An interceptor aircraft, or interceptor, is a type of fighter aircraft designed to attack enemy aircraft bombers and reconnaissance aircraft, as they approach. There are two general classes of interceptor: lightweight aircraft built for high performance, heavier aircraft designed to fly at night or in adverse weather and operate over longer ranges. For daytime operations, conventional fighters fill the interceptor role, as well as many other missions. Daytime interceptors have been used in a defensive role since the World War I era, but are best known from several major actions during World War II, notably the Battle of Britain where the Supermarine Spitfire and Hawker Hurricane developed a good reputation. Few aircraft can be considered dedicated daytime interceptors. Exceptions include the Messerschmitt Me 163B—the only rocket-powered, manned military aircraft to see combat—and to a lesser degree designs like the Mikoyan-Gurevich MiG-15, which had heavy armament intended for anti-bomber missions.
Night fighters and bomber destroyers are, by definition, interceptors of the heavy type, although they were referred to as such. In the early Cold War era the combination of jet-powered bombers and nuclear weapons created air forces' demand for capable interceptors. Examples of classic interceptors of this era include the F-106 Delta Dart, Sukhoi Su-15, English Electric Lightning. Through the 1960s and 1970s, the rapid improvements in design led to most air-superiority and multirole fighters, such as the Grumman F-14 Tomcat and McDonnell Douglas F-15 Eagle, having the performance to take on the interceptor role, the strategic threat moved from bombers to intercontinental ballistic missiles. Dedicated interceptor designs became rare, with the only used examples designed after the 1960s being the Tornado F3, Mikoyan MiG-25 "Foxbat", Mikoyan MiG-31 "Foxhound", the Shenyang J-8 "Finback"; the first interceptor squadrons were formed during World War I to defend London against attacks by Zeppelins and against fixed-wing long-range bombers.
Early units used aircraft withdrawn from front-line service, notably the Sopwith Pup. They were told about their target's location before take-off from a command centre in the Horse Guards building; the Pup proved to have too low performance to intercept Gotha G. IV bombers, the superior Sopwith Camels supplanted them; the term "interceptor" was in use by 1929. Through the 1930s, bomber aircraft speeds increased so much that conventional interceptor tactics appeared impossible. Visual and acoustic detection from the ground had a range of only a few miles, which meant that an interceptor would have insufficient time to climb to altitude before the bombers reached their targets. Standing combat air patrols were only at great cost; the conclusion at the time was that "the bomber will always get through". The invention of radar made possible early, long-range detection of aircraft on the order of 100 miles, both day and night and in all weather. A typical bomber might take twenty minutes to cross the detection zone of early radar systems, time enough for interceptor fighters to start up, climb to altitude and engage the bombers.
Ground controlled interception required constant contact between the interceptor and the ground until the bombers became visible to the pilots and nationwide networks like the Dowding system were built in the late 1930s. The introduction of jet power increased speeds from 400 miles per hour to 600 miles per hour in a step and doubled operational altitudes. Although radars improved in performance, the gap between offense and defense was reduced. Large attacks could so confuse the defense's ability to communicate with pilots that the classic method of manual ground controlled interception was seen as inadequate. In the United States, this led to the introduction of the Semi-Automatic Ground Environment to computerize this task; the introduction of the first useful surface-to-air missiles in the 1950s obviated the need for fast reaction time interceptors as the missile could launch instantly and air forces turned to much larger designs, with enough fuel for longer endurance, to avoid the need for rapid reaction.
In the 1950s, during the Cold War, a strong interceptor force was crucial for the great powers as the best means to defend against an unexpected nuclear attack by strategic bombers. Hence for a brief period of time they faced rapid development. At the end of the 1960s, a nuclear attack became unstoppable with the introduction of ballistic missiles capable of approaching from outside the atmosphere at speeds as high as 5–7 km/s; the doctrine of mutually assured destruction replaced the trend of defense strengthening, making interceptors less strategically logical. The utility of interceptors waned as the role merged with that of the heavy air superiority fighter, dominant in military thinking; the interceptor mission is, by its nature, a difficult one. Consider the desire to protect a single target from attack by long-range bombers; the bombers have the advantage of being able to select the parameters of the mission – attack vector and altitude. This results in an enormous area. In the time it takes for the bombers to cross the distance from first detection to being on their targets, the interceptor must be able to start, take off, climb to altitude, maneuver for attack and attack the bomber.
