In November 2015, China became the Su-35's first export customer when the Russian and Chinese governments signed a contract worth $2 billion to buy 24 aircraft for the People's Liberation Army Air Force.[111][112] Chinese officials had reportedly first shown interest in the Su-35 in 2006,[113] it was not until 2010 that Rosoboronexport, the Russian state agency responsible for the export and import of defence products, was ready to start talks with China over the Su-35.[114] Russian officials publicly confirmed that talks had been going on in 2012, when a protocol agreement on the purchase was signed.[115] There were subsequent reports of the two countries signing a contract and of imminent deliveries,[116][117] but negotiations would not actually conclude until 2015.


China already imported 24 Su-35 in order to reverse engineer the planes to upgrade its technology, but why would the PLAAF consider buying additional planes if it has already enough planes to reverse engineer the planes?

“We are expecting a response from China on our offer to purchase modern weapons and military equipment manufactured in Russia, including additional batches of Su-35 fighter jets,” the service said on the sidelines of the “Army-2019″ forum outside of Moscow. According to Chinese media reports, the PLAAF is considering the acquisition of additional Su-35 fighter aircraft.


Are there other reasons why the PLAAF would buy additional Su-35 fighters?

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    Hold on. The initial Su-35 purchase was not to reverse engineer. Sukhoi had serious concerns with it because they had gotten burned before, on Su-27. The Chinese may have intended to reverse-engineer, but the sale was not agreed to on those terms. Can you clarify that? Commented Sep 13, 2021 at 7:18
  • 3
    Good answers below. Another speculative reason could be the China-India rivalry. India flies Russian and European planes, and had been modernizing its forces. China may also see a benefit in taking these planes off the market, even if indigenous alternatives exist. The added value of that, combined with the value of cementing relationships in the aerospace industry, might be enough to tip the scales.
    – Pete W
    Commented Sep 13, 2021 at 23:13
  • @PeteW You mean by dangling prospects of fat arms sales contracts to Russia, China can manipulate Russia into not selling to India, who is going to have a hard time matching Chinese purchase volumes? Commented Sep 15, 2021 at 4:01
  • @Italian Philosophers- I was thinking more directly, from the fact that overall production rate is limited in the short term
    – Pete W
    Commented Sep 15, 2021 at 13:33

3 Answers 3


There are a few possible reasons:

  1. Time - China wants the aircraft sooner than it can provide them domestically via reverse engineering.

  2. Equivalency - China can reverse engineer their existing aircraft, but that doesn't mean that what they can build is 1:1 equivalent in terms of performance, weight etc. Often, their reverse engineered variants of Russian aircraft have performance characteristics which differ from the originals enough for pilots to have issues transitioning, so China doesn't mix its originals/licensed builds and its reverse engineered variants in its squadrons - which means that if China wants to increase a particular foreign-equipped squadrons size, it either means replacing it entirely with its own variant or buying more aircraft from the OEM.

  3. Inability to produce high technology components - reverse engineering from an existing example gives you the physical dimensions and working parts, but it doesn't tell you how the advanced engine components or electronics were actually produced. Producing high performance, high energy, high temperature, resilient engine components is a high technology skill which China currently lacks, for example.

  4. Diplomatic reasons - China wants to butter up Russia for some reason, or Russia wants to be repaid for something. Horse trading, in other words.

  • first is the most likely. They feel the need for rapid expansion and their own industry isn't able to provide enough production capability quickly enough for the type or equivalents (like the J20) so they shop abroad at the only country willing to supply them, which is Russia.
    – jwenting
    Commented Sep 15, 2021 at 4:48

China used to depend on Russia in aircraft engines for jet fighters. Chinese engineers were unable to properly copy engines like AL-31 for a long time. Domestic engines like WS-10 were unreliable and had short service life. This put China in uncomfortable position because they have a significant air fleet that depend on AL-31 and can't move to WS-10 without significant penalty to Chinese combat capabilities. An unofficial rumor is that Russia used this as a leverage, offering to ship AL-31 engines only if China also purchases Russian fighters. This apparently worked in the past and it looks like Russia simply continues this practice.


There are a number of possible reasons (we wouldn't know unless the PLAAF tells us and they probably want to keep their actual motivations secret from the Russians anyway)

First, the original contract was not "to reverse engineer". China may have wanted to do that, but the Russians were not keen, having been burned on the SU-27. That's part of the wiki entry linked to (At one stage, Rosoboronexport demanded that China issue a legally binding guarantee against copying.) and Sergei's answer also mentions it (+1).

Does China's J-11 Fighter Jet Have Russian SU-27 "DNA"?

Key Point: China wants to build its own fighters and that means using any means to do it. In fact, Beijing has been buying, stealing, and copying foreign weapon systems for decades now.

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.

