Future PLA combat aircraft composition

tphuang said:

What CAC did with J-20 was quite exceptional. I don't know if it's fair to expect SAC to proceed at the same speed when they have to develop 2 variants at the same time + completing development of J-15B.

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On the other hand, the development of any FC-31 derivative started almost a decade ago, so any further lead time for FC-31 variants should be quite truncated. One of the most time consuming parts in the R&D of a new plane is going to be aerodynamic testing and flight control system development, and from that standpoint FC-31 based designs should already be quite mature. Similarly, if any FC-31 derived design shares subsystems with the J-20, those subsystems should also be quite mature, which means all the systems integration testing should be a lot more straightforward, low risk, and ultimately pretty quick.

tphuang said:

CAC has produced J-10s for 4 years after J-20 induction and GAIC is likely to produce it for a couple of more years. I think 2040 is more likely to be when they stop producing J-20s.

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Newer generations may not see the same staggered production schedule as older generations, since one of the primary drivers of the stagger we’ve seen historically has just been the rush to catch up and close the gap on fielded capabilities relative to other militaries. Realistically there will of course be a stagger I think. But it may not stretch to 2040. Furthermore from a resource planning perspective it might make sense for SAC to take over any stagger of fifth gen fighter production to let CAC focus on ramping up production for 6th gen fighter production, if CAC is indeed expected to be the primary provider of a 6th gen fighter.

tphuang said:

engine could be something that slows down J-35 mass production, since WS-13 hasn't been tested as widely as WS-10s. I'm not sure how reliable it is right now.

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A lot of the quality improvements for the WS-10 likely spills over to other engine designs, because many of the WS-10’s problems were general to the quality of China’s engine production capabilities. Insofar as there are design specific concerns, the WS-10 was a higher risk design than the WS-13. The WS-13 was a copy of a known design, while the WS-10 was a bit of a kit bash development.

Bltizo said:

So, starting from a fresh post, I want to elaborate about my reasoning for the PLA's future land based 5th generation fighter procurement.

I have a few foundational assumptions:
A) The PLA (which is to be understood as the PLAAF and/or PLANAF's land based fighter units) should aim to have some 1200-1400, land based, 5th (and/or "5.5th") generation fighters in service by around 2040. This does not include PLANAF carrier compatible 5th generation fighter aircraft, which will be deployed aboard carriers but of course have land bases to operate and train from as well when they are not embarked.
B) The PLA will seek to start initial low rate production of the 6th generation manned fighter (a component of the overall future aerial combat system), sometime in the early 2030s, with the aim to achieve a credible operational capability by 2035, a number that has been spoken of multiple times in official and semi-official capacity
C) The only two Chinese institutes/factories that can produce manned fighter aircraft of 5th generation or above, are assumed to be CAC and SAC.


Based on those assumptions, A, B and C, I present this simple graph:

View attachment 86599


It is mostly self explanatory, but I will specify a few bits.
(The "LB J-XY" refers to "land based J-XY/35 variant" as shorthand)

... [deleted due to size limits]...


So to sum up, my belief is:
- To achieve 1200-1400 5th gen land based fighters by around 2040, a "J-20 + LB J-XY" fleet format, with about a 50/50 split between the two types, is viable. It also does not place any undue burden on consumption of WS-15 family engines, because J-20 and LB J-XY will be using two different types of engines with their own separate rate limiting factors on engine production.
- To achieve 1200-1400 5th gen land based fighters by around 2040, using an "only J-20" fleet format, would require CAC to significantly expand annual J-20 production capacity (compared to the "J-20 + LB J-XY" scenario) -- but more importantly it may also either compromise CAC's ability to produce 6th generation fighters, OR it will require the 6th generation fighter to be given to SAC to be developed (which in turn might not even be possible due to SAC's commitment to the carrierborne J-XY project), OR it will require the J-20 production to be also given to SAC, which would be quite unprecedented. All of this is on top of the fact that such a large production run of J-20s will also place burden on the WS-15 engine family production, which may or may not be able to cope with such high demands for both J-20s and also the initial variants of the 6th generation fighter. However it is also viable, depending on how those factors play out.

