The F9F-7 was identical to the F9F-6 with the exception of the substitution of a 6350 lb.s.t. Allison J33-A-16 turbojet in place of the Pratt & Whitney J48. Contracts were placed for 168 F9F-7s. However, the J33 was less powerful and reliable than the J48, and the last fifty F9F-7s were delivered with J48s and were therefore indistinguishable from F9F-6s. In service, most F9F-7s were re-engined with the J48.
Like the F9F-6, many F9F-7s were fitted in service with a UHF homing beacon in a fairing underneath the nose.
A pair of F9F-7s took part in a very interesting experiment in 1954. This was the evaluation of the feasibility of landing wheels-up on an inflated rubber mat, or "flexdeck" as it came to be known. The basic idea behind flexdeck was that aircraft equipped to land on such a surface could dispense with the weight and complexity of a retractable undercarriage. Referred to as Design 94A by the company, the project involved the modification of F9F-7 BuNos 130862 and 130863. A false bottom was added underneath the center fuselage and the aircraft were re-engined with J48-P-8 engines. The leading edge slats were bolted permanently in the down position and the center flap section was locked shut. The first wheels up arrested landing took place on an inflated mat at NATC Patuxent River, Maryland on February 18, 1955. The tests proved that such landings could be performed safely and reliably. However, the Navy concluded that the basic idea was impractical, since aircraft without undercarriage could not divert to airfields or carriers that did not have flexdeck. The project was finally terminated in March of 1956.
In 1962, the F9F-7 was redesignated F-9H under the new Defense Department Tri-Service unified designation scheme.
Serials of Grumman F9F-7 Cougar
130752/130919 Grumman F9F-7 Cougar (130870/130919 delivered as F9F-6s)
Specification of the Grumman F9F-7 Cougar:
One Allison J33-A-16A turbojet rated at 6350 lb.s.t. dry and 7000 lb.s.t. with water injection. Performance: Maximum speed 628 mph at sea level, 559 mph at 35,000 feet. Cruising speed 541 mph. Stalling speed 130 mph. Initial climb rate 5100 feet per minute. An altitude of 30,000 feet could be attained in 11.6 minutes. Service ceiling 40,200 feet. 1157 miles normal range. Internal fuel was 919 US gallons. With two 150-gallon drop tanks, total fuel load was 1219 US gallons. Dimensions: wingspan 34 feet 6 inches, length 41 feet 5 inches, height 12 feet 4 inches, wing area 300 square feet. Weights: 11,225 pounds empty, 16,577 pounds combat, 18,905 pounds gross. 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.
Sources:
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United States Navy Aircraft Since 1911, Gordon Swanborough and
Peter M. Bowers, Naval Institute Press, 1990.
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The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.
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Grumman Aircraft Since 1929, Rene J. Francillon, Naval Institute
Press, 1989.
- American Combat Planes, 3rd Enlarged Edition, Ray Wagner, Doubleday, 1982.
