Russia is not conceding defeat in its effort to halt Chinese theft of Russian military technology. This can be seen in China having more difficulty than it will admit in its battle to free itself from dependence on Russia for high-performance jet engines for its top-line jet fighters. This surfaced recently when China protested restrictions Russia was insisting on for the use of AL-31FN engines China ordered two months ago. Russia wants guarantees that the AL-31FNs will only be used to power Chinese warplanes, and that none of them will be disassembled to assist Chinese engineers in perfecting the illegal Chinese clone of the AL-31FN, the WS-10A. China is resisting these restrictions, which simply makes the Russians more insistent. China has been stealing Russian military tech for years, especially since the end of the Cold War. Back then, Russia could no longer to buy new military gear, and it was only orders from China and India that were keeping many Russian defense firms in business. This was, and still is, particularly true with Russian manufacturers of military jet engines. Thus Russia wants, and still needs, the sales, but does not want China to become a competitor by using stolen Russian technology.
And then there's the problem with China not wanting to admit that its own engine development efforts have consistently come up short. For example, last year, China revealed that it was replacing the engines in its J-10 fighter, installing Chinese made WS-10A in place of the Russian made AL-31FN. Then, two months ago, China ordered another 123 AL-31FNs, to be delivered over the next two years.
The Chinese claim the WS-10A is superior to the AL-31F, even though the WS-10A copied a lot of the Russian technology. The Chinese say they have improved on that. For example, as delivered from Russia, the original AL-31 was good for 900 hours of operation. Chinese engineers figured out how to tweak the design of the engine so that it would last for 1,500 hours. Russia has since improved their basic AL-31 lifetime to 1,500 hours, and, most recently, 2,000 hours. When pressed, the Chinese will claim that they cannot produce enough WS-10As for all the new airframes they are building. But the reality is that the WS-10As have some serious, and unpredictable, reliability problems.
China believes it will be free from dependence on Russia for military jet engines within the next five years, which implies that Chinese engine manufacturers still have a way to go. For years, China has imported two Russian engines, the $3.5 million AL-31, and the $2.5 million RD-93 (a version of the MiG-29's RD-33) for the JF-17 (a F-16 type aircraft developed in cooperation with Pakistan.) But in the meantime, Chinese engineers have managed to master the manufacturing techniques needed to make a Chinese copy of the Russian AL-31 engine. This Chinese copy, the WS-10A, is part of a program that has also developed the WS-13, to replace the RD-93 as well. While the Chinese have been able to build engines that are durable, they are still having problems with reliability.
China has long copied foreign technology, not always successfully. But in the last decade, China has poured much money into developing a jet engine manufacturing capability. The Chinese encountered many of the same problems the Russians did in the beginning. Developing the necessary engine design and construction skills is difficult. But China has several advantages. First, they knew of the mistakes the Russians had made, and so were able to avoid many of them. Then there was the fact that China had better access to Western manufacturing technology (both legally and illegally). Finally, China was, unlike the Soviets, able to develop their engine manufacturing capabilities in a market economy. This was much more efficient than the command economy that the Soviets were saddled with for seven decades. The Chinese consider the J-10 and WS-10A part of the learning process, and they do learn from their mistakes.
