J-35A fighter (PLAAF) + FC-31

ismellcopium said:

Wait, how could production of the twin engine J-35 already be nearing J-20? I thought the new SAC facility is nowhere near up at full capacity yet?

Edit: ah, missed the rumour about J-16 production halting. OTOH I'm a bit sad about that if true but would explain a lot if they pivot the existing lines. Range and payload of the J-35A must truly be pretty good if they're confident with it fully replacing rather than complementing J-16.

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SAC new production facility completed but not yet fully ramp up.

seems like you missed this news.

Shenyang Aviation & Aerospace City has a planned total area of 79.2 square kilometers. The SAC new plant zone is planned to include core facilities such as the final assembly building and a runway, fully covering needs for aviation product manufacturing and flight testing. By the end of June last year, the main structure of the new plant’s final assembly building was successfully completed and product assembly has officially begun, marking substantive progress in SAC’s key task of partial relocation.

00CuriousObserver said:

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Main structure of SAC’s new plant core assembly building completed

Mass production expected to begin next year

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tphuang said:

What evidence do you have that J-35 is cheaper to fly?

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No specific evidence; those calculations are obviously not public.

It just makes sense from 3 angles:
One is pure evidence: smaller aircraft built with more demanding service environment(carrier) in mind, smaller components, lower class engines with lesser fuel use.
Second is common sense: ultimately, J-20 (including absolutely contemporary J-20A) exists.

Finally, J-20 family, flying on 2 WS-10/15 (or AL-31) is unlikely to cost below f-15/flankers - same or higher weight class, but add more equipment with harder access(stealth) and more packed airframe. Flankers and F-15s are already some of the most expensive fighter per flight hour in the world(circulated numbers fly between 35 and 50k usd/hr). Higher than that is right towards F-22 numbers.
J-35A, on the other hand, is way smaller, and its engines come from lineage beginning from RD-33. If we use Flanker to Fulcrum per hour ratio, it can differ by factor of 2 or more(<20 per hr for fulcrum), despite RD-33s not exactly being user friendly engines(early fighter turbofan, optimized for rigidity rather than efficiency). J-35 is stealth, sure, but WS-19/21 are unlikely to be built for dirt runways and FOB damage.

There are plenty of reasons to buy J-35 family. Not having ground attack in current PLA family certainly isn't one of them.

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J-20 aren't strikers in full sense, as they with ~90% chance doesn't have corresponding sensor (its configuration perfectly matches ATF IRST, which was one big LWIR mirror with limited AoR). We don't know about J-20A/S though.
Unlike them, J-35(A) EOTS is arranged exactly like a dual-use sensor with significant(if not primary) a2s use.

J-16, J-10 aren't VLO and as such aren't first day strikers.
LWs are additional link in a kill chain, which by itself has limited SO and benefits strongly from presense of manned strike fighter.

Finally, there's frequent argument that J-35, unlike F-35 is not optimized towards deep bay. Which is true, but Up to debate if Chinese 1000kg class munitions are even meant for internal carriage.

Aval said:

Apart from being a cheaper plane (and perhaps slightly stealthier?), what would make the J-35/A a better striker than J-20? Is it purely opportunity cost, that being that J-20 is too few and thus precious to spare for the strike role?

For LO striking, we roughly know the depth of J-20's IWB but we've never seen J-35/A IWB, and its length and width look similar from compared photos. Are we expecting J-35/A IWB to be deeper? Have there been any credible rumours on this? J-20 IWB seems too shallow to carry anything other than thin A2A missiles.

F-35 is a better striker than F-22 because it has deeper IWBs, better sensors and integration, and has EOTS (while F-22 does not). None of these differences may be present for J-35/A vs J-20.

Even for non-LO striking, we've seen photos of J-20 with external carry of munitions and as a larger plane it should be able to carry more externally, so the J-20 can do better in that role too (but moot anyway as J-16 exists).

(Obviously for PLANAF the J-35 being the only LO option altogether makes it an important new addition. But I still fail to see why PLAAF would need J-35A purely for strike, except on cost grounds).

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Aval said:

Makes sense. But as a subsystem (that's seemingly mostly contained to just its small physical container + software), wouldn't it be cheaper to refit J-20s with new 360 (with laser) EOTS than making and inducting (training, logistics etc.) an entirely new plane for it? If engines can be retrofitted, why can't EOTS?

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Firstly, I don't think anyone who is reasonably credible would seriously suggest that the PLAAF procures the J-35A purely for strike missions.

