A mockup of Grumman ‘s Design 50 was inspected by the Navy on January 12, 1941, and an enlarged development with 1,700 hp Wright R-2600-16 Cyclones was specified for two XF6F-1 prototypes ordered June 30, 1941, and for the F6F-1 production contract made January 7, 1942. This contract originally called for 434 aircraft, plus a lend-lease allotment for Britain, establishing a completely standardized Hellcat for both navies.
An XF6F-2 version with a turbosupercharged XR-2600-10 was projected by April 29, but Grumman was also studying the 2,000-hp Pratt & Whitney Double Wasp for an XF6F-3 model given priority and chosen for the second prototype.
By June 3, 1942, the Navy decided that all production Hellcats would have Double Wasp, so the XF6F-1 flown June 26 by Robert Hall was the only Cyclone-powered Hellcat completed, and had a Curtiss propeller in a large spinner, bulky landing gear, and no guns. The XF6F-3 was flown July 30 with a 2,000 hp R-2800-10.
The first prototype was also fitted with an R-2800-10 in September, while the second became the XF6F-4 flown October 3 with a single-stage R-2800-27 rated at 1,600 hp at 13,500 feet, and in April 1943 tested a wing with four 20-mm guns. A turbosupercharged XF6F-2 finally appeared in January 1944 with an XR-2800-16 Wasp, but was no longer desired.
Meanwhile, the expedited production contract hadbeen changed to the F6F-3 model, the first flying October 3 with an R-2800-10, three-bladed Hamilton propeller without spinner, a simplified landing gear, and six guns. Ten F6F-3s were delivered by 1942’s end, and production accelerated rapidly, the 2,545 Hellcats delivered in 1943 being enough to equip every fighter squadron on the fast carriers. There was little change in the basic configuration, although the R-2800-l0W with water injection for emergency power was introduced in January 1944.
To keep wing loading low, the Hellcat had the largest wing area of any U.S. single-engine service fighter. The wheels folded backward flat into the wings, which folded backward aboard ship. Seating the pilot high on top of the fuel tanks gave him fine visibility. A downward angle given the engine thrust line enhanced his view, and keeping the tail down in relation to the thrust line made climb the aircraft’s natural tendency.
Installations on the F6F-3 included six .50-caliber guns with 2,400 rounds in the wings, 212 pounds of armor, and the self-sealing fuel tanks standard on wartime Navy types. An 150-gallon drop tank was added in August 1943. In September 1943, acceptances began on F6F-3N night fighters with Sperry APS-6 radar on the starboard wing, while the F6F-3E was delivered in January 1944 with the lighter Westinghouse APS-4 radar below the wing. A total of 4,156 F6F-3, 229 F6F-3N, and 18 F6F-3E Hellcats were completed by April 20, 1944.
First flown April 4, 1944, the F6F-5 had a modified cowl and windshield, armor increased to 232 pounds, could substitute 20-mm guns for the two inner wing weapons, and fittings for six rockets under the wings or two 1,000-pound bombs under the fuselage were provided. Contracts for 6,436 F6F-5s and 1,432 F6F-5Ns were completed, bringing Hellcat totals to 12,275 when deliveries ended November 21, 1945. Two XF6F-6s with the 2,100-hp R-2800-18W and four-bladed propeller were first flown July 6, 1944, but this advanced power plant was reserved for the F4U-4.
Hellcats joined the Navy at the same time as the new carriers begun in 1941; the Essex, name-ship of the class, got the first F6F-3 squadron in January 1943. The new ship and fighter went into action together, along with its sister ship, the new Yorktown, and the Independence, first of the new light carriers, with an attack on Marcus Island August 31, 1943. This was only 14 months after the prototype’s first flight. (Corresponding time on the Corsair was over 32 months.)