Wildcat
The US Navy’s requirement of 1936 for a new carrier-based fighter resulted in the Brewster Aeronautical Corporation receiving an order for a prototype of its Model 39 under the designation XF2A-1. This became the US Navy’s first monoplane fighter in squadron service, but so tentative was the US Navy in its decision to order this aircraft that it ordered also a prototype of Grumman’s competing biplane design under the designation XF4F-1. However, a more careful study of the performance potential of Brewster’s design, plus the fact that Grumman’s earlier F3F biplane was beginning to demonstrate good performance, brought second thoughts. This led to cancellation of the biplane prototype and the initiation of an alternative Grumman G-18 monoplane design. Following evaluation of this new proposal, the US Navy ordered a single prototype on 28 July 1936 under the designation XF4F-2.
Rolled out of Grumman’s Bethpage, Long Island, assembly shed and flown for the first time on 2 September 1937, the XF4F-2 was powered by a 1,050 hp (783 kW) Pratt & Whitney R-1830-66 Twin Wasp engine, and was able to demonstrate a maximum speed of 290 mph (467 km/h). Of all-metal construction, with its cantilever monoplane wing set in a mid-position on the fuselage, and provided with retractable tailwheel landing gear, it proved to be marginally faster than the Brewster prototype when flown during competitive evaluation in the early months of 1938. Speed, however, was its major credit. In several other respects it was decidedly inferior, with the result that Brewster’s XF2A-1 was ordered into production on 11 June 1938.
Although the new ship was not a true “aerobatic” performer, it was stable and easy to fly and displayed excellent deck-handling qualities. One problem that would remain with the F4F throughout its life, however, was its manual landing gear retraction mechanism. The gear required 30 turns with a hand crank to retract, and a slip of the hand off the crank could result in a serious wrist injury.
Clearly the US Navy believed the XF4F-2 had hidden potential, for it was returned to Grumman in October 1938, together with a new contract for its further development. The company adopted major changes before this G-36 prototype flew again in March 1939 under the designation XF4F-3. These included the installation of a more powerful version of the Twin Wasp (the XR-1830-76 with a two-stage supercharger), increased wing span and area, redesigned tail surfaces, and a modified machine-gun installation. When tested in this new form the XF4F-3 was found to have considerably improved performance. A second prototype was completed and introduced into the test programme, this aircraft differing in having a redesigned tail unit in which the tailplane was moved higher up the fin, and the profile of the vertical tail was changed again. In this final form the XF4F-3 was found to have good handling characteristics and manoeuvrability, and a maximum speed of 335 mph (539 km/h) at 21,300 ft (6490 m). Faced with such performance, the US Navy had no hesitation in ordering 78 F4F-3 production aircraft on 8 August 1939.
With war seemingly imminent in Europe, Grumman offered the new G-36A design for export, receiving orders for 81 and 30 aircraft from the French and Greek governments respectively. The first of those, intended for the French navy, powered by a 1,000 hp (746 kW) Wright R-1820 Cyclone radial engine, flew on 27 July 1940 but by then, of course, France had already fallen. Instead, the British Purchasing Commission agreed to take these aircraft, increasing the order to 90, and the first began to reach the UK in July 1940 (after the first five off the line had been supplied to Canada), becoming designated Martlet Mk I. They first equipped No. 804 Squadron of the Fleet Air Arm, and two of the aircraft flown by this squadron were the first American-built fighters to destroy a German aircraft during World War 11, in December 1940.
Subsequent Grumman-built versions to serve with the FAA included the Twin Wasp-powered folding-wing Martlet Mk II; 10 F4F-4As and the Greek contract G-36A aircraft as Martlet Mk III; and Lend-Lease F4F-4Bs with Wright GR-1820 Cyclone engines as Martlet Mk IV. In January 1944 they were all redesignated as Wildcats, but retained their distinguishing mark numbers.
The first F4F-3 for the US Navy was flown on 20 August 1940, and at the beginning of December the type began to equip Navy Squadrons VF-7 and VF-41. Some 95 F4F-3A aircraft were ordered by the US Navy, these being powered by the R-1830-90 engine with single-stage supercharger, and deliveries began in 1941. An XF4F-4 prototype was flown in May 1941, this incorporating refinements which resulted from Martlet combat experience in the UK, including six-gun armament, armour, self-sealing tanks, and wing-folding. Delivery of production F4F-4 Wildcat fighters, as the type had then been named, began in November 1941, and by the time that the Japanese launched their attacks on Pearl Harbour a number of US Navy and US Marine Corps squadrons had been equipped, As additional Wildcats entered service they equipped increasing numbers of US Marine and US Navy squadrons. In particular they served with the carriers USS Enterprise, Hornet and Saratoga, being involved with conspicuous success in the battles of the Coral Sea and Midway, and the operations in Guadalcanal. They were at the centre of all significant action in the Pacific until superseded by more advanced aircraft in 1943, and also saw action with the US Navy in North Africa during late 1942.