Secondly, we do have indications of the J-35/A having a deeper IWB than the J-20/A/S (albeit indirectly):

ACuriousPLAFan said:

Illustrations from academic papers which likely indicates the longitudinal cross-sectional diagram of the internal weapons bay (IWB) of the J-35A (for the PLAAF) and the J-35 (for the PLAN).

Posted by @Captain小潇 on Weibo.

View attachment 139896
View attachment 139897
View attachment 139902
View attachment 139898

Assuming the lengths of IWBs on both the J-20/As and J-35/As are similar, if not exactly the same:

Through comparison, the IWBs of the J-35/A seems to considerably differ from the IWB of the J-20, such that the J-35/A's IWB actually has a deeper depth towards the front than the J-20's IWB, mainly due to the differences in the placement of the IWBs and the designs of the engine inlets on both the J-20 and J-35/A.

View attachment 139900
View attachment 139905

This has likely resulted in the J-35/As being actually capable of carrying larger-dimension payloads inside her IWB than the J-20.

The upper four diagrams should refer to the J-35/As, whereas the lower four diagrams should refer to the J-20.

View attachment 139901

Honestly, didn't realise the the IWB of the J-20 actually doesn't have a uniform depth across the entire length until today.

View attachment 139904

Such features could also explain why the J-20/As and J-35As are given different mission sets by the PLAAF.

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So yes, it does lend credence to the J-35A being better than the J-20/A/S in terms of strike capabilities in LO mode (i.e. it can carry larger/thicker payloads inside its IWB for strike missions while also maintaining stealth), despite the IWBs on both fighters likely having the same length and width. And it's not limited to the 240-degree vs 360-degree IRST difference between them either.

Thirdly, during the Zhuhai Expo 2024, the CCTV has already iterated that the J-35A is a multirole fighter, in contrast to the J-20/A/S, which is way more slanted towards air superiority. To put it simply: If the A2A-A2G weightage for the J-20/A/S lies about 90-10 or 80-20, then the A2A-A2G weightage for the J-35A would be about 70-30 or 60-40.

Additionally, one of the primary reasons for the PLAAF to procure the J-35A in large numbers is to enable the rapid expansion of its 5th-generation fighter fleet, especially given the worsening geopolitical developments around China and the increasing number of Gen-4.5 and Gen-5 fighters fielded by China's adversaries that surround China. Hence, the main goal here would be to enable the PLAAF to achieve air superiority and secure air dominance within the vicinity of the Chinese soil, preferably up to the 2IC. The best way to achieve this goal would be the simultaneous, combined high-volume production runs of the J-20/A/S and the J-35/A.

In retrospect, the ability to conduct strike missions comes more as a secondary for the J-35/A. Not that such a capability is not important (if anything, it's very important to be able to lob ARMs against enemy radar systems while maintaining LO-mode) - Just that it comes more as part of the overall package.

Gloire_bb said:

J-35A, on the other hand, is way smaller, and its engines come from lineage beginning from RD-33. If we use Flanker to Fulcrum per hour ratio, it can differ by factor of 2 or more(<20 per hr for fulcrum), despite RD-33s not exactly being user friendly engines(early fighter turbofan, optimized for rigidity rather than efficiency). J-35 is stealth, sure, but WS-19/21 are unlikely to be built for dirt runways and FOB damage.

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WS-19 has 0 relationship to RD-33 so comparing it with that would be completely pointless

ACuriousPLAFan said:

Secondly, we do have indications of the J-35/A having a deeper IWB than the J-20/A/S (albeit indirectly):

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Wow, i missed that post.
With your permission, i'll copy this image here, as it is(provided it's indeed match) more or less summary answer in its own right.

Tomboy said:

WS-19 has 0 relationship to RD-33 so comparing it with that would be completely pointless

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I don't know if it's 0 or not, neither of us do; this is most certainly not a hill i'll die on. What's important here is that engines of different classes(major source of running costs) are very different in terms of these very running costs, and whatever degree of difference there is between RD-33 and WS-19 - it will favour WS-19.
RD-33 was a older tech engine (compared to AL-31), optimized for ruggedness. 50 yrs old soviet design, which is by design intent worse(more expensive) than it could've been.
WS-19 is ~same generation as WS-15, and i'd be quite surprized if it is optimized for flying dirt instead of efficiency.

ACuriousPLAFan said:

Firstly, I don't think anyone who is reasonably credible would seriously suggest that the PLAAF procures the J-35A purely for strike missions.

Secondly, we do have indications of the J-35/A having a deeper IWB than the J-20/A/S (albeit indirectly):


So yes, it does lend credence to the J-35A being better than the J-20/A/S in terms of strike capabilities in LO mode (i.e. it can carry larger/thicker payloads inside its IWB for strike missions while also maintaining stealth), despite the IWBs on both fighters likely having the same length and width. And it's not limited to the 240-degree vs 360-degree IRST difference between them either.

