In late 1950, as USAF B-29s were bombing North Korean supply lines in support of UN ground troops, they encountered a swept-winged North Korean aircraft capable of great speed. While the introduction of the MIG-15 caught United Nations forces by surprise, its counterpart would prove to be a legend among jet fighter aircraft.
As early as 1944, North American Aviation had proposed a jet aircraft design to the US Navy, as a result of combat against the early German jet fighters, such as the ME-262. This design, the FJ-1 Fury was, in essence, a jet version of the P-51 MUSTANG. Though its speed was impressive compared to piston-powered fighters, its overall performance failed to meet expectations. However, within a few months, the USAAF approached North American with a requirement for a medium-range, single-seat, high-altitude, jet-powered day escort fighter/fighter-bomber. In early 1945, North American submitted four designs to the Air Corps with North American granted permission to produce three examples of the XP-86 (Experimental Pursuit) aircraft. While the XP-86 was a lighter plane than the Fury, and could attain 582 mph, as opposed to 547 for the FJ-1, the XP-86 could not meet the Air Corps requirement for a top speed of 600 mph. Furthermore, two rival designs, the XP-80 and XP-84 having speeds in the range of the XP-86 were already under development and might result in cancellation of the contract for the XP-86.
North American was able to solve this problem with a leapfrog in technology. The XP-86 was the first American aircraft to take advantage of captured German test data at the end of World War II, which indicated a thin swept wing could greatly reduce drag and delay compressibility problems when an aircraft approached the speed of sound. Further study of the tests revealed a swept wing would solve the speed problem, while a slat on the wing’s leading edge would enhance low-speed stability. Since the 86 was approaching an advanced stage of development, North American’s senior management was hesitant to incorporate a swept wing design. However, after a series of wind tunnel tests, a 35-degree sweep offered the best performance with automatic front slats and an electrically adjusted stabilizer based on the ME-262. As a result of combat experience gained in Korea, the front edge wing slats were phased out in favor of a leading edge chord extending 6 inches from the wing root to 3 inches at the tip.
Though much of the design work was delayed until after the end of World War II, the first F-86 SABRE was completed on August 8, 1947, with the first flight occurring on October 1 of that year. The SABRE was first assigned to the USAF Strategic Air Command in 1949 prior to its deployment to Korea in late 1950. The F-86 set a number of speed records during its early years, an official world speed record of 671 mph in September 1948, a 1951Bendix Trophy for an average speed of 553.76 mph, as well as the first woman, Jacqueline Cochran, to break the speed of sound in May 1953.
When the Soviet MIG-15 was introduced in November 1950, it outperformed all UN aircraft, such as the straight-winged F-80 and F-84. The MIG was clearly a generation ahead of both types, as well as the F9F PANTHER, flown by the US Navy from carriers offshore. Three squadrons of F-86s were dispatched to the Far East in December 1950. Though the F-86 and the MIG-15 were evenly matched and based on similar design concepts, there were a number of differences. SABRES were more aerodynamically stable and could turn, roll and dive faster than the MIG. The F-86 could also go supersonic in a dive, while the MIG would experience structural damage attempting to do so. The SABRE was also equipped with a radar gunsight, which allowed pilots to quickly aim their .50 caliber guns more accurately-even compensating for speed. The MIG-15s key advantages were faster climbing and acceleration rates, effective handling at high altitudes and being somewhat more maneuverable. Firepower between the two aircraft was a tradeoff, with the SABRE firing more smaller rounds more accurately aimed and the MIG firing less accurate but larger bore (23mm and 37mm) ammunition. Perhaps the deciding factor in the air war over Korea was the quality of pilots. Many of the MIGs were flown by Soviet pilots for about the first year of their deployment. Many of these were aces from World War II and were thus capable pilots. The USAF followed the same philosophy, sending a number of World War II aces to Korea as well. While the Soviet pilots were well trained, the USAF training program at Nellis AFB was both more broad and intense. As Soviet pilots were rotated home, they were replaced by less capable Chinese and North Korean pilots. As the war progressed, this was reflected in the loss ratio between the two aircraft. While the overall loss ratio was in favor of the SABRE of about eight to one by wars end (78 to 687), the loss ratio against Soviet pilots has been disputed in recent years, with a number of former Soviet pilots stating a loss ratio of two to one in favor of the SABRE. The most hotly contested battles were fought over an area near the mouth of the Yalu River known as MIG ALLEY.
After the Korean War, the SABRE was exported to a number of nations to include NATO allies such as the United Kingdom, Canada, West Germany, Greece, Spain, Norway and Turkey, as well as Taiwan, Japan, Pakistan and Saudi Arabia. The last SABRE was retired from the Bolivian Air Force in 1994. Though the SABRE was in service for many years, the high point of its career was in Korea-in which a few brave pilots and planes made the difference in saving a nation.