China is believed to have been conducting preliminary research on its fourth-generation fighter aircraft since the late 1990s. The fighter, codenamed by Western intelligence as J-XX or XXJ, was described as an advanced F-22-class twin-engine stealth fighter with extensive radar cross section (RCS) reduction features such as internal weapon bay. So far very little information regarding the project has been revealed, though it is understood that the two primary fighter aircraft design institutes of the China Aviation Industries Corporation (AVIC) – Shenyang Aircraft Design Institute (601 Institute) and Chengdu Aircraft Design Institute (611 Institute) – have both been working on their own designs to bid for the PLA’s contract.
In 1997, the U.S. Office of Naval Intelligence (ONI) reported that an advanced F-22-class twin-engine stealth fighter XXJ was being developed by 601 Institute and Shenyang Aircraft Corporation (SAC). In 2001, an Internet source photo showed a F-22-like aircraft model was being tested in a wind tunnel at 601 Institute. At the same time, it was revealed that 611 Institute was also working its own advanced fighter aircraft design, possibly based on the design and technology of its J-10 fighter.
Despite intensive media interest, it is very likely that the fighter programme is still in its early theoretical evaluation (论证) and programme definition (方案) stage, during which various technologies are examined to meet operational requirements. Theoretical evaluation of the programme and development of key technologies and sub-systems would also be carried out in these stages. While China may be able to benefit from some “off-the-shelf” dual-use technologies available in the commercial market, it will almost definitely seek assistance from its traditional military technology supplier such as Russia, as well as some Western countries.
There has been speculations China’s fourth-generation fighter could enter service as early as 2015. However, designing and developing a fighter of this class will involve huge amount of investment and technology advancement across many fields, including new materials, high-performance aero-engine, avionics, flight control software, stealth technology, computer-aid design and manufacture (CAD/CAM). Only very few countries in the world nowadays possess the capability of designing and developing a modern high-performance fighter aircraft independently, and a project of this scale could last decades before the aircraft finally enters service.
Russian Sukhoi Company (JSC), which has developed close ties with Shenyang over the licensed co-production of its Su-27SK fighter as J-11, has been reportedly working with Shenyang in developing the next-generation fighter technology and sub-systems. Although Russia has yet been able to develop an operational stealth fighter, the J-XX project may benefit from its technologies in two particular areas: thrust vectoring engine and stealth design. Additionally, China may also seek potential partners from Russia, Israel and Europe to co-develop avionics and weapon suites for its 4th-generation fighter aircraft.