The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic, jet-powered fighter aircraft. Produced by North American Aviation, the Sabre is best known as the United States' first swept-wing fighter that could counter the swept-wing Soviet MiG-15 in high-speed dogfights in the skies of the Korean War (1950–1953), fighting some of the earliest jet-to-jet battles. Considered one of the best and most important fighter aircraft in that war, the F-86 is also rated highly in comparison with fighters of other eras."MiG-15 'Fagot'." mnangmuseum.org. Retrieved: 19 July 2011. Although it was developed in the late 1940s and was outdated by the end of the 1950s, the Sabre proved versatile and adaptable and continued as a front-line fighter in numerous air forces.
Its success led to an extended production run of more than 7,800 aircraft between 1949 and 1956, in the United States, Japan, and Italy. In addition, 738 carrier-modified versions were purchased by the US Navy as FJ-2s and -3s. Variants were built in Canada and Australia. The Canadair Sabre added another 1,815 aircraft and the significantly redesigned CAC Sabre (sometimes known as the Avon Sabre or CAC CA-27), had a production run of 112. The Sabre is by far the most-produced Western jet fighter, with a total production of all variants at 9,860 units.
Development
North American Aviation had produced the propeller-powered P-51 Mustang in World War II, which saw combat against some of the first operational jet fighters. By late 1944, North American proposed its first jet fighter to the U.S. Navy, which became the FJ-1 Fury. It was an unexceptional transitional jet fighter that had a straight wing derived from the P-51.Goebel, Greg. vectorsite.net. Retrieved: 19 July 2011. Initial proposals to meet a United States Army Air Forces (USAAF) requirement for a medium-range, single-seat, high-altitude, jet-powered day escort fighter/fighter bomber were drafted in mid-1944. In early 1945, North American Aviation submitted four designs. The USAAF selected one design over the others and granted North American a contract to build three examples of the XP-86 ("experimental pursuit"). Deleting specific requirements from the FJ-1 Fury, coupled with other modifications, allowed the XP-86 to be lighter and considerably faster than the Fury, with an estimated top speed of , versus the Fury's . Despite the gain in speed, early studies revealed the XP-86 would have the same performance as its rivals, the XP-80 and XP-84. Because these rival designs were more advanced in their development stages, North American feared that the XP-86 would be cancelled.
Crucially, the XP-86 was not able to meet the required top speed of ; North American had to quickly devise a radical change that could leapfrog its rivals. The F-86 was the first American aircraft to take advantage of flight-research data seized from the German aerodynamicists at the end of World War II."North American F-86." Aviation History On-line Museum. Retrieved: 20 August 2010. These data showed that a thin, swept wing could greatly reduce drag and delay compressibility problems By 1944, German engineers and designers had established the benefits of swept wings based on experimental designs dating back to 1940. A study of the data showed that a swept wing would solve their speed problem, while a slat on the wing's leading edge that extended at low speeds would enhance low-speed stability.
Because development of the XP-86 had reached an advanced stage, the idea of changing the sweep of the wing was met with resistance from some senior North American staff. Despite stiff opposition, after good results were obtained in wind tunnel tests, the swept-wing concept was eventually adopted. Performance requirements were met by incorporating a 35° swept-back wing using modified NACA four-digit airfoils, NACA 0009.5–64 at the root and NACA 0008.5–64 at the tip,Lednicer, David. "The Incomplete Guide to Airfoil Usage." ae.illinois.edu, 15 October 2010. Retrieved: 19 July 2011. with an automatic slat design based on that of the Messerschmitt Me 262 and an electrically adjustable stabilizer, another feature of the Me 262A. Many Sabres had a "6–3 wing" (a fixed leading edge with a 6-inch extended chord at the root and a 3-inch extended chord at the tip) retrofitted after combat experience was gained in Korea.Bevan, Duncan. "F-86 Sabre wings explained." tripod.com. Retrieved: 7 June 2011. This modification changed the wing airfoils to the NACA 0009-64 modified configuration at the root and the NACA 0008.1–64 mod at the tip.
The XP-86 prototype, which led to the F-86 Sabre, was rolled out on 8 August 1947. The first flight occurred on 1 October 1947 with George Welch at the controls,"North American F-86 Sabre (Day-Fighter A, E and F Models)." National Museum of the United States Air Force. Retrieved: 7 June 2011. flying from Muroc Dry Lake (now Edwards AFB), California.
The United States Air Force's (USAF) Strategic Air Command had F-86 Sabres in service from 1949 through 1950. They were assigned to the 22nd Bomb Wing, the 1st Fighter Wing, and the 1st Fighter Interceptor Wing."Planes of Perrin, North American F-86L "Dog Sabre." perrinairforcebase.net. Retrieved: 20 August 2010. The F-86 was the primary U.S. air combat fighter during the Korean War, with significant numbers of the first three production models seeing combat.
The F-86 Sabre was also produced under license by Canadair, Ltd, as the Canadair Sabre. The final variant of the Canadian Sabre, the Mark 6, is generally rated as having the highest capabilities of any Sabre version.
