Su-7 | |
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A Polish Su-7BKL photographed in 1991. | |
General information | |
Type | Fighter and fighter-bomber / ground-attack aircraft |
National origin | Soviet Union |
Manufacturer | Sukhoi |
Status | In limited service with the Korean People's Army Air Force |
Primary users | Soviet Air Forces (historical)
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Number built | 1,847 |
History | |
Manufactured | 1957–1972 |
Introduction date | 1959 |
First flight | 7 September 1955 |
Developed into | Sukhoi Su-17 |
The Sukhoi Su-7 (NATO designation name: Fitter-A) is a swept wing, supersonic fighter aircraft developed by the Soviet Union in 1955. Originally, it was designed as a tactical, low-level dogfighter, but was not successful in this role. On the other hand, the soon-introduced Su-7B series became the main Soviet fighter-bomber and ground-attack aircraft of the 1960s. The Su-7 was rugged in its simplicity, but its Lyulka AL-7 engine had such high fuel consumption that it seriously limited the aircraft's payload, as even short-range missions required that at least two hardpoints be used to carry drop tanks rather than ordnance. [1]
After Joseph Stalin's death, the Sukhoi OKB was reopened [2] and by the summer, it began work on a swept-wing front-line [N 1] fighter. The first prototype, designated S-1, was designed to use the new Lyulka AL-7 turbojet engine. It was the first Soviet aircraft to utilize the all-moving tailplane and a translating centerbody, a movable inlet cone in the air intake for managing airflow to the engine at supersonic speeds. [3] The aircraft also had a wing sweep of 60°, irreversible hydraulically boosted controls, and an ejection seat of Sukhoi’s own design. [2]
The S-1 first flew on 7 September 1955 with A. G. Kochetkov at the controls. Fitted with an afterburning version of the AL-7 engine after the first eleven flights, the prototype set a Soviet speed record of 2,170 km/h (1,170 kn, 1,350 mph, Mach 2.04) in April 1956. [3] The prototype was intended to be armed with three 37 mm Nudelman N-37 cannons and 32 spin-stabilized 57 mm (2.25 in) unguided rockets in a ventral tray. [3] The second prototype, S-2, introduced some aerodynamic refinements. Testing was complicated by the unreliable engine, and S-1 was lost in a crash on 23 November 1956, killing its pilot I. N. Sokolov. [2] Only 132 have been produced between 1957 and 1960, and the aircraft entered service as Su-7 in 1959.
The first production variant: a frontline [N 1] fighter that saw limited operational use in the Far East from 1958. However, in 1959, a decision was made to prioritize production of the MiG-21, thus less than 200 Su-7As were deployed. The Su-7A was retired in 1965 with operational deployment. [2]
On July 31, 1958, Soviet tactical aviation (Frontovaya Aviatsiya, [N 1] фронтовая авиация) tasked Sukhoi with developing a ground-attack variant of the Su-7, which could replace the scrapped Ilyushin Il-40. The resulting prototype, designated the S-22, incorporated structural refinements for low-altitude operations at high-speed. The prototype first flew in March 1959; entering service in 1961 as the Su-7B. [3]
Operationally, Su-7s were hampered by a high landing speed of 340–360 km/h. [4] This was dictated by the highly swept wing. Combined with poor visibility from the cockpit and the lack of an instrument landing system, operations were very difficult, especially in poor weather or airfields. [5] In 1961–1962, Sukhoi experimented with blown flaps on S-25 but the benefit was too small to warrant implementation. JATO rockets tested on S-22-4 proved more useful and were incorporated into the Su-7BKL. Attempts to improve takeoff and landing performance eventually resulted in the variable geometry Sukhoi Su-17.
The Su-7B and its variants became the main Soviet ground-attack aircraft of the 1960s. They were also widely exported (691 planes, [2] including some trainers). However, the very short combat radius and need for long runways limited the Su-7's operational usefulness. On the other hand, despite its notoriously heavy controls, the Su-7 was popular with pilots for its docile flight characteristics, simple controls and considerable speed even at low altitudes. It also had a reputation for easy maintenance.
In 1977–1986 the Su-7s remaining in Soviet service were replaced by Su-17s and MiG-27s.
The Su-7 saw combat with Egypt in the 1967 Six-Day War, the subsequent War of Attrition, and saw use in the Yom Kippur War by the Egyptians to attack Israeli ground forces.
The Indian Air Force (IAF) used the Su-7 extensively in the 1971 war with Pakistan. Six squadrons, totaling 140 aircraft, flew almost 1,500 offensive sorties during the war, [4] and undertook the bulk of the daytime attack missions. The IAF managed to retain a very high operational tempo with its Su-7s, peaking at a sortie rate of six per pilot per day. [4] Fourteen Su-7s were lost during the war, mostly due to anti-aircraft fire. [4] After the war, it was found that the aircraft had high survivability, being able to fly home safely despite receiving heavy damage. For example, Wing Commander H.S. Mangat's Su-7 was badly damaged by a PL-2 missile fired by a Pakistan Air Force F-6. The impact was so severe that half the rudder was missing, the elevators, ailerons, and flaps were severely damaged, and half the missile was stuck in the chute pipe. [4] [6] The pilot made it back to his base. The death of at least one Indian pilot can be attributed, at least indirectly, to poor cockpit design. A pilot had moved his seating forward to a dangerous position, "because he found the bombsight and the front gun sight easier to operate" while in that position and was killed on ejection. [7]
Indian Su-7BMKs shot down at least two Shenyang F-6s in the 1971 war, [4] while losing three Su-7s to F-6s according to Pakistani sources. [8]
A total of 1,847 Su-7 and its variants were built. [2]
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Current | Former |
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Data from Green, [3] Sukhoi [2]
General characteristics
Performance
Armament
Related development
Aircraft of comparable role, configuration, and era
Related lists
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: CS1 maint: numeric names: authors list (link)