THEY HELD THE LINE
What aircraft was in production throughout World War II, was developed from a biplane design, one of the first aircraft to use the Grumman Sto-Wing concept, and was flown by four aces who earned the Congressional Medal of Honor? If your answer was the Grumman F4F Wildcat, you are correct. During the course of this blog, we'll follow the development of the Wildcat, as well as its distinguished combat career.
The Wildcat's ancestry began in 1935 when Grumman began the development of the FF, a two-seater fighter biplane. The FF was the first US Navy fighter with a retractable landing gear. The wheels retracted into the fuselage, leaving the tires visibly exposed, flush with the sides of the fuselage. Leroy Grumman designed the landing gear system in the 1920's as an engineer with Grover Loening Aircraft Company. The manual crank system provided more safety of operation than previous landing gear types, which would not always lock properly. Two single-seat biplane designs, the F2F and the F3F, followed on the heels of the FF. Both the F2F and the F3F bore a resemblance to the Wildcat. As a follow on to the F series biplanes, Grumman began work on the G-16 biplane fighter, which debuted in late 1935. About the time of the G-16's first flight, the US Navy began to have a change of philosophy in aircraft design, favoring a monoplane concept. Because of this, the Navy ordered production of the Brewster F2A-1 in early 1936, though the Navy also ordered a number of G-16s as a backup in case of problems with the Brewster aircraft.
For Grumman, it was back to the drawing board. The monoplane design was the trend of things to come. With the XF4F-1 not advancing past the design stage, Grumman chose to forge ahead with a new monoplane. The XF4F-2 was a cantilever mid-wing all-metal monoplane, with fabric covered control surfaces and had a gross weight of 5,535 lbs. The wing utilized the newly-developed NACA 230-series airfoil, which was capable of a maximum speed of 290 mph. The XF4F-2 was powered by a Pratt & Whitney R-1830-66 Twin Wasp engine with a mechanically-driven, single-stage, single-speed supercharger, driving a Hamilton Standard constant speed propeller. The XF4F-2 had the same unique hand crank landing gear used by previous Grumman biplane fighters, which required thirty turns to fully lower or retract the gear. The pilot had to exercise care while cranking, as a slip of the hand could cause serious wrist injury. Fuel capacity was 110 gallons in the main tank located beneath the cockpit with a 20 gallon reserve tank behind the pilot's seat. Armament consisted of two .30 caliber guns in the fuselage, with provisions for two .50 caliber guns in the wings, or two hundred pound bombs beneath the wings.
Test flights of the XF4F-2 began in 1937 with the aircraft flown to the Naval Air Factory in Philadelphia the following year for further evaluation. Shortly after its arrival in Philadelphia in 1938, the XF4F-2 was tested for simulated carrier landings. During one exercise, engine failure caused a test pilot to make a forced landing in a farm field, which flipped the airplane on its back. Though the pilot experienced minor injuries, the plane was extensively damaged and had to be sent back to the factory. Though the crash cast doubt about the XF4F-2 program, the Navy decided to continue the project with the next variant, the XF4F-3. The XF4F-3 design was almost identical to the XF4F-2, with a few exceptions. The XF4F-3 had a slightly longer fuselage and wings, the wingtips being squared off to improve maneuverability. The tail section was also redesigned, in addition to an increased wing area, increasing the gross weight by 600 lbs. The XF4F-3 was powered by a 1,200 hp. Pratt & Whitney XR-1830-76 radial engine with a two-stage, two-speed supercharger driving a Curtiss Electric propeller. The first flight took place on February 12, 1939, with the F4F achieving a speed of 334 mph. As a result of this flight, the Navy awarded Grumman a production contract on the now designated Wildcat with an initial production run of 54 examples beginning in February 1940.
Since the Wildcat was to be deployed on Navy aircraft carriers, storage became a prime issue. Folding wings were necessary to stow as many aircraft as possible in the limited hangar space on the deck of an aircraft carrier. Most folding-wing naval aircraft of the time were able to fold their wings via a simple hinge point outboard of the landing gear. However, the Sto-Wing used a compound angle approach, which was initially only used on Grumman aircraft. Leroy Grumman developed the idea by experimenting with a rubber eraser in place of a fuselage and a paper clip in the place of a wing. Attaching the paper clip into the side of the eraser as a wing attached to a fuselage, through trail and error he found the angle where the wing would fold flat against the fuselage. The Sto-Wing concept was so successful on the Wildcat, that it was used on later Grumman aircraft such as the F6F Hellcat and the TBF Avenger.
