Sukhoi Su-27 / Shenyang J-11

Type: Air-superiority fighter
Designer: Sukhoi Design Bureau
Manufacturer: KnAAPO (Su-27SK); IAPO (Su-27UBK); Shenyang Aircraft Industry Corporation (J-11)
First flight: 1981 (Su-27S), 1985 (Su-27UB)
Introduction: 1992
Operators: PLA Air Force
Crew: 1 (Su-27SK/J-11), 2 (Su-27UBK)
In-flight refuelling: No

The Sukhoi Su-27 (NATO reporting name: ‘Flanker’) fighter was developed during the Cold War-era to counter the Western 4th-generation fighters such as the F-14 and F-15. China acquired a total of 76 examples of the aircraft between 1992 and 1999. Another 100 examples were built by Shenyang Aircraft Corporation (SAC) under license as the J-11. The Su-27 was the first PLAAF fighter aircraft capable of competing with modern Western fighters. The aircraft and its derivatives remain the backbone of the Chinese air power today.

History

The Su-27 front-line fighter was developed in the 1970s and first entered service with the Soviet Air Force in 1985. The aircraft was promoted to the international market in the early 1990s by a cash-hungry Soviet Union and later Russia. High-level negotiations between Beijing and Moscow over a possible fighter deal began in 1990. Soviet pilots demonstrated aircraft in Beijing in March 1991.

A contract was signed in 1991 to acquire 26 Su-27 fighters, including 20 examples of the single-seat Su-27SK ‘Flanker-B’ built by by KnAAPO at Komsomolsk-on-Amur and 6 examples of the two-seater Su-27UBK ‘Flanker-C’ built by IAPO at Irkusk. China also ordered unknown numbers of the R-27 (AA-10 ‘Alamo’) medium-range air-to-air missile and R-73 (AA-11 ‘Adder’) short-range air-to-air missile. The delivery of these aircraft and missiles was completed by 1992, making China the first non-CIS country to operate the Su-27. These aircraft were initially deployed by the PLAAF 3rd Air Division based at Wuhu Airbase, Anhui Province.

In 1995, China ordered a second batch of 22 Su-27s (16 SKs and 6 UBKs) in a deal worth about US$710 million. In reporting to the United Nations, both China 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 1,400 km combat radius. These aircraft are operated by the PLAAF 2nd Aviation Division based at Suixi Airbase, Guangdong Province.

The Su-27 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.

After China expressed its interest in a licensed co-production of the Su-27, in 1996 Sukhoi Company (JSC) and Shenyang Aircraft Industry Corporation (SAC) entered into a contract worth US$2.5 billion to build 200 examples of the Su-27 locally under the designation J-11. Under the terms of the agreement, Sukhoi/KnAAPO would supply aircraft kits to be assembled in SAC. Russia was also responsible for supplying the avionics suite and AL-31F turbofan engines.

To address the shortage of suitable training aircraft in the PLAAF for Su-27 pilot training, China ordered the third batch of 28 Su-27s, all in the two-seater UBK fighter-trainer variant, in 1999. These aircraft were delivered to the PLAAF in 2002 and were operated by the PLAAF 33rd Air Division based at Baishiduo Airbase, Chongqing.

The first kit-built J-11 rolled out in December 1998, but full-scale production did not commence until 2000 due to technical issues. Russian sources confirmed that 48 aircraft had been produced by 2002, and another 48 between 2002 and 2003. However, SAC hinted as early as 2000 that not all 200 J-11s would be built. In November 2004, Russian media reported that the J-11 production had stopped after about 100 examples were built. According to the report, the Chinese side had requested Sukhoi Company to stop deliveries of the assembly kits. The report citing a source within the PLAAF suggested that the basic variant Su-27SK/J-11 could no longer meet PLAAF requirements.

A number of reasons may have contributed to the stop of the J-11 production. Firstly, the co-production agreement did not include the transfer of avionics and engine technologies, and the Chinese-built J-11 would have to continue relying on Russia to supply these systems. Secondly, the Russian-made fire-control system was not compatible with Chinese weapons. As a result, the PLAAF had to import additional R-27 and R-73 missiles from Russia to support its Su-27/J-11 operations. Thirdly, as a single-mission air superiority fighter, the Su-27SK/J-11 could only deliver “dumb” munitions such as free-fall bombs and unguided rockets for ground attack missions.

Design

The aircraft features a mid-mounted and semi-delta wings with square tips. The leading-edge extension (LERX) extends downward and forward of the wing roots, with two rectangular air intakes underneath the fuselage and a large tail boom. The tail fins are swept-back, tapered with square tips, and mounted outboard of the engines. The horizontal stabilisers are mid-mounted, swept-back, and tapered. The nose is pointed with a bubble canopy.

The Su-27 was the first Soviet fighter aircraft to have adopted a fly-by-wire (FBW) control system. Combined with relatively low wing loading and powerful basic flight controls, it makes for an exceptionally agile aircraft, controllable even at very low speeds and high angle of attack.

Avionics

The Su-27 is equipped with a N001 Myech Pulse-Doppler fire-control radar developed by Tikhomirov Scientific Research Institute of Instrument Design (NIIP). The radar has track while scan and look-down/shoot-down capability, with a detecting-range of 80—100 km against fighter targets.

The aircraft also has an OEPS-27 electro-optic system, which consists of the OLS-27 infrared search and track (IRST) sensor and laser rangefinder. The system can detect enemy targets passively without requiring to turn on the fire-control radar, thus reducing the chance of the aircraft being detected.

Other avionics include:

– RLPK-27 helmet-mounted sight (HMS)
– SEI-31 integrated indication system
– ILS-31 head-up display (HUD) and CRT
– SPO-15 Beryoza RWR
– APP-50 IR decoy dispenser
– Sorbtsiya active jamming ECM pods (on wingtips)

Armament

Fixed weapon includes a single-barrel 30 mm GSh-301 internal cannon with 150 rounds. Up to 4,430 kg weapon load can be carried on the aircraft’s 10 external stores hardpoints, including 2 tandem under the fuselage centreline, 2 under the air ducts, 4 under the wings, and 2 on the wingtips.

For air-to-air mission, the aircraft can carry the Vympel R-73E/M (AA-11 ‘Archer’) IR-homing SRAAM (30 km range) and the Vympel R-27R/ER/T/ET (AA-10 ‘Alamo’) semi-active radar-homing MRAAM (80—130 km range).

For ground strike roles, the aircraft can carry the FAB-500/RBK-500 500 kg freefall bomb, FAB-250 250 kg freefall bomb, and B-8MI/B-13L/S-25 rocket pods.

Engines

The aircraft is powered by two Lyulka-Saturn AL-31F turbofan engine, each rate at 75.22 kN (7,670 kgf, 16,910 lbf) dry and 122.6 kN (12,500 kgf, 27,560 lbf) with afterburning. The aircraft cannot receive in-flight refuelling.

Specifications
Length (m): 21.9. Wingspan (m): 14.7. Height (m): 5.92 (Su-27SK/J-11), 6.30 (Su-27UBK). Empty weight (kg): 16,380. Loaded weight (kg): 23,430. Max take-off weight (kg): 30,450. Internal fuel capacity (kg): 9,400. Max level speed (Mach): 1.13 (sea-level), 2.35 (at altitude). Max climb rate (m/s): 300. Service ceiling (m): 19,000. Ferry range (km): 3,530. Combat radius (km): N/A. Max g-load: +9.
Image Gallery
Su-27SK / J-11
Su-27UBK

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