Future PLA combat aircraft composition

Blitzo

Lieutenant General
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I think a twin engine stealth fighter as a replacement for the J-10 would just be too expensive to produce in enough numbers.
The cost to develop a new airframe wouldn't be that high. They will already have most of the components available.

China needs an aircraft which will be cost effective against the JSF.

Just because an aircraft is "twin engined" doesn't mean it is necessarily larger than a single engined aircraft.
The J-XY/J-35 may even end up being a little bit lighter than their respective F-35 variants in terms of weight.

In which case the costs basically come down to the engine procurement and engine operating costs as the main difference.

In which case IMO that depends on the engine and the availability of the industry.

An aircraft equipped with two WS-13E and going forwards WS-19 will ultimately still reduce demands for WS-15, and for a proper single engine 5th generation aircraft you will likely need the WS-15 to be further uprated, in turn consuming more turbofan industry resources.


All things considered, given how tight the timeline is for needing a medium weight 5th gen fighter, and considering the likely proliferation and rising profile of UCAVs and loyal wingman aircraft (which are able to be effective using older generation WS-10 and WS-13 variants, reducing demand on WS-15 and WS-19), and in turn considering that WS-15s and variants will likely be prioritized for J-20 production and 6th gen production... Imo whatever limited benefits there are for operating a single engine medium weight 5th gen aircraft over a twin engine medium weight 5th gen aircraft just aren't enough to outweigh the service fleet and industry demands and limitations.


Going into the mid early to mid 2030s onwards (which is when I expect the earliest J-10s will need true retirement), I expect a combination of twin engine J-XY land based variants, and loyal wingman UCAVs to be an appropriate and feasible replacement for them.
 

latenlazy

Brigadier
Yeah, but 4th gens are still in production concurrently with 5th gens, there's no reason to believe 5th gens wouldn't still be produced in overlap with 6th gens.
J-XY (carrier and potential land based variant) will likely still be in production going into the mid 2030s at minimum.

I can see J-20 production continuing into the early 2030s, but assuming CAC starts producing their first 6th gen efforts around 2030 I could see J-20 production being stopped in favour of 6th gen.

Continued production of 4th gen aircraft is as much a reflection of delays and costs of 5th gen aircraft than anything.
Whether the same will hold true in the exact same way for the 5th gen and 6th gen relationship is another matter.

I wouldn't get too caught up in the details.
They might discontinue J-20 production for a 6th Gen fighter but continue J-XY/J-35 production as a 5th gen mainstay. But all speculative on our parts.
 

Blitzo

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No way is China stopping J-20 production in 2030. I expect WS-15 equipped J-20s to be mature by then and J-20s will likely form the backbone of PLAAF.

Never said it would stop in 2030, but I could see it stopping after the early 2030s in favour of 6th gen which I expect CAC to take the contract on.
Chances are when the 6th gen effort begins production there will be a number of years where both J-20 and the 6th gen effort are produced at the same time with overlap, where J-20 winds down and 6th gen ramps up.

Of course it depends on how quickly the 6th gen efforts result in operational viable systems, and rapid prototyping will likely be as much of a PLA focus as it will be for the USAF.


Overall, point is that WS-15s and future derivatives will be prioritized for J-20s and then the 6th gen effort afterwards.
Any 5th gen medium fighter that is single engined would need WS-15, likely uprated, but chances are production of WS-15 will be needed to meet J-20 and 6th gen demands.

A twin engine J-XY/J-35 land based 5th gen effort OTOH can leverage WS-19 instead, in addition to the various industry and force structure requirements and limitations I mentioned in #620
 

Totoro

Major
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If the goal is to seek a more attritable, less gold plated and mass producible stealthy aircraft, IMO UCAVs are the way to go.
Sure, I agree a working, effective UCAV would be ideal. But it's impossible to know if technology and threats out there will allow an UCAV design to be truly effective by 2030. If not, PLAAF still might go for a similar mission set requirement from a platform, but make it a manned one.

We'll what the future will bring, and if PLAAF deems having enough fighters is important enough to go for yet another design. I certainly do not expect PLAAF to remain at numbers it was at during the past decade, but to increase its overall numbers. Just as the navy is seeing pretty big increases. Some of those will inevitably be unmanned planes, but i think it's possible even just the manned portion will increase in absolute numbers.