I certainly think both the "J-20 + LB J-XY" and "only J-20" options are viable, and at this stage I'm not definitively saying one is better than the other..... but it does mean that the "J-20 + LB J-XY" option is one that might eventuate, which is why I don't think we should dismiss rumours of the LB J-XY being intended primarily for the PLA as if it is something so outlandish, when in reality it should be seen as quite a reasonable procurement choice.



@tphuang @latenlazy @Deino @weig2000

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A couple of my thoughts and comments:

1. I'm a bit reluctant to project beyond 2035, because of the uncertainties involving geopolitical environment, technology development and how the competition/adversaries respond. Already, we're seeing drastic changes in these areas in the last few years. 2035 is a "magic" year because it's the year CCP has set as a milestone year for Chinese military modernization and it's also reasonable to assume that's the year China will have its 6th generation in production, at least from a planning perspective. Of course, this is strictly my own thinking.

2. We should change our paradigm of observing and projecting PLAAF orbat from now on (and other PLA branches too, but we focus on PLAAF here). For the last three decades, we've been observing China in a stage of catching-up and filling the gaping hole compared with other advanced air forces. Time was, rumors about any advanced aircraft China had her hands on whether import or domestic development would cause a lot of excitement or stirring. A display model, a new model or better yet, a maiden flight of a model would be considered more or less a breakthrough if not a milestone. An over 200 serial production would be considered massive. That era has passed. What China needs going forward is mass production of a few mutually complementary models, and 200-300 per model should be considered the bare minimum of a serial production model.

3. With above said, I think J-20 and its various upgrades and variants will be the focus during the said period (before 2030) and they should ramp up and maintain relatively high annual production rates. I'm projecting the cumulative total production numbers (by year) as follows: 300 (2025), 400+ (2027), 600 (2030), 1000 (2035). After 2035, J-20 may continue to be produced, likely at reduced rates.

4. I think PLAAF should eventually procure a LB J-XY, but, as I stated in several posts in the last few days, I don't see the urgency and necessity for PLAAF/SAC to devote too much efforts on rolling out the LB J-XY around 2025. I understand there have been rumors in the last years or two opposite to what I think, but I remain unconvinced and until the rumors turn out to be true, I stick to my belief. (Plus, even if those rumors had some grounds, circumstances have changed so much such that I believe they should slow down - but that's another topic). I agree with your reasoning to support a LB J-XY for PLAAF, i.e., shifting the stealth aircraft production burden from CAC to SAC to allow CAC to focus on the 6th gen. The more strategic reason that I think they should support a LB J-XY is that China needs to have two competitive, world-class fighter aircraft manufacturers to sustain and maintain the technology and competitive edge of her MIC. But the presumed LB J-XY order should not be a charity; SAC has to deliver. It's another reason that I believe they should plan for LB J-XY to be ready late in the decade, to allow more time for the platform and subsystems to mature and develop. Assume LB J-XY goes into production in 2029, we should expect 200-300 LB J-XY by 2025.

5. After 2035, 6th gen and UCAVs will start to ramp up.

To summarize, CAC will focus on J-20 and its various upgrades and variants and produce total 1000 of them till 2035, after which it will switch to 6th gen and start to ramp down the production of J-20 - maybe even transfer the production to GAC gradually. SAC should focus on J-XY/J-35 and PLAN before the end of the decade and start to produce LB J-XY by then. All told, PLAF will have 1200 -1300 stealth fighter aircraft by 2035, split between J-20 (1000) and LB J-XY (200-300).

tphuang said:

Interesting thing to think about. CAC went from getting picked to putting J-20 into service in 10 years. That was exceptionally quick by any measure. So 2023 to 2025 probably makes most sense for PLAAF picking its 6th gen design. PLAAF need to make a decision by 2023 if they want to get 6th gen into service in some numbers before a possible Taiwan scenario in the second half of 2030s.

Right, I think given the amount of work ahead for SAC and the presence of what appears to be numerous 6th planform at CAC factory, it would be CAC's project to lose at this point.

It's likely that SAC would be tasked develop the 6th gen naval fighter for entry in early 2040s.