A dedicated interceptor aircraft sacrifices the capabilities of the air superiority fighter and multirole fighter (i.e. countering enemy fighter airc
North American F-86 Sabre
The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic jet 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, fighting some of the earliest jet-to-jet battles in history. Considered one of the best and most important fighter aircraft in that war, the F-86 is rated in comparison with fighters of other eras. 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 until the last active operational examples were retired by the Bolivian Air Force in 1994, its success led to an extended production run of more than 7,800 aircraft between 1949 and 1956, in the United States and Italy. Variants were built in Australia; the Canadair Sabre added another 1,815 airframes, the redesigned CAC Sabre, had a production run of 112.
The Sabre is by far the most-produced Western jet fighter, with total production of all variants at 9,860 units. 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. Initial proposals to meet a United States Army Air Forces 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, granted North American a contract to build three examples of the XP-86. Deleting specific requirements from the FJ-1 Fury, coupled with other modifications, allowed the XP-86 to be lighter and faster than the Fury, with an estimated top speed of 582 mph, versus the Fury's 547 mph.
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. It was feared that, because these designs were more advanced in their development stages, the XP-86 would be canceled. Crucially, the XP-86 would not be able to meet the required top speed of 600 mph; the North American F-86 Sabre was the first American aircraft to take advantage of flight research data seized from the German aerodynamicists at the end of World War II. This data showed that a thin swept wing could reduce drag and delay compressibility problems that had bedeviled prop-powered fighters such as the Lockheed P-38 Lightning approaching the speed of sound. By 1944, German engineers and designers had established the benefits of swept wings based on experimental designs dating back to 1940. 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 adopted. Performance requirements were met by incorporating a 35° swept-back wing, using NACA 4-digit modified airfoils, using NACA 0009.5–64 at the root and NACA 0008.5–64 at the tip, 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 the "6 -- 3; this modification changed the wing airfoils to the NACA 0009-64 mod at the root and the NACA 0008.1–64 mod at the tip. The XP-86 prototype, which would lead 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, flying from Muroc Dry Lake, California. The United States Air Force's Strategic Air Command had F-86 Sabres in service from 1949 through 1950.
The F-86s were assigned to the 22nd Bomb Wing, the 1st Fighter Wing and the 1st Fighter Interceptor Wing. 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 produced under license by Canadair, Ltd as the Canadair Sabre; the final variant of the Canadian Sabre, the Mark 6, is rated as having the highest capabilities of any Sabre version. The F-86A set its first official world speed record of 671 miles per hour on September 15, 1948 at Muroc Dry Lake flown by Major Richard L. Johnson, USAF. Five years 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. The F-86 was produced as both a fighter-bomber. Several variants were introduced over its production life, with improvements and different armament implemented.
The XP-86 was fitted with a General Electric J35-C-3 jet engine. This engine was built by GM's Chevrolet division until production was turned over to Al
The Mikoyan-Gurevich MiG-19 is a Soviet second generation, single-seat, twin jet-engined fighter aircraft. It was the first Soviet production aircraft capable of supersonic speeds in level flight. A comparable U. S. "Century Series" fighter was the North American F-100 Super Sabre, although the MiG-19 would oppose the more modern McDonnell Douglas F-4 Phantom II and Republic F-105 Thunderchief over North Vietnam. On 20 April 1951, OKB-155 was given the order to develop the MiG-17 into a new fighter called "I-340", to be powered by two Mikulin AM-5 non-after-burning jet engines delivering 19.6 kN of thrust. The I-340 was supposed to attain 1,160 km/h at 2,000 m, 1,090 km/h at 10,000 m, climb to 10,000 m in 2.9 minutes, have a service ceiling of no less than 17,500 m. The new fighter, internally designated "SM-1", was designed around the "SI-02" airframe modified to accept two engines in a side-by-side arrangement and was completed in March 1952; the I-340 suffered from poor cockpit pressurization and the engines proved temperamental with frequent flameouts and surges with rapid throttle movements.
The engines were upgraded to the AM-5A standard delivering 21.1 kN of thrust each, which exceeded the power output of the Klimov VK-1F in afterburner while providing better fuel economy. The SM-1 was supersonic, reaching 1,193 km/h at 5,000 m; this performance was deemed insufficient for the new supersonic fighter and an after-burning version of the engine, the AM-5F, was proposed. While not implemented, the AM-5F served as the basis for the Tumansky RD-9 which powered production aircraft. Further development of the twin-engine concept resulted in a government request for the "I-360", internally designated "SM-2", powered by the AM-5F engines, but featured a swept wing; the I-360, built in 1952, had 1.6 m longer fuselage, wingspan reduced to 9.04 m, weight increased to 6,802 kg and a new 55° sweep wing. The Nudelman N-37D cannon were moved to the wing roots to open space in a nose for the radar. Cockpit and landing gear were redesigned and a vertical stabilizer of increased area mounting a T-tail was fitted.
