Grumman F6F-3K Hellcat

The Grumman F6F Hellcat was originally conceived as an advanced version of the U.S. Navy's then current front-line fighter, the F4F Wildcat (see NASM collection). The Wildcat's intended replacement, the Vought F4U Corsair (see NASM collection), first flown in 1940, was showing great promise, but development was slowed by problems, including the crash of the prototype.

The National Air and Space Museum's F6F-3 Hellcat, BuNo. 41834, was built at Grumman's Bethpage, New York, factory in February 1944 under contract NOA-(S)846. It was delivered to the Navy on February 7, and arrived in San Diego, California, on the 18th. It was assigned to Fighter Squadron 15 (VF-15) on USS Hornet (CV12) bound for Hawaii. On arrival, it was assigned to VF-3 where it sustained damage in a wheels-up landing at NAS Barbers Point, Hawaii. After repair, it was assigned to VF-83 where it was used in a training role until February 21, 1945. After numerous transfers 41834 was converted to an F6F-3K target drone with the installation of sophisticated radio-control equipment. It was painted red with a pink tail that carried the number 14. Its mission was to be used in Operation Crossroads - the atomic bomb tests at Bikini Atoll. It flew on June 24, 1946, with a pilot, on a practice flight and was launched, unmanned, soon after the first bomb test. Instrumentation on board and photographic plates taped to the control stick obtained data on radioactivity. Three more manned flights preceded the final unmanned flight on July 25, 1946, which evaluated the first underwater explosion. Records indicate that exposure of this aircraft to the radioactive cloud was minimal and residual radiation is negligible.

F6F-3K 41834 was transferred to NAS Norfolk and logged its last flight on March 25, 1947, with a total of 430.2 flying hours. It was assigned to the National Air Museum on November 3, 1948, and remained at Norfolk until October 4, 1960, when it was moved by barge to Washington and placed in storage. In 1976 this Hellcat was loaned to the USS Yorktown Museum at Charleston, South Carolina. A superficial restoration was performed at the museum, but because of the harsh environment and its poor condition the Hellcat was returned to NASM on March 16, 1982. In 1983, it was sent to Grumman Aerospace where a team of volunteers completely restored the aircraft. In 1985, it was shipped back to the Paul E. Garber Preservation, Restoration and Storage Facility in Suitland, Maryland, and put in storage. NASM's F6F-3 Hellcat is on display at the Steven F. Udvar-Hazy center near Dulles International Airport in Virginia.

The Grumman F6F Hellcat was originally conceived as an advanced version of the U.S. Navy's then current front-line fighter, the F4F Wildcat (see NASM collection). The Wildcat's intended replacement, the Vought F4U Corsair (see NASM collection), first flown in 1940, was showing great promise, but development was slowed by problems, including the crash of the prototype. As a precaution against possible delays in the Corsair reaching the fleet, in June 1941, the Navy asked Grumman to develop an improved version of the Wildcat. It had been designed in the 1930s and its performance was not up to the standard of the newer fighters.

Clearly the most pressing need in the Wildcat was a larger engine to boost performance. A bigger powerplant, however, would require the use of a larger propeller, which in turn necessitated a taller landing gear for increased ground clearance. More power also called for more wing area, and an increase in the area of the vertical and horizontal tail surfaces. The wing would also need to be lowered from the Wildcat's mid-fuselage position to accommodate the newer hydraulically-operated landing gear, which would replace its predecessor's obsolete manual system. What Grumman proposed to the Navy, therefore, was an entirely new fighter. The advanced Wildcat had turned, by a process of evolution, into the Hellcat.

The F6F Hellcat still bore a family resemblance, however, to its predecessor and there was little that was revolutionary in its design. Simplicity was a hallmark of Grumman aircraft. Known components were used, and ease of manufacture was always a priority.

Grumman chief engineer William Schwendler was an advocate of building components to twice the strength required in specifications. This practice would make the F6F a tough, uncomplicated, easy-to-manufacture aircraft. The Hellcat was legendary for its ruggedness and it was even jokingly rumored to be made of steel. This story arose from the fact that, because of wartime shortages, Grumman had been unable to acquire the structural steel to construct the new factory in which the Hellcats would be produced. In a resourceful move, Grumman general manager Jake Swirbul was able to purchase some of the needed steel from the scrapped remains of a New York City elevated railway. The joke was that the steel had not gone to making the factory, but in to making Hellcats.

The XF6F-1 Hellcat first flew in June of 1942 with a 1,600-hp Wright R-2600 Cyclone engine. It proved to be easy to fly, with no bad characteristics. In 1944 Leroy Grumman would, on a whim, successfully fly a production Hellcat, even though he had not been in a cockpit in many years. Speed and rate-of-climb were not up to expectations, however, so Grumman replaced the Wright engine with the 2,000-hp Pratt & Whitney R-2800-8 Double Wasp, 18-cylinder engine. Like the Hellcat, the R-2800 was rugged and easily maintained. It would also power the Corsair and is considered to be one of the best reciprocating engines ever produced. At the same time a Hamiliton Standard Hydromatic propeller replaced the Curtiss propeller. The re-engined Hellcat was designated the XF6F-3.

