The second production FM-2, BuNo. 15953, during flight tests. Photo: NHHC
Text: Richard plos
The Wildcat was the first single-wing fighter aircraft produced by Grumman for active service. It bore the main burden of battles in the Pacific from the attack on Pearl Harbor until around February 1943, when the significantly more powerful F4U-1 Corsair and Wildcat’s direct successor, the F6F Hellcat, entered the scene. It was expected that the days of the Wildcat would be numbered with the arrival of these new powerful beasts, but the opposite turned out to be true. Thanks to the highly modernized version, FM-2, the Wildcat continued to participate in combat operations almost until the end of the war.
Due to the Navy’s dissatisfaction with the Corsair’s landing characteristics on aircraft carrier decks, the Hellcat became the Navy’s main fighter type until the second half of 1944, when the Navy accepted the improved Corsairs that were previously serving with the USMC units. Both types were powered by the big and exceptionally powerful Pratt & Whitney R-2800 Double Wasp engine, an eighteen-cylinder, double-row engine, which designers decided to install into quite volumious airframe. In June 1943, squadrons equipped with the F4F-4 Wildcats still represented a significant combat force, and by that time, a version that aimed to address several issues of its predecessor at once, was already in production.
The Successor Worse Than Its Predecessor
The F4F-4 represented the worst-performing version among all the Wildcat variants. The aircraft, burdened with an additional pair of machine guns and with significantly reduced ammunition per barrel compared to the F4F-3, required around 50 minutes to climb to an altitude that would allow it to attack Japanese bombers flying at about 20,000 ft. Moreover, with only 250 rounds of ammunition per gun, the pilots found themselves facing a shortage of ammo even in relatively short dogfights.
It became clear early on that the F4F-4 version was not a wise step, but by mid-1942, when the F4F-4 was being introduced into service, Grumman was fully occupied with the development of the Hellcat, as well as the mass production of Wildcats, Avengers, Ducks, and Widgeons. They simply did not have the capacity for further development of a type that was supposed to be replaced soon. The preparations for Hellcat production had the highest priority, leading to the decision to entrust the production of the first two mentioned types to another manufacturer.
Aircraft Instead of Cars
Shortly after the outbreak of war with Japan, General Motors halted production at its five automobile factories on the East Coast. The company’s management was prepared to put them to use for wartime production, especially to produce aircraft components. As early as 1942, the Navy organized a meeting between General Motors representatives and people from Grumman, a key supplier to the Navy’s aviation. Grumman’s factory in Bethpage, New York, was operating at full capacity, so a solution was sought to shift the production of Wildcats and Avengers. GM representatives were somewhat surprised when they were asked to take over the entire production of aircraft instead of just manufacturing parts and subassemblies for Grumman. To their credit, they accepted the challenge. Numerous delegations and work teams followed. Grumman’s teams prepared the automotive factories for aircraft production, while GM personnel learned about aircraft production in Bethpage. The advantage was the proximity of all the factories. Trenton was about 160 km from Bethpage, and Linden was roughly halfway along this route. In the vast country’s terms, these plants were nearly neighbors ...
By June 1942, all five GM factories had been fully converted and ready to start aircraft production as an independent division called Eastern Aircraft Division. The Trenton factory in New Jersey was responsible for producing Avengers. Unlike Grumman’s production, designated TBF, the Avengers from Trenton were labeled as TBM. The second factory in New Jersey, located in Linden, was to manufacture F4F-4 Wildcats under the designation FM-1 (F for Fighter, M for General Motors, and 1 as the manufacturer’s first type). The remaining three Eastern Aircraft Division factories in Bloomfield and Baltimore supplied both final manufacturers with the necessary parts.
The Eastern Aircraft Division
received a contract to produce 1800 Wildcats on April 18, 1942, and Grumman
subsequently delivered prototype subassemblies and parts for assembling the
first ten F4F-4s. At the same time, the factory received training examples
marked as PK, where the joints were not riveted but rather connected with
Parker-Kalon fasteners for repeated assembly and disassembly. These examples
were used to train the workers.
