The fighter planes.
The Real Problem with China’s Aircraft Carriers
At the end of the day, the Chinese reverse engineered the J-15 design from an incomplete prototype of the Sukhoi Su-33 that it acquired from Ukraine. While Chinese engineers might have gained considerable insight into the Flanker design from the T-10K-3 and other Su-27 derivatives in Beijing’s possession, because they did not develop the jet or its systems, they do not fully understand the airframe due to some of the traditional limitations inherent to reverse engineering. These gaps in knowledge probably led to the some of the problems the Chinese are now encountering with the J-15 design.
China is developing a new carrier-based fighter aircraft to succeed the Shenyang J-15 Flying Shark.