The Sabre first flew as the XF-86 in 1 October 1947, but it wasn't operational until 1948 as North American Aviation incorporated as much of the new jet technology captured from the Germans as was possible. Most important of which was the concept of the swept-back wing that enabled much higher speeds, approaching the speed of sound (Mach 1).It was first built as the FJ-1 Fury for the American Navy with a straight wing, but it was much slower, and therefore, less capable than the F-86. from the pilots perspective the major improvements were the ejector seat, powered controls, pressurised cockpits,and hard "bonedome" helmets. 

The seats and powered controls were required with the high speeds they were flying at, and a pressurized cockpit was a necessity flying and fighting from ground level to 40,000 ft. The major adversary they faced was the MiG-15 in Korea. Technically it should have been the Sabres falling to the ground in flames based on the flying abilities of the MiG-15. It generally had the edge on the Sabre, however, pilot training and willingness to engage in battle swung the pendulum way over to the United Nations (read Americans) side. They achieved a 15:1 kill ratio over their Chinese, Korean and Russian opponents. By the final stage of the Korean War Sabres were used in ground straffing as no opposition was encountered in the air.

Initially armament was six 0.5 in machine-guns in the nose and two 1,000 lb bombs instead of the drop tanks. With bombs the effective radius of operations was a mere 50 miles, with drop tanks it was more like 250. The Americans were committed to the 0.50 in machine gun when most air forces had gone with at least one cannon and several machine guns on jet fighters. Eventually it was equipped to fire two Sidewinder missiles, to drop two 453 kg (1,000 lb) bombs or fire eight 5 in rockets mounted under the wings.