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I agree with these in general -- though I don't think putting a timeline for a Taiwan contingency that the PLA is seeking to actively "prepare for" is useful.
Instead, I believe the PLA's procurement is generally one of seeking to deter and defer confrontation (i.e.: a Taiwan contingency) into the future, (well after 2030s), while possessing the capabilities to carry out that deterrence in increasing capability and to establish a medium to long term balance of capability that allows them to establish general regional superiority.

tphuang said:

What CAC did with J-20 was quite exceptional. I don't know if it's fair to expect SAC to proceed at the same speed when they have to develop 2 variants at the same time + completing development of J-15B.

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I think it is quite fair, given that SAC has had FC-31V1 and V2 flying since 2012 and 2016 respectively, which are very much technology demonstrators relevant for the J-XY and LB J-XY aircraft types.
Development of J-15B should have already largely been completed, and is no more of a major derivative from the standard J-15 as say J-10B/C was to the J-10A (which overlapped with the development and testing of J-20 as well).

tphuang said:

I'm thinking 100 J-10Cs, 200 J-16s, 200 6th gen aircraft + 1500 5th gen aircraft (1000 J-20s + 500 LB J-35s) - 2000 manned fighter by then. There is a good chance PLAAF will retires J-10s before USAF retires F-16s and flankers before USAF retires F-15s.

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No major comment on this.

tphuang said:

CAC has produced J-10s for 4 years after J-20 induction and GAIC is likely to produce it for a couple of more years. I think 2040 is more likely to be when they stop producing J-20s.

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We do not yet know if GAIC is producing J-10Cs for the export market or for the PLA, and if it is for the PLA, we don't know if that's for newly formed units or perhaps attrition or augmentation of units.

In any case, my projection of J-20 production ending around 2036, is after the 6th gen begins initial production in 2032 -- an overlap of simultaneous J-20 and 6th gen production lasting 4 years. I think that is quite a fair amount of time, and I also believe that the PLA by then would be looking to try and reduce the overlap of past+new generation aircraft compared to 4th+5th generation overlap (which in turn was reduced compared to 3rd+4th gen overlap).

tphuang said:

When considering that PLAAF had been planning to be ready by around 2027, that is quite a bit below my expectations. I think they probably need to produce another 300 over the next 5 to 6 years.

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Do we have any estimates or knowledge for how many J-20s the PLAAF will have by 2027?
The only "number" I know of is when ShiLao a while back said that by 2027 the PLAAF will definitely have at least the same number of J-20s produced by that time, as the USAF did for F-22s. That sets a minimum number of J-20s we can expect by 2027 (i.e.: slightly below 200 aircraft), but

tphuang said:

I think PLAAF's LB J-35 numbers is very much dependent on how quickly they can get it into production. If it can actually enter service by 2026 (assuming 2022 first flight and 4 years from that point to service entrance), they'd be able to start mass produce before CAC really hits its high production pace. If it's not ready until 2028 or 2029, then CAC may have already ramped up J-20 production to 70 a year.

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I agree, but I think these are all long lead procurement and funding decisions that would've had to been made 2-3 years ago.
It's not like they can wait by 2026 and then make a decision to either scale up LB J-XY production.
Similarly, for J-20, there is a limit to how high its production rate can ramp up. J-20 production is not going to ramp up continuously, instead it will reach a peak rate that can be sustained for a number of years, but the question is basically one of what that peak will be.

IMO "peak J-20 production rate" and "duration of J-20 production" and "when 6th gen will be introduced" are probably the key determinants of this discussion of the PLAAF's likelihood to procure LB J-XY.

tphuang said:

engine could be something that slows down J-35 mass production, since WS-13 hasn't been tested as widely as WS-10s. I'm not sure how reliable it is right now.

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That is technically true, but the fact they were comfortable enough to install it on the J-XY prototype for maiden flight (assuming those are indeed WS-13 variants) is somewhat unprecedented as well, which in turn reflects somewhat positively on the assessment of its reliability.

weig2000 said:

A couple of my thoughts and comments:

1. I'm a bit reluctant to project beyond 2035, because of the uncertainties involving geopolitical environment, technology development and how the competition/adversaries respond. Already, we're seeing drastic changes in these areas in the last few years. 2035 is a "magic" year because it's the year CCP has set as a milestone year for Chinese military modernization and it's also reasonable to assume that's the year China will have its 6th generation in production, at least from a planning perspective. Of course, this is strictly my own thinking.

