposed between the vent and the at least one fuel tank and configured to enable the at least one fuel tank to increase by a predetermined pressure over ambient air pressure, and an outward vent pressure valve disposed between the at least one fuel tank and the vent and configured to enable the at least one fuel tank to decrease by a predetermined pressure below ambient air pressure.

An aircraft fuel system including at least one fuel tank, a source of inerting gas, an inlet for introducing the inerting gas into the at least one fuel tank, and a vent system arranged to allow the inward and outward venting of air from the fuel tank. In embodiments, the vent system includes a vent, an inward vent pressure valve disposed between the vent and the at least one fuel tank and configured to enable the at least one fuel tank to increase by a predetermined pressure over ambient air pressure, and an outward vent pressure valve disposed between the at least one fuel tank and the vent and configured to enable the at least one fuel tank to decrease by a predetermined pressure below ambient air pressure.

Fuel tank inerting systems and methods for aircraft are described. The systems and methods include controlling of (i) a first reactant control element, (ii) a second reactant control valve, (iii) a ram air control valve, (iv) a driving mechanism, and (v) a flow control valve, to control a state of a fuel tank inerting system. The states of the fuel tank inerting system include an OFF state, a CIRCULATE state, a PRIME state, a CATWARM state, an ON state, a DEPRESSURIZE state, and a COOLDOWN state, wherein the states are determined in part by a prior state and/or a position/actuation of a given element of the system.

Fuel tank inerting systems and methods for aircraft are described. The systems and methods include controlling of (i) a first reactant control element, (ii) a second reactant control valve, (iii) a ram air control valve, (iv) a driving mechanism, and (v) a flow control valve, to control a state of a fuel tank inerting system. The states of the fuel tank inerting system include an OFF state, a CIRCULATE state, a PRIME state, a CATWARM state, an ON state, a DEPRESSURIZE state, and a COOLDOWN state, wherein the states are determined in part by a prior state and/or a position/actuation of a given element of the system.

A fuel extraction system for extracting a gaseous fuel from a fuel tank. The fuel extraction system includes a conveying device which is configured to convey gaseous fuel and to bring it from a first pressure level to a second pressure level, a first line which is configured to connect the conveying device fluidically to the interior of the fuel tank, a buffer tank which is configured to store the fuel at the second pressure level, and which has a first outlet and a second outlet, at least one valve with a pneumatic actuating device, and a second line which is connected to the first outlet of the buffer tank and is configured to conduct a part of the fuel at the second pressure level to the pneumatic actuating device of the at least one valve. Furthermore, a fuel tank apparatus and a fuel cell system are described.

An aircraft fuel system including at least one fuel tank, a source of inerting gas, an inlet for introducing the inerting gas into the at least one fuel tank, and a vent system arranged to allow the inward and outward venting of air from the fuel tank. In embodiments, the vent system includes a vent, an inward vent pressure valve disposed between the vent and the at least one fuel tank and configured to enable the at least one fuel tank to increase by a predetermined pressure over ambient air pressure, and an outward vent pressure valve disposed between the at least one fuel tank and the vent and configured to enable the at least one fuel tank to decrease by a predetermined pressure below ambient air pressure.

A tanker aircraft capacity extension system shaped to fit within an aircraft cargo area may include a first portable fuel container having a first outlet port adapted to connect to an integral fuel system of the aircraft, and a first inlet port; and a second portable fuel container having a second outlet port adapted to connect to the first inlet port and a second inlet port adapted to connect to a third fuel container; when the second outlet port is connected to the first inlet port and the first outlet port is connected to the integral fuel system of the aircraft, fuel flows from the second fuel container, through the outlet port to the first inlet port into the interior of the first container, and out from the first outlet port of the first container.

A tanker aircraft capacity extension system shaped to fit within an aircraft cargo area may include a first portable fuel container having a first outlet port adapted to connect to an integral fuel system of the aircraft, and a first inlet port; and a second portable fuel container having a second outlet port adapted to connect to the first inlet port and a second inlet port adapted to connect to a third fuel container; when the second outlet port is connected to the first inlet port and the first outlet port is connected to the integral fuel system of the aircraft, fuel flows from the second fuel container, through the outlet port to the first inlet port into the interior of the first container, and out from the first outlet port of the first container.

A fuel storage device (10) having at least one tank (15), the tank (15) having a casing (20) extending upwards from a bottom (21) to a top wall (22). The storage device (10) is provided with at least one inflatable bag (25) arranged inside said casing, said device including inflation/deflation means (35) for inflating each inflatable bag (25) at least in part so as to reach an inflated volume prior to filling the tank, and for deflating said inflatable bag after filling in order to guarantee the presence of an expansion volume inside said tank.

A fuel storage device (10) having at least one tank (15), the tank (15) having a casing (20) extending upwards from a bottom (21) to a top wall (22). The storage device (10) is provided with at least one inflatable bag (25) arranged inside said casing, said device including inflation/deflation means (35) for inflating each inflatable bag (25) at least in part so as to reach an inflated volume prior to filling the tank, and for deflating said inflatable bag after filling in order to guarantee the presence of an expansion volume inside said tank.