Grumman F4F-3,4 Wildcat

On 2 March 1936, Grumman was awarded a contract for the development of its model G-16, a shipboard biplane fighter for the US Navy, under the designation XF4F-1. The G-16, which was designed by Dick Hutton and Bill Schwendler, was very similar in general layout to the earlier biplane fighters of Grumman, the F2F and its development the F3F. It was smaller, with a wing span of 27ft, compared with 32ft for the F3F. Its length was 23ft 3in, and its gross weight 4500lb. The XF4F-1 had only a marginal improvement over the performance of last models of the F3F. The armament consisted of two cowl-mounted .50 guns, or one .50 and one .30.

The performance of the XF4F-1 was inferior to that of its rival the Brewster F2A Buffalo, which was to become the USNs first operational monoplane fighter. The future of the XF4F-1 held little promise, because it was considered merely as a back-up design to the F2A. Nobody was very happy about the model G-16, and after four months the USN canceled the contract. The XF4F-1 was never flown.

To compete with the Brewster F2A, Grumman developed the model G-18. The fuselage had, because of the radial engine and voluminous undercarriage retraction mechanism, a rotund, tubby shape. This was already a trademark of Grumman, established with the earlier F2F and F3F. The cockpit was moved much forward by comparison with the XF4F-1, so that the pilot now sat over the wing. This assured that the pilot had a good forward view, which was essential for a deck-landing. The cockpit was fitted with a telescopic gunsight, which protruded through the windscreen. Two down looking windows were cut in each side of the lower fuselage.

The model G-18 was powered by the Pratt & Whitney R-1830-66 Twin Wasp engine, a two-row, fourteen-cylinder radial. A Hamilton Standard two-position propeller was fitted. The armament installation was basically the same as that of the XF4F-1, with two 0.50 guns with 200 rounds each in the top of the engine cowling, and provision for two 100lb bombs under the wings. The gross weight of the aircraft was 5635lb, a substantial increase over the XF4F-1 biplane. The G-18 was ordered on 28 July 1936. Despite the substantial differences to the G-16, the designation XF4F-2 was applied. The prototype, BuNo 0383, was first flown on 2 September 1937. During trials it demonstrated a maximum level speed of 290mph, which was faster than the XF2A-1, but still below the USN requirement of 300mph.

The XF4F-2 was delivered to NAS Anacostia on 23 December 1937 for evaluation. During trials the prototype suffered from a series of snags and accidents. None of these was particularly serious, but their undermined the confidence of the USN. The XF4F-2 suffered repeated engine crankshaft failures. The arrestor hook proved too weak. On 24 February 1938 there was an on board fire when ballast bags in the aft fuselage began to burn. And on 11 April 1938 the XF4F-2 suffered a crash when the engine failed during a simulated deck landing. As a result, the US Navy selected the more reliable Brewster F2A-1 Buffalo for production, after NACA tests had suggested that minor aerodynamic improvements could boost the speed of the XF2A-1 by 30mph. The USN ordered 54 F2A-1s on 11 June 1938. Despite this setback, the USN continued to show interest in the F4F. This was probably partly due to its unwillingness to rely fully on the production of Brewster: The order for the F2A-1 was the first production contract for Brewster, and the manufacturer did not even possess a factory which was adequate for the production of aircraft. Grumman had already built the FF, F2F and F3F for the Navy, and the F4F showed some promise. A development contract was awarded in October 1938.

The Grumman G-36, designated XF4F-3 by the USN, was first flown 12 February 1939. It had been evolved from the XF4F-2 (the prototype of which was modified to become the XF4F-3) by installing the Pratt & Whitney XR-1830-76 engine with a two-stage, two-speed supercharger. Two intercoolers were also installed. This was the first fighter to enter service with such an engine installation. (The first version of the Mitsubishi A6M 'Zeke' with a two-stage supercharger was the A6M3, which began to enter service when Battle of Guadalcanal began.) The two-bladed, two-position propeller of the XF4F-2 was replaced by a three-bladed Curtiss-Electric constant-speed propeller, which was initially distrusted by the pilots. Because of the increased engine weight, a larger wing with rectangular tips was fitted. This increased the wing span from 34ft to 38ft and the wing area from 232ft2 to 260ft2. Also, the fuselage was revised and lengthened. At this stage the prototype still had the tail surfaces of the XF4F-2 with a canted rudder hingeline. Thanks to its new engine, the XF4F-3 reached 333.5mph at 21000ft.

