Mark Styling. Corsair Aces of World War 2 . , Osprey Publishing, 1995.

The first prototype XF4U-1 took to the air on 29 May 1940 and a production order was issued on 30 June 1940. The design incorporated the use of the largest and most powerful radial engine of the time, the Pratt and Whitney R-2800, which was to turn the largest propeller ever used on a single-seat fighter To gain the necessary ground clearance for the prop, Chance Vought incorporated an inverted gull wing which avoided the use of an exceptionally long main undercarriage and had the added bonus of reducing drag. As the wing met the fuselage at roughly right angles, it did not require the usual farge fairing associated with the standard design (via Phil Jarrett