The prototype of the F4U was designed in 1938. The aims of the F4U development were to produce an aircraft with minimum air resistance and maximum speed. For that the most powerful engine being available at this time, the Pratt & Whitney R-2800, with a power of 1,324 kW (1,824 hp), was mounted in a fuselage, which was built to be as small as possible.The first prototype, which was called V-166B by Vought, was ordered in June 1938. The first flight of the XF4U-1 was on 29th May 1940. It reached in horizontal flight a maximum speed of 708 km/h (404 mph). In the middle of the year 1941, the US Navy ordered multiple aircraft, which should have some modifications. So that the F4U was equipped with self-healing fuel tanks and instead of the R-2800 an R-2800-8 was included, which had 149 kW more power. The cockpit was placed 91 cm backwards. The first definitive aircraft had its first flight on 25th June 1942 and one month later the first aircraft were delivered. Carrier testing, last in September 1942 on the USS Sangamon, showed some problems, like problematic landings and bad pilot visibility. The Navy did not use the aircraft until the appearance of the more advanced F4U-1A in April 1943. The upgraded variant had better pilot visibility because of a new canopy and the upwards placed cockpit. To realise the large numbers, the F4U was also produced by Chance Vought Aircraft in Dallas, as well as by Brewster in Long Island and by Goodyear in Akron Ohio.