In April 1952 the first prototype was sent to the Letno-Issledovatel'skiy Institut, flying for the first time on 27 May 1952 by G. A. Sedov, it was clear that the AM-5A engines were not powerful enough, they were replaced with AM-5F delivering 21.09–26.49 kN, allowing a maximum speed of M=1.19 in horizontal flight. Flight testing prompted modifications to the air-brakes and control surfaces, re-designated as the SM-2A and after further modifications the prototype was re-designated again as the SM-2B; the second prototype, SM-2/2 introduced horizontal stabilizers mounted on the upper rear fuselage and guns with shorter barrels. However the AM-5F engine was still not considered powerful enough, both prototypes received yet more powerful 25.5–31.9 kN Mikulin AM-5B engines. Production versions of the AM-5 were re-designated RD-9B and the SM-2B was re-designated SM-9/1 when these engines were fitted becoming the prototype of the MiG-19 series, flying for the first time on 5 January 1954, piloted by G. A. Sedov, making a total of 132 flights.
Final changes included a modified air intake, new 23 mm Nudelman-Rikhter NR-23 guns with 340 rpg, RSIU-3M "Klen" radio, "Uzel-1" transponder, SRDM-1M "Konus" radio-rangefinder. Initial enthusiasm for the aircraft was dampened by several problems, the most alarming inherited from MiG-15/MiG-17 was the danger of mid-air tank implosions when more than half of the fuel had been used—the leaking fuel of the crushed fuselage fuel tanks located between the engines would ignite, leading to a fatal explosion. Furthermore, deployment of air-brakes at high speeds caused a high-g pitch-up, elevators lacked authority at supersonic speeds, the aircraft possessed a high landing speed of 230 km/h. Absence of a two-seat trainer version slowed pilot transition to the type. Handling problems were addressed with the second prototype, SM-9/2, which added a third ventral air-brake and introduced all-moving tail-planes with a damper to prevent pilot-induced oscillations at subsonic speeds, flying for the first time on 16 September 1954, entering initial production as the MiG-19.
The Council of Ministers of the Soviet Union issued an order #286-133 to start serial production on 17 February 1954 at factories in Gorkiy and Novosibirsk. Factory trials were completed on 12 September 1954, government trials started on 30 September. Problems with the initial production MiG-19, were addressed in the SM-9/3 prototype which presaged the MiG-19S production version, which supplanted the initial MiG-19 in production at Gorkiy and Novosibirsk from June 1956. 5,500 MiG-19s of all versions were produced, in the USSR, Czechoslovakia as the Aero S-105 and People's Republic of China as the Shenyang J-6. The aircraft saw service with a number of other national air forces, including those of Cuba, North Vietnam, Egypt and North Korea; the aircraft saw combat during the Vietnam War, the 1967 Six-Day War, the 1971 Bangladesh War. All Soviet-built MiG-19 variants were single-seaters only, although the Chinese developed the Shenyang JJ-6 trainer version of the Shenyang J-6. With stabilization problems and "numerous crashes", the Russians had lost faith in the MiG-19, moved on to the newly emerging MiG-21
The Soviet Union the Union of Soviet Socialist Republics, was a socialist state in Eurasia that existed from 1922 to 1991. Nominally a union of multiple national Soviet republics, its government and economy were centralized; the country was a one-party state, governed by the Communist Party with Moscow as its capital in its largest republic, the Russian Soviet Federative Socialist Republic. Other major urban centres were Leningrad, Minsk, Alma-Ata, Novosibirsk, it spanned over 10,000 kilometres east to west across 11 time zones, over 7,200 kilometres north to south. It had five climate zones: tundra, steppes and mountains; the Soviet Union had its roots in the 1917 October Revolution, when the Bolsheviks, led by Vladimir Lenin, overthrew the Russian Provisional Government which had replaced Tsar Nicholas II during World War I. In 1922, the Soviet Union was formed by a treaty which legalized the unification of the Russian, Transcaucasian and Byelorussian republics that had occurred from 1918. Following Lenin's death in 1924 and a brief power struggle, Joseph Stalin came to power in the mid-1920s.