Before the war, the modern factory in Linden had produced cars for Buick, Oldsmobile, and Pontiac and it was capable of a takt time one car per minute. After the transition to Wildcat production, during the period when the parallel production was ongoing at Grumman, the factory had to maintain strict technological discipline to ensure that parts from both manufacturers were interchangeable. Many parts manufactured by GM factories were sent to Grumman’s assembly line and vice versa.
A Wildcat FM-2 landing on the deck of the escort aircraft carrier USS Anzio (CVE-57). Photo: NHHC
The First “Fine Modification” (FM-1)
The first Wildcat produced in Linden had its maiden flight on August 31, 1942, i.e., at the time of the intense battles for Guadalcanal, which exposed the shortcomings of the F4F-4 version. Its poor climb rate and significantly reduced ammo supply per gun compared to the F4F-3 did not win much favor among the pilots. The first ten FM-1 aircraft were assembled from Grumman parts in their original form, but starting with the eleventh aircraft, it was decided to remove the external machine guns to reduce the aircraft’s weight, resulting in improved climbing performance. After solving some problems related to the wing folding system, the ammunition supply was almost restored to the original level. While the F4F-3 carried 1800 rounds (450 per gun), FM-1 pilots had 1720 rounds available (430 per gun). This was a significant improvement compared to the mere 250 rounds per gun on the F4F-4.
In May 1943, Grumman ceased the production of Wildcats entirely. By that time, Linden’s production was running relatively smoothly, although out of the initial order for 1800 aircraft, only 839 were produced. Some of them were assigned to Composite Squadrons, which combined fighter and attack aircraft, i.e., Wildcats and Avengers. Many of FM-1s were allocated to training units, and 311 aircraft were delivered to the British Fleet Air Arm (FAA) under the initial designation Martlet V, which was later changed to Wildcat V in January 1944.
With the introduction of Hellcats
and Corsairs, it seemed that the fate of the aging Wildcat was sealed. However,
the enormous need for air cover for numerous task forces and transport convoys
required more aircraft carriers than the Navy had available. Building one
Essex-class aircraft carrier took at least 20 months (pre-war periods could
take up to 37 months) despite increased war efforts. Due to the required
construction time and limited shipyard capacity, it was not possible to expect
any significant increase in the number of conventional aircraft carriers before
the end of 1944, which was too late. However, a solution was found. At the end
of 1942, the Navy began to receive the first escort aircraft carriers of the
Casablanca and Bogue classes. These were mostly conversions of merchant and
cargo ships that received flight decks and other necessary equipment for
carrying up to 27 aircraft in composite squadrons (although there were
exceptions, and some operated purely fighters, such as VF-26).
Compared to Essex-class carriers, the escort carriers were more than 110 yards shorter, lacked armor, multiple elevators for rapid flight deck and hangars exchanges, and other amenities. As a result, their designation CVE was ironically interpreted by the crew as Combustible, Vulnerable, Expendable. They were slow vessels with limited space on the flight deck, where at least nine or ten Avengers had to be accommodated as part of the composite squadron. This left little space for fighters, and the large Hellcats were not suitable for these carriers. The Navy demanded a small and lightweight fighter that could operate from these ships, but there was no time to develop an entirely new type. Although the development of the Bearcat, which was to meet all the requirements, began in 1943, it did not reach combat in time. Therefore, the only option was to continue producing Wildcats, preferably in a more powerful version. Grumman thus prepared two prototypes of the XF4F-8, the precursor to the following FM-2 production version.
FM-2 from the aircraft carrier USS Card (CVE-11) of the Bogue class. The aircraft, in its typical Atlantic camouflage, was photographed on February 10, 1944, and belonged to VC-55. Photo: NHHC
Lightened, Strengthened, and Ready
The FM-2 version of the Wildcat is often overlooked among its counterparts, as the F4F-3 and F4F-4 versions gained greater fame due to the heroic performances of their pilots during the battles in the Coral Sea, at the Midway or Guadalcanal. These successful operations produced a whole series of famous fighter aces from both the Marine Corps and the Navy. However, the purpose and operational deployment of the FM-2 were different; it was no more the Navy’s main fighter type. Nevertheless, at least five more pilots achieved ace status with the FM-2 (compared to 54 aces flying earlier versions), and the most successful of all squadrons flying the FM-2, VC-27 “Saints,” eventually became the second most successful unit operating Wildcats, regardless of the combat area or period. Its pilots managed to shoot down a total of 61.5 enemy aircraft during the four-month battle for the Philippines. Only VF-5 with 79 kills surpassed them. In this respect, the FM-2 ultimately made its mark.
