A duct stringer assembly with a bulkhead. The duct stringer assembly has duct walls providing a duct with a closed cross-section. The duct is adapted to transport fluid. A bulkhead is in the duct, and the bulkhead is adapted to block the flow of fluid along the duct. The bulkhead has a bulkhead body, and a gasket sealing a gap between the bulkhead body and the duct walls.

Aircraft hydrogen fuel systems and methods and systems of starting such systems are described. The aircraft hydrogen fuel systems include a hydrogen burning main engine, a main tank configured to contain liquid hydrogen to be supplied to the main engine during a normal operation, and a starter tank configured to contain gaseous hydrogen to be used during a startup operation of the main engine. Methods and processes for starting and/or restarting such systems are described.

Tunable multi-layer thermoplastic polymer sealants and tunable two-layer conductive thermoplastic polymer sealants, and substrates and assemblies comprising the tunable multi-layer sealants; and edge seals and fillet seals produced comprising such sealants; and substrates, components and objects comprising the tunable edge seals and fillet seals, and methods for making and applying such edge seals and fillet seals are disclosed.

Tunable multi-layer thermoplastic polymer sealants and tunable two-layer conductive thermoplastic polymer sealants, and substrates and assemblies comprising the tunable multi-layer sealants; and edge seals and fillet seals produced comprising such sealants; and substrates, components and objects comprising the tunable edge seals and fillet seals, and methods for making and applying such edge seals and fillet seals are disclosed.

A tank assembly for a helicopter is provided. The tank assembly comprises a retractable tank for storing liquid or other substances. The retractable tank comprises an upper frame structure. The tank assembly further comprises an attachment mechanism attached to the upper frame structure and configured to engage a main rotor transmission of the helicopter to suspend therefrom. A helicopter comprising a fuselage, a main rotor transmission, and a tank assembly is also provided.

Tunable multi-layer thermoplastic polymer sealants and tunable two-layer conductive thermoplastic polymer sealants, and substrates and assemblies comprising the tunable multi-layer sealants; and edge seals and fillet seals produced comprising such sealants; and substrates, components and objects comprising the tunable edge seals and fillet seals, and methods for making and applying such edge seals and fillet seals are disclosed.

Tunable multi-layer thermoplastic polymer sealants and tunable two-layer conductive thermoplastic polymer sealants, and substrates and assemblies comprising the tunable multi-layer sealants; and edge seals and fillet seals produced comprising such sealants; and substrates, components and objects comprising the tunable edge seals and fillet seals, and methods for making and applying such edge seals and fillet seals are disclosed.

A cryogenic fluid pressure vessel for an aircraft, having: a first wall layer, which contains carbon fiber-reinforced plastic, having an inner contact surface for the contact with a pressurized cryogenic fluid to be accommodated inside the cryogenic fluid pressure vessel; a second wall layer, which is arranged on an outer surface of the first wall layer and has a thermal barrier; a closable inlet/outlet opening for cryogenic fluid, which extends through the first and the second wall layer; and a structural insert integrated in the first and the second wall layer, which has a fastening connecting piece located on the outside of the cryogenic fluid pressure vessel for mechanically coupling the cryogenic fluid pressure vessel with external structures; wherein the cryogenic fluid pressure vessel forms an essentially cylindrical main body. Furthermore, the present invention provides an aircraft having such a cryogenic fluid pressure vessel.

A seal for sealing an aircraft fuel tank, an aircraft wing rib and stringer sealing assembly, an aircraft wing fuel tank, an aircraft structural wing box, an aircraft wing, and a method of sealing an aperture are disclosed. The seal is for sealing a wing rib to a stringer passing through an aperture in the rib at a variable position in the aperture. The seal includes self-adjustment means to absorb any tolerance when forming the seal, upon the stringer being assembled into the aperture in the rib.

A fuel freeze mitigation and/or prevention system includes a power generator configured and adapted to be positioned within a fuel storage tank. A fluid mover device is in electrical communication with the power generator. The fluid mover device is configured and adapted to be positioned within a fuel storage tank to mitigate or prevent fuel freeze in the fuel storage tank. A method for mitigating or preventing fuel freeze in a fuel storage tank includes harvesting energy with a power generator positioned within the fuel storage tank, charging a battery with the harvested energy, monitoring a fuel temperature inside the fuel storage tank, and turning a fluid mover device positioned within the fuel storage tank ON or OFF depending on at least one of a manual command or the fuel temperature inside the fuel storage tank to mitigate or prevent fuel freeze in the fuel storage tank.