Stalin committed the state's ideology to Marxism–Leninism and constructed a command economy which led to a period of rapid industrialization and collectivization. During his rule, political paranoia fermented and the Great Purge removed Stalin's opponents within and outside of the party via arbitrary arrests and persecutions of many people, resulting in at least 600,000 deaths. In 1933, a major famine struck the country. Before the start of World War II in 1939, the Soviets signed the Molotov–Ribbentrop Pact, agreeing to non-aggression with Nazi Germany, after which the USSR invaded Poland on 17 September 1939. In June 1941, Germany broke the pact and invaded the Soviet Union, opening the largest and bloodiest theatre of war in history. Soviet war casualties accounted for the highest proportion of the conflict in the effort of acquiring the upper hand over Axis forces at intense battles such as Stalingrad and Kursk; the territories overtaken by the Red Army became satellite states of the Soviet Union.
The post-war division of Europe into capitalist and communist halves would lead to increased tensions with the United States-led Western Bloc, known as the Cold War. Stalin died in 1953 and was succeeded by Nikita Khrushchev, who in 1956 denounced Stalin and began the de-Stalinization; the Cuban Missile Crisis occurred during Khrushchev's rule, among the many factors that led to his downfall in 1964. In the early 1970s, there was a brief détente of relations with the United States, but tensions resumed with the Soviet–Afghan War in 1979. In 1985, the last Soviet premier, Mikhail Gorbachev, sought to reform and liberalize the economy through his policies of glasnost and perestroika, which caused political instability. In 1989, Soviet satellite states in Eastern Europe overthrew their respective communist governments; as part of an attempt to prevent the country's dissolution due to rising nationalist and separatist movements, a referendum was held in March 1991, boycotted by some republics, that resulted in a majority of participating citizens voting in favor of preserving the union as a renewed federation.
Gorbachev's power was diminished after Russian President Boris Yeltsin's high-profile role in facing down a coup d'état attempted by Communist Party hardliners. In late 1991, Gorbachev resigned and the Supreme Soviet of the Soviet Union met and formally dissolved the Soviet Union; the remaining 12 constituent republics emerged as independent post-Soviet states, with the Russian Federation—formerly the Russian SFSR—assuming the Soviet Union's rights and obligations and being recognized as the successor state. The Soviet Union was a powerhouse of many significant technological achievements and innovations of the 20th century, including the world's first human-made satellite, the first humans in space and the first probe to land on another planet, Venus; the country had the largest standing military in the world. The Soviet Union was recognized as one of the five nuclear weapons states and possessed the largest stockpile of weapons of mass destruction, it was a founding permanent member of the United Nations Security Council as well as a member of the Organization for Security and Co-operation in Europe, the World Federation of Trade Unions and the leading member of the Council for Mutual Economic Assistance and the Warsaw Pact.
The word "Soviet" is derived from a Russian word сове́т meaning council, advice, harmony and all deriving from the proto-Slavic verbal stem of vět-iti, related to Slavic věst, English "wise", the root in "ad-vis-or", or the Dutch weten. The word sovietnik means "councillor". A number of organizations in Russian history were called "council". For example, in the Russian Empire the State Council, which functioned from 1810 to 1917, was referred to as a Council of Ministers after the revolt of 1905. During the Georgian Affair, Vladimir Lenin envisioned an expression of Great Russian ethnic chauvinism by Joseph Stalin and his supporters, calling for these nation-states to join Russia as semi-independent parts of a greater union, which he named as the Union of Soviet Republics of Europe and Asia. Stalin resisted the proposal, but accepted it, although with Lenin's agreement changed the name of the newly proposed sta
The JSC Klimov presently manufactures internationally certified gas turbine engines, main gearboxes and accessory drive gearboxes for transport aircraft. Established as Kirill Klimov Experimental Design Bureau in Saint-Petersburg under the direction of Vladimir Yakovlevich Klimov, Klimov designed engines for Soviet aircraft based on Renault aircraft engine designs; the Klimov OKB was formed in the early 1930s to produce and improve upon the liquid-cooled Hispano-Suiza 12Y V-12 piston engine for which the USSR had acquired a license. At that time Klimov manufactured motorcycles. In 1946 the British government allowed Rolls-Royce to sell a number of Nene and Derwent V turbojet engines to the Soviet Union. Klimov OKB was given the task of "metrifying" the British designs, without the knowledge or permission of the West, as the VK-1 and RD-500. Klimov United Engine Company is now located in Saint-Petersburg region. M-100 - Hispano-Suiza 12Ydrs built under license M-103 - improved M-100 M-105 - improved M-103.