I guess it also depends on how complex and expensive JXY will be. If it is closer to J20, then I don't see it becoming a mainstay of PLAAF. If it is very much a budget design with similarly limited capabilities i described for a single engine plane - just 4 AAMs, just small bombs, only front sector high frequency bandwidth stealth - then the differences between such a plane and a newly developed single engine one would be small enough so making yet another plane and sustaining it may not be worth while.

Such a design might even be partially competitive as an export product, to a hypothetical single engine stealthy plane offering from China.

Of course, that means the current "31" series demonstrators may not be very representative of the final thing. While most people expect the naval variant to be at least as big or a bit bigger, a PLAAF variant might then be quite a reworked variant - to be kept as cheap as possible within a set of performance parameters.

When one is talking about a few hundred planes for PLANAF and possibly 1000 planes for PLAAF (over the whole production run) then economies of scale for forcing a single airframe variant on both PLAAF and PLANAF may not make sense. IT may be more worthwhile to invest another 10 billion into developing a specific PLAAF variant.

And i do think run of over 1000 JXY planes for PLAAF are going to be part of PLAAF's requirements if there is not going to be a single engine supersonic plane to add to it. (be it manned or unmanned)
 

latenlazy

Brigadier
Sure, I agree a working, effective UCAV would be ideal. But it's impossible to know if technology and threats out there will allow an UCAV design to be truly effective by 2030. If not, PLAAF still might go for a similar mission set requirement from a platform, but make it a manned one.

We'll what the future will bring, and if PLAAF deems having enough fighters is important enough to go for yet another design. I certainly do not expect PLAAF to remain at numbers it was at during the past decade, but to increase its overall numbers. Just as the navy is seeing pretty big increases. Some of those will inevitably be unmanned planes, but i think it's possible even just the manned portion will increase in absolute numbers.

I guess it also depends on how complex and expensive JXY will be. If it is closer to J20, then I don't see it becoming a mainstay of PLAAF. If it is very much a budget design with similarly limited capabilities i described for a single engine plane - just 4 AAMs, just small bombs, only front sector high frequency bandwidth stealth - then the differences between such a plane and a newly developed single engine one would be small enough so making yet another plane and sustaining it may not be worth while.

Such a design might even be partially competitive as an export product, to a hypothetical single engine stealthy plane offering from China.

Of course, that means the current "31" series demonstrators may not be very representative of the final thing. While most people expect the naval variant to be at least as big or a bit bigger, a PLAAF variant might then be quite a reworked variant - to be kept as cheap as possible within a set of performance parameters.

When one is talking about a few hundred planes for PLANAF and possibly 1000 planes for PLAAF (over the whole production run) then economies of scale for forcing a single airframe variant on both PLAAF and PLANAF may not make sense. IT may be more worthwhile to invest another 10 billion into developing a specific PLAAF variant.

And i do think run of over 1000 JXY planes for PLAAF are going to be part of PLAAF's requirements if there is not going to be a single engine supersonic plane to add to it. (be it manned or unmanned)
Keep in mind that as technology improves you might be able to get more RCS reduction for cheaper. Also, supposedly part of the J-35/XY development work is being put into making the manufacturing process cheaper and simpler. The J-35/XY may not cost as much per unit of capability as the J-20, just as was the intentions with the F-35 vis a vis the F-22.
 

Blitzo

Lieutenant General
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Sure, I agree a working, effective UCAV would be ideal. But it's impossible to know if technology and threats out there will allow an UCAV design to be truly effective by 2030. If not, PLAAF still might go for a similar mission set requirement from a platform, but make it a manned one.

We'll what the future will bring, and if PLAAF deems having enough fighters is important enough to go for yet another design. I certainly do not expect PLAAF to remain at numbers it was at during the past decade, but to increase its overall numbers. Just as the navy is seeing pretty big increases. Some of those will inevitably be unmanned planes, but i think it's possible even just the manned portion will increase in absolute numbers.