The increase in the Wildcat’s performance was mainly achieved by installing a more powerful yet 230 lb lighter Wright R-1820-56 engine instead of the Pratt & Whitney R-1830-86. Along with other modifications, the FM-2 was “slimmed down” by 500 lb and gained a power improvement of 150 hp compared to the F4F-4 version. As the new engine was supercharged by a single-stage, dual-speed compressor, the FM-2 lost its performance advantage at higher altitudes. However, this was not an issue since these aircraft were primarily intended for anti-submarine operations, convoy protection from low-level air threats, and attacks against ground or surface targets. High-altitude combat was not considered part of their combat activities. Additionally, most of the FM-2s were equipped with engines in versions 56W or 56WA, featuring water injection to temporarily boost the engine output for up to ten minutes.
The cooling system underwent a fundamental change. The two protruding radiators on the lower wing were removed, and their function was taken over by a compact radiators located in the lower and upper part of the fuselage behind the engine. The wing openings were covered with shaped metal panels.
The engine change and cooling system
redesign necessitated alterations to the nose cowlings. The exhaust outlets were
not combined for the new engine; instead, each cylinder had its individual
exhaust. Three exhausts ended on the right side, two on the left, and two pairs
on the bottom of the fuselage. The second fuselage tank was removed, leaving
the FM-2 with only one 117 gallons volume. Due to this, FM-2 aircraft often
flew with additional drop tanks (each of 58 gallons volume). Starting with
aircraft BuNo. 57044, the fuselage tank was slightly enlarged to 126 gallons.
The glass windows under the cockpit were covered, and a new universal tailwheel with a larger tire was developed for the FM-2. But the most noticeable change compared to all previous versions was the taller vertical tail fin and rudder to eliminate the increased torque from the propeller driven by more powerful engine. However, even with more power and more efficient propeller, the flight decks of escort aircraft carriers were too short for a conventional takeoff, and catapults had to do most of the job. Nevertheless, the FM-2’s dimensions were very advantageous. With folded wings, it was only 14 ft wide, allowing an entire composite squadron to be accommodated on a single ship’s deck. While up to 12 Avengers could be carried, the number of FM-2s typically ranged from 12 to 14.
One of the aces on FM-2 was Lt. Thomas B. Sedaker. In the photo, he poses with a cake baked by the cooks of the USS Makin Island to celebrate the 2,000th catapult launch from the deck of that ship. Thomas Sedaker was the one who performed the launch. Photo: NHHC
The Wildcat aircraft modified into the FM-2 version quickly won the favor of pilots. It was a nimble and reasonably fast aircraft that retained one of its typical characteristics – the ability to withstand significant damage in combat. Additionally, the pilot was protected by a new armor plate behind their back (though not all aircraft were equipped with it). No wonder the new version earned the nickname Wilder Wildcat.
Deliveries of the FM-2 began in the first half of 1944, and squadrons operating both in the Pacific and the Atlantic received them. However, their main tasks were different. In the Pacific, the FM-2s were often used to support ground units during landing operations, aided by their ability to carry two 250 lb bombs under the wings (from BuNo. 74359, FM-2s could also carry HVAR rockets). In the Atlantic, they primarily provided air cover for supply convoys from the US coast to Europe and often assisted Avengers in hunting German submarines. Of course, in the Pacific, FM-2 pilots also provided cover for supply ships or engaged in anti-submarine operations.
The FM-2 scored its first kill on March 20, 1944, when Lt.(jg) J. H. Dinnen and Ens. R. P. Kirk of VC-63 encountered and shot down a Japanese Ki-61 Tony. The most intense aerial combat for FM-2 pilots occurred during the two-day Battle of Leyte Gulf. On the first day of the battle, October 24, 1944, all American carrier-based fighters claimed a total of 270 kills, with FM-2 pilots achieving 65 of them.
