The Shenyang J-11A arises from an agreement between Russia and China to manufacture 200 Su-27SK in China. The cost of the operation was about 2.5 billion US dollars, and the obligation, clearly fixed in the agreement, to install Russian engines, radars and avionics.Despite the agreement, China began to include a series of improvements with indigenous equipment that have practically turned the J-11A into a different aircraft. However, they had serious problems integrating the Chinese engines, because it seems that they were of lower quality than the Russians, and must be checked completely every few hours of flight.The modified model was finally “presented in public” in 2009, being designated as J-11B. Externally the aircraft is practically indistinguishable from the Su-27SK, but it has better aptitudes to perform a wide variety of missions, especially ground and anti-ship attack.One of the main modifications on J-11B consisted in the replacement of the Russian radar NIIP Tikhomirov N001VE Myech by a new Chinese Type 147X / KLJ-X radar family. Another important modifications has been the change of the Russian AL-31F engine by a Chinese WS.10A Taihang model and to adopt the Chinese PL-9 and PL-12 air to air missiles and dispose the Russians R-77 (AA-12 Adder) missiles.The J-11B became internationally known for the events that occurred on August 19, 2014, when a US Navy P-8 Poseidon aircraft was intercepted over the South China Sea. The reason for the scandal was not the interception itself, but the accusations by the Americans of the exceptionally dangerous maneuvers performed by the Chinese pilot, who endangered the American aircraft. China replied that these accusations lacked argument and blamed the problem to the constant American surveillance flights in that area, quite close to Chinese territory.Since 2009, different variants of the J-11 have been appearing, and one of the most outstanding is the one designated as J-11BH, which is a naval varian and has served as the basis for the subsequent J-15 Flying Shark multirole fighter. Here we can see one of the prototypes during their tests on the Liaoning aircraft carrier.The two-seater model is designated as J-11BS and is the variant created for attack missions. China attaches great importance to perform long-range air strike missions against the U.S. Navy’s Carrier Strike Groups (CSG), so the integration of anti-ship missiles is essential and the J-11BS is an ideal platform for this task. Here we see a J-11BS, currently, the Chinese Air Force has in service more than 200 J-11A, J-11B and J-11BS aircrafts. In addition, the Naval Aviation operates more than 70 J-11BH. Along with these units, the Air Force also has more than 30 unmodified Russians Su-27SK. The J-11A, J-11B and the two-seater J-11BS, (on the image), has the same features as the Su-27SK. The maximum speed, ceiling, range and weapons capacity is practically the same in all these models, although it is true that J-11 models are 10% heavier at full load.
