Chinese purchase of Su-35

SinoSoldier said:

That statement is an example of something without proof or evidence.



The Chinese also operate long-wavelength and ground-based AESA radars; in fact, that J-16's AESA radar is thought to be a L-band system that allows it to achieve extreme ranges. However, lower-frequency radars have trouble with tracking fast-moving objects, if I'm not mistaken, and hence both ends of the spectrum have their strong and weak points. The thing that separates China and Russia is that there are multiple Chinese institutes performing R&D on AESA systems, and subsystems for the PLAAF are selected via competition, whereas the same cannot be said for Russia or even most European countries. The Chinese have also deployed such systems longer, and on a wider variety of platforms, than has Russia.

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I agree with b787 that the arguments being presented that the Chinese are ahead than the Russians are simply assertions or conjectures rather than facts or evidence (at least in the last 30 or more recent posts I have seen on this subject). The Chinese are typically not forthcoming with the details and in the absence of facts how can one possibly conclude objectively? For example just on the subject of AESA, the capabilities and performance are highly dependent on many variables like TR count, antenna size, power ratings (peak and average), transmit/receive losses, signal processing, data bus architecture, software, integration architecture, drift algorithm filters, search vs track, use of multiple waveform and tech adoption (LNA, LPI et al). Unless there is some form of comparative analysis, I don't see how you can conclude one way or another.

Brumby said:

The way I see it, the SU-35 purchase is plan B being kicked into gear for the J-20 program. The WS-15 engine was always a difficult proposition in terms of delivery timeline. The SU-35 negotiations was a fall back plan in the event that the indigenous engine development doesn't come in on schedule. The tide waits for no one, and the show must go on. The 117S engine will have to make do as an interim solution to keep the J-20 going. China is not in the charity business. Having the knowledge to build and being able to build is not the same thing - not in the aircraft engine business.

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I don't necessarily see Su-35 purchase "only" as an interim -- after all there's a host of other alternatives they could have done and are doing that could deliver an interim product as well, such as J-11D or upgrading J-11Bs. If they'd purchased more Su-35s then it would look more convincing but 24 Su-35s (despite their degree of qualitative superiority over any other fighter in Chinese military FOC) simply seems too few to act as any meaningful interim force, especially when one considers the domestic alternatives aforementioned.

I've argued that there are a host of reasons that should all be taken together, including being able to access some of the latest Russian technology to take a look at it, simply having more advanced flankers to supplement SAC production, as well as geopolitical and defence cooperation reasons.

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Brumby said:

I agree with b787 that the arguments being presented that the Chinese are ahead than the Russians are simply assertions or conjectures rather than facts or evidence (at least in the last 30 or more recent posts I have seen on this subject). The Chinese are typically not forthcoming with the details and in the absence of facts how can one possibly conclude objectively? For example just on the subject of AESA, the capabilities and performance are highly dependent on many variables like TR count, antenna size, power ratings (peak and average), transmit/receive losses, signal processing, data bus architecture, software, integration architecture, drift algorithm filters, search vs track, use of multiple waveform and tech adoption (LNA, LPI et al). Unless there is some form of comparative analysis, I don't see how you can conclude one way or another.

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Hmm. I think we have no definitive proof or evidence that China is "way ahead" of Russia in avionics, because to do that we'll need to know relatively the detailed state of military aerospace avionics is for China and also for Russia, and we do not know either.

However it is not a point of conjecture that it has been a long time since China has required ToT of Russian avionics or other similar systems.

Therefore by definition one has to settle for the null hypothesis that no difference exists, but at the same time the general information and advancements we have witnessed in recent years cannot be ignored even if they lack detail.

Richard Santos said:

When one says


In all honesty, the possibility that China might get into a conflict with the US or Japan has not been this high in many years either. This is not to say the risk of war is in absolutely sense high, just that it is higher than before. One adjusts the balance between buying off the shelf foreign tech and developing domestic tech based partly on how urgently the tech could actually be needed.

So the fact that China has not seen fit to buy Russian in the years past, and has chosen to develop domestic alternatives instead when the threats were less, does not necessarily mean Chinese technology had already equalled or surpassed Russian technology. China could well have chosen to accept a moderate technology gap in order to encourage domestic development when the threat of conflict was more remote. China could well be procuring Su-35 now because the increased possibility of conflict in the near future required an accelerated delivery of functioning tech to operational units.

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That is true, but the reverse of what you suggested could also be true.

We don't have enough information to definitively say so either way.

