F9F-6,7, & 8 Grumman Cougar
The MiG-15ís appearance in the Korean War accelerated the Navyís interest in swept wings to delay the effects of compressibility encountered at sonic or near-sonic speeds. Difficulties adapting this design style to carrier-deck landings had delayed development until Grummanís G-93 proposal to add swept back wings and tail to the standard Panther fuselage.
Three XF9F-6 prototypes were ordered converted from F9F-5s on March 2, 1951, and Fred Rowley flew the first September 20 at Bethpage. Powered by a J48-P-6, the XF9F-6 raised critical Mach number from .79 to .86, but the original ailerons had to be replaced by spoilers on the wingís top surface. Wing fences were added to smooth airflow, and all-movable horizontal tail surfaces replaced the conventional elevators.
The first swept-wing fighter actually in carrier service was the production F9F-6 Cougar first delivered December 28, 1951. Four 20-mm guns with 190 rpg, and 180 pounds of pilot armor were provided, and the power plant was a J48-P-8, although an Allison J33-A-16 was used on the F9F-7. A pair of 150-gallon drop tanks or 1,000-pound bombs could be carried under the wings.
From February 1952 to June 1954, 646 F9F-6 and 168 F9F-7 fighters and 60 F9F-6P reconnaissance models were delivered. Cougars joined VF-32 in November 1952, and Cougars became the most numerous Navy fighter, used by 20 squadrons. Most of those with J33 engines had them replaced with J48s in service.
Grummanís G-99 design became the F9F-8 flown December 18, 1953, with a J48-P-8A, more internal fuel, an inflight refueling probe in the nose of a longer fuselage, and cambered leading edge extensions, instead of the slats of the previous models. Sidewinder I missiles were first successfully fired on September 11, 1953, from a F9F-6, so four could supplement the usual four 20-mm guns, and were first deployed overseas with the F9F-8s of VA-46 on the Randolph in July 1956.
Grumman delivered 601 F9F-8s from February 1954 to March 1957, many of them becoming the F9F-8B for Marine and Navy attack squadrons with an LABS for a 1,125-pound Mk 7 nuclear bomb, or six rocket pods. However, that special store was seldom fitted and their pilots practiced with conventional bombs, until those squadrons got more suitable A4Ds. The last Cougars were 110 seven-camera F9F-8Ps that served photographic squadrons until February 1960, and 400 F9F-8T two-place trainers whose completion brought Cougar production to an end in February 1960 with 1,985 delivered. That trainer version, as the TF-9J, remained in service until 1974.