An aircraft wing box is disclosed having a fuel tank with a fuel-tight boundary, upper and lower covers, forward and aft spars, and a partition including an inboard portion, an outboard portion, and a third portion between the inboard and outboard portions. Each cover is attached to each spar, the inboard portion of the partition is joined to each cover and joined to one of the spars, the outboard portion of the partition is joined to each cover and joined to one of the spars, each cover is joined to the partition. The inboard part, outboard part and third part of the partition are integrally formed as a single-piece; and the single-piece provides part of the fuel-tight boundary of the fuel tank.

Embodiments of the present invention provide a fuel tank communication system. The communication system includes a main body (30) used to connect two fuel bladder flanges (12, 20) to one another. The communication system provides two separate, independent locking features (42, 60) that can secure fuel bladders to one another.

Embodiments of the present invention provide a fuel tank communication system. The communication system includes a main body (30) used to connect two fuel bladder flanges (12, 20) to one another. The communication system provides two separate, independent locking features (42, 60) that can secure fuel bladders to one another.

This fuel tank dam closes a gap between a first structural component fixed to the inside surface of the outer plate of a fuel tank and a second structural component provided with a cutout part into which the first structural component is inserted. This fuel tank dam includes: a first portion that can be fixed to the first structural component; a second portion that has a surface extending in a direction intersecting with the first portion and can be fixed to the second structural component; and a third portion that has a bellows and is disposed between the first portion and the second portion. This fuel tank dam is configured such that the first portion, the second portion, and the third portion are integrated, the bellows has a thickness of 0.381 to 1.524 mm, and the second portion has a thickness of 0.762 to 7.620 mm.

This fuel tank dam closes a gap between a first structural component fixed to the inside surface of the outer plate of a fuel tank and a second structural component provided with a cutout part into which the first structural component is inserted. This fuel tank dam includes: a first portion that can be fixed to the first structural component; a second portion that has a surface extending in a direction intersecting with the first portion and can be fixed to the second structural component; and a third portion that has a bellows and is disposed between the first portion and the second portion. This fuel tank dam is configured such that the first portion, the second portion, and the third portion are integrated, the bellows has a thickness of 0.381 to 1.524 mm, and the second portion has a thickness of 0.762 to 7.620 mm.

Various techniques are provided for an expandable energy absorbing fluid bladder. In one example, the fluid bladder includes a primary portion and a secondary portion. The secondary portion can be configured to expand or increase in volume when the fluid bladder is subjected to a pulse greater than a threshold pulse. Expansion of the secondary portion can allow fluid or additional fluid to flow into the secondary portion and thus decrease a peak pulse and, thus, avoid rupture of the fluid bladder.

A method of joining an interior wall and a composite channel together is disclosed. The method includes wrapping one or more first composite plies around a first end portion of a first mandrel and wrapping one or more second composite plies around a second end portion of a second mandrel. The method includes positioning the one or more first composite plies located on the first end portion of the first mandrel against the one or more second composite plies located on the second end portion of the second mandrel to create the interior wall, and inserting the first mandrel and the second mandrel into a passageway of a composite channel. The interior wall created by the one or more first composite plies and the one or more second composite plies creates a barrier to block a flow of fluid within the passageway of the composite channel.

In another aspect, a method for fueling an aircraft, the method including storing liquified gas fuel using a fuel tank, wherein the fuel tank is configured to store liquified gas fuel, fueling an aircraft using a fuel line. Fueling the aircraft may additionally include the fuel tank with liquified gas fuel to a desired level, wherein a desired level comprises fuel for a plurality of flights plus reserves. Filling may also include removing the fuel line as a function of the desired level. The method may additionally include venting the fuel tank using a vent line in fluid connection to the fuel tank. The fuel tank may then be prepared for flight as a function of a desired level. Finally, the method includes flying a plurality of flights using the aircraft.

In another aspect, a method for fueling an aircraft, the method including storing liquified gas fuel using a fuel tank, wherein the fuel tank is configured to store liquified gas fuel, fueling an aircraft using a fuel line. Fueling the aircraft may additionally include the fuel tank with liquified gas fuel to a desired level, wherein a desired level comprises fuel for a plurality of flights plus reserves. Filling may also include removing the fuel line as a function of the desired level. The method may additionally include venting the fuel tank using a vent line in fluid connection to the fuel tank. The fuel tank may then be prepared for flight as a function of a desired level. Finally, the method includes flying a plurality of flights using the aircraft.

An autonomous propeller propulsion system for an aircraft. The autonomous system comprises a chassis with first attachment systems which engage with second attachment systems of the wing to ensure detachable attachment of the autonomous system, a fuel cell attached to the chassis, an electric motor attached to the chassis and having an output shaft, a propshaft rotated by the output shaft, a propeller attached to the propshaft, a controller converting an electric current delivered by the fuel cells into an electric current delivered to the electric motor, a hydrogen feed duct and an air feed duct, a set of auxiliary equipment, and a first connection arrangement, which connects with a second connection arrangement of the aircraft.