The XF4U-4 prototype first flew May 1940 and was the first US fighter capable of exceeding 400 mph. the type had been planned round the most powerful engine and largest propeller yet envisaged for a fighter, the wing's inverted gull layout shortening the landing gear legs and reducing folded height to ease stowage in carrier hangars. The US Navy decided that the Corsair had poor carrier landing performance., and first deliveries were made to the US Marine Corps for land based combat from February 1943. Revisions allowed carrier operations from September of the same year, and the corsair and the Corsair then became possibly the finest American fighter of the Second World War with victory, loss ratio of 11 to 1 and superb ground attack capability. Total production up to December 1954 was 12,571.