The final production variant built by Grumman was the long-range reconnaissance F4F-7 with increased fuel capacity, camera installations in the lower fuselage and armament deleted. Only 20 were built, but Grumman also produced an additional 100 F4F-3s and two XF4F-8 prototypes. With an urgent need to concentrate on development and production of the more advanced F6F Hellcat, Grumman negotiated with General Motors to continue production of the F4F-4 Wildcat under the designation FM-1. Production by General Motors’ Eastern Aircraft Division began after finalisation of a contract on 18 April 1942, and the first of this company’s FM-ls was flown on 31 August 1942. Production totalled 1,151, of which 312 were supplied to the UK under the designation Martlet Mk V (later Wildcat Mk V).
At the same time, General Motors was working on the development of improved version, designated FM-2 which was the production version of two Grumman XF4F-8 prototypes. Its major change was the installation of 1,350 hp (1007 kW) Wright R-1820-56 Cyclone 9 radial engine, but a larger vertical tail was introduced to maintain good directional stability with this more powerful engine, and airframe weight was reduced to the minimum. A total 4,777 FM-2s was built by General Motors, 370 of them supplied to the UK these entering service with the FAA a designated Wildcat Mk VI from the outset.
Combat History
First combat for the F4F was not with the U.S. Navy but with Britain’s Royal Navy, and its first victim was German. The British had shown great interest in the Wildcat as a replacement for the Gloster Sea Gladiator, and the first were delivered in late 1940. On Christmas Day 1940, one of them intercepted and shot down a Junkers Ju-88 bomber over the big Scapa Flow naval base. The Martlet, as the British also called it, saw further action when 30 originally bound for Greece were diverted to the Royal Navy following the collapse of Greece and were used in a ground attack role in the North African Desert throughout 1941.
The Wildcat’s American combat career got off to a more inauspicious start. Eleven of them were caught on the ground during the December 7, 1941, Pearl Harbour attack, and nearly all were destroyed. It was with Marine squadron VMF-211 at Wake Island that the Wildcat first displayed the tenacity that would bedevil the Japanese again and again. As at Pearl Harbour, the initial Japanese attacks left seven of 12 F4F3s wrecked on the field. But the survivors fought on for nearly two weeks, and on December 11, Captain Henry Elrod bombed and sank the destroyer Kisaragi and helped repel the Japanese invasion force. Only two Wildcats were left on December 23, but the pair managed to shoot down a Zero and a bomber before being overwhelmed.
Carrier-based F4F3s engaged the enemy soon after. On February 20, 1942, Lexington came under attack from a large force of Mitsubishi G4M1 Betty bombers while approaching the Japanese base at Rabaul. The F4F fighter screen swarmed over the unescorted bombers, and Lieutenant Edward H. “Butch” O’Hare shot down five of them. He was awarded the Medal of Honour and became the first Wildcat ace.
During the Coral Sea battle in May, F4Fs from the carriers Lexington and Yorktown inflicted heavy losses on the air groups from Shokaku, Zuikaku and Shoho but could not prevent the sinking of Lexington. While the air battles were by no means one-sided, they were clearly a shock to many Zero pilots, who had faced little serious opposition up to that time.
By the time of the Midway engagement in June, the fixed-wing F4F-3 had been replaced by the folding-wing F4F-4. Although the new wings enabled the carriers to increase their fighter complement from 18 to 27, the F4F-4’s folding mechanism, coupled with the addition of two more machine guns, raised its weight by nearly 800 pounds and caused a fall-off in climb and manoeuvrability.
Nearly 85 Wildcats flew from Yorktown, Enterprise and Hornet during Midway, but it was the Douglas SBD Dauntless dive bomber that was destined to be the hero of the battle, sinking the carriers Akagi, Kaga, Hiryu and Soryu, and dealing the Imperial Navy a disastrous defeat.
When news of the U.S. invasion of Guadalcanal reached the Japanese on August 7, 1942, they launched air strikes from Rabaul. Flying escort was the elite Tainan Kokutai (air group), which counted among its pilots Sakai (64 victories), Nishizawa (credited with 87 before his death in October 1944) and other leading aces. But over Guadalcanal, the Zeros were off-balance from the start. Their first glimpse of the new enemy came when Wildcats of Saratoga’s VF-5 dived into their formation and scattered it. Sakai and Nishizawa recovered and claimed eight Wildcats and a Dauntless between them, but they were the only pilots to score. The Navy F4Fs, in return, brought down 14 bombers and two Zeros.
