An aircraft fuel tank, which includes a water sensor, arranged at the bottom of the tank and connected to a calculation and processing mechanism in order to receive a presence of water signal sent by the sensor, and to return information regarding the need, or not, to perform a fuel tank drainage operation.

A fuel cell power pack used as a power source in a multicopter includes a fuel tank and a fuel cell stack for producing electrical energy using hydrogen supplied from the fuel tank and supplying the electrical energy to a battery, and since the fuel cell stack is disposed at a certain point of an arm extended from the aircraft body in the radius direction (a point affected by a descending air current generated by each rotating blade), the electrical energy can be produced using the descending air current generated by the rotating blade without configuring a separate blowing apparatus.

A fuel cell power pack used as a power source in a multicopter includes a fuel tank and a fuel cell stack for producing electrical energy using hydrogen supplied from the fuel tank and supplying the electrical energy to a battery, and since the fuel cell stack is disposed at a certain point of an arm extended from the aircraft body in the radius direction (a point affected by a descending air current generated by each rotating blade), the electrical energy can be produced using the descending air current generated by the rotating blade without configuring a separate blowing apparatus.

A fuel tank or bladder-free fuel tank having a reservoir on its inside area, limited to an outside area by a double-walled structure. The double-walled structure has an outer wall and an inner wall. A rib structure includes at least one rib extending inwardly into the inside area of the bladder-free fuel tank from the double-walled structure.

A fuel tank or bladder-free fuel tank having a reservoir on its inside area, limited to an outside area by a double-walled structure. The double-walled structure has an outer wall and an inner wall. A rib structure includes at least one rib extending inwardly into the inside area of the bladder-free fuel tank from the double-walled structure.

A fiber-reinforced composite structure includes a cut edge; an elastomeric cap covering the cut edge; and an adhesive sealant bonding the elastomeric cap to the cut edge. The fiber-reinforced composite structure is joined to a component and the elastomeric cap includes a generally Z or L-shaped cap with a web bonded to the cut edge of the fiber-reinforced structure and a flange bonded to the component and extending away from the fiber-reinforced structure.

A fiber-reinforced composite structure includes a cut edge; an elastomeric cap covering the cut edge; and an adhesive sealant bonding the elastomeric cap to the cut edge. The fiber-reinforced composite structure is joined to a component and the elastomeric cap includes a generally Z or L-shaped cap with a web bonded to the cut edge of the fiber-reinforced structure and a flange bonded to the component and extending away from the fiber-reinforced structure.

Systems for removing gas from a sealant and transferring gas-less sealant to an applicator are provided. The system may comprise: a rotatable chamber including: a first opening for receiving sealant; a hollow conduit arranged such that when gas accumulates in the center of the rotatable chamber when the rotatable chamber is rotating, the gas is ventable from the rotatable chamber; a second opening for receiving gas-less sealant from the rotatable chamber after the gas is vented from the hollow conduit; and a motor operatively configured to rotate the rotatable chamber; and a gas-less sealant applicator in fluid communication with the second opening of the rotatable chamber such that gas-less sealant released by the second opening is flowable into the applicator. The system may also include a robot arm including an end effector with a sealant dispensing nozzle. A method for applying sealant to an aircraft structure is also provided.

Systems for removing gas from a sealant and transferring gas-less sealant to an applicator are provided. The system may comprise: a rotatable chamber including: a first opening for receiving sealant; a hollow conduit arranged such that when gas accumulates in the center of the rotatable chamber when the rotatable chamber is rotating, the gas is ventable from the rotatable chamber; a second opening for receiving gas-less sealant from the rotatable chamber after the gas is vented from the hollow conduit; and a motor operatively configured to rotate the rotatable chamber; and a gas-less sealant applicator in fluid communication with the second opening of the rotatable chamber such that gas-less sealant released by the second opening is flowable into the applicator. The system may also include a robot arm including an end effector with a sealant dispensing nozzle. A method for applying sealant to an aircraft structure is also provided.

A vehicle fuel tank assembly including a tank for storing fuel and a sensor device disposed inside the tank. The sensor device is integrated with a component of the tank. The sensor device detects the presence of a plurality of different chemical and/or biological entities in fuel stored in the tank. The plurality of different chemical and/or biological entities are suitable for use in determining whether at least two different types of contaminant are present in the fuel.