Shenyang J-11

The Shenyang J-11 (Chinese: 歼-11) is a twin-engine jet fighter of the People's Republic of China derived from the Soviet-designed Sukhoi Su-27. It is manufactured by the Shenyang Aircraft Corporation (SAC). The aircraft is operated by the People's Liberation Army Air Force (PLAAF) and the People's Liberation Army Naval Air Force (PLANAF).

Proposed J-11
Based on experience from the Vietnam War, the PLAAF issued a requirement in 1969 for a STOL light fighter to replace the Shenyang J-6 and Nanchang Q-5. The proposal from the Shenyang Aircraft Design Institute and Shenyang Aircraft Factory was designated "J-11"; it resembled a French Dassault Mirage F1 and was powered by a British Rolls-Royce Spey 512 engine. The project was abandoned as no suitable engine could be procured, and the competing Nanchang J-12 was far more advanced.

Su-27 purchase
China was the Su-27's first export customer. China turned to the Soviet Union for weapons following the 1989 Tiananmen Square protests and the resulting Western arms embargo. China selected the Su-27 over the Mikoyan MiG-29. Three orders were made in the 1990s, and the deliveries of 36 Su-27SKs and 42 Su-27UBKs started in 1992 and continued into the 2000s.

J-11
In 1996, China and Rosoboronexport entered a US$1.2 billion agreement permitting SAC to produce 200 Su-27UBKs under license. Production would start using kits manufactured by Komsomolsk-on-Amur Aircraft Plant (KnAPPO). Subsystems (avionics, radars and engines) would be imported from Russia and not be produced under license. Furthermore, the agreement prohibited China from exporting its production. Production began in 1997. The first two were completed in December 1998 but were poorly assembled and required Russian assistance to rebuild. Five were built by 2000, and another 20 by 2003, by which time production was of high quality and incorporated local airframe parts; Russia did not object to local airframe parts, which allowed KnAPPO to reduce the contents of the kits supplied. Russia resisted China's demands for upgraded avionics, eventually upgrading the obsolescent N001 pulse-Doppler radar with the improved N001V. Production of the J-11A, an "indigenous" variant, began in 2000. By 2006, at least 105 J-11 and J-11As had been produced with improved domestic avionics.

Co-production reportedly ended in 2004 with the development of the J-11B "Flaming Dragon". - a variant with domestic subsystems, which was in violation of the co-production agreement. However, through 2009 China continued to hold licenses to produce Russian aircraft and components, which included previously confidential provisions concerning intellectual property. The original licence did not officially include carrier-capable aircraft (e.g. Sukhoi Su-33) or variants (e.g. Shenyang J-15).

By 2015, J-11s were upgraded with Chinese-made missile approach warning systems (MAWS). Unconfirmed upgrades included improved cockpit displays, and fire control systems for R-77 or PL-10 missiles.

J-11B
The J-11B is a multirole variant of the J-11 incorporating Chinese subsystems. It was conceived as a way to remove the J-11's dependency on Russia. SAC unveiled a J-11B mockup in mid-2002. Three prototypes were delivered to the PLAAF for testing in 2006. The two-seater J-11BS followed two years after the J-11B. By 2011, reportedly 90% of the J-11B was based on subsystems and parts designed in China, with the engine presumably being a major part of the remainder. Many domestic subsystems are improvements of those found on the Su-27SK.

Chinese subsystems on the J-11B include Type 1474 radar, 3-axis data system, power supply system, emergency power unit, brake system, hydraulic system, fuel system, environment control system, molecular sieve oxygen generation systems, digital flight control system, and glass cockpit. The airframe is slightly lighter due to greater use of composites.

The J-11B may carry the PL-12 and PL-15 air-to-air missiles

Engine replacement
By 2004, the J-11 was being tested with the Shenyang WS-10. Testing may have started as early as 2002; an image from the 2002 China International Aviation & Aerospace Exhibition allegedly depicted a J-11 with one engine replaced with a WS-10. WS-10 development proved difficult. One regiment converted to WS-10-powered J-11Bs in 2007, but was grounded for an extended period due to poor operational reliability. The WS-10A reportedly matured enough after 2009 to power the J-11B Block 02 aircraft, and Jane's reported the J-11B as powered by the WS-10 in 2014.

