One embodiment is a system comprising fuel tank comprising a pressure vessel for storing fuel for a vehicle, the fuel tank disposed within a fuselage of the vehicle and extending a majority of a length of the fuselage, wherein a center of gravity of the fuel tank is substantially aligned with a center of gravity of the fuselage. The fuel tank may be disposed within the fuselage such that the fuel tank bears at least a portion of a load borne by the fuselage. Alternatively, the fuel tank may be disposed within the fuselage such that the fuel tank is isolated from loads borne by the fuselage. In certain embodiments, the fuel tank comprises a filament wound pressure vessel.