Key Point: China is known for buying and stealing foreign technology in order to reverse engineer them. It looks like the Su-27 was no exception.
The Shenyang J-11 is a Chinese copy of the excellent Russian Sukhoi Su-27 “Flanker” multirole fighter. In fact, it was at first an authorized copy—but Chinese ambitions to adapt it with locally produced technology transformed it into a reverse-engineered headache for Russian industry. In successive variants, the J-11 and the Flanker-derived J-15 and J-16 have been at the forefront of Chinese efforts to produce long-range fourth-generation fighters that can contest the seas around China—if only Chinese engineers can work out the kinks in their domestically produced jet engines.
I’ve written before about the latest version of the Su-27, the Su-35, but let’s review the basics. The Flanker was a late Cold War design that in most respects served as a Russian counterpart to the F-15 Eagle: a “heavy,” but maneuverable, twin-engine multirole fighter that can fly at high speeds across long distances with a heavy missile or bomb load. The early Flanker can pull off even tighter maneuvers than the relatively agile F-15, and originally came with better short-range air-to-air missiles (the R-73); however, it lagged behind later F-15s in terms of sensors, though not nearly as much as its lighter stablemate, the MiG-29 Fulcrum.