Sir Richard Stafford Cripps, was a British Labour politician of the first half of the twentieth century. A wealthy barrister by background, he entered Parliament at a by-election in 1931, was one of a handful of Labour front-benchers to retain his seat in the general election that autumn, he became a leading spokesman for the left-wing and cooperation in a Popular Front with Communists before 1939, in which year he was expelled from the Labour Party. During World War II he served as Ambassador to the USSR, during which time he grew wary of the Soviet Union, but achieved great public popularity because of the entry of the USSR into the war, causing him to be seen in 1942 as a potential rival to Winston Churchill for the premiership, he became a member of the War Cabinet of the wartime coalition, but failed in his efforts to resolve the wartime crisis in India, where his proposals were too radical for Churchill and the cabinet, too conservative for Gandhi and other Indian leaders. He served as Minister of Aircraft Production, an important post but outside the inner War Cabinet.
Rejoining the Labour Party in 1945, after the war he served in the Attlee Ministry, firstly as President of the Board of Trade and between 1947-50 as Chancellor of the Exchequer. In the latter position, Cripps was responsible for laying the foundations of Britain's post-war economic prosperity, was, according to historian Kenneth O. Morgan, "the real architect of the improving economic picture and growing affluence from 1952 onwards"; the economy improved after 1947, benefiting from American money given through grants from the Marshall Plan as well as loans. However it was hurt by the devaluation of the pound in 1949, he kept rationing in place to hold down consumption during an "age of austerity", promoted exports and maintained full employment with static wages. The public respected "his integrity and Christian principles". Cripps was born in London, the son of Charles Cripps, a barrister and Conservative MP, the former Theresa Potter, the sister of Beatrice Webb and Catherine Courtney. Cripps grew up in a wealthy family and was educated at Winchester College, where the Headmaster described him as "a good fellow" and at University College London, where he studied Chemistry.
He left science for the law, in 1913 was called to the bar by the Middle Temple. He served in the First World War as a Red Cross ambulance driver in France, managed a chemical factory producing armaments, he remained a barrister during the 1920s, where he specialised in patent cases, was reported to be the highest paid lawyer in England. He was appointed a King's Counsel in 1927, he belonged to no church. In the 1920s he became a leader in the World Alliance to Promote International Friendship through the Churches, as his father had been. In 1923 to 1929 Cripps was its most energetic lecturer. At the end of the 1920s Cripps moved to the left in his political views, in 1930 he joined the Labour Party; the next year, Cripps was appointed Solicitor-General in the second Labour government, received the customary knighthood. In 1931, Cripps was elected in a by-election for Bristol East. During this time in parliament, he was a strong proponent of Marxist social and economic policies, although his strong faith in evangelical Christianity prevented him from subscribing to the Marxist rejection of religion.
In the 1931 general election, Cripps was one of only three former Labour ministers to hold their seats alongside the party leader George Lansbury and deputy leader Clement Attlee. In 1932 he helped found and became the leader of the Socialist League, composed of intellectuals and teachers from the Independent Labour Party who rejected its decision to disaffiliate from Labour; the Socialist League put the case for an austere form of democratic socialism. He argued that on taking power the Labour Party should enact an Emergency Powers Act, allowing it to rule by decree and thus "forestall any sabotage by financial interests,” and immediately abolish the House of Lords. In 1936, Labour's National Executive Committee dissociated itself from a speech in which Cripps said he did not "believe it would be a bad thing for the British working class if Germany defeated us". Cripps opposed British rearmament: "Money cannot make armaments. Armaments can only be made by the skill of the British working class, it is the British working class who would be called upon to use them.
To-day you have the most glorious opportunity that the workers have had if you will only use the necessity of capitalism in order to get power yourselves. The capitalists are in your hands. Refuse to make munitions, refuse to make armaments, they are helpless, they would have to hand the control of the country over to you". Cripps was an early advocate of a United Front against the rising threat of fascism and he opposed an appeasement policy towards Nazi Germany. In 1936 he was the moving force behind a Unity Campaign, involving the Socialist League, the Independent Labour Party and the Communist Party of Great Britain, designed to forge electoral unity against the right. Opposed by the Labour leadership, the Unity Campaign failed in its intentions. Rather than face expulsion from Labour, Cripps dissolved the Socialist League in 1937. Tribune, set up as the campaign's newspaper by Cripps and George Strauss, survived. In early 1939, Cripps was expelled from the Labour Party for his advocacy of a Popular Front with the Communist Party, the Independent Labour Party, the Liberal Party and anti-appeasement Conservatives.