Breaking sound barrier and other records
The F-86A set its first official world speed record of on 15 September 1948, at Muroc Dry Lake, flown by Major Richard L. Johnson, USAF.Wagner, The North American Sabre Retrieved: 20 August 2010. Five years later, on 18 May 1953, Jacqueline Cochran became the first woman to break the sound barrier, flying a "one-off" Canadian-built F-86 Sabre Mk 3, alongside Chuck Yeager. Col. K. K. Compton won the 1951 Bendix air race in an F-86A with an average speed of 553.76 mph (891.19 km/h).
On 2 February 1958, a team of Pakistan Air Force F-86 Sabres called "Falcons" set a world record at PAF Base Masroor by performing a loop while in a 16 aircraft diamond formation. The team was led by then-Wing Commander Zafar Masud.
Design
Overview The F-86 was produced as both a fighter-interceptor and fighter-bomber. Several variants were introduced over its production life, with improvements and different armament implemented (see below). The XP-86 was fitted with a General Electric J35-C-3 jet engine that produced of thrust. This engine was built by GM's Chevrolet division until production was turned over to Allison. The General Electric J47-GE-7 engine was used in the F-86A-1 producing a thrust of , while the General Electric J73-GE-3 engine of the F-86H produced of thrust.
The fighter-bomber version (F-86H) could carry up to of bombs, including an external fuel-tank type that could carry napalm. Unguided rockets were used on some fighters on training missions, but rockets were later carried on combat operations. The F-86 could also be fitted with a pair of external jettisonable jet fuel tanks (four on the F-86F beginning in 1953) that extended the range of the aircraft. Both the interceptor and fighter-bomber versions carried six M3 Browning machine guns with electrically boosted feed in the nose (later versions of the F-86H carried four cannons instead of machine guns). Firing at a rate of 1,200 rounds per minute, the guns were harmonized to converge at in front of the aircraft, using armor-piercing (AP) and armor-piercing incendiary (API) rounds, with one API tracer for every five AP or API rounds. The API rounds used during the Korean War contained magnesium, which were designed to ignite upon impact, but burned poorly above as oxygen levels were insufficient to sustain combustion at that height. Initial planes were fitted with the Mark 18 manual-ranging, computing gun sight. The last 24 F-86A-5-Nas and F-86Es were equipped with the A-1CM gunsight-AN/APG-30 radar, which used radar to automatically compute a target's range, which later proved to be advantageous against MiG opponents over Korea.
Flying characteristics The transition to the Sabre's swept wings and jet engine saw many accidents and incidents, since even experienced pilots had to learn new handling techniques and flying characteristics. Early on in the jet age, some US manufacturers instituted safety and transition programs where experienced test and production pilots toured operational fighter squadrons to provide instruction and demonstrations designed to lower the accident rate.
As F-86 models continued to be upgraded, the learning process continued. Important design changes included switching from an elevator/stabilizer to an all-flying tail, discontinuation of leading-edge slats for a solid wing with a small, forward-mounted wing fence, increased internal fuel capacity, increased engine power, and an internal missile bay (F-86D). While the solid leading edge and increased internal fuel capacity increased combat performance, they exacerbated a dangerous and often fatal handling characteristic; the nose was raised prematurely from the runway during take-off. The danger of over-rotation is now a major area of instruction and concern for current F-86 pilots. The 1972 Sacramento Canadair Sabre accident resulting in 22 fatalities and 28 other casualties was a result of over-rotation on take-off.
Operational history
Korean War
The F-86 entered service with the USAF in 1949, joining the 1st Fighter Wing's 94th Fighter Squadron and became the primary air-to-air jet fighter used by the Americans in the Korean War. While earlier straight-winged jets such as the P-80 and F-84 initially achieved air victories, when the swept-wing MiG-15 was introduced in November 1950, it outperformed all UN-based aircraft.
Introduction of the MiG-15 and comparisons In response, three squadrons of F-86s were rushed to the Far East in December. The MiG-15 was superior to early F-86 models in ceiling, firepower, acceleration, turning, rate of climb, and ability to zoom climb. The F-86 was marginally faster, and could out-dive the MiGs. When the F-86F was introduced in 1953, the two aircraft became more closely matched, and by the end of the war, many American combat-experienced pilots were claiming a marginal superiority for the F-86F.
The heavier firepower of the MiG, and many other contemporary fighters, was addressed by Project Gun-Val, which saw the combat testing of seven F-86Fs, each armed with four 20 mm T-160 cannons (such F-86s were designated as F-86F-2s). Despite being able to fire only two of the four 20 mm cannons at a time, the experiment was considered a success and signaled the end of the decades-long use of the Browning .50 caliber in the air-to-air role.Ray Wagner, The North American Sabre
Although the F-86A could be safely flown through Mach 1, the F-86E's all-moving tailplane greatly improved maneuverability at high speeds. The MiG-15 could not safely exceed Mach 0.92, an important disadvantage in near-sonic air combat. Far greater emphasis had been given to the training, aggressiveness, and experience of the F-86 pilots. American Sabre pilots were trained at Nellis, where the casualty rate of their training was so high, they were told, "If you ever see the flag at full staff, take a picture." Despite rules of engagement to the contrary, F-86 units frequently initiated combat over MiG bases in the Manchurian "sanctuary".
In October 1951, the Soviets managed to recover a downed Sabre, and in their investigation of the type, they concluded that the Sabre's advantage in combat was due to the APG-30 radar gunsight that facilitated accurate fire at longer ranges.
Deployment of MiGs and Sabres