Although exact Japanese losses over Guadalcanal are not known, they lost approximately 650 aircraft between August and November 1942 and an irreplaceable number of trained, veteran airmen. It is certain that the F4Fs were responsible for most of those losses. During the Battle of Santa Cruz on October 26, 1942, Stanley W. “Swede” Vejtasa of VF-10 from the carrier Enterprise downed seven Japanese planes in one fight. Marine pilot Joe Foss racked up 23 of his 26 kills over Guadalcanal; John L. Smith was close behind with 19; and Marion Carl, Richard Galer and Joe Bauer were among other top Marine aces.
A large part of the Wildcat success was tactics. The agile Zero, like most Japanese army and navy fighter craft, had been designed to excel in slow-speed manoeuvres. U.S. Navy aviators realized early on that the Zero’s controls became heavy at high speeds and were less effective in high-speed rolls and dives. Navy tacticians like James Flatley and James Thach preached that the important thing was to maintain speed, whenever possible, no matter what the Zero did. Although the Wildcat was not especially fast, its two-speed supercharger enabled it to perform well at high altitudes, something that the Bell P-39 and Curtiss P-40 could not do. The F4F was so rugged that terminal dive airspeed was not redlined. The A6M2’s 7.7 mm (0.303 in) cowl guns and slow-firing 20 mm cannons were effective against an F4F only at point-blank range. But F4F pilots reported that hits from their 12.7 mm (0.50 in) calibre wing guns usually caused complete disintegration of a Zero.
The Zero and Wildcat shared one serious liability, though. Neither could be modified successfully to keep pace with wartime fighter development. It was determined that the F4F airframe could not accommodate a larger engine without an almost complete redesign, which ultimately did take shape as the new 2,000 hp (1492 kW) F6F Hellcat. The Wildcat’s air combat role began to wane when the Chance-Vought F4U Corsair arrived at Guadalcanal in February 1943. Nevertheless, the stalwart F4F was still the front-line fighter when Admiral Isoroku Yamamoto launched Operation I-Go against Allied forces in the Solomons in April, and Marine Lieutenant James Swett shot down seven (and possibly eight) Aichi D3A1 Val dive bombers in a single combat.
As 1943 wore on, the Wildcat gradually was relegated to a support role as the F6F replaced it aboard fleet carriers. The F4F’s small size, ruggedness and range (enhanced by two 58 gallon drop tanks) continued to make it ideal for use off small escort carrier decks. The little warrior, in both US and Royal Navy markings contributed to eliminating the U-boat menace in the Atlantic.
A General Motorsbuilt version of the F4F received a marginal boost when a Wright 1,350 hp (1007 kW) single-row radial was installed in place of the 1,200 hp (895 kW) Pratt & Whitney. The first production models of the new variant, designated the FM-2, arrived in late 1943. The FM-2’s new engine, coupled with a 350 pound weight reduction, produced improvements in performance over the F4F. In fact, postwar tests revealed the late-model A6M5 Zero to be only 13 mph (21 km) faster.
FM-2s were normally teamed with TBF Avengers in so-called VC “composite” squadrons on small escort carriers. During the Battle of Savo on 25 October 1944, FM-2s and Avengers from several “baby flattops” aided destroyers in disrupting an overwhelming Japanese battleship task force that surprised the American invasion fleet off the Philippines. The aircraft, although handicapped by a lack of anti-shipping ordnance, so demoralized the Japanese that a potential American disaster was averted.
Although opportunities for air combat were few, FM-2s notched a respectable 422 kills (many of them kamikaze aircraft) by the end of the war. On 5 August 1945, a VC-98 FM-2 from USS Lunga Point shot down a Yokosuka P1Y1 Frances recon bomber to score the last Wildcat kill of the war.
Variants
XF4F-1: Grummans biplane design with the Navy designation XF4F-1. This was cancelled in favour of the monoplane design.
XF4F-2: Grummans first monoplane design (Grumman G-18) with the Navy ordering one example designated XF4F-2.
XF4F-3: further development of the XF4F-2 led to the XF4F-3 (Grumman G-36) with many new design changes. Powered by a XR-1830-76 Twin Wasp engine and a two-stage supercharger.
F4F-3: designation given to the production aircraft of XF4F-3 prototype.
F4F-3A: designation given to US Navy aircraft with the R-1830-90 engine with a single stage supercharger.
G-36A: export version which flew as the Martlet Mk I, II, III, IV. Later they all reverted back to the Wildcat designation.
XF4F-4: prototype incorporating changes learned from Marlet combat experiences.
F4F-4: US Navy production aircraft of the above.
F4F-7: final production variant built as a long range reconnaissance aircraft. Only twenty were built.