USS Makin Island (CVE-93) sailing in the South Pacific.
During the Philippine campaign, the Wilder Wildcat pilots were also known for providing close air support and air cover over the invasion beaches. During the Battle of Samar, they directly attacked Japanese ships.
Many Japanese pilots underestimated the FM-2 based on its familiar silhouette and were subsequently unpleasantly surprised. Several Japanese pilots fell victim to their misjudgment, and until the surrender of Japan, FM-2 pilots achieved a total of 432 kills. Lt. Kenneth G. Hippe became the last American “ace in a day” when he shot down a total of five Ki-48 Lily bombers on October 24, 1944. On the same day but slightly earlier, Lt. Cdr. Harold N. Funk achieved the same feat, shooting down five enemy aircraft with his FM-2, adding one more kill in the afternoon.
And the most intriguing fact: While the Hellcat is generally considered the fighter aircraft with the best victory-to-loss ratio, 19:1, there was one type that significantly surpassed it. Yes, it was the FM-2. Its ratio of aerial victories to losses in air combat was 432:13, or 33:1! For comparison, the F4F-3 and F4F-4 versions recorded a ratio of 5.9:1 in 1942.
In British service, FM-2s were designated as Wildcat VI. They were the only version of this type that did not receive the Martlet designation. They performed similar tasks as in the US Navy. In addition to providing air protection for their own ships and covering bombers, they also conducted ground attacks. For example, during Operation Dragoon, to support the Allied landings in southern France in August 1944, Wildcat VI aircraft carried out bombing attacks with 250 lb bombs, carried on the modified racks used for drop tanks. They also used RP-3 rockets. In the North Sea, Wildcat VI pilots engaged in air combat with German aircraft and scored several kills. Perhaps the most interesting encounter occurred on March 26, 1945, when aircraft from No. 882 Squadron of HMS Searcher clashed with eight Bf 109G planes. German fighters catch the opponents with surprise and shot down one Wildcat, but subsequently, British pilots used the agility of their planes and, according to reports, shot down four Bf 109Gs and damaged one. Although none of the British pilots became aces flying Martlets and Wildcats, it was a highly popular type.
The most successful FM-2 pilot with nine confirmed victories was Ralph Earle Elliott Jr. Photo: Patricia Elliott family collection
With a total of 4,437 produced units, the FM-2 became the most numerous version of the Wildcat (a total of 7,905 Wildcats of all versions were produced). Production only ceased in May 1945 when Grumman began manufacturing the Bearcat, which was meant to replace the FM-2. The first operational squadrons of this type were enroute to the Japanese islands when the enemy surrendered, and the war ended.
While the Bearcat represented a significant increase in performance compared to the FM-2, it ultimately did not leave as remarkable a mark in history as the FM-2 did. It was the Wilder Wildcat that made sense for escort aircraft carriers of the Casablanca and Bogue classes, ensuring the safety of millions of tons of material and hundreds of thousands of transported personnel in the Pacific and Atlantic. In some respects, the FM-2 can thus be considered the most significant Wildcat version of them all.
Main differences of FM-2 compared to F4F-4:
1. Taller vertical tail surfaces
2. Different cooling flaps
3. Distinct exhaust system
4. Different location of the gun camera port
5. Reduced armament to four machine guns
6. Relocated landing light
7. Ability to install HVAR or RP-3 rockets
8. Upright antenna mast
9. Removal of the second fuel tank and its filling port
10. Wright R-1820-56 engine
11. Different propeller
12. Different metal skin shaping under the exhausts
13. Removed wing-mounted radiators
14. Blanked windows under the cockpit
15. New tailwheel
Different shapes of the exhaust pipes framing.
F4F Wildcat in detail & scale, Bert Kinzey, SQUADRON/SIGNAL PUBLICATIONS, INC.
F4F Wildcat in action, Richard S. Dann, SQUADRON/SIGNAL PUBLICATIONS, INC.
Fleet Air Arm, British Carrier Aviation 1039–1945, Ron Mackay, SQUADRON/SIGNAL PUBLICATIONS, INC.
Wildcat Aces of WW2, Barrett Tillman, Osprey Publishing, 1995