And this was part of the game here:

There are fears China’s decision to procure only 24 fighters indicates an intention to reverse engineer and copy the fighter, as it did with the Su-27SK. In 1995, China secured a $2.5 billion production license deal from Russia to build 200 Su-27SKs, dubbed the J-11A. In 2006, Russia killed the contract after 95 aircraft when it discovered China had reverse engineered the aircraft and was covertly manufacturing an indigenous variant, the J-11B, with Chinese-built avionics and weapons. ... Cliff, author of the new book, "China's Military Power: Assessing Current and Future Capabilities," said he was more skeptical of China reaping as much as many fear from the Su-35.

"Just buying examples of technologies, however, doesn't immediately convey the ability to make them oneself," he said. The best example of that is the AL-31 engine that goes into the Su-27 and Su-30.

"China has had access to that technology for over 20 years and apparently is still struggling to make its own high-performance turbofan engines."

Chinese cleverness in research and mass manufacturing is as well-known as their tendency to "appropriate" intellectual property. However, knowing what something is doesn't mean you know how to make it. Modern jet engines by the like of Rolls Royce have all sorts of wonderful arcane metallurgical stuff going on and you can look at them, but you can't look at the foundry that made them. That's what makes manufacturers like Pratt & Whitney, Rolls Royce or Snecma, as well as Sukhoi/Saturn special: decades of expertise and tinkering. Ditto with high-end chip manufacture: you can look at the finished products, but only the likes of TMSC and Intel know how to mass-produce really small chips on 5-7nm technology. And even Intel... hasn't been doing 10nm too well lately.

So that leaves us with another possible reason to buy another Su-35 lot: they want to use them, NOW.

China both will benefit from having Su-35s in its fleet directly. But perhaps more importantly, they can start experimenting with tactical military doctrine built around 4.5 generation fighters. It might be less the actual immediate firepower, or the extra access for copying reasons, than it is to train their air force.

Modern militaries are not just about owning a stable of high-end weapons. By that token, Saudi Arabia would be a military powerhouse. It is about, for decades, taking lots of very smart soldiers, running military exercises and seeing how best to use certain classes of weapons. You don't need the final weapons, but you need something in their class. For example, the Germans were testing tank doctrine in the USSR till the early 30s (great idea, comrade Stalin).

China has also done this, since 2012, with their first, Soviet-built, carrier.

Liaoning (16; Chinese: 辽宁舰; pinyin: Liáoníng Jiàn) is a Chinese Type 001 aircraft carrier. The first aircraft carrier commissioned into the People's Liberation Army Navy Surface Force, she was originally classified as a training ship, intended to allow the Navy to experiment, train and gain familiarity with aircraft carrier operations. Following upgrades and additional training in late 2018, Chinese state media announced that the ship would shift to a combat role in 2019.

The F-35 apparently routinely is out-dogged by F-16s, yet its pilots are still enthusiastic about it ("the other guys are fighting blind"). That requires a new doctrine, avoiding visual combat range engagements to maximize stealth advantages. So a SU-35 may want to close into specifically F35s instead. But again, you need multiple operational planes to practice, practice, practice with, way ahead of time. Rather than a few planes sitting around all disassembled. Citing Defense News again:

"In the mid-term, the development of this family is much more important for Chinese air power than their stealth aircraft programs," the J-31 and J-20 stealth fighters, Kashin said. "Exercising with one regiment of Su-35s will help them understand what direction can be chosen for the future of their heavy fighters fleet, what they can do themselves, when they have to go to the Russians for help, etc."

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    "At one stage, Rosoboronexport demanded that China issue a legally binding guarantee against copying" - as if China would ever respect such a guarantee.
    – Vikki
    Commented Sep 14, 2021 at 22:20
  • 1
    @Vikki Yeah, I immediately pictured the Chinese doing the Spanish laughing guy meme when reading that stipulation. It's doubly amusing because the Russians are equally unethical weasels who would happily do the exact same thing if the situation was reversed. The amusement builds when you realise that Russia is so broke that they don't have the wherewithal to walk away from any potential sale, regardless of how much the buyer is going to screw them over. (cont'd)
    – Ian Kemp
    Commented Sep 15, 2021 at 10:42
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    @Vikki (cont'd) Finally and most amusingly, China is likely to be the greatest threat to Russia in the long term, yet Russia is selling China weapons that will allow the latter to build the military that will one day crush the former.
    – Ian Kemp
    Commented Sep 15, 2021 at 10:44
  • @IanKemp is that any difference to the US funding the growth of an economy which will fairly soon eclipse all other economies?
    – user16741
    Commented Sep 20, 2021 at 11:09
  • 1
    @Moo The difference is that until around 2010, it seemed that China was content with being the factory of the world, and the US was happy with that. But that all changed with Xi Jinping.
    – Ian Kemp
    Commented Sep 20, 2021 at 11:19

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