In May, 2007, the existence of J-11B was finally acknowledged by the Chinese government for the first time when the state-run Chinese TV stations first aired the report on J-11B in PLAAF service. According to the Chinese report, which is agreed by some western sources such as Jane's Information Group, the J-11B is superior to Su-27SK in the following areas.
1) The wide adoption of composite material (mainly carbon fiber) for the surfaces, reducing the weight of the aircraft for more than 700 kg, while the life of the composite part is increased over 10,000 hours in comparison to the original part built from steel.
2) Redesigned air inlets of engine intakes to reduce the radar cross section, this coupled with the adoption of composite material, and application of radar absorbent material has reduced the radar cross section (RCS) of 15 square meters of Su-27SK to just >3 square meters of J-11B.
3) Full air-to-surface / sea capability is added and J-11B is able to launch various precision guided air-to-surface and air-to-sea munitions.
4) Certified to be equipped with WS-10 (will be upgraded to WS-10A in the future) turbofan engine, which is claimed to be cheaper to operate than AL-31F.
5) Incorporation of on-board oxygen generating system (OBOGS): With the exception of Su-35 and Su-37, J-11B is the first of the Su-27 family to incorporate such technology. Due to the adoption of western style design features such as fully digitized computerized controls and solid state micro-electronics, Chinese claimed that the domestic OBOGS is superior than the analog system Russia offered to China.
6) Improved radar. The new radar is able to track 8 targets at the same time, and engage 4 of the 8 tracked simultaneously. When used against large surface target such as a destroyer, the maximum range of the radar was in excess of 350 km. The range against aerial targets was not disclosed, but it would be definitely much shorter, as in all radars. The Chinese official report claims that the radar is better than the 147x/KLJ-X radar family, but stop short of identifying the exact type. Contrary to many erroneous comments by many domestic Chinese sources, which mistakenly claimed that the radar had adopted a passive phased array antenna, the official claims of many Chinese governmental sources such as technical journals and publications have revealed that the radar still adopted a slotted planar array antenna.
7) Fully digitized solid-state avionics has replaced the analogue one in Su-27SK. In the mid-2007, the Chinese governmental television station CCTV-7 released news clips of Chinese pilots in the cockpits of J-11B, with the LCD of glass cockpit of J-11B clearly visible, despite that the official report itself only claimed replacing the original avionics with domestic Chinese fully digitized solid-state avionics, and nothing of EFIS or glass cockpit was mentioned. In comparison to the earlier EFIS on J-11A, the most obvious difference is that LCD MFDs on J-11B are aligned in a straight line, instead of the middle one being slightly lower. The arrangement, appearance and layout of MFDs and EFIS of J-11B are similar to the general design concept of the west.
8) Missile Approach Warning System.
Professor Wang also revealed in the same interview that the J-11B will be equipped with domestic engines and J-11B is aerial refueling capable.
J-11BS is the tandem twin seater version of J-11B, J-11BS under development, reportedly as the Chinese version of Su-30MK2/3. It is rumored that the letter S stands for Shuangzuo, meaning twin seater in Chinese.
The existence of J-11BS is officially acknowledged by the Chinese government in 2007, and a large model of J-11BS was revealed public on June 9, 2007 during the opening ceremony of the new aerospace museum of the Harbin Institute of Technology at the 20-year anniversary of the establishment of its school of astronautics, where it is displayed. Some sources outside China have claimed that the successful development of J-11BS is one of reasons that China lacks the enthusiasm on purchasing Su-30MK3, but the Chinese government appears to be rather cautious with official reports only claiming that the project is very promising, instead of declaring it is successful already.
J-11C is the aircraft carrier version of J-11B, J-11C under development, reportedly as the Chinese version of Su-33. The first mock-up of J-11C was displayed in public at air shows and defense exhibitions in China in late 2002, and the mock-up is shown to be able to be armed with all currently available Chinese anti-ship missiles, as well as air-to-air missile including PL-12.