Editing Grumman F6F Hellcat (section)

===Further development===
[[File:Grumman F6F-3 Hellcat of VF-1 in flight over California (USA), in 1943 (80-G-K-605).jpg|thumb|An early F6F-3 in blue-gray over light gull-gray (1943)]]

The F6F series was designed to take damage and get the pilot safely back to base. A bullet-resistant windshield was used and a total of {{cvt|212|lb}} of cockpit armor was fitted, along with armor around the oil tank and oil cooler. A {{cvt|250|USgal|L}} [[self-sealing fuel tank]] was fitted in the fuselage.<ref name= "Kinzey p. 6"/> Standard armament on the F6F-3 consisted of six .50&nbsp;in (12.7&nbsp;mm) [[M2 Browning machine gun|M2/AN Browning]] air-cooled [[machine gun]]s with 400 rounds per gun. A center-section [[hardpoint]] under the fuselage could carry a single {{cvt|150|USgal|L}} disposable [[drop tank]], while later aircraft had single bomb racks installed under each wing, inboard of the undercarriage bays; with these and the center-section hard point, late-model F6F-3s could carry a total bomb load in excess of {{cvt|2,000|lb}}. Six {{cvt|5|in|mm|0}} [[High Velocity Aircraft Rocket]]s (HVARs) could be carried – three under each wing on "zero-length" launchers.<ref>Sullivan 1979, pp. 24, 30, 33.</ref><ref>Parsch, Andreas. [http://www.designation-systems.net/dusrm/app4/5in-rockets.html "5 inch FFAR/HVAR."] ''designation-systems.net,'' 2010. Retrieved: 28 October 2012.</ref>

Two night-fighter subvariants of the F6F-3 were developed; the 18 F6F-3Es were converted from standard-3s and featured the [[AN/APS-4]] 10&nbsp;GHz frequency radar in a pod mounted on a rack beneath the right wing, with a small radar scope fitted in the middle of the main instrument panel and radar operating controls installed on the port side of the cockpit.<ref>Kinzey 1996, pp. 30–31.</ref> The later F6F-3N, first flown in July 1943, was fitted with the AN/APS-6 radar in the fuselage, with the antenna dish in a bulbous fairing mounted on the leading edge of the outer right wing as a development of the AN/APS-4; about 200 F6F-3Ns were built.<ref>Kinzey 1996, pp. 28–29.</ref> Hellcat night fighters claimed their first victories in November 1943.<ref>Green 1975, p. 91.</ref> In total, 4,402 F6F-3s were built through until April 1944, when production was changed to the F6F-5.<ref name="Kin966"/>

[[File:F6F-5 HVAR NOTS NAN4-2-45.jpg|thumb|An early-production F6F-5 being tested with eight 5-inch HVAR rockets (''circa'' 1944–45)]]

The F6F-5 featured several improvements, including a more powerful R-2800-10W engine employing a water-injection system and housed in a slightly more streamlined engine cowling, spring-loaded control [[Trim tab|tabs]] on the [[aileron]]s, and an improved, clear-view windscreen, with a flat armored-glass front panel replacing the F6F-3's curved plexiglass panel and internal armor glass screen.<ref name="Taylor p. 503.">Taylor 1969, p. 503.</ref><ref name="Kin966"/> In addition, the rear fuselage and tail units were strengthened, and apart from some early production aircraft, most of the F6F-5s built were painted in an overall gloss sea-blue finish.<ref>Kinzey 1996, pp. 6–7.</ref> After the first few F6F-5s were built, the small windows behind the main canopy were deleted.<ref>Kinzey 1996, p. 7.</ref> The F6F-5N night-fighter variant was fitted with an AN/APS-6 radar in a fairing on the outer-starboard wing. A few standard F6F-5s were also fitted with camera equipment for reconnaissance duties as the F6F-5P.<ref>Green 1975, pp. 93–94.</ref> While all F6F-5s were capable of carrying an armament mix of one 20-mm (.79-in) [[Hispano-Suiza HS.404#US production|M2 cannon]] in each of the inboard gun bays (220 rounds per gun), along with two pairs of .50-in (12.7-mm) machine guns (each with 400 rounds per gun), this configuration was only used on later F6F-5N night fighters.<ref name= "Kinzey p. 27">Kinzey 1987, p. 27.</ref> The F6F-5 was the most common F6F variant, with 7,870 being built.<ref name="Kin966"/>{{Refn|US produced 20 mm cannon were troubled by reliability issues delaying their introduction {{citation needed|date=April 2021}} |group=Note}}

Other prototypes in the F6F series included the XF6F-4 (02981, a conversion of the XF6F-1 powered by an R-2800-27 and armed with four 20-mm M2 cannon), which first flew on 3 October 1942 as the prototype for the projected F6F-4. This version never entered production and 02981 was converted to an F6F-3 production aircraft.<ref>Kinzey 1996, p. 32.</ref> Another experimental prototype was the XF6F-2 (66244), an F6F-3 converted to use a Wright R-2600-15, fitted with a Birman-manufactured mixed-flow [[turbocharger]], which was later replaced by a Pratt & Whitney R-2800-21, also fitted with a Birman turbocharger.<ref>White 2001, pp. 260, 508.</ref> The turbochargers proved to be unreliable on both engines, while performance improvements were marginal. As with the XF6F-4, 66244 was soon converted back to a standard F6F-3.<ref>Kinzey 1996, pp. 17–18.</ref> Two '''XF6F-6s''' (70188 and 70913) were converted from F6F-5s and used the 18-cylinder {{cvt|2,100|hp|kW|0}} Pratt and Whitney R-2800-18W two-stage supercharged radial engine with water injection and driving a Hamilton-Standard four-bladed propeller.<ref>Kinzey 1996, pp. 50–51.</ref> The XF6F-6s were the fastest version of the Hellcat series with a top speed of {{cvt|417|mph|km/h|0|abbr=on}}, but the war ended before this variant could be mass-produced.<ref name="Taylor p. 503."/><ref>Sullivan 1979, p. 46.</ref> The last Hellcat rolled out in November 1945, the total production being 12,275, of which 11,000 had been built in just two years.<ref>Winchester 2004, p. 110.</ref> This high production rate was credited to the sound original design, which required little modification once production was under way.