12/15/2017. Remarks by Johan Visschedijk: "Following receipt on February 1, 1938 of a USN Bureau of Aeronautics request for single-seat shipboard fighter proposals, a Vought team led by Rex B. Beisel effectively designed the smallest practical airframe that could be built around the largest and most powerful air-cooled radial engine then under development.
Assigned the company designation V-166B, the fighter employed an inverted gull wing in order to provide the necessary ground clearance for the immense Hamilton Standard propeller demanded by the big engine while keeping undercarriage length and ground angle to a minimum, and simultaneously obtain the optimum right angle for minimum drag at the junction of the wing and fuselage. Armament comprised a 0.5 in (12.7 mm) gun in each wing, a similar weapon plus a 0.3 in (7.62 mm) gun in the forward fuselage and a receptacle in each wing for ten light bombs which were to be dropped on bomber formations.
A prototype was ordered on June 30, 1938 as the XF4U-1, powered by a Pratt & Whitney XR-2800-4 Double Wasp eighteen-cylinder radial of 1,850 hp for takeoff. Two years later, May 29, 1940, the prototype was first flown by Lyman A. Bullard, Jnr., and the prototype's sensational performance was immediately apparent. Weighing 7,505 lb (3,404 kg) empty and 9,357 lb (4,252 kg) in normal loaded condition, the XF4U-1 had an initial climb rate of 2,660 ft (811 m)/min and a service ceiling of 35,200 ft (10,668 m). On October 1, 1940, the XF4U-1 became the first US aircraft of any type to exceed 400 mph (644 kmh) in level flight, attaining 404 mph (650 kmh) during a flight between Stratford and Hartford.
In the light of European combat reports, modifications were requested by the USN to improve the operational capability of the series F4U-1 (named Corsair), for which an initial contract calling for 584 aircraft was placed on June 30, 1941."