2. We should change our paradigm of observing and projecting PLAAF orbat from now on (and other PLA branches too, but we focus on PLAAF here). For the last three decades, we've been observing China in a stage of catching-up and filling the gaping hole compared with other advanced air forces. Time was, rumors about any advanced aircraft China had her hands on whether import or domestic development would cause a lot of excitement or stirring. A display model, a new model or better yet, a maiden flight of a model would be considered more or less a breakthrough if not a milestone. An over 200 serial production would be considered massive. That era has passed. What China needs going forward is mass production of a few mutually complementary models, and 200-300 per model should be considered the bare minimum of a serial production model.

3. With above said, I think J-20 and its various upgrades and variants will be the focus during the said period (before 2030) and they should ramp up and maintain relatively high annual production rates. I'm projecting the cumulative total production numbers (by year) as follows: 300 (2025), 400+ (2027), 600 (2030), 1000 (2035). After 2035, J-20 may continue to be produced, likely at reduced rates.

4. I think PLAAF should eventually procure a LB J-XY, but, as I stated in several posts in the last few days, I don't see the urgency and necessity for PLAAF/SAC to devote too much efforts on rolling out the LB J-XY around 2025. I understand there have been rumors in the last years or two opposite to what I think, but I remain unconvinced and until the rumors turn out to be true, I stick to my belief. (Plus, even if those rumors had some grounds, circumstances have changed so much such that I believe they should slow down - but that's another topic). I agree with your reasoning to support a LB J-XY for PLAAF, i.e., shifting the stealth aircraft production burden from CAC to SAC to allow CAC to focus on the 6th gen. The more strategic reason that I think they should support a LB J-XY is that China needs to have two competitive, world-class fighter aircraft manufacturers to sustain and maintain the technology and competitive edge of her MIC. But the presumed LB J-XY order should not be a charity; SAC has to deliver. It's another reason that I believe they should plan for LB J-XY to be ready late in the decade, to allow more time for the platform and subsystems to mature and develop. Assume LB J-XY goes into production in 2029, we should expect 200-300 LB J-XY by 2025.

5. After 2035, 6th gen and UCAVs will start to ramp up.

To summarize, CAC will focus on J-20 and its various upgrades and variants and produce total 1000 of them till 2035, after which it will switch to 6th gen and start to ramp down the production of J-20 - maybe even transfer the production to GAC gradually. SAC should focus on J-XY/J-35 and PLAN before the end of the decade and start to produce LB J-XY by then. All told, PLAF will have 1200 -1300 stealth fighter aircraft by 2035, split between J-20 (1000) and LB J-XY (200-300).

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Good thoughts, I'll address points individually or by theme.

1. 2035 may reflect that, but the phrasing of 2035 in the past by Wang Haifeng did describe the date as when the 6th gen fighter would be actively "defending the seas and skies" which I interpret to mean as some form of credible operational service (in turn meaning production would've started a few years before, based on past precedent of initial production to credible service). Perhaps I'm reading a bit much into that phrase/quote, but I do think that aiming for early 2030s initial production for 6th gen is not only reasonable, but desirable for the PLA, so as to aim to further close the tech/generation gap with the US and their own 6th gen efforts.

2. I agree with this in general. For new fighter types, but I think especially for "mainline" new fighter types of the new generation, 300ish aircraft should be seen as a minimum number for which procurement is worth the development costs and aerospace resource consumption. (The number would of course be different for bombers, transporters, UAVs/UCAVs etc)

3. to 5. I think these points really strike at the heart of the matter in regards to the prospects of PLAAF procuring LB J-XY, and in turn future PLAAF strategic fighter procurement.

There are basically three major factors at play, which I mentioned in my reply to Feng.
Those are:
A) Peak sustained (and average) annual J-20 production rate
B) Duration of active J-20 production
C) Initiation of 6th generation production

My view is that I think the peak sustained J-20 production rate will have a ceiling to it that may be somewhat lower than what others think -- I think a peak rate of below 50 is viable, with perhaps an annualized average of about 40 a year. Based on how many J-10s and J-20s CAC has been able to build with current floor space, and based on the lack of any major expansion of factory floor space, and limitations of long lead items like factory tooling, experienced production personnel, anymore than that in the next 5 years seems a bit difficult to entertain.

