Abstract: A collapsible fuel tank system for use on aircraft and the like includes a plurality of nestable shell sections which, when assembled in proper edgewise orientation, form a shell for the fuel tank. A nose cone and a number of shell-reinforcing bulkheads are axially spaced within the fuel tank and have a ring-and-groove construction for facilitating manual assembly of a fuel tank. A preassembled fuel management system includes an elongated flexible liner encapsulating the bulkheads and having snap connections for quick attachment to the shell interior. All of the components of a plurality of fuel tanks are housed in a single container for shipping and handling purposes.