First-flight was recorded May 29th, 1940 (as the XF4U-1) and changes were soon ordered. When first tested in 1940, V-166B exceeded 400 miles per hour (403mph) and became the first American fighter to reach such speeds. In development, the aircraft would be known under the designation of 'XF4U-1'. The USN favored the B-model prototype and placed its contract within months of Vought's submission. Vought produced two prototype aircraft - V-166A and V-166B - to which V-166A received the Pratt & Whitney R1830 'Twin Wasp' engine while V-166B was given the Pratt & Whitney R2800-2 'Double Wasp'.

Pilots also noted difficulties in cockpit access because of the unique wing bend. Despite the inherent strong points in the F4U design, the aircraft held an obstructed forward view (due to the wing's location and long nose) and reduced rearward vision for the pilot due to the raised fuselage spine. Original armament included 4 x 0.50 Browning heavy machine guns. The undercarriage was of the traditional 'tail dragger' arrangement and wholly-retractable. The empennage consisted of a single, short (curved) vertical tail fin with low-set horizontal planes. The wing mainplanes were seated ahead of midships while the fuselage was well-streamlined and tapered to the rear. The engine was fitted at the front of the airframe in the traditional way with the single-seat cockpit located just aft.

The inverted 'gull wing' mainplane arrangement was chosen to keep the spinning propeller blades from hitting the ground and this forced full-length main landing gear legs to be used. To this was added a massive three-bladed propeller unit. Vought engineers gave their compact design the largest possible engine - the experimental Pratt & Whitney XR-2800 'Double Wasp' of 2,000 horsepower output. The Corsair was born from a 1938 USN requirement calling for a new high-performance carrier-based fighter and Chance Vought of United Aircraft answered the call with their Model V-166. While the United States Navy moved on to the equally-excellent Grumman F6F 'Hellcat', the F4U continued to make a name for itself in the Pacific Theater - even earning the respect of its Japanese foes as one of the most feared combat aircraft in the region. The F4U originally appeared as a USN carrier-based fighter design until difficulties in landing the aircraft on a moving carrier led to its expanded use as a land-based fighter in the hands of US Marine aviators. The design was attributed to Igor Sikorsky and Rex Beisel and went on to see production totals reach over 12,500 units with manufacturing ending in 1952 - an impressive total for an aircraft initially rejected by the United States Navy (USN). One of the greatest fighter aircraft of all time, the American Vought F4U 'Corsair' became the stuff of legend for its part in the air wars of World War 2 (1939-1945), the Korean War (1950-1953) and several Cold War conflicts that followed.

Vought f4u corsair fuselage plan