Abstract: The present invention relates to apparatus and methods for winding filament to create a structure. In one embodiment, the invention includes the application of filament to a rotating mandrel to create a desired shape. The invention includes the filament winding of both simple and complex shapes.

Abstract: A fuel tank for aircraft includes a rigid securement for securing the tank to the aircraft, a skin connected to the securement, and a liner inside the skin. The skin includes an elastic fiber and a tensile fiber embedded in a flexible matrix. In one embodiment, the elastic fiber and the tensile fiber are wound in layers within the flexible matrix, and the elastic fiber is wrapped spirally about the tensile fiber. The elastic fiber is preferably an elastomeric fiber such as an elastic, segmented polyurethane fiber. The tensile fiber is preferably an aramid polymer fiber such as an aromatic polycarbonamide fiber. The flexible matrix may be formed of natural rubber or neoprene rubber. When the tank is filled, the elastic fiber lengthens until the tensile fiber resists further stretching. The elastic fiber tends to contract as the tank is emptied, substantially reducing the storage space required by the tank. The tank is nestable when empty, but is nonetheless substantially ready to receive fuel.