Abstract: An aircraft fuel tank system including a fuel tank compartment for containing liquid fuel and having a float-activated valve arranged to become positively buoyant when immersed in liquid fuel so that the float moves up to a raised position which causes the valve to close and prevent liquid fuel from flowing out of the fuel tank compartment through the valve. The float is also arranged to move down to a lowered position in response to a level of the liquid fuel in the fuel tank compartment dropping, the movement of the float to the lowered position causing the valve to open and permit liquid fuel to flow out of the fuel tank compartment through the valve. A pressure-activated valve may be used as an alternative to the float-activated valve.

Abstract: An aircraft fuel system having a fuel tank and a baffle dividing the fuel tank into a primary fuel containing space and a secondary fuel containing space. A fuel drain is provided through which fuel flows from the primary fuel containing space into the secondary fuel containing space. A primary fuel outlet draws fuel from the primary fuel containing space and a secondary fuel outlet draws fuel from the secondary fuel containing space, wherein fuel flow through the primary fuel outlet causes fuel flow through the secondary fuel outlet. The mass flow rate of fuel through the fuel drain is restricted so that the allowable mass flow rate of fuel through the secondary fuel outlet is configured to be greater than the allowable mass flow rate of fuel through the fuel drain in the baffle.

Abstract: An aircraft fuel tank system including a fuel tank compartment for containing liquid fuel and having a float-activated valve arranged to become positively buoyant when immersed in liquid fuel so that the float moves up to a raised position which causes the valve to close and prevent liquid fuel from flowing out of the fuel tank compartment through the valve. The float is also arranged to move down to a lowered position in response to a level of the liquid fuel in the fuel tank compartment dropping, the movement of the float to the lowered position causing the valve to open and permit liquid fuel to flow out of the fuel tank compartment through the valve. A pressure-activated valve may be used as an alternative to the float-activated valve.

Abstract: An aircraft fuel system having a fuel tank and a baffle dividing the fuel tank into a primary fuel containing space and a secondary fuel containing space. A fuel drain is provided through which fuel flows from the primary fuel containing space into the secondary fuel containing space. A primary fuel outlet draws fuel from the primary fuel containing space and a secondary fuel outlet draws fuel from the secondary fuel containing space, wherein fuel flow through the primary fuel outlet causes fuel flow through the secondary fuel outlet. The mass flow rate of fuel through the fuel drain is restricted so that the allowable mass flow rate of fuel through the secondary fuel outlet is configured to be greater than the allowable mass flow rate of fuel through the fuel drain in the baffle.

Abstract: An aircraft fuel system has a fuel tank for containing liquid fuel, the fuel tank having a base. The aircraft fuel system also has a fuel pump for drawing liquid fuel from the fuel tank, a fuel conduit having a fuel outlet through which fuel is permitted to flow from the fuel tank, and a filter defining a filtered fuel space enclosing the fuel outlet. The fuel conduit extends between the fuel outlet and the fuel pump, and the filter extends from the base to enclose the fuel outlet. The fuel conduit extends into the filtered space and the fuel outlet faces and is spaced from the base. This helps to minimise the quantity of unusable fuel in the aircraft fuel system. The present application also relates to an aircraft wing having an aircraft fuel system, and an aircraft having an aircraft fuel system.