Thirdly, during the Zhuhai Expo 2024, the CCTV has already iterated that the J-35A is a multirole fighter, in contrast to the J-20/A/S, which is way more slanted towards air superiority. To put it simply: If the A2A-A2G weightage for the J-20/A/S lies about 90-10 or 80-20, then the A2A-A2G weightage for the J-35A would be about 70-30 or 60-40.

Additionally, one of the primary reasons for the PLAAF to procure the J-35A in large numbers is to enable the rapid expansion of its 5th-generation fighter fleet, especially given the worsening geopolitical developments around China and the increasing number of Gen-4.5 and Gen-5 fighters fielded by China's adversaries that surround China. Hence, the main goal here would be to enable the PLAAF to achieve air superiority and secure air dominance within the vicinity of the Chinese soil, preferably up to the 2IC. The best way to achieve this goal would be the simultaneous, combined high-volume production runs of the J-20/A/S and the J-35/A.

In retrospect, the ability to conduct strike missions comes more as a secondary for the J-35/A. Not that such a capability is not important (if anything, it's very important to be able to lob ARMs against enemy radar systems while maintaining LO-mode) - Just that it comes more as part of the overall package.

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Very interesting, thanks for the link the comment. If the J-35/A does indeed have deeper IWBs then that neatly solves my original question.

I've reread the original post about 100 J-35 this years, and seeing that many are surprised at the number seemingly being this year's potential production, could it be that 100 refers to the TOTAL number built INCLUDING those built in previous years? I don't know what the latest count of J-35/35A produced by end of 2025 is, probably several dozens, maybe 2-3? If so, adding another several (more) dozens this year, say 4-5, and we get to the magic 100 number.

mack8 said:

I've reread the original post about 100 J-35 this years, and seeing that many are surprised at the number seemingly being this year's potential production, could it be that 100 refers to the TOTAL number built INCLUDING those built in previous years? I don't know what the latest count of J-35/35A produced by end of 2025 is, probably several dozens, maybe 2-3? If so, adding another several (more) dozens this year, say 4-5, and we get to the magic 100 number.

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What you describe is correct, and people are acting surprised because they are reading the original post wrong.

It is "over 100 by end of the year" not "over 100 will be produced this year".

Putting it another way:
"Over 100 by end of the year" = "number of J-35/A family aircraft produced by end of 2025" + "number of J-35/A family aircraft produced between end of 2025 and end of 2026"

We do not know what the numbers for either "end of 2025" and "between end of 2025 and end of 2026" are.


The problem with this forum increasingly is that literacy issues are degrading the ability to have coherent conversations, and people click "post reply" too quickly.

siegecrossbow said:

200 fifth gen a year. Will this be the year F-35 production is bested???

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This is what I mean -- there are multiple layers of logical leaps that must be made to reach "200 fifth gen a year" from the prior post of "over 100 J-35/A units by end of the year".

And really those multiple layers should be explained probably by a couple of paragraphs to justify it rather than just throwing out a conclusion and then leaving people to try and interpret and reverse engineer out the basis of the conclusion.

Blitzo said:

What you describe is correct, and people are acting surprised because they are reading the original post wrong.

It is "over 100 by end of the year" not "over 100 will be produced this year".

Putting it another way:
"Over 100 by end of the year" = "number of J-35/A family aircraft produced by end of 2025" + "number of J-35/A family aircraft produced between end of 2025 and end of 2026"

We do not know what the numbers for either "end of 2025" and "between end of 2025 and end of 2026" are.


The problem with this forum increasingly is that literacy issues are degrading the ability to have coherent conversations, and people click "post reply" too quickly.

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I'm almost sure he is referring to neither but instead saying the total production capacity will be brough to ~100 aircraft per year. Like how COMAC claims to have expanded production lines to 50 aircraft per year.

Tomboy said:

I'm almost sure he is referring to neither but instead saying the total production capacity will be brough to ~100 aircraft per year. Like how COMAC claims to have expanded production lines to 50 aircraft per year.

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That is also a viable interpretation, certainly much more realistic than "100 J-35/A family aircraft will be produced in 2026 overall"..

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The problem with reading these statements is there are many reasonable ways to interpret them, and it's vital that we do not end up writing conclusions based off premises which are in turn based on interpreting statements... Without explaining how we interpret a statement to begin with!


Writing to explain one's rationale to justify one's conclusion is more important than just throwing a conclusion out there and causing people to go "????".