I guess it also depends on how complex and expensive JXY will be. If it is closer to J20, then I don't see it becoming a mainstay of PLAAF. If it is very much a budget design with similarly limited capabilities i described for a single engine plane - just 4 AAMs, just small bombs, only front sector high frequency bandwidth stealth - then the differences between such a plane and a newly developed single engine one would be small enough so making yet another plane and sustaining it may not be worth while.

Such a design might even be partially competitive as an export product, to a hypothetical single engine stealthy plane offering from China.

Of course, that means the current "31" series demonstrators may not be very representative of the final thing. While most people expect the naval variant to be at least as big or a bit bigger, a PLAAF variant might then be quite a reworked variant - to be kept as cheap as possible within a set of performance parameters.

When one is talking about a few hundred planes for PLANAF and possibly 1000 planes for PLAAF (over the whole production run) then economies of scale for forcing a single airframe variant on both PLAAF and PLANAF may not make sense. IT may be more worthwhile to invest another 10 billion into developing a specific PLAAF variant.

And i do think run of over 1000 JXY planes for PLAAF are going to be part of PLAAF's requirements if there is not going to be a single engine supersonic plane to add to it. (be it manned or unmanned)

I mean, what is "budget"?

New technology, open architecture, investment into more effective production methods, large production run, are all things that will reduce costs in terms of both procurement and operation.

Given how many carriers the PLAN are going to go for in the longer term come the mid to late 2030s when J-XY will likely still be in production, I can conceivably see 500 plus carrier based J-XY variants eventually being produced.
The purpose of a PLAAF land based variant will be to maintain as much commonality with the carrier based variant in terms so as to reduce additional development costs and time as well as having common subsystems and upgrade paths and operating costs as well.
In that sense, if the goal is to reduce costs of procurement and operation, the whole point of leveraging a carrier based aircraft with a land based variant would be to keep as much of the aircraft common as possible and remove the carrier specific parts (strengthened undercarriage, folding wings, tailhook and catapult nosegear etc).


If you want a credible medium weight fifth generation fighter, I think something like F-35 or something like J-XY/J-35 will be the minimum of what you need.
The "limited capabilities" that you describe IMO are unacceptable for an "affordable/mainstay" 5th generation fighter.
IMO what a "mainstay/affordable" 5th generation fighter requires is having equivalent or better stealth to a high end heavy weight fighter (F-22, J-20 etc), similar or better sensors, but whose cost savings are primarily through larger scale production, more affordable and maintainable stealth, and smaller size/weight.

I.e.: in terms of J-XY/J-35's cost savings relative to J-20.... I expect J-XY/J-35 to have a lighter MTOW than J-20, to have a smaller internal weapons load than J-20 (J-XY/J-35 will almost definitely only have a ventral weapons bay lacking lateral weapons bays, but there are indications the ventral weapons bay could have similar or identical dimensions to J-20's main ventral weapons bay), to leverage advancements in stealth maintainability and production methods, and also ultimately to potentially be procured in larger numbers than J-20 in terms of its combined carrier based and land based variants.




In your vision for 1000 J-XY planes for the PLAAF, how many carrier based J-XYs do you see the PLANAF procuring, and how many J-20s do you see the PLA procuring?

Because I myself could envision a split of about 1000, 500, 500, in which case I certainly think it would make sense to continue with the medium weight 5th gen fighter being a J-XY/J-35 derivative given how many carrier based J-XYs the PLANAF will be buying anyway.

And more importantly, it's not like a clean sheet, single engine medium weight 5th gen fighter will be able to cut corners anyway -- it will still have the same requirements as a land based J-XY/J-35 derivative, the only main difference is it would be using a single high thrust engine rather than two medium thrust engines.
The requirements for stealth, MTOW/size, payload, range, production scale, maintainability, would be the same for both prospective options, the only difference being the specific procurement and operating costs of being powered by one high thrust engine versus two medium thrust engines.
 

