Back in the 1990s, China bought a prototype of the Russian built Su-33 Falcon (a navalized version of the Su-27 Flanker) from Ukraine, and has reverse engineered the plane to produce its own naval fighter, designated the J-15. The Chinese plan to fly the J-15 off an aircraft carrier, if they're ever able to produce a working one.
A Russian military official now says the Chinese fighter knock-off will be an inferior product:
"The Chinese J-15 clone is unlikely to achieve the same performance characteristics of the Russian SU-33 carrier-based fighter, and I won’t rule out the possibility that China could return to negotiations with Russia on the purchase of a substantial batch of SU-33s," said Col. Igor Korotchenko, a member of the Defense Ministry's Public Council.Of course, this could be an indication that Russia fears China is encroaching on potential foreign military sales. Or, the Chinese still aren't able to produce cutting edge fighter aircraft of their own. Although, its not like a lot of countries are flying jets off carriers so I'm not sure how many sales the Chinese could potentially take away from Sukhoi.
Korotchenko said that China was unlikely to solve technical problems related to the design of the folding wings and to develop a reliable engine for the aircraft, although the first J-15 prototype reportedly made its maiden flight on August 31, 2009, powered by Chinese WS-10 turbofan engines."
-- Greg Grant