The engine cooling was a problem, and a series of cowl and propeller spinner designs was tried to improve it. Finally the propeller spinner was deleted, and cuffs were fitted to the propeller blade roots. NACA tests at Langley field resulted in some redesign. The tail fin was made larger, and the fuselage spine aft of the cockpit, which previously ended just in front of the tail fin, was extended and faired into the fin root. The tailplane was raised 20in, from the fuselage onto the fin. The wing dihedral was increased, and the ailerons reduced in area. The radio mast was moved from in front of the cockpit to behind the cockpit. The armament of the XF4F-3 was two 0.3 cowl guns and two 0.5 wing guns. A telescopic gun sight was still fitted.

In this form, the F4F-3 was accepted by the USN, and an order for 54 was received in August 1939. After the first two, the cowl guns were removed, and four 0.50 wing guns fitted. The production aircraft were powered by the R-1830-76 engine, which initially gave some problems. The first delivery was made on 5 December 1940, to VF-4. Then later VF-7, VF-42, VF-71 were equipped. The F4F-3 was also given to USMC, beginning with VMF-121, VMF-211 and VMF-221. The first cruise was made with USS Ranger and USS Wasp, in early 1941. The name 'Wildcat' was officially adopted on 1 October 1941.

At the time of Pearl Harbor only USS Enterprise had a fully-equipped Wildcat squadron, VF-6 with F4F-3As. The USS Enterprise was then transferring a detachment of VMF-211, also equipped with F4F-3s, to Wake. The USS Saratoga was in San Diego, working up for operations of the F4F-3s of VF-3. Eleven F4F-3s of VMF-211 were at the Ewa Marine Air Corps Station on Oahu; nine of these were damaged or destroyed during the Japanese attack. The detachment of VMF-211 on Wake lost 7 Wildcats to Japanese attacks on 8 December, but the remaining five put up a fierce defense, making the first bomber kill on 9 December. The destroyer Kisagara was sunk by the Wildcats, and the Japanese invasion force retreated. In these dark days the defense of Wake generated enthusiasm in the USA, but it was impossible to send help, and later Wake surrendered to a much superior invasion force.

In May 1942 the F4F-3s of VF-2 and VF-42, on board of USS Yorktown and USS Lexington, participated in the Battle of the Coral Sea. The USS Lexington and USS Yorktown fought against the Zuikaku, Shokaku and the light Shoho in this battle, in an attempt to halt a Japanese invasion of Port Moresby on Papua New Guinea. On 7 May a force of 93 US aircraft, of which 18 Wildcats, found the light carrier Shoho --- a small ship of 11200 tons, which carried only 12 Zeros for its own defense. Shoho was sunk, and the attackers lost only three aircraft. It was claimed that eight Zeroes had been shot down. An unescorted counterattack by B5N Kates and D3A Vals in the evening was successfully repelled with heavy losses on the side of the attackers. Eight aircraft were shot down, eleven more failed to find their carriers. However, when 69 Japanese aircraft attacked again the next day, the fighter cover of USS Lexington and USS Yorktown consisted of only eight Wildcats, because all others had been sent to escort an attack on the Japanese carriers Shokaku and Zuikaku. The Shokaku was seriously damaged, but the USS Lexington had to be abandoned and the USS Yorktown was damaged. The aircraft losses were high on both sides, taking into account the small number of aircraft committed to battle; the Japanese lost 40 aircraft, the US 33.

During these battles, it became clear that attacks without fighter escort amounted to suicide, but that the fighter component on the carriers was completely insufficient to provide both fighter cover for the carrier and an escort for an attack force. Most US carriers carried less than 20 fighters. The introduction of the F4F-4 with its folding wings improved this situation, because it increased the number of fighters that could be parked on a surface by more than a factor 2. The F4F-3 was replaced by the F4F-4 in June 1943, during the battle of Midway; only VMF-221 still used them at that time. The total production of the F4F-3 was 285. After the Italian attack of 1941, 30 F4F-3s were sent to Greece, and were used after the Greek surrender by the British Fleet Air Arm as Martlet Mk.III.