Gloire_bb

Captain
Registered Member
I.e.: in terms of J-XY/J-35's cost savings relative to J-20.... I expect J-XY/J-35 to have a lighter MTOW than J-20, to have a smaller internal weapons load than J-20 (J-XY/J-35 will almost definitely only have a ventral weapons bay lacking lateral weapons bays, but there are indications the ventral weapons bay could have similar or identical dimensions to J-20's main ventral weapons bay), to leverage advancements in stealth maintainability and production methods, and also ultimately to potentially be procured in larger numbers than J-20 in terms of its combined carrier based and land based variants.
So where significant savings/operational benefits would come from? Lower MTOW don't save that much, by itself.
As of now, you're simply describing a worse J-20, stating commonality with the navy as a benefit. (read:subsidizing PLANAF)

Mig-29/Su-27 and F-18/F-14 pairs(i.e. actual twin/twin pairs) were not born from savings alone. And in both cases one plane ultimately ate another one anyway.
 

Blitzo

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So where significant savings/operational benefits would come from? Lower MTOW don't save that much, by itself.
As of now, you're simply describing a worse J-20, stating commonality with the navy as a benefit. (read:subsidizing PLANAF)

Mig-29/Su-27 and F-18/F-14 pairs(i.e. actual twin/twin pairs) were not born from savings alone. And in both cases one plane ultimately ate another one anyway.

Relative to J-20 -- larger production run, more maintainable stealth, more advanced production methods.
And yes, what you described -- a "worse" J-20, with commonality with the navy, and a larger production run, more maintainable stealth, more advanced production method -- sounds like a hell of an aircraft to me, especially as such an aircraft would not need the additional development time needed for a clean sheet design.

In the case of the PLA specifically, it is also based on the understanding that WS-15 and WS-15 variants will be a commodity prioritized for J-20 production and 6th gen efforts.
And of course all of this talk of a single engine medium weight 5th gen aircraft operates on the understanding that it would need an uprated WS-15 variant to power it.


In the broader context, IMO there are a two additional "program requirements" the PLA faces that are necessary for a prospective medium weight land based 5th gen fighter, beyond the aforementioned larger production run + maintainability + advanced production methods etc.
1. Such an aircraft should enter service before the end of the decade, preferably sooner rather than later. Speed and risk from project initiation to service is important, not only in general, but also for the PLA given the proliferation of 5th gens and additional high capability aircraft in the region. If a project can be 2-3 years faster than a competitor with lower risk (say, if the competitor is a clean sheet design), then that is a very desirable trait.
and,
2. Engine availability, where the medium weight land based 5th gen fighter's production in the above timeline and its powerplant should not be limited by the prioritization of WS-15 production for J-20s and 6th gen aircraft in the same period. Either there is enough WS-15 production to satisfy production of J-20, initial 6th gen aircraft AND said medium weight land based 5th gen aircraft --- OR, this aircraft should adopt an alternative powerplant configuration which is not limited by WS-15 production/availability.


I.e.: the way I can see a clean sheet medium weight single engine 5th gen aircraft being pursued instead of a land based J-XY/J-35 derivative, is if the above two criteria can be satisfied, as described below
1. If said clean sheet design can developed with at least equally low risk and equally short time compared to a land based J-XY/J-35 derivative (to enter service in the late 2020s time period)....
AND,
2. If AECC was able to ramp up the production rate of WS-15 sufficiently to meet the production demand and timeline for J-20s, initial production 6th generation aircraft, and said single engine medium weight 5th gen aircraft in the late 2020s to early/mid 2030s time period.


But as it stands I don't think the prospects for either option look that viable, and the only obvious solution therefore is a land based J-XY/J-35 variant. Far from a poor aircraft imo.
 

Totoro

Major
VIP Professional
Keep in mind that as technology improves you might be able to get more RCS reduction for cheaper. Also, supposedly part of the J-35/XY development work is being put into making the manufacturing process cheaper and simpler. The J-35/XY may not cost as much per unit of capability as the J-20, just as was the intentions with the F-35 vis a vis the F-22.

Definitely, but that cascades down even further. So an even simpler plane might be even cheaper than JXY, just as JXY might be cheaper than J20. It's all about the exact price/effectiveness curve and that's something we don't have insight in. If for example the curve flattens down so quickly that you simply can't eek out more meaningful savings without sacrificing a lot of capabilities - then that's the bottom which will decide the design of the planes and composition of plaaf. The more complex and costly jxy is - the lower the chances are that will happen. But if jxy is designed to be quite cheap and simple then a single engine plane design will have a harder time competing.

