Chengdu next gen combat aircraft (?J-36) thread

[zyklon]

A 20kg warhead will work on soft targets like aircraft on the ground eg. bombers, tankers and AEW&C aircraft
Radars and air-defence vehicles also fit into this category.

A 500kg warhead on a large, expensive AGM is arguably overkill for these sorts of targets

1. What if the targeted aircraft are kept inside hardened shelters?

2. Or you can just crater the runways without going out of your way to target airframes individually.

But if you're looking for a relatively low-cost, fast, small and stealthy AGM - then the PL-15/PL-17 is an viable option for soft ground targets.

The PL-15 and PL-17 are no longer "low-cost" once you factor in:

1. The number of successful hits needed to disable or destroy targets that aren't quite as delicate as radars.

2. The expenses and risks of operating airborne platforms capable of launching these missiles.

There's obviously an use case for missiles like the PL-15 and PL-17 in SEAD/DEAD, but beyond that, I'm afraid you're just arguing for the sake of arguing . . .

 

[AndrewS]

1. What if the targeted aircraft are kept inside hardened shelters?

What hardened shelters in the 1st and 2nd Island Chains??

2. Or you can just crater the runways without going out of your way to target airframes individually.

Runways are too easy to repair.
Remember, the objective is likely sustained air superiority to the 2nd Island Chain.
They might as well go for flattening an entire airbase, rather than hit empty concrete on a runway

The PL-15 and PL-17 are no longer "low-cost" once you factor in:

1. The number of successful hits needed to disable or destroy targets that aren't quite as delicate as radars.

As I said "soft ground targets".
And it shouldn't be too difficult to add a ground-attack mode because this should be a straightforward software update.

Once the air defences and opposing aircraft are dealt with (on the ground and in the air), then

2. The expenses and risks of operating airborne platforms capable of launching these missiles.

There's obviously an use case for missiles like the PL-15 and PL-17 in SEAD/DEAD, but beyond that, I'm afraid you're just arguing for the sake of arguing . . .

If the J-36 was launching SDBs (which are truly low-cost AGMs), that would mean approaching to 100km of a target. I would say this is a little too risky, at least at the beginning.

But if the J-36 is launching at 300km or 500km at ground targets, it should be fine.
After all, in the A2A role, we could expect J-36 missile launches at 200-300km.

And remember that for existing 5th gen fighters, we're talking about radar detection ranges of less than 100km.

 

[gelgoog]

I think the J-36 will quickly be put into service. I expect around 2030. It seems to be at a similarly advanced prototype stage to the initial J-20 prototypes. Those J-20 took 6 years to enter service after the initial prototypes flew.

The J-36 will be way more effective at its missions than either the J-16 or the H-6K. There is no reason to delay entry into service once the design is mature enough.

I expect it to enter service with WS-15 engines. But even if it had WS-10 engines it would be way better than an H-6K.

 

[Tomboy]

I think the J-36 will quickly be put into service. I expect around 2030. It seems to be at a similarly advanced prototype stage to the initial J-20 prototypes. Those J-20 took 6 years to enter service after the initial prototypes flew.

The J-36 will be way more effective at its missions than either the J-16 or the H-6K. There is no reason to delay entry into service once the design is mature enough.

I expect it to enter service with WS-15 engines. But even if it had WS-10 engines it would be way better than an H-6K.

I have my doubts on the capability of even using WS-15 for a 6th generation jet, IMO we are at the point of a large shift in turbine technology just like how 2nd/3rd generation aircrafts used turbojets while 4th generation aircrafts started using turbofans. Now with aircraft design more and more intrinsically linked to their powerplants with electrical and cooling capacity now the main design goals, VCE can offer much better thermal management and power generation capabilities compared to low bypass turbofans even not counting in the massive efficiency boost. Some fluidic TVC designs basically requires a VCE's third bypass bleed air to function and it is likely some other systems(especially eletrical and cooling) will be designed to take full advantages of VCE's third stream. My point is to say unlike the J-20 where you are using an interim low bypass turbofan and then swapping it for another low bypass turbofan which requires relatively less changes when compared to J-36 where the aircraft itself is designed with VCE in mind, but you are trying to put a low bypass turbofan in there as a interim. The aircraft might not even be fully combat capable without it's intended engines. IMO, it could be useful to produce a few LRIP aircraft with WS-15 just to test out operational capabilities at FTTB even if it means some key features might not be fully functional, it just have to be enough for pilots to get a reasonable understanding of the full capability of this aircraft. But I do not think it'll be a smart idea to rush J-36 into production and start making hundreds of WS-15 powered J-36 like how the J-20s were made with WS-10Cs. Serial production of the type should only begin when all capabilities are fully functional.