There are just too many possibilities that we have to consider when looking to explain this purchase, all of which seem somewhat reasonable:
-Is it related to wanting Russian technology, which would imply a technology gap between Russia and China...
-Is it related to China simply wanting more fighters, which in turn could suggest a need for an interim for J-20, or possibly even because leadership views conflict in the short term as more likely... or simply something as innocent as SAC flankers being unable to keep up with the modernization rate the Air Force would like...
-Is it related to certain specific capabilities of Su-35 which China would like to gain experience with, such as having an operational fighter with TVC which could be useful for DACT...
-Is it related to certain subsystems of the Su-35 which China may want, such as the engines...
-Is it related to China wanting more geopolitical cooperation and defence cooperation overall with Russia and this is viewed as a way of further enhancing that relationship...
-Or could it be any of the above reasons to differing degrees acting together?

Bltizo said:

I don't necessarily see Su-35 purchase "only" as an interim -- after all there's a host of other alternatives they could have done and are doing that could deliver an interim product as well, such as J-11D or upgrading J-11Bs. If they'd purchased more Su-35s then it would look more convincing but 24 Su-35s (despite their degree of qualitative superiority over any other fighter in Chinese military FOC) simply seems too few to act as any meaningful interim force, especially when one considers the domestic alternatives aforementioned.

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Given the proposal is to acquire only 24 SU-35's, it would suggest to me the corresponding number of spare engines would be limited. This limited number fits better with the J-20 program in terms of unit requirement in the foreseeable future even if it goes onto LRIP. In contrast, an established program like the J-11 program would be best served by the local indigenous engine i.e. the 137kN rated WS-10 in terms of quantity. More importantly, the J-20 being a strategic program is currently constrained by an underrated engine.

Bltizo said:

Hmm. I think we have no definitive proof or evidence that China is "way ahead" of Russia in avionics, because to do that we'll need to know relatively the detailed state of military aerospace avionics is for China and also for Russia, and we do not know either.

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Agree and that was the point.

Brumby said:

Given the proposal is to acquire only 24 SU-35's, it would suggest to me the corresponding number of spare engines would be limited. This limited number fits better with the J-20 program in terms of unit requirement in the foreseeable future even if it goes onto LRIP. In contrast, an established program like the J-11 program would be best served by the local indigenous engine i.e. the 137kN rated WS-10 in terms of quantity. More importantly, the J-20 being a strategic program is currently constrained by an underrated engine.

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Wait, are you suggesting the Su-35s would be purchased for their engines to be used on J-20, or are you suggesting that the Su-35s are purchased as an interim for J-20, and that their engines with greater thrust could serve as an interim capability for J-20's capability?

Because if it is the latter, then obviously Su-35s cannot really serve as an interim for J-20 given the key capabilities J-20 will offer will be as a stealthy aircraft which Su-35 despite all its qualitative capabiltiies, is not. More importantly, if Su-35 is considered "acceptable" as an interim aircraft for J-20, J-11D could probably have similar capabilities in many domains to Su-35 without having to resort to the hassle of buying Su-35s. Which is one reason why I think that Su-35s coudl have been bought simply as a general additional supplement to the Chinese Air Force's existing flanker fleet

Agree and that was the point.

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Yes, but I also added that there are some general physical indicators over the years which prompt the initial suggestions to begin with...

Richard Santos said:

When one says


In all honesty, the possibility that China might get into a conflict with the US or Japan has not been this high in many years either. This is not to say the risk of war is in absolutely sense high, just that it is higher than before. One adjusts the balance between buying off the shelf foreign tech and developing domestic tech based partly on how urgently the tech could actually be needed.

So the fact that China has not seen fit to buy Russian in the years past, and has chosen to develop domestic alternatives instead when the threats were less, does not necessarily mean Chinese technology had already equalled or surpassed Russian technology. China could well have chosen to accept a moderate technology gap in order to encourage domestic development when the threat of conflict was more remote. China could well be procuring Su-35 now because the increased possibility of conflict in the near future required an accelerated delivery of functioning tech to operational units.

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I doubt that. For one thing, the possibility of China having an armed conflict over the issues of East China Sea or South China Sea is extremely remote. Exposing China's true strength over issues other than Taiwan prematurely will be a grave strategic blunder for China. In other words, China is highly unlikely to fight anyone in the ECS or SCS before they can solve the Taiwan problem. On the other hand, 24 won't be enough for a conflict over the Taiwan Strait. I don't think China is making this deal now for any specific reasons other than paying back Russia.

Bltizo said:

Wait, are you suggesting the Su-35s would be purchased for their engines to be used on J-20, or are you suggesting that the Su-35s are purchased as an interim for J-20, and that their engines with greater thrust could serve as an interim capability for J-20's capability?

