A duct stringer is disclosed and forms at least part of a duct with a closed cross-section along which a fluid flows. An aperture is formed through a duct wall of the duct stringer and communicates with the duct. An insert is adhered in the duct stringer and is configured to engage with a fastening member to mount a fluid transporting conduit, such as a pipe, over the aperture.

A fuel containment system for an aircraft is provided. The fuel containment system comprises an upper fuel barrier under a cabin floor, an aft wheel well bulkhead, an aft fuel barrier opposite the aft wheel well bulkhead, a lower fuel barrier associated with a cargo floor, and a lower fuselage skin panel. A fuel tank is created by the upper fuel barrier, the aft wheel well bulkhead, the aft fuel barrier, the lower fuel barrier, and the lower fuselage skin. The fuel tank is integrated into the aircraft and existing structural components are sealed to prevent fuel from leaking out of the integrated fuel tank.

A fuel containment system for an aircraft is provided. The fuel containment system comprises an upper fuel barrier under a cabin floor, an aft wheel well bulkhead, an aft fuel barrier opposite the aft wheel well bulkhead, a lower fuel barrier associated with a cargo floor, and a lower fuselage skin panel. A fuel tank is created by the upper fuel barrier, the aft wheel well bulkhead, the aft fuel barrier, the lower fuel barrier, and the lower fuselage skin. The fuel tank is integrated into the aircraft and existing structural components are sealed to prevent fuel from leaking out of the integrated fuel tank.

Coupler assemblies are described that removably couple sides of an auxiliary fuel tank in a cargo area of an aircraft. In one embodiment, a first coupler of the coupler assemblies includes a first attachment member that supports a body with a hollow channel having a centerline disposed longitudinally in the fuselage between a first end and a second end, and a slot between an outer surface of the body and the hollow channel. A second coupler of the coupler assemblies includes an engagement member, a second attachment member, and an arm extending between the engagement member and the second attachment member. The engagement member is slidably received within the hollow channel from the first end, and fits slidably within the hollow channel to engage with the body of the first coupler, with the arm extending through the slot.

Coupler assemblies are described that removably couple sides of an auxiliary fuel tank in a cargo area of an aircraft. In one embodiment, a first coupler of the coupler assemblies includes a first attachment member that supports a body with a hollow channel having a centerline disposed longitudinally in the fuselage between a first end and a second end, and a slot between an outer surface of the body and the hollow channel. A second coupler of the coupler assemblies includes an engagement member, a second attachment member, and an arm extending between the engagement member and the second attachment member. The engagement member is slidably received within the hollow channel from the first end, and fits slidably within the hollow channel to engage with the body of the first coupler, with the arm extending through the slot.

A floor system designed for use with an aircraft is provided. The aircraft comprises a cabin characterized by a first capacity defined by the number of personnel in a predetermined position which may be accommodated therein, and comprises an auxiliary fuel port. The floor system is configured to be detachably installed within the cabin and comprises one or more top panels constituting, when the floor system is installed in the aircraft, a floor of the cabin, and one or more fuel tanks disposed below the top panels and defining an internal space for containing liquid fuel there within. At least one of the fuel tanks is configured for connection to the auxiliary fuel port for supplying the fuel to the aircraft. The cabin with the floor system installed therein is characterized by a second capacity being equal to the first capacity.

A floor system designed for use with an aircraft is provided. The aircraft comprises a cabin characterized by a first capacity defined by the number of personnel in a predetermined position which may be accommodated therein, and comprises an auxiliary fuel port. The floor system is configured to be detachably installed within the cabin and comprises one or more top panels constituting, when the floor system is installed in the aircraft, a floor of the cabin, and one or more fuel tanks disposed below the top panels and defining an internal space for containing liquid fuel there within. At least one of the fuel tanks is configured for connection to the auxiliary fuel port for supplying the fuel to the aircraft. The cabin with the floor system installed therein is characterized by a second capacity being equal to the first capacity.

A system comprises a non-transitory machine readable storage medium storing instructions and a database identifying a plurality of assets and a state of each asset. The instructions configure a processor for receiving updates to a distributed electronic ledger managed by plural peer processors. Each update includes an event or change affecting one of the assets. The peer processors verify portions of the ledger describing each event or change. At least one of the updates has not yet been recorded in the ledger at a time of the receiving. The processor computes a state of each asset, based on the updates, receives a request for a state of one of the assets; and responds to the request, reflecting each event and change affecting that asset. The response is performed without waiting for the peer processors to verify an update that has not yet been recorded in the ledger.

An aircraft wing box is disclosed having a first cover, a second cover, a partition extending between the first and second cover and configured to provide a fuel tight boundary between the first and second covers, a first joint coupling the partition to the first cover, and a second joint coupling the partition to the second cover. The first joint is a slip joint configured to inhibit fuel leakage across the slip joint whilst permitting relative movement between the partition and the first cover.

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.