XF4F-8: two prototype aircraft.
FM-1: F4F-4 aircraft built by General Motors Eastern Aircraft Division. Export aircraft of this type served as the Martlet V (later the Wildcat V).
FM-2: The General Motors built production aircraft based on the XF4F-8 prototypes. Powered by a 1,350 hp (1007 kW) Wright R-1820-56 Cyclone 9 radial engine.
Hellcat
The highly successful follow-on to the Wildcat. Built specifically to counter the Japanese Zero, the Hellcat filled the bill, and earned the nickname “ace maker.” Its docile handling characteristics, especially important for a carrier-based plane to be used by a large number of reasonably well-trained pilots, made it the Navy’s first choice fighter to deploy with the Essex-class carriers. In the critical years 1943 and 1944, the Hellcat ruled the skies of the Western Pacific.
Eugene Valencia, one of the Navy’s top aces, quipped. “I love this airplane so much, that if it could cook, I’d marry it.”
Development
Although the F6F had been on the drawing boards at Grumman, even before Pearl Harbour, the advent of the war gave great impetus to the development of the replacement for the Wildcat. From the start it was a much bigger airplane. Leroy Grumman, and his two top engineers, Leon Swirbul and Bill Schwendler, laid out a plane with higher performance, more fuel & ammunition, and huge wings. The wings extended over 334 square feet; the average was less than 250 sq. ft.. The wings folded back and pivoted ingeniously, so that they folded up next to and alongside the fuselage.
The first prototype, the XF6F-1, was under development when the war started. Based on combat experience against the Zero and the intact A6M captured in the Aleutians, it was clear that speed and better climb would be needed from the Hellcat. Test pilot Robert L. Hall first flew the XF6F-1 in late June, 1942. Powered by a Wright Cyclone R-2600-16 engine (1,600 horsepower), the aircraft didn’t have the needed performance. Grumman proposed the Pratt & Whitney 2800 Double Wasp (2,000 horspower). Equipped with the P&W 2800, the original prototype airframe became the XF6F-3. A month later, Bob Hall flew the new configuration. Despite a crash of the XF6F-3 in August, the Navy placed an order.
Grumman had to build a new facility, Plant Number 3, to produce the Hellcat. Obtaining the structural steel for the buildings was a challenge, met in part by the purchase of scrap from the Second Avenue El. Even before Plant Number 3 was finished, Hellcats began rolling off the production lines. Another Grumman test pilot, Selden “Connie” Converse took up a production F6F-3 for the first time on October 3, 1942. Grumman’s Hellcat output picked up quickly: 12 planes in the last quarter of 1942, 128 in the first quarter of 1943, and then 130 in the month of April, 1943. Eventually they would be churning out 500 per month. The company built over 12,000 in three years.
During “The War,” Grumman was an outstanding example of American productivity, employing 20,000 workers, few of whom had ever worked in the aircraft industry before; many of them were women. Bethpage was a happy place; there were no strikes, work stoppages, nor unions. Grumman took care of its employees with day-care centres for working mothers, social events for all, Christmas turkeys, and the famous “Green Car Service” to help employees with dead batteries and other minor problems.
F6F Performance
Especially with the delays in the F4U program, the US Navy needed a superior carrier-based fighter in 1942-43. The Hellcat filled the bill. On average, it flew 55 MPH faster than the Zero; at about 20,000 feet it was 70 MPH faster. At altitudes in excess of 10,000 feet, it had a comparable rate of climb. At all altitudes, due to its heavier weight and greater power, it could out-dive the A6M. (This was generally true of American fighters; in a tough spot, the pilots could nose over, firewall the throttle, and zoom down.)
The ‘dash Five’ closely resembled the ‘dash Three.’ It had some extra armour, stronger main gear legs, spring tabs on the ailerons (for better manoeuvrability), and most of them had water-injection engines (the R-2800-10W). Both versions had 250 gallons capacity in internal tanks and a 150 gallon belly drop-tank.
Its armament, power, and range gave the Hellcat great versatility. The basic weaponry consisted of six wing-mounted .50 calibre machine guns, each with 400 rounds of ammunition. Many, including all F6F-5N and F6F-5P variants substituted a 20mm cannon with 200 rounds for the innermost machine gun in each wing. The Hellcat could carry a up two 1,000 pound bombs. Its most destructive weapons were six 5-inch HVAR’s (High Velocity Aircraft Rockets), which the author Barrett Tillman described as “equal to a destroyer’s broadside.”
This variety of weapons and equipment permitted the Hellcat to carry out a broad range of missions: fighter versus fighter combat, strike plane escort, combat air patrol, long range search, ground support over invasion beaches, night fighting (see F6F-5N), and photo recon (see F6F-5P).