Because if it is the latter, then obviously Su-35s cannot really serve as an interim for J-20 given the key capabilities J-20 will offer will be as a stealthy aircraft which Su-35 despite all its qualitative capabiltiies, is not. More importantly, if Su-35 is considered "acceptable" as an interim aircraft for J-20, J-11D could probably have similar capabilities in many domains to Su-35 without having to resort to the hassle of buying Su-35s. Which is one reason why I think that Su-35s coudl have been bought simply as a general additional supplement to the Chinese Air Force's existing flanker fleet

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Specifically I believe is for the 117S engine. The quantity buy of the SU-35 would not make a significant difference to the overall force structure even if it is an excellent plane.

Bltizo said:

Yes, but I also added that there are some general physical indicators over the years which prompt the initial suggestions to begin with...

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They are simply indicators that may fit a preferred narrative without the strength to conclude or exclude other possibilities.

Brumby said:

I agree with b787 that the arguments being presented that the Chinese are ahead than the Russians are simply assertions or conjectures rather than facts or evidence (at least in the last 30 or more recent posts I have seen on this subject). The Chinese are typically not forthcoming with the details and in the absence of facts how can one possibly conclude objectively? For example just on the subject of AESA, the capabilities and performance are highly dependent on many variables like TR count, antenna size, power ratings (peak and average), transmit/receive losses, signal processing, data bus architecture, software, integration architecture, drift algorithm filters, search vs track, use of multiple waveform and tech adoption (LNA, LPI et al). Unless there is some form of comparative analysis, I don't see how you can conclude one way or another.

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The view of China being ahead of Russia in avionics, in general terms, is based on it's current domestic Tech Industry, related R&D and yearly Patent Papers, combined with what we see being fielded in the form of military systems present and near future.

As an example if you do some research on the topic (SMIC is a good place to start) you will find that while China has a very large Fab industry for producing electronic components and microprocessors of foreign design, it is also designing it's own processors and building it's own Fabs at a pace of sophistication that will rival IBM and Intel next decade.

Russia has absolutely nothing on the scale of technological advancement that China does in this area, and Chinese R&D grows significantly year on year. Now this isn't to knock Russia; China has reached this point as a result of it's place in the world economy, through it's sheer size and strong investment in education and research. But one cannot deny the contrast between each countries development here.

On Su-35 purchase I really do not have an insight as to why China would want the aircraft (and it is a very good 4th Gen Fighter) based on where they are with their own domestic programs. All of the plausible reasons have already been discussed and for myself, I would lean towards the combination of: Good price and deal that will allow future purchase of additional 117S class engines to also outfit China's indigenous Flankers, while dedicating WS-15 production strictly for the J-20 program until the initial manufacturing line is fully operational and new lines are built to support China's wider fleet of aircraft.

But then where would that scenario leave WS-10? Perhaps the updated variant would be used to outfit J-10C and equip a block upgrade for the the A/B's? Who knows.

Brumby said:

Specifically I believe is for the 117S engine. The quantity buy of the SU-35 would not make a significant difference to the overall force structure even if it is an excellent plane.

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Oh okay. I suppose we will see in coming years when first LRIP of J-20 emerges if they are powered by 117S.

They are simply indicators that may fit a preferred narrative without the strength to conclude or exclude other possibilities.

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I'm not sure about that -- I think there is a case to be made that the narrative has arisen due to the indicators rather than individuals seeking to put indicators into a specific narrative... putting it another way, the narrative may not have emerged if these indicators did not exist.

supercat said:

I doubt that. For one thing, the possibility of China having an armed conflict over the issues of East China Sea or South China Sea is extremely remote. Exposing China's true strength over issues other than Taiwan prematurely will be a grave strategic blunder for China. In other words, China is highly unlikely to fight anyone in the ECS or SCS before they can solve the Taiwan problem. On the other hand, 24 won't be enough for a conflict over the Taiwan Strait. I don't think China is making this deal now for any specific reasons other than paying back Russia.

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You are not incorrect... Heck you are probably right on HOWEVER wars have been fought for much much less and if anyone knows this better it's china knowing their history and how unprepared they were in some events.

By the time you wait until war is at your doorstep before you start getting ready it's all over. I concur that the odds of a hot war in SCS or Taiwan etc is quite remote however Richard santos is rightin saying that tensions are at an all time high.

24 su 35s may not turn the tide of a conflict however it is not chump change either. They would make a good deterent and can certainly add to PLAAF's combat capabilities. The best kind of war is the type that never needs to be fought. The presence of su35s may bolster that thought process.

Like i said this purchase has many many reasons behind it but I do think one of them albeit a small one is due to the stop gap measures and the added capabilities that it will give to PLAAF.