Since a long time there have been talks of China working on some type of stealthy fighter attack aircraft which is called XX-J ,J-X or J-XX by western intelligence sources. The information available is scarce about this new advanced combat aircraft coupled with informed speculation, wild guesstimates, and active disinformation. The Chinese government is under no obligation to set the record straight, and indeed has every incentive to add to the general speculation.
Russia and India are in a joint venture of developing the Sukhoi PAK FA / T-50 , which first flew in January 2010. In June 2001, India was offered ‘joint development and production’ of this new 5th generation fighter by Russia. Russia had been trying to sell this concept both to China and India for some time. It seems probable that China declined to participate in this project given a belief that Russia stood to gain more from Chinese participation than did China. China had determined that it could produce a superior product without Russian help. With the first flight of the Russian stealth fighter in 2010, an arguably superior Chinese steath fighter might be expected to take to the skies not too long thereafter.
A 2006 article in Military Technology referred to three designs; Shenyang J-12 and Shenyang J-14 by 601 Institute Shenyang Aircraft Corporation [SAC] and Chengdu J-13 by 611 Institute Chengdu Aircraft Corporation [CAC]. The report in Military Technology featured a picture of a completely different design, speculatively dubbed J-14 and said to be a Shenyang project, with the designations J-12 and J-13 being applied to (possibly competing) designs by Shenyang and Chengdu respectively.
Shenyang Airplane Corporation (SAC) is in charge of the large, twin-engine J-8 fighters in service with the PLAAF (People’s Liberation Army Air Force) as well as of licence production of the Su-27SK under the local designation of J-11. The other study group is the 611 Institute from Chengdu Airplane Corporation (CAC).
By January 2007 Shenyang Aircraft Corporation (SAC) and Chengdu Aircraft Industry Co. (CAC), China’s two major fighter aircraft enterprises, were both reportedly working on advanced fighter designs slated to enter the PLAAF service as soon as 2015. Chengdu was focused in developing an enlarged twin-engine, 4th generation stealthy version of the J-10 fighter, possibly designated J-13. Shenyang was focusing on an entirely new 5th generation F-22-class stealth fighter, possibly designated the J-12. Both projects were believed to have benefited from Russian technologies.