When Winston Churchill formed his wartime coalition government in 1940 he appointed Cripps
The Mikoyan-Gurevich MiG-21 is a supersonic jet fighter and interceptor aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. It was popularly nicknamed "balalaika", from the aircraft's planform-view resemblance to the Russian stringed musical instrument or ołówek by Polish pilots due to the shape of its fuselage, it was nicknamed "Én bạc" by North Vietnamese, now Vietnam People's Air Force and the Vietnamese people. 60 countries over four continents have flown the MiG-21, it still serves many nations six decades after its maiden flight. It made aviation records, became the most-produced supersonic jet aircraft in aviation history, the most-produced combat aircraft since the Korean War and the longest production run of a combat aircraft; the MiG-21 jet fighter was a continuation of Soviet jet fighters, starting with the subsonic MiG-15 and MiG-17, the supersonic MiG-19. A number of experimental Mach 2 Soviet designs were based on nose intakes with either swept-back wings, such as the Sukhoi Su-7, or tailed deltas, of which the MiG-21 would be the most successful.
Development of what would become the MiG-21 began in the early 1950s, when Mikoyan OKB finished a preliminary design study for a prototype designated Ye-1 in 1954. This project was quickly reworked when it was determined that the planned engine was underpowered. Both these and other early prototypes featured swept wings; the first prototype with delta wings as found on production variants was the Ye-4. It made its maiden flight on 16 June 1955 and its first public appearance during the Soviet Aviation Day display at Moscow's Tushino airfield in July 1956. In the West, due to the lack of available information, early details of the MiG-21 were confused with those of similar Soviet fighters of the era. In one instance, Jane's All the World's Aircraft 1960–1961 listed the "Fishbed" as a Sukhoi design and used an illustration of the Su-9'Fishpot'; the MiG-21 was the first successful Soviet aircraft combining fighter and interceptor characteristics in a single aircraft. It was a lightweight fighter, achieving Mach 2 with a low-powered afterburning turbojet, is thus comparable to the American Lockheed F-104 Starfighter and Northrop F-5 Freedom Fighter and the French Dassault Mirage III.
Its basic layout was used for numerous other Soviet designs. However, the characteristic layout with the shock cone and front air intake did not see widespread use outside the USSR and proved to have limited development potential because of the small space available for the radar. Like many aircraft designed as interceptors, the MiG-21 had a short range; this was exacerbated by the poor placement of the internal fuel tanks ahead of the centre of gravity. As the internal fuel was consumed, the center of gravity would shift rearward beyond acceptable parameters; this had the effect of making the plane statically unstable to the point of being difficult to control, resulting in an endurance of only 45 minutes in clean condition. This can be somewhat countered by carrying fuel in external tanks closer to the center of gravity; the Chinese variants somewhat improved the internal fuel tank layout, carry larger external fuel tanks to counter this issue. Additionally, when more than half the fuel was used up, violent maneuvers prevented fuel from flowing into the engine, thereby causing it to shut down in flight.
This increased the risk of tank implosions, a problem inherited from the MiG-15, MiG-17 and MiG-19. The short endurance and low fuel capacity of the MiG-21F, PF, PFM, S/SM and M/MF variants—though each had a somewhat greater fuel capacity than its predecessor—led to the development of the MT and SMT variants; these had an increased range of 250 km compared to the MiG-21SM, but at the cost of worsening all other performance figures, such as a lower service ceiling and slower time to altitude. The delta wing, while excellent for a fast-climbing interceptor, meant any form of turning combat led to a rapid loss of speed. However, the light loading of the aircraft could mean that a climb rate of 235 m/s was possible with a combat-loaded MiG-21bis, not far short of the performance of the F-16A. Given a skilled pilot and capable missiles, it could give a good account of itself against contemporary fighters, its G-limits were increased from +7Gs in initial variants to +8.5Gs in the latest variants. It was replaced by the newer variable-geometry MiG-23 and MiG-27 for ground support duties.
However, not until the MiG-29 would the Soviet Union replace the MiG-21 as a maneuvering dogfighter to counter new American air superiority types. The MiG-21 was exported and remains in use; the aircraft's simple controls, engine and avionics were typical of Soviet-era military designs. The use of a tail with the delta wing aids stability and control at the extremes of the flight envelope, enhancing safety for lower-skilled pilots. While technologically inferior to the more advanced fighters it faced, low production