Operational history
PLAAF J-11Bs participated in Shaheen 1, a joint Sino-Pakistani exercise, in March 2011. This was the first time the PLAAF conducted "operational" aerial maneuvers in Pakistan with the PAF.

P-8 interception
On 19 August 2014 a J-11B intercepted a U.S. Navy P-8 Poseidon anti-submarine warfare aircraft that was over the South China Sea.

The U.S. Department of Defense released details at a press conference on 22 August 2014 with Admiral John Kirby as spokesperson. According to Kirby, the incident occurred 135 mi east of Hainan Island, in international airspace. The Chinese jet "crossed under the aircraft with one pass having only 50–100 feet [50 - 100 ft] separation. The Chinese jet also passed the nose of the P-8 at 90 degrees with its belly toward the P-8 Poseidon, believed to be displaying its weapons load-out. Afterwards, the J-11 flew directly under and alongside the P-8, bringing their wingtips, as I said, to within 20 feet [20 ft]. And then conducted a roll over the P-8, passing within 45 feet [45 ft]." He said the "unprofessional" and "unsafe" actions of the Chinese pilot was "not keeping with the kind of military-to-military relationship" the U.S. sought to establish with China. An official complaint was sent to China through regular diplomatic channels. The Pentagon commented further that: "Military activities may be conducted within the Exclusive Economic Zone of another nation as an exercise of the freedoms of navigation and overflight."

In response, the Chinese Ministry of National Defense spokesman Yang Yujun said that the U.S. criticisms were "totally groundless" as the Chinese pilot professionally maintained a safe distance. Furthermore, he blamed the "massive and frequent close-in surveillance" by the U.S. as the root cause, and called for the end of surveillance flights to improve bilateral military ties.

Variants

 * J-11: License-produced Su-27UBKs from Russian-provided kits.
 * J-11A: J-11s produced with greater domestic content and improved avionics and cockpit displays. Some older J-11s and J-11As were upgraded to similar standard.
 * J-11A MLU: J-11 mid-life upgrade program for the J-11A matching up to the J-11B standard, and includes improved avionics, such as missile approach warning system (MAWS), full glass cockpit, and new radar systems.
 * J-11B (Flanker-L ): Chinese-developed variant with domestic subsystems including Type 1493 radar and an added internal ECM system. Block 02 was powered by Shenyang WS-10 turbofan.
 * J-11BS (Flanker-L ): A twin-seat version of the J-11B. In 2012, the number of J-11B and J-11BS in service was over 120.
 * J-11BH: Naval version of the J-11B. It was first sighted in May 2010.
 * J-11BSH: Naval version of the J-11BS.
 * J-11BG: Image first shown in September 2019 of an upgraded variant with light-grey radome. Further information confirmed the existence of the J-11BG upgrade including AESA radar, avonics upgrade, helmet-mounted sight, and the capability to launch PL-10 and PL-15 missiles.
 * J-11BGH: Upgrade of J-11BH, the naval version of the J-11BG.
 * J-11D: Variant possibly equipped with fixed electronically scanned array radar, IRST, and capability to fire heavier imaging/infrared (IIR) air-to-air missiles. The airframe makes greater use of composite materials, especially in the engine intakes, for lower radar observability. The wings have three hardpoints each. Unconfirmed reports claim it has a new fly-by-wire control system, glass cockpit, improved EW systems, and an improved version of the WS-10A engine, called WS-10B. Three prototypes were built between 2015 and 2016 with test flight conducted during the same period. The project was reportedly abandoned in favor of J-11BG upgrades for PLAAF and J-15B upgrades for PLANAF.

Operators

 * People's Liberation Army Air Force: 100 J-11A, 180 J-11B and 90 J-11BS
 * 1st Fighter Aviation Division
 * 6th Fighter Division
 * 7th Fighter Division
 * People's Liberation Army Naval Air Force: 40 J-11BH and 32 J-11BSH
 * Naval Aeronautics University Regiment
 * 22nd Air Regiment
 * 24th Air Regiment
 * 25th Air Regiment
 * 25th Air Regiment