Key Point: China is still dependent on Russia for its jet engines.
The Chinese defense industrial base is infamous for its tendency to “borrow” from foreign designs, particularly in the aerospace industry. Almost the entirety of China’s modern fighter fleet have either borrowed liberally from or directly copied foreign models. The J-10 was reputedly based on the Israeli IAI Lavi and by extension the United States’ General Dynamics F-16; the J-11 is a clone of the Russian Su-27; the JF-17 is a modern development of the Soviet MiG-21; the J-20 bears an uncanny resemblance to the F-22, and finally, the J-31 is widely believed to rely heavily on technology appropriated from the F-35 Joint Strike Fighter. Appropriation saves China time and money on research and development, allowing it to modernize the PLAAF at a fraction of the cost of its competitors. However, the appropriation strategy remains constrained by bottleneck technologies due to lack of testing data and industrial ecology. This problem is starkly illustrated by China’s ongoing difficulty in producing a high-quality indigenous jet engine.
The problem of technology mismatch, at its root, is that the thief lacks trade secrets and human capital associated with the manufacturing and assembly of a system. At the very least, this absence can make the replication of foreign systems a costly and time-consuming process, as the thief needs to develop manufacturing procedures from scratch. At worst, it can lead to seriously substandard components that reduce the capabilities and reliability of a system. Chinese efforts to reverse engineer certain Russian jet engines during the 1990s and 2000s invariably produced engines with extremely short lifespans, and without the power of their Russian counterparts. Even today, jet engines remain an obstacle for PLAAF fighter modernization, with its early 5th generation prototypes notably underpowered. Further complicating the problem, Russia is wary of supplying engines more powerful than the AL-31 used to power its Su-27s. However, China has several avenues to work around this.