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.