The XF8B-1 fighter-bomber was the heaviest carrier-based airplane built before the end of World War II. It was the first fighter Boeing built after the P-26 Peashooter of 1936 and the last before the F/A-22 in 1990. The XF8B-1 could be flown as a torpedo bomber and, because of its single-seat configuration, could also be used as a fighter. Because of its size and great horsepower, the XF8B-1 used an unusual dual six-blade contrarotating propeller. It carried bombs internally and extra fuel externally, and its six machine guns were mounted inside the folding wings.