The major difference between the F4F-4 and the F4F-3 was the introduction of a wing folding mechanism. A single hinge was placed in the wing spar. The hinge line was reportedly experimentally determined by Roy Grumman with the help of an eraser in which two bent paperclips were inserted, representing the wings. The main spar was angled forward, so that the top of the hinge line was well in front of the bottom; there were small blisters on the wing covering the top of the hinge. When folding the wing backwards, the leading edge of the wing moved downwards, so that the wings were stored parallel with the fuselage, leading edge down. They were secured to the tailplane with struts. Unfolded, they were secure by a locking cylinder in the leading edge, which was screwed in with a crank. Five F4F-4s could be parked in the place previously used by two F4F-3s. Also, aircraft handling on the deck and through the lift became much easier. The first XF4F-1 had hydraulic wing folding, but this was abandoned because of the excess weight. All production aircraft had manual wing folding. The F4F-4 had also other modifications to make the aircraft more combat-capable. Armament was increased to six guns, with 1440 rounds. Armor and self-sealing fuel tanks, previously only fitted to the British Martlets and a few F4F-3s, were fitted. This much improved the survival chances of the pilot. There was a provision for 50 or 58 US gal drop tanks under the fixed parts of the wing, as well as bombs. The engine was the R-1830-86 of 1200hp, also fitted to the last F4F-3s, but because of the additional weight, the performance suffered. The F4F-4 also proved less suitable for operations for escort carriers, which lead to the development of the lighter FM-2. The US Navy orders totaled 1169 F4F-4s. It had replaced the F4F-3 by August 1942.

The most famous battle in which the Wildcat participated was the Battle of Midway. While six Wildcats were based on Midway itself, as well as 21 F2A Buffalos, most of the fighter component was contributed by the carriers. With the lessons of the Coral Sea in mind, the fighter strength of the US fleet was increased by one third. The USS Yorktown carried 25 fighters, the USS Hornet and USS Enterprise each 27. Their contribution was not, however, decisive, being limited only by their still relatively small number of aircraft. Of the 116 aircraft which attacked the Japanese fleet on 4 June, only 20 were Wildcats; all others were torpedo and dive bombers. 36 Wildcats were kept behind to protect the US carriers. Half of the fighter escort did not find the Japanese fleet and later had to ditch because they had run out of fuel. During the attack the weak fighter cover (six Wildcats) of VT-3 was unable to protect its 12 TBDs, while VT-6 and VT-8 attacked without any fighter escort, with disastrous results. However, the battle turned around dramatically when two formations of SBD Dauntless dive bombers arrived and encountered no opposition. They hit and sunk the Japanese carriers Akagi, Kaga and Soryu. While the Wildcats were reasonably able to defend themselves --- claiming four kills, for the loss of one --- it was clear that the battle had been won more by luck than by strength. When the surviving Japanese carrier, the Hiryu, counterattacked, the fighter cover of the Yorktown, 12 Wildcats, claimed 13 of the 18 attacking D3A 'Val' dive bombers, and three of the six A6Ms. A follow-up attack force of 10 B5N 'Kate' torpedo bombers and six A6Ms also lost four aircraft. However, this did not prevent the Yorktown from being hit by three bombs and two torpedoes, which eventually caused its loss.

The qualities of the F4F were proven in the next large series of battles in the Pacific, the fights around the island of Guadalcanal. Guadalcanal is one of the Solomon islands, which are North-East of Australia. The island is 100 miles long by 50 miles wide and is mountainous and covered with a dense jungle. Most of the fights centered around Henderson Field, the airbase near Cap Lunga.