In late 1939, the French placed an order for 81 Wildcats to supply their new Joffre-class aircraft carriers, Joffre and Painleve. These aircraft lacked the two-stage supercharger in use on the F4F-3. The instrumentation was French, as well as the radio and gunsight. The armament consisted of six 7.5mm machine guns with two mounted in the fuselage and two additional guns mounted in each wing. The throttle lever was moved toward the rear of the cockpit to conform to the French pre-war practice to increase engine power. The first flight of the French Wildcats (G-36A) took place on May 11, 1940. After the fall of France, Britain assumed control of both the French aircraft and related contracts. Belgium had also placed an order for ten G-36A Wildcats, but surrendered before they could be delivered with the Royal Navy assuming delivery. Prior to acceptance of the French and Belgian Wildcats, Britain had placed an order for 100 G-36B Wildcats. These were to be powered by the Pratt & Whitney R-1830-S3C4-G engine with a single- stage, two-speed supercharger. Grumman decided to delay delivery of the British Wildcat (Martlet) in order to equip them with a Sto-Wing system, as used on US F4Fs. The Sto-Wing system was deemed necessary due to the fact the Martlet was designed to operate from the first three Illustrious class aircraft carriers, which had elevators that were too narrow to accommodate non-folding wing aircraft. Even so, the first ten Martlets delivered had fixed wings, with the first Martlet with folding wings finally delivered in August 1941.
The F4F drew its first blood in British service, when a Martlet intercepted and shot down a Junkers JU-88 flying over the Scapa Flow naval base in December 1940. The Royal Navy began to use Marlets in a ground support role the following year in North Africa. Wildcats in US service got off to a less than stellar start when eleven of them were caught on the ground during the Pearl Harbor attack. However, during the attack on Wake Island in December 1941 the Wildcat displayed its true tenacity. Though the initial Japanese attacks left 12 F4F3s damaged on the field, the remnant of the Wildcats fought on for nearly two weeks with Captain Henry Elrod bombing and sinking the destroyer Kisaragi, which beat back the Japanese invasion force. By December 23 there were only two Wildcats remaining on the island, but the pair managed to shoot down a Zero and a bomber before they were overcome. F4Fs participated in a number of carrier raids during the early months of the war, holding their own in engagements with Japanese aircraft. The Wildcat also saw action in the carrier battles of the Coral Sea and Midway as well as Guadalcanal, in which the F4F gained respect from both friend and foe for its ability to take punishment as well as dish it out. The ruggedness of the Wildcat was repeatedly demonstrated during the Guadalcanal campaign, downing nearly 650 Japanese fighters and bombers between August and November 1942. Tactics played a large role in the success of the Wildcat. The agile Zero, like most Japanese army and navy fighter aircraft, had been designed to excel in slow-speed maneuvers. Naval aviators such as James Thach and James Flatley emphasized the important thing when engaging a Zero was to maintain speed-whenever possible-no matter what the Zero did. While the Wildcat was not particularly fast, its two-speed supercharger enabled it to perform well at high altitudes, unlike the Bell P-39 and Curtiss P-40. Because of the speed tactic, the theater command placed no safety limits on its diving speed.
As the bigger and faster F6F Hellcat began to take over operations on the large fleet carriers from the Wildcat in 1943, it was used on the smaller escort carriers during the island hopping campaign in the Pacific, as well as anti-submarine hunter-killer groups operating against U boats in the Atlantic. With its light weight and Sto-Wing design, as well as its range, the F4F was the ideal choice for operations from the smaller carriers. In combat against the Wildcat, the Zero's 7.7mm cowl guns and slow-firing 20 mm cannons were only effective against an F4F at point blank range, while the Wildcat's .50 cal. wing guns usually caused the complete disintegration of the Zero. During the Battle of Leyte Gulf in 1944, it was Wildcats flying off escort carriers that helped turn back a larger Japanese fleet threatening the invasion. Four Wildcat pilots were awarded the Congressional Medal of Honor during World War II, Captain Henry Elrod, USMC, Lieutenant Edward O'hare, USN, Major John Smith, USMC and Major Robert Galer, USMC. The F4F produced a number of aces, such as Major Joe Foss, who would later be Governor of South Dakota. Foss had 26 victories flying from Henderson Field at Guadalcanal. Though it wasn't the fastest, nor the most maneuverable aircraft of its era, the Wildcat was an effective plane in the hands of a good pilot, achieving a 7 to 1 kill ratio by the end of the war. Both the Wildcat and its pilots held the line at a critical time.