The Grumman F9F Cougar is the swept-wing version of its forerunner, the F9F PantherGrumman's first jet fighter plane. As MiG-15s tangled with the slower, less-agile Panthers and McDonnell Banshees over Korea, the U.S. Navy requested a swept-wing F9F design from Grumman. The first Cougars were delivered in November of 1951, a year after the debut of the MiG-15 and too late to see combat in Korea. But the Cougar, built as a stop-gap, became a successful design with 1,988 built. The last Cougar, an advanced trainer version, was phased out in 1974.