The duration of active J-20 production and initiation of 6th gen production are both closely tied together -- my view is that the 6th gen project is almost certainly going to go to CAC (if it hasn't already), and that it would be in the PLA's interest to ensure that the duration of overlap of simultaneous production between J-20s and the 6th gen fighter is as short as practically possible. Which is to say, that I think they should aim to ramp up 6th gen production as soon as possible after its initial low rate production begins, to capitalize on expected generational/airframe advancements between the 6th generation aircraft versus the J-20 variant of the time.

However, the PLA will still require continued 5th generation production while 6th generation fighter production ramps up -- IMO it just can't be at CAC "as we know it," meaning the outcome will have to be:
- CAC expands J-20 production to other institutes/factories
- CAC massively expands their overall aircraft production line (though then I think they would also seek to uptitrate the ramp up the production of the 6th gen fighter as well accordingly)
- .... or, they could have made a decision sometime in the late 2010s to procure the LB J-XY as a 5th generation fighter whose production run will overlap longer with the 6th generation fighter, helped by the LB J-XY being a SAC product rather than CAC, and in turn helped by having (expected) major subsystems commonality with the already committed carrier J-XY



Depending on how we alter those A), B) and C) factors, I think the outcomes would also be different -- but as of right now, I personally cannot see CAC expanding annual J-20 production rate beyond a peak of some 50 aircraft a year, unless we get indications of significant expansion of factory floor space, IMO.

Apart from cost, and taking advantage of the new 3rd gen mid-thrust engine production line (WS-13) and SAC production capacity, what would be some other benefits of a land base J-35? Are there any other bottlenecks in China's fighter production beyond the engine and main frame production?

Volpler11 said:

Apart from cost, and taking advantage of the new 3rd gen mid-thrust engine production line (WS-13) and SAC production capacity, what would be some other benefits of a land base J-35? Are there any other bottlenecks in China's fighter production beyond the engine and main frame production?

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"Engine production capacity" and "airframe production capacity" are both pretty huge bottlenecks for determining the production viability for a fighter aircraft. The engine and the airframe together basically make up the entire aircraft.


As for comparative benefits and costs of LB J-XY versus simply buying more J-20s, those are primarily on the industry and logistics/commonality side.
There are of course going to be some minor differences in performance/payload/range between LB J-XY and J-20, but that is slightly beyond us in terms of detail, and likely are not sufficiently significant in scale to overrule the outright numbers of 5th generation fighters being discussed in general.

Bltizo said:

I personally cannot see CAC expanding annual J-20 production rate beyond a peak of some 50 aircraft a year, unless we get indications of significant expansion of factory floor space, IMO.

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If a decision has been made to hand CAC a blank cheque to expand J-20 production to 1.5-2x the current rate as quickly as possible, how long would it take to build new factories, train personnel, etc. and how soon after such a decision would we start seeing indications of that?

The other components of a aeroplane includes avionics including radar and stealth costing material. But I think those are more like off the shelf components so they shouldn't be a bottleneck.

The other thing is J-35 being newer will have upgraded electronics and might have better pilot machine interface.

I think what we have seen in the past 10 years from cac is far from the peak j10 capacity that they are capable of. There has been quite a few big shrimps in the past years who have said that cac has the capabilities to build a lot more j10s if they had the orders and the engine supply to do so. So their peak production rate of j20 is probably based on a combination of factors including engine production, plaaf demand, possible factory space expansion and greater production rate in their existing production lines. I think they will hit 50 a year either this or next year. By the second half of this deacde, they will hit a steady state of about 70 a year imo.

The other question for me is their ucav plans. I could see plaaf deciding that they don't need as many j20s if they want to pair them up with a large number of loyalman ucavs. But thus far, I would put that as something more likely for 2030s when 6th gen is getting close to entering service.

ZeEa5KPul said:

If a decision has been made to hand CAC a blank cheque to expand J-20 production to 1.5-2x the current rate as quickly as possible, how long would it take to build new factories, train personnel, etc. and how soon after such a decision would we start seeing indications of that?

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My guestimate would be 2-3 years to ramp up to this level