The F9F-8 was the last fighter version of the Cougar to see production. It was an attempt to reduce the stalling speed, to improve the control at high angles of attack, and to increase the range of the basic F9F-6. Known as Design 99 by the company, work on the project began in April of 1953. It featured an 8-inch extension of the center fuselage. In order to reduce the stalling speed, Design 99 was fitted with extended and cambered leading edges in place of the slats outboard of the fences. In addition, the trailing edges of the wing were extended further aft. This increased chord resulted in an increase of wing area from 300 to 337 square feet. It produced a wing with a relatively thinner cross section which resulted in an improved critical Mach number. Internal fuel was increased from 919 to 1063 gallons by adding a fuel tank in the extended wing leading edge and by enlarging the forward fuselage tank. The F9F-8 was fitted with a reinforced sliding canopy. The engine was the J48-P-8A or P-8C turbojet, rated at 7250 lb.s.t. dry.
The first F9F-8 flew on January 18, 1954. A total of 601 F9F-8s were delivered to the Navy between April 1954 and March 1957. During the course of production, a fixed inflight refuelling probe was added to the nose. Most F9F-8s were fitted with a UHF homing antenna in a fairing underneath the nose. Late production F9F-8s were fitted with the capability of carrying two Sidewinder infrared-homing air-to-air missile underneath each wing. This feature was retrofitted to many earlier F9F-8s. The first Sidewinder-equipped Cougars were deployed overseas by VA-48 in July of 1956.
On October 5, 1956, three VF-144 pilots set an unofficial round trip record by flying their F9F-8s from NAS Miramar, California to Long Island, New York and back with refuelling stops each way at NAS Olathe, Kansas. The total time was 10 hours 49 minutes 11 seconds.
The Blue Angels exchanged their F9F-5 Panthers for F9F-8s in 1954. They flew the Cougars until they transitioned to F11F-1 Tigers in the summer of 1957.
Several F9F-8s were converted into F9F-8B tactical nuclear bombers. They were fitted with the Low-Altitude Bombing System (LABS), additional instruments, as well as with the control and arming equipment needed for the nuclear weapon, or "special store" as it was euphemistically called. However, in service most F9F-8Bs were operated as conventional fighter-bombers and were provided with six underwing weapons pylons.
The F9F-8 and F9F-8B were withdrawn from fleet squadron service in 1958 and 1959 respectively. They served with reserve units until the mid-1960s, when they were retired to the boneyards at Davis-Monthan
The Cougar was extremely popular with its crews, who admired it for its ease of piloting, its superb carrier handling capabilities, and its robust construction. However, the F9F-8 Cougar was rapidly made obsolete by newer supersonic designs that began to enter service in the late 1950s. The service life of the Cougar was consequently relatively brief. The F9F-8 and F9F-8B were phased out of active Navy squadron fleet service during 1958-59. They continued to serve with Naval and Marine Corps reserve outfits until the mid-1960s. Some obsolescent F9F-8s served for a time as drones and drone directors. Most were retired to the boneyards at Davis-Monthan AFB in Arizona. None were still in service by the time of the Vietnam War.
In 1962, the F9F-8 was redesignated F-9J under the new Defense Department Tri-Service designation scheme. The F9F-8B fighter-bomber became AF-9J. Later, when used as advanced trainers, some of these aircraft became TAF-9J.
131063/131251 Grumman F9F-8 Cougar 134234/134244 Grumman F9F-8 Cougar 138823/138898 Grumman F9F-8 Cougar 141030/141229 Grumman F9F-8 Cougar 141648/141666 Grumman F9F-8 Cougar 144271/144376 Grumman F9F-8 Cougar
Engine: One Pratt & Whitney J48-P-8A turbojet rated at 7250 lb.s.t. dry and 8500 lb.s.t. with water injection. Performance: Maximum speed 642 mph at sea level, 647 mph at 2000 feet, 593 mph at 35,000 feet. Cruising speed 516 mph. Landing speed 132 mph. Initial climb rate 5750 feet per minute. An altitude of 20,000 feet could be attained in 4 minutes. Service ceiling 42,000 feet. Combat ceiling 42,500 feet. 1050 miles normal range. 1209 miles combat range. 1312 miles maximum range. Internal fuel was 1063 US gallons. With two 150-gallon drop tanks, total fuel load was 1363 US gallons. Dimensions: wingspan 34 feet 6 inches, length 42 feet 2 inches, height 12 feet 3 inches, wing area 337 square feet. Weights: 11,866 pounds empty, 20,098 pounds loaded, 24,763 pounds maximum takeoff. Armament: The armament consisted of four 20-mm cannon in the nose plus two underwing racks for 1000-pound bombs or 150-US gallon drop tanks. Two AIM-9 Sidewinder air-to-air missiles could be carried underneath each wing.