Grumman was so confident of the Hellcat that production started in October 1942, while the prototype was still in testing. This gamble paid off and the Navy accepted the first production F6F-3 in January 1943. The aircraft had become more important than ever with the continued delay of the Corsair. The battles of 1942 had also given navy pilots first-hand experience with Japan's Mitsubishi A6M Zero (see NASM collection), whose capabilities came as quite a shock for the Americans, and the Wildcat's shortcomings were now readily apparent. The Navy desperately needed the increased performance of the Hellcat to combat the Zero's dominance.

The Hellcat would prove superior to its main Japanese opponent in most performance categories, especially at high altitude. The only advantage that the Zero retained throughout the war was its legendary turning ability at slower speeds. This advantage disappeared, however, at speeds above 200 knots, because of aerodynamic forces on the Japanese fighter's controls. The lightly armored Zeros were also no match for the Hellcat's rugged construction and six .50 caliber guns. Not until late in the war would Japanese aircraft such as the Kawanishi N1K George (see NASM collection) challenge the Hellcat. But they were never available in sufficient quantity and the Zero remained the most numerous of Japanese fighters.

Because of Grumman's foresight in starting production early, Hellcats began rolling off the assembly line immediately and construction continued at an ever-increasing rate. Hellcat production was all the more remarkable considering that many of the Grumman employees had never built airplanes before. Much of the credit for the remarkable rate at which F6Fs were produced goes to the management abilities of Grumman and Swirbul. They fostered a family atmosphere and provided many modern services for their workers, such as day-care centers and counseling offices. As a result, Grumman's employee turnover rate was half that of other airplane manufacturers.

The Hellcat saw remarkably little modification throughout the war. F6F-3s served until the end of the conflict, but in mid-1944 Grumman introduced the F6F-5. Externally, the new model differed only slightly from its predecessor. The main differences were additional armor plate, a reinforced empennage, and the addition of the R-2800-10W engine, which had water injection for a limited boost in combat power. Spring tabs on the ailerons also increased maneuverability. The F6F-5's greatest feature was its versatility. It could carry rockets as well as bombs. This became more important as the number of bombers on the carriers was reduced and fighters had to carry out a wider range of missions. There were also versions of both models that were equipped with radar to serve as night fighters, as well as a photo-reconnaissance version. One of the last versions to serve in the U.S. Navy was the F6F-5K target drone. 12,275 Hellcats were produced up to November 1945. They would see post-war service in a limited role in the U.S. Navy until 1953, and also in the French and Uruguayan navies.

American and British Hellcats would claim the destruction of 5,203 Japanese aircraft in the Pacific and 13 German aircraft in Europe for a loss of only 270 F6Fs. This amounted to a kill-loss ratio of 19 to 1. One of the most remarkable figures related to the F6F, however, was its effectiveness as an escort fighter for strike aircraft. From 1943-1945, when the Hellcat was in service, only 42 carrier-based bombers or torpedo planes are known to have been lost to Japanese aircraft.

The National Air and Space Museum's F6F-3 Hellcat, BuNo. 41834, was built at Grumman's Bethpage, New York, factory in February 1944 under contract NOA-(S)846. It was delivered to the Navy on February 7, and arrived in San Diego, California, on the 18th. It was assigned to Fighter Squadron 15 (VF-15) on USS Hornet (CV12) bound for Hawaii. On arrival, it was assigned to VF-3 where it sustained damage in a wheels-up landing at NAS Barbers Point, Hawaii. After repair, it was assigned to VF-83 where it was used in a training role until February 21, 1945.

After numerous transfers, 41834 was converted to an F6F-3K target drone with the installation of sophisticated radio-control equipment. It was painted red with a pink tail that carried the number 14. Its mission was to be used in Operation Crossroads - the atomic bomb tests at Bikini Atoll. It flew on June 24, 1946, with a pilot, on a practice flight and was launched, unmanned, soon after the first bomb test. Instrumentation on board and photographic plates taped to the control stick obtained data on radioactivity. Three more manned flights preceded the final unmanned flight on July 25, 1946, which evaluated the first underwater explosion. Records indicate that exposure of this aircraft to the radioactive cloud was minimal and residual radiation is negligible.

F6F-3K 41834 was transferred to NAS Norfolk and logged its last flight on March 25, 1947, with a total of 430.2 flying hours. It was assigned to the National Air Museum on November 3, 1948, and remained at Norfolk until October 4, 1960, when it was moved by barge to Washington and placed in storage. In 1976 this Hellcat was loaned to the USS Yorktown Museum at Charleston, South Carolina. A superficial restoration was performed at the museum, but because of the harsh environment and its poor condition the Hellcat was returned to NASM on March 16, 1982. In 1983, it was sent to Grumman Aerospace where a team of volunteers completely restored the aircraft. In 1985, it was shipped back to the Paul E. Garber Preservation, Restoration and Storage Facility in Suitland, Maryland, and put in storage. NASM's F6F-3 Hellcat is on display at the Steven F. Udvar-Hazy center near Dulles International Airport in Virginia.