Concept The Bearcat concept began during a meeting between
Battle of Midway veteran
F4F Wildcat pilots and
Grumman vice president
Jake Swirbul at
Pearl Harbor on 23 June 1942. At the meeting, Lieutenant Commander
Jimmie Thach emphasized one of the most important requirements in a good fighter plane was "
climb rate". Climb performance is strongly related to the
power-to-weight ratio, and is maximized by wrapping the smallest and lightest possible airframe around the most powerful engine. Another goal was that the
G-58 (Grumman's design designation for the aircraft) should be able to operate from
escort carriers, which were then limited to the obsolescent F4F Wildcat, as the
Grumman F6F Hellcat was too large and heavy. A small, lightweight aircraft would make this possible. After intensively analyzing
carrier warfare in the
Pacific Theater of Operations for a year and a half, Grumman began development of the G-58 Bearcat in late 1943.
Design . In 1943, Grumman was introducing the
F6F Hellcat, powered by the
Pratt & Whitney R-2800 engine, which provided . The R-2800 was the most powerful American engine, so it would be retained for the G-58. This meant that improved performance would have to come from a lighter airframe. To meet this goal, the Bearcat's fuselage was about shorter than the Hellcat, and was cut down vertically behind the cockpit. This allowed the use of a
bubble canopy, the first to be fitted to a US Navy fighter. The vertical stabilizer was the same height as the Hellcat's, but had an increased aspect ratio, giving it a thinner look. The wingspan was less than the Hellcat's. Structurally, the fuselage used flush riveting and spot welding, with a heavy-gauge 302W aluminum alloy skin suitable for carrier landings. The design team had set the goal that the G-58 should weigh fully loaded. As development continued, but this was found to be impossible to achieve, as the structure of the new fighter had to be made strong enough for aircraft carrier landings. Weight-saving measures included restricting the internal fuel capacity to (later ) and limiting the fixed armament to four
.50 cal Browning AN/M2 machine guns, two in each wing. Compared to the Hellcat, the Bearcat was 20% lighter, had a 30% better rate of climb, and was faster. Another weight-saving concept the designers found was detachable wingtips. The wings were designed to fold at a point about out along the span, reducing the space taken up on the carrier. Normally, the hinge system would have to be built very strong to transmit loads from the outer portions of the wing to the main spar in the inner section, which adds considerable weight. Instead of building the entire wing to be able to withstand high-g loads, only the inner portion of the wing was able to do this. The outer portions were more lightly constructed, and designed to snap off at the hinge line if the force exceeded 7.5 g. In this case, the aircraft would still be flyable and could be repaired after returning to the carrier. This saved . Langley Research Facility in 1945
Prototypes The design was completed in November 1943 and an order for two prototypes was placed on 27 November 1943 under the BuAir designation XF8F-1. The first prototype flew on 21 August 1944, only nine months after the design effort started. The initial flight test demonstrated a climb rate and a top speed of . Compared to the
Vought F4U Corsair, the Bearcat was marginally slower, but more maneuverable and climbed more quickly. Testing demonstrated a number of problems, notably a lack of horizontal stability, an underpowered trim system, landing gear that could be extended only at slow speeds, an unreliable airspeed indicator, and a cramped cockpit. The test pilots also requested that six guns be installed. The stability problem was addressed on the second prototype by adding a triangular fillet to the front of the vertical stabilizer. The extra guns could not be incorporated due to weight and balance considerations.
Production The Navy placed a production contract for 2,023 aircraft based on the second prototype on 6 October 1944. On 5 February 1945, they awarded another contract for 1,876 slightly modified aircraft from
General Motors'
Eastern Aircraft Division, given the designation F3M-1. These differed primarily in having the R-2800-34W engine and a small increase in fuel capacity. Deliveries from Grumman began on 21 May 1945. The end of the war led to the Grumman order being reduced to 770 examples, with the GM contract being cancelled outright. An additional order was placed for 126 F8F-1Bs replacing the .50 cal machine guns with the 20 mm M2 cannon, the US version of the widely used
Hispano-Suiza HS.404. Fifteen of these were later modified as F8F-1N night fighters with an APS-19 radar mounted under the starboard wing. An unmodified production F8F-1 set a 1946 time-to-climb record (after a run of ) of in 94 seconds (). The Bearcat held this record for 10 years until it was broken by a jet fighter (which still could not match the Bearcat's short takeoff distance). In 1948, Grumman introduced a number of improvements to produce the F8F-2. Among the changes were a modified cowling design, taller vertical fin, and the slightly more powerful R-2800-30W engine producing . In total, 293 F8F-2s were produced, along with 12 F8F-2N night fighters and 60 F8F-2P reconnaissance versions. Production ended in 1949, and the first units began to convert off the type that year. The last Bearcats were withdrawn in 1952. ==Operational history==