The Grumman F9F/F-9 Cougar is a carrier-based jet-powered fighter aircraft designed and produced by the American aircraft manufacturer Grumman.
It was developed during the early 1950s on behalf of the United States Navy (US Navy) and United States Marine Corps (USMC), which were keen to quickly introduce a naval fighter equipped with a swept wing. Grumman's design team decided to adapt its earlier F9F Panther, replacing the straight wing of the Panther with a new swept wing. Thrust was also increased with the installation of a newer and more powerful engine, nevertheless, the aircraft remained limited to subsonic speeds. The first prototype (XF9F-6), which was produced by modifying an existing Panther, performed its maiden flight on 20 September 1951. The Navy considered the Cougar to be an updated version of the Panther, despite having a different official name, and thus Cougars started off from F9F-6.
During December 1952, the F9F-6 was introduced to service, VF-32 being the first squadron to receive the type; while developed at a relatively rapid pace, the Cougar's arrival was too late for it to engage in active combat during the Korean War. While initial production aircraft were powered by a single Pratt & Whitney J48 turbojet engine, the F9F-7 were furnished by an Allison J33 powerplant instead. In the mid 1950s, the improved F9F-8 was introduced, which had a lower stall speed, improved handling when flown at high angles of attack, and increase range. The twin-seat F9F-8T was procured by the US Navy to perform various forms of training. The F9F-8P photo-reconnaissance variant was created by converting existing F9F-8s; most of the modifications were made to the aircraft's nose.
On 1 April 1954, US Navy Cougars established a new transcontinental crossing record. The US Navy's flight demonstration team, the Blue Angels, adopted the type in place of its Panthers. The Cougar gained a favourable reputation as a highly maneuverable and easy to fly aircraft. The only foreign air service to operate the Cougar was the Argentine Naval Aviation. The F9F-8 was withdrawn from front-line duties during the late 1950s, having been replaced by more capable aircraft such as the F11F Tigers and F8U Crusaders. While the Naval Reserves flew Cougars into the mid-1960s, only the TF-9J trainer model saw actual combat, having been deployed as a Forward Air Control aircraft during the Vietnam War. Following its withdrawal from active service, many F9F-6s were used as unmanned drones for combat training, designated F9F-6D, or as drone controllers, designated F9F-6K.
Design and development
Early development
Rumors that the Soviet Union had produced a swept wing fighter had circulated a year before the Mikoyan-Gurevich MiG-15 first appeared at air shows in 1949. Despite the level of activity taking place with swept wing aircraft, the US Navy was not initially focused on the development of such aircraft. This was largely because the US Navy's focus at the time was defending the battle group against high speed, high altitude bombers with interceptors, as well as escorting medium-range carrier-based bombers in all weather conditions; air-to-air combat was of less interest at that time. Nonetheless, the US Navy appreciated the importance of getting a capable carrier-based swept wing jet fighter. Grumman was awarded a contract for the development of a swept-wing fighter jet in early 1951. The arrival of the MiG-15, which easily outclassed straight-wing fighters in the air war over North Korea, was a major factor.
Development proceeded at a relatively rapid pace, in part due to Grumman's pre-existing experience of studying prospective derivatives of the Panther guiding several of their design choices. One example of this was the design team's decision to retain the center fuselage section of the Panther relatively unchanged, as studies of various alternative arrangements had been determined to have introduced center of gravity issues that in turn would have compelled substantial redesigns of other elements of the aircraft, including its propulsion. Instead, the aircraft shared the Panther's engine, landing gear, and various other systems. By changing as little as possible, the company was able to produce a swept wing fighter for the US Navy in mere months, rather than the years involved in delivering a clean-sheet design.