SAVED BY THE SABRE
In November 1950, as United Nations fighter aircraft were conducting missions against North Korean ground targets, they came across a revolutionary swept-wing fighter which tore through their formations. The following month, the UN responded with a swept-wing fighter of its own, the North American F-86 Sabre. During this blog, we'll trace both the development and history of the Sabre, an aircraft which became one of the greatest jet fighters of all time.
North American, which had produced the P-51 Mustang during World War II, began development of a jet fighter based upon U.S. Navy requirements in late 1944. This aircraft, the FJ-1 Fury, was essentially an updated version of the P-51 powered by a jet engine with a straight-wing design. However, due to a mediocre performance during a series of trials, only a few of the type were produced. And yet, the United States Army Air Forces (USAAF) had a requirement for a medium-range, single-seat, jet-powered day escort fighter/fighter bomber at the same time as the Fury project. In response to the USAAF requirements, North American submitted four design proposals in early 1945. The USAAF selected one design from the four and awarded North American a contract to produce three examples of the XP-86, or Experimental Pursuit Model Eighty-Six. By trimming requirements from the FJ-1 Fury, as well as other modifications, allowed the XP-86 to be lighter and considerably faster than the Fury with a top speed of 582 mph, as opposed to 547 for the Fury. Despite gains in speed over the Fury, the XP-86 would have an identical performance to its chief rivals, the XP-80 and the XP-84. The XP-86 design was at risk for cancellation, due to the fact both the XP-80 and XP-84 were in a more advanced stage of development. The XP-86 also could not meet the speed requirement set by North American at 600 mph.
The speed problem forced North American to gamble on a new wing design for the XP-86. Reviewing flight data from captured German aeronautical engineers at the end of World War II, which suggested that a thin, swept-wing could greatly reduce drag and delay compressibility problems experienced by World War II fighters such as the Lockheed P-38 Lightning, when approaching the speed of sound. The 35 degree swept-wing design would solve the speed problem along with an automatic slat design in the leading edges of the wings, as well as an electrically adjustable tail stabilizer, the slats improving low speed performance. Though senior North American management initially opposed the swept-wing concept, wind tunnel tests, in addition to those conducted on captured ME-262s proved the design a reliable one. The XP-86, now designated the F-86 Sabre, was presented to the USAF on August 8, 1947, with the first test flight on October 1 of that year. The Sabre entered service with the Strategic Air Command in 1949.
When the Korean War began in 1950, much of the aerial combat was conducted by earlier straight-winged jets, such as the F-80 Shooting Star and the F-84 Thunderstreak. While these achieved good results in both the ground attack role and aerial combat against North Korean piston aircraft, such as the Yak-9 and the Lavochkin La-11, this situation changed rapidly when the swept-wing Soviet Mig-15 was introduced in November 1950. The Mig-15 was a generation ahead of the opposing UN jets and clearly outperformed them. In response, the USAF dispatched three squadrons of Sabres to Korea the following month. While the Mig-15 had a superior performance to the early Sabre models in ceiling, rate of climb, acceleration and zoom, many of the Sabre pilots saw action during World War II, which offered them an advantage in experience, as well as a rigorous training program at Nellis AFB. The Sabre had several advantages over the Mig-15 such as a higher diving speed, as the Mig-15 could not exceed Mach .92 in a dive. Another advantage held by the Sabre was it being equipped with the APG-30 radar gun sight, which provided accurate gunfire at maximum ranges- a major technological advantage over the Mig. With the introduction of the F-86F in 1953, the two aircraft were more evenly matched, with the Sabre gaining a slight edge. A number of F-86Fs were armed with eight 20 mm cannon, instead of the usual six .50 caliber machine guns, in order to provide the Sabre with more firepower against the Migs, which were equipped with a single 37 mm cannon and two 23 mm cannons. Although only two of the 20 mm cannons could be fired from the Sabre at a time, these aircraft were largely successful in their missions. Later Sabre models, such as the F, had a flying tail design, in which the tail was positioned above the fuselage, which made the Sabre more agile at high speeds. The most hotly contested area of action was near the mouth of the Yalu River, which formed the boundary between China and North Korea, which was nicknamed Mig Alley. After the war, according to USAF estimates, the loss ratio was 1 to ten in favor of the Sabre with a loss of 78 Sabres against 792 Migs. Both Chinese and Soviet estimates place Sabre losses from 200 to 600 aircraft. After a Rand report and research by several other private surveys, the loss ratio of Sabre to Mig dropped by almost 50 per cent. Data from a number of former Communist sources after the Cold War appear to bear this out. A more recent USAF study put the Sabre to Mig loss ratio at 1 to 2 when flying against Soviet pilots, who were active participants for about the first year of Mig-15 operations, with the Chinese and North Korean pilots assuming a larger role, once a cadre of pilots was trained. The loss ratio of the Sabre against Mig with Chinese and North Korean pilots was approximately 1 to 5. In the heat of battle, both sides tended to overstate their victories.
Although the Sabre was supplanted after the Korean War by the century series of jet fighters such as the F-100 Super Sabre and the F-102 Delta Dagger, both with supersonic capability, the F-86 remained a viable gun platform. Sabres were transferred to stateside National Guard units, where they served for nearly twenty years. The F-86 was also exported to a number of allied nations, such as Germany, Italy and the Republic of China (Taiwan). These deliveries, which began in 1954, amounted to 327 F-86s received by the ROC air force until mid 1958. In August of that year, forces of the People's Republic of China (PRC), attempted to force Republic of China (ROC) forces off of the islands of Quemoy and Matsu by shelling and a naval blockade. ROC F-86s encountered a number of PRC Mig-15s and Mig-17s, resulting in multiple dogfights. However, about twenty of the ROC Sabres were equipped with the AIM-9 Sidewinder, an infrared-homing air-to-air missile, which had just entered service with the United States Navy and Air Force. While the Migs had a similar altitude advantage, as in Korea, the Sidewinder equipped Sabres negated that advantage, destroying a large number of Migs in the process.
The Sabre was later used in the Indo-Pakistani War of 1965 and adopted by a number of third world countries. Some 9,800 examples were built between 1949 and 1957 with Sabres produced under license in Canada, Italy and Japan. The last F-86 was retired by the Bolivian Air Force in 1994, the longevity of the Sabre being a tribute to its durability and adaptability.