Su-27 Air-Superiority Fighter Aircraft
Last updated: 29 February 2008
The Sukhoi Su-27 (NATO codename: Flanker) is the twin-engine front-line fighter aircraft designed by the Russian Sukhoi Design Bureau in the late 1970s as a counter to the U.S. third-generation air-superiority fighters such as F-14 and F-15. The PLA Air Force (PLAAF) has acquired three batches totalling 76 Su-27 fighters from Russia since 1992. Two variant are currently serving with the PLAAF: the single-seat Su-27SK fighter manufactured by KnAAPO at Komsomolsk-na-Amur and the two-seat Su-27UBK fighter-trainer manufactured by IAPO at Irkusk. The Su-27SK is also built under license at Shenyang Aircraft Industry Co. (SAC) as the J-11.
High-level negotiations between Beijing and Moscow over a possible fighter deal began in 1990. Soviet pilots demonstrated the Mikoyan-Gurevich MiG-29 Fulcrum and Sukhoi Su-27 Flanker fighters in Beijing in March 1991. After careful evaluations, the PRC signed the contract of 26 Su-27 fighters, including 20 single-seat Su-27SK (Flanker-B) and 6 two-seater Su-27UBK (Flanker-C). The delivery of these aircraft was completed by 1992, making the PRC the first non-CIS country to operate the Su-27. These aircraft were initially operated by the PLAAF 3rd Aviation Division / 7th Fighter Regiment based at Wuhu AFB, Anhui Province, and later transferred to 19th Air Division / 55th Fighter Regiment based at Jining, Henan Province.
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| Su-27SK of the 19th Air Division / 55th Fighter Regiment (Chinese Internet) |
After showing interest in 1993 in acquiring a second batch of the Su-27, the PRC ordered 22 of the fighters (16 Su-27SKs and 6 Su-27UBKs) in 1995 in a deal worth about US$710 million. In reporting to the United Nations, both the PRC and Russia confirmed that the transfer of 22 aircraft took place in 1996. A Russian source noted that China requested special modifications for its aircraft, which included strengthened landing gear to enable the aircraft to carry its designed fuel load and enable its intended 1,400km combat radius. These aircraft are operated by an aviation regiment organic to the PLAAF 2nd Aviation Division based on Suixi AFB, Guangdong Province.
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| Su-27SK of the 2nd Air Division / 6th Fighter Regiment (Chinese Internet) |
In 1995, the PRC expressed interest in a licensed co-production of the Su-27SK single-seat fighter. In 1996, Sukhoi Company (JSC) and Shenyang Aircraft Corporation (SAC) entered into a contract worth US$2.5 billion for the co-production of 200 Su-27SK fighters as the J-11. Under the terms of the agreement, Sukhoi/KnAAPO would supply the aircraft in kit form to be assembled in SAC. Russia was also responsible for supplying the PRC with the avionics suite and AL-31F turbofan engines for the J-11 production. (Main article: J-11 fighter)
The shortage of comparable training aircraft in the PLAAF for the new Su-27 pilots started to emerge in the late 1990s. This has resulted in the purchase of the third batch of 28 Su-27s, all in the two-seat UBK fighter-trainer variant, in 1999. These aircraft were delivered to the PLAAF in 2002 and are deployed by an aviation regiment organic to the PLAAF 33rd Aviation Division based at Baishiduo AFB, Chongqing.
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| Su-27UBK fighter-trainers of the 33rd Air Division and 1st Air Division (Chinese Internet) |
The Su-27 is the first PLAAF fighter aircraft capable of competing with modern Western fighters. The aircraft was demonstrated to the public for the first time during the 1996 PLA exercise to intimidate Taiwan, when China Central Television broadcasted images of PLAAF Su-27s flying in four-plane formation and attacking ground targets with unguided bombs and rockets. Later in the summer of 1999, Suixi-based Su-27s also flew round-trip missions over the Taiwan Strait during the PLA joint exercises. At least five Su-27s were reportedly destroyed during a typhoon in 1998, with several more lost during flight training over the years.
The limitations of the Su-27, however, soon became apparent to the PLAAF. As a single mission air superiority fighter, it could only perform secondary attack missions, and only with “dumb” munitions that include a range of free-fall bombs and unguided rockets. Using such munitions in combat unnecessarily exposes the expensive fighter to enemy air defence systems. This later led to the decision to purchase the multirole Su-30MKK.
Design
The Su-27 is a highly integrated twin-finned aircraft. The airframe is constructed of titanium and high-strength aluminium alloys. The engine nacelles are fitted with trouser fairing to provide a continuous streamlined profile between the nacelles and the tail beams. The fins and horizontal tail consoles are attached to tail beams. The central beam section between the engine nacelles consists of the equipment compartment, fuel tank and the brake parachute container. The fuselage head is of semi-monocoque construction and includes the cockpit, radar compartments and the avionics bay.
Each engine has two air intakes: a primary wedge intake and a louvered auxiliary air intake. The twin-shaft, turbo-fan engine has after-turbine flow mixing, a common afterburner, an all-mode variable area jet exhaust nozzle, an independent start and a main electronic control, and a reserve hydromechanical engine mode control system. The high-temperature sections of the engines are made of titanium alloy.
The Su-27 is powered by two Lyulka Engine Design Bureau (NPO Saturn) AL-31F turbofan engines. Each engine is rated at 17,857lb (79.43kN) dry and 27,557lb st (122.58kN) with afterburning. The aircraft only use internal fuel tank and does not carry any auxiliary tanks.
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