The Thunderbolt was the most famous of all the Republic aircraft in WWII. First flown on 6 May 1941, the P-47 was designed as a (then) large, high-performance fighter/bomber, utilizing the large Pratt and Whitney R-2800 Double Wasp engine to give it excellent performance and a large load-carrying capability. The first deliveries of the P-47 took place in June 1942, when the US Army Air Corps began flying it in the European Theater.