The Republic P-47 Thunderbolt was a World War II fighter aircraft produced by the American aerospace company Republic Aviation from 1941 to 1945. Its main armament was eight .50-calibre machine guns,and in the fighter-bomber ground attack role, it could carry five-inch rockets or a 2,500 lb (1,100 kg) bomb load. Fully loaded, the P-47 weighed up to eight tons, making it one of the heaviest fighters of the war.
The Thunderbolt was effective as a short- and medium-range escort fighter in high-altitude air-to-air combat and ground attack in the European and Pacific theatres. The P-47 was designed around the powerful Pratt & Whitney R-2800 Double Wasp 18-cylinder star engine that also powered two US Navy/U.S. Marine Corps fighters, the Grumman F6F Hellcat and the Vought F4U Corsair. An advanced turbocharger system ensured the aircraft's eventual dominance at high altitude, while influencing its size and design.