The battles began with the landing of the 1st Division of the USMC on Guadalcanal, on 7 August 1942, protected by a large part of the US fleet. During three days of intensive fighting between US Navy aircraft of the USS Enterprise, USS Saratoga and USS Wasp (a total of 99 fighters, 103 dive-bombers, and 41 torpedo-bombers) and Japanese aircraft from Rabaul on New Ireland (75 fighters, 48 twin-engined bombers, 18 long-range reconnaissance flying boats, 12 floatplane fighters, and 16 dive-bombers) the Japanese suffered disproportionate losses. Of course, this was partly due to the large distance between Guadalcanal and their base at Rabaul --- flights of over 1,200 miles were required --- which made it impossible for some of the used aircraft, notable the D3A dive bombers, to return to their base. Also, the G4M 'Betty' bomber was extremely vulnerable. The A6M 'Zeke' fighter force had some successes. In a famous incident, the Japanese fighter pilot Saburo Sakai witnessed how a single F4F fought off three A6Ms, until Sakai himself intervened.

Finally, the US force did establish some kind of air superiority over Guadalcanal when the Japanese decided to suspend air attacks after two days, because of the excessive losses. However, at this moment Rear-admiral Fletcher decided to remove the US carrier fleet from the battle zone, handling them according to the principle that the carriers, which were as vulnerable as they were valuable, should not stay in the same area for more than two days. The decision was not illogical in itself, but combined with the disastrous end of the naval battle at Savo Island on the next day, it contributed to ending his career in the navy.

Two weeks later the carriers had returned, and in the fight known as the Battle of Eastern Solomons, the USS Enterprise and USS Saratoga fought a battle with the Zuikaku, Shokaku and the light carrier Ryujo. While US carrier aircraft found and sank the Ryujo, a Japanese counterattack of the main force managed to damage the USS Enterprise, despite a fighter cover of 53 Wildcats, which was largely kept at a distance by the escorting A6Ms. In this case, inefficient fighter control was largely to blame. This remained a problem during the next fights, despite the advantage of radar. Enterprise was only temporarily disabled, however. At the end of the month, Japanese submarines damaged USS Saratoga and sank USS Wasp.

On 26 October, during the battle of the Santa Cruz islands, the pattern repeated itself. US aircraft damaged the Zuiho and Shokaku, while Japanese aircraft hit USS Hornet and USS Enterprise, and finally sank USS Hornet. While this undoubtedly was a tactical victory for the Japanese, the aircraft losses of both parties were again so high that they had to retreat. The presence of US aircraft on Henderson Field, near Cap Lunga on Guadalcanal, outweighed any Japanese advantage gained.

The result of these battles suggests that overall, the Wildcat failed to fulfill its role. While the Wildcats did shoot down a considerable number of enemy aircraft, thereby limiting the strength of Japanese attacks on the US fleet, the carriers invariably suffered serious damage whenever they were the target of a Japanese attack. And attacks on the Japanese fleet often resulted in the loss of a considerable number of aircraft. After 1942, newer fighters replaced the Wildcat as carrier-borne fighter, and the US Navy established air superiority. One would be inclined to blame the Wildcat. However, this is too simplistic. There is no doubt that the F6F and F4U were better aircraft than the old F4F, but the Wildcat was not as inferior to the A6M as some sources suggest. In a combat situation, the two fighters were fairly evenly matched, if the Wildcat pilot was wise enough to use the strong points of their aircraft --- dogfighting with the A6M was always to be avoided.

The low impact of the fighter force in the battles of 1941 and early 1942 can be attributed to their numerical weakness. Large carriers as the USS Lexington and USS Saratoga began the war with only 18 fighters on board, a fourth of all aircraft they carried. At the battle of Okinawa in March 1945, the large fleet carriers had 70 or more fighters, or two thirds of all aircraft they carried were fighters. At Okinawa, a small escort carrier had a more powerful fighter cover than the USS Lexington in the Battle of the Coral Sea. Of course, this change towards a larger complement of fighters was made possible by the fact that the newer, larger fighters could carry a substantial armament load. The F6F could carry two 1000lb bombs, a load comparable to that of the TBF Avenger or the SBD Dauntless. The inability to carry a substantial bomb load was always a weakness of the Wildcat. There was also important tactical changes, with a much stronger attempt to gain air superiority. Instead of escorting torpedo bombers and dive bombers, the fighters were sent out alone to attack Japanese bases, achieving air superiority before the final attack was done. These tactics finally culminated in the 'Big Blue Blanket' designed by Jimmy Thach as a defense against Kamikaze attacks.

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