The Grumman F9F/F-9 Cougar was an aircraft carrier-based fighter aircraft for the United States Navy and United States Marine Corps. Based on Grummans earlier F9F Panther, the Cougar replaced the Panthers straight wing with a more modern swept wing, the Navy considered the Cougar an updated version of the Panther, despite having a different official name, and thus Cougars started off from F9F-6 upward. Rumors that the Soviet Union had produced a swept-wing fighter had been circulating since 1948, despite the level of activity taking place with swept-wing aircraft, the Navy was initially not heavily focused on the development of such aircraft. Nonetheless the 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 1951. The arrival of the Mig 15, which easily outclassed straight-wing fighters in the air war over North Korea was a contributing factor. Prototypes were quickly produced by modifying Panthers, and the first flew on 20 September 1951. The aircraft was still subsonic, but the critical Mach number was increased from 0.79 to 0.86 at sea level and to 0.895 at 35,000 ft, improving performance markedly over the Panther. Instead of using conventional ailerons for roll control, the F9F-6 uses spoilers on the surfaces of the wing. Wing fences were added and the spoilers extended from the fences to the tips of the wing. The rudder pedals controlled the part of the rudder below the tail surface. This allowed the Cougar to fly safely and easily without the portion of the tail. Initial production was the F9F-6, delivered from mid-1952 through July 1954, the F9F-6 first flew on September 20,1951, seven months after Grumman signed a contract with the Navy for swept-wing fighter. The first 30 production aircraft used the same J42 P-6 engine used in the F9F-5, Armament was four 20 mm It had AN/M3 cannons in the nose and provisions for two 1,000 lb bombs or 150 US gal drop tanks under the wings. Most were fitted with a UHF homing antenna under the nose, the F9F-6 used an Aero 5D-1 weapons sight with an APG-30A gun-ranging radar. The F9F-6 was later designated F-9F in 1962, sixty were built as F9F-6P reconnaissance aircraft with cameras instead of the nose cannon. The F9F/F-9 Cougar is one of few aircraft which do not have ailerons, after 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. The F9F-6K and the F9F-6D were redesignated the QF-9F and DF-9F, the F9F-7 referred to the next batch of Cougars that were given the Allison J33 also found in the F9F-4, instead of the Pratt & Whitney J48. A total of 168 were built, but the J33 proved both powerful and less reliable than the J48
Grumman F9F-6 Cougar, 1952
A swept-wing F9F-6 Cougar (foreground) and a straight-wing F9F-5 Panther in flight
The F9F-8 was fitted with an inflight refueling probe and Sidewinder missiles.