With the Grumman F4F Wildcat in operational service and feedback being received from both their Allies and United States Navy pilots, including combat reports against the Mitsubishi A6M
Zero, Grumman set to work on an improved fighter plane which led to the birth of the Hellcat. Whilst the cosmetic appearance to it's predecessor was obvious a number of major changes
separated the two planes. One of these saw the Wildcat's mid-wing layout replaced with a low wing layout that provided a couple of benefits in relation to the landing gear. Firstly the
landing gear was now able to be housed in the wing and secondly the landing gear could be placed further outboard resulting in a much more stable undercarriage. After evaluating the new
design the US Navy placed an order on the 30th June 1941 for four prototypes of the aircraft with a different powerplant, these were:
||XF6F-1 - two-stage turbocharged 1,700-hp Wright R-2600-10 Cyclone 14.
||XF6F-2 - turbocharged R-2600-16.
||XF6F-3 - two-stage turbocharged 2,000-hp Pratt & Whitney R-2800-10 Double Wasp.
||XF6F-4 - R-2800-27 and two speed turbocharger.
The first of these prototypes to fly was the XF6F-1 which flew on the 26th June 1942.
The need for more fighters to reinforce the Wildcats in service took on a greater importance when during the Battle of Midway Douglas TBD Devastators of VT-8 were all shot down with
only one pilot surviving with VT-6 Devastators nearly succumbing to the same fate. This lead to the decision to install the most powerful engine available at the time, the Pratt & Whitney
R-2800-10, into the first Hellcat airframe and a little over a month later, after the first prototype flight, on the 30th July 1942 the XF6F-3 made it's first flight. However the decision
had been taken before any prototypes had flown to order the aircraft as the F6F-3 Hellcat, which would have six 0.50-in machine-guns as standard armament.
When production of the Hellcat started the similarity's between the Wildcat and Hellcat would play off as workers on the Wildcat were able to switch over to building the Hellcat with
minimal fuss and on the 4th October 1942 the first production aircraft flew and another ten were built by the end of 1942. The 16th January 1943 would see the Hellcat begin to equip US
Navy squadron VF-9 which was stationed aboard USS Essex although it was VF-5 stationed aboard the USS Yorktown which was the first to meet the Japanese in combat on the 31st August 1943 just fourteen
months after the first prototype flight.
The Grumman F6F Hellcat went from strength to strength with 2,500 delivered during 1943 enabling F4F Wildcat squadrons to upgrade to the new type quickly and the Hellcat would serve
alongside the Vought F4U Corsair when this aircraft entered service with the US Navy during 1944. Despite the success of the F6F-3 version of the Hellcat, which included the F6F-3N night
fighter, Grumman introduced the F6F-5 which flew for the first time on the 4th April 1944 and entered US Navy service shortly after. This featured the same powerplant as the F6F-3 but due
to the introduction of a water injection system, which could increase power by 10% for short periods, was known as the R-2800-10W. The new Mk could also carry either two 1,000lb or six
5-in rockets and later production models would have two 0.50-in machine-guns, one in each wing, replaced with 20-mm cannons. A number of these were also converted into night fighters
The Grumman Hellcat would also see service with the Fleet Air Arm and the F6F-3 was originally called the Gannet Mk I before reverting back to it's original Hellcat name later and equipped
No. 800 Squadron with whom it would first see action with the Fleet Air Arm stationed aboard HMS Emperor during December 1943. Although most of the Fleet Air Arm Hellcats would serve in
the Far East with the British Pacific Fleet, with twelve squadrons equipped with either the Mk I or Mk II (F6F-5) by VJ Day. Two night fighter squadrons, Nos. 891 and 892 based at
Eglinton, Northern Ireland, were set-up with the Hellcat Mk NF.II night fighter though these would not see service during World War 2.
When production of the Hellcat ceased in November 1945 12,275 examples had been built and the aircraft remained in service with the US Navy for a few years after VJ Day but was eventually
replaced by the Grumman F8F Bearcat.