If you want a credible medium weight fifth generation fighter, I think something like F-35 or something like J-XY/J-35 will be the minimum of what you need.
The "limited capabilities" that you describe IMO are unacceptable for an "affordable/mainstay" 5th generation fighter.
IMO what a "mainstay/affordable" 5th generation fighter requires is having equivalent or better stealth to a high end heavy weight fighter (F-22, J-20 etc), similar or better sensors, but whose cost savings are primarily through larger scale production, more affordable and maintainable stealth, and smaller size/weight.

Well i agree that one of the F-35s is the minimum plaaf would find useful. Only difference is that it seems you may be thinking of F-35A while I am seeing the F-35B as that minimum point. F-35, to be designed from the start to be just a conventional take off plane, to be designed around a 160-ish kn or more powerful engine, to be designed to carry as much fuel and armaments as F-35B carries, to have the same avionics - would in fact be at the very least on par with an actual F-35B, even with its more powerful engine. And likely in some regards like agility/acceleration/fuel consumption even a bit better. Possible downsides, but ones stemming from PLAAF's operational needs might be not as good stealth in some sectors and shorter life span due to less beefy construction.

Of course, this VERY much depends on the engine performance. If for some reason WS15 will not be able to deliver at least 160 kn of thrust in a good weight class, then the prospects of a single engine fighter drop quite a bit. But given that WS10 is up to 140 kn or so, I do find it unlikely reaching at least 160 kn would be problematic for WS15.

It really is about nuances, as i too agree scale of production, affordable maintenance and smaller size is the goal. We just differ on the exact curve of it, as I do believe there's some savings to be had in the 11 ton empty weight region, without seriously compromising performance. While other people may believe 13 ton or so is where performance can be kept adequate.
In your vision for 1000 J-XY planes for the PLAAF, how many carrier based J-XYs do you see the PLANAF procuring, and how many J-20s do you see the PLA procuring?

The 1000 JXY vision was only if no single engine fighters were procured for PLAAF. And of course, to even get to a 1000 airframes just for PLAAF, many years would have to pass.

In such a case i guess around 2040 we might see:
800 J20 fighters/next gen big fighters (with likely 700 being J20)
1000 PLAAF's JXY
A few hundred J16 remaining
A few hundred J10 variant planes remaining
A few hundred either more strike oriented J20 variants or novel design planes, which may include various large unmanned designs.
roughly 200 bombers (H6 and H20 mix)

In addition to those, PLANAF might operate:
300-ish JXY carrier variants
Possibly less than 100 various flanker variants
200-ish either more strike oriented J20 variants or novel design planes, which may include various large unmanned designs.
Possibly a few dozen H6 variants.

Of course, the above basically suggests 50% bigger air forces than PLAAF/PLANAF have today, combined.


If a single engine plane IS in the cards, then i envision only barely bigger total numbers, but PLAAF getting a lot less (possibly none?) JXY planes. And some more J20 class planes/strikers. Roughly lets say 1200 J20/ strike variant/new unmanned strikers and 1000 single engine fighters, if no JXY is present. With PLANAF numbers remaining roughly the same as in previous table.
And more importantly, it's not like a clean sheet, single engine medium weight 5th gen fighter will be able to cut corners anyway -- it will still have the same requirements as a land based J-XY/J-35 derivative, the only main difference is it would be using a single high thrust engine rather than two medium thrust engines.
The requirements for stealth, MTOW/size, payload, range, production scale, maintainability, would be the same for both prospective options, the only difference being the specific procurement and operating costs of being powered by one high thrust engine versus two medium thrust engines.
This is where i have a different opinion. FC31 is not necessarily what PLAAF wants. It may indeed be just a demonstrator roughly based on what AVIC thought an export market will seek from a fighter. While FC31 derived design, for PLANAF, if it's changed enough, may be more or less what PLANAF will want, that too will not necessarily be what PLAAF wants. It may very well that PLAAF will explicitly want less payload and less stealth, for example. Even less range wanted might be possible. (given the trade offs of performance/cost) But it's all about nuances at this level so it's hard to go into such unknown details.
 
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