 

[AndrewS]

I have my doubts on the capability of even using WS-15 for a 6th generation jet, IMO we are at the point of a large shift in turbine technology just like how 2nd/3rd generation aircrafts used turbojets while 4th generation aircrafts started using turbofans. Now with aircraft design more and more intrinsically linked to their powerplants with electrical and cooling capacity now the main design goals, VCE can offer much better thermal management and power generation capabilities compared to low bypass turbofans even not counting in the massive efficiency boost. Some fluidic TVC designs basically requires a VCE's third bypass bleed air to function and it is likely some other systems(especially eletrical and cooling) will be designed to take full advantages of VCE's third stream. My point is to say unlike the J-20 where you are using an interim low bypass turbofan and then swapping it for another low bypass turbofan which requires relatively less changes when compared to J-36 where the aircraft itself is designed with VCE in mind, but you are trying to put a low bypass turbofan in there as a interim. The aircraft might not even be fully combat capable without it's intended engines. IMO, it could be useful to produce a few LRIP aircraft with WS-15 just to test out operational capabilities at FTTB even if it means some key features might not be fully functional, it just have to be enough for pilots to get a reasonable understanding of the full capability of this aircraft. But I do not think it'll be a smart idea to rush J-36 into production and start making hundreds of WS-15 powered J-36 like how the J-20s were made with WS-10Cs. Serial production of the type should only begin when all capabilities are fully functional.

The J-36 is an all-aspect stealth 6th gen airframe, whether it has WS-15 engines or VCE.

It should still be able to perform the same missions, albeit with less range and endurance.

It potentially has less sustained electrical power, but I see the bottleneck here being more about getting rid of excess electronics heat, rather than the electricity generation (from a third bypass airstream or elsewhere)

Large numbers of WS-15 equipped J-36s will bring an entirely new set of capabilities and still means Chinese Air Superiority to the Second Island Chain.

And once the VCE is ready, those WS-15 engines can be replaced. It's not like those WS-15 engines will go to waste, as they can be reused on the J-20s.

Note that China has a surplus of mechanics and technicians to do engine swaps quickly and at low cost, unlike the USA.

So I don't see any reason to hold back on J-36 production, if the VCE is not ready.

 

[Tomboy]

The J-36 is an all-aspect stealth 6th gen airframe, whether it has WVacation5 engines or VCE.

It should still be able to perform the same missions, albeit with less range and endurance.

It potentially has less sustained electrical power, but I see the bottleneck here being more about getting rid of excess electronics heat, rather than the electricity generation from a third bypass airstream.

Large numbers of WS-15 equipped J-36s will bring an entirely new set of capabilities and still means Chinese Air Superiority to the Second Island Chain.

And once a VCE is ready, those WS-15 engines can be replaced. It's not like those WS-15 engines will go to waste, as they can be reused on the J-20s.

Note that China has a surplus of mechanics and technicians to do engine swaps quickly and at low cost, unlike the USA.

So I don't see any reason to hold back on J-36 production, if the VCE is not ready.

That's just not how this works, if you read my post you'd see that some systems might be specifically designed for VCE and quite literally be non functional without it. Cooling issue is not a trivial concern, look at the F-35 it's not even at original design specs with the latest upgrade due to F-135 being underspeced and had been facing constant thermal management issues. J-36 with WS-15 would face the same problem but 10 times worse. FYI the third bypass stream is what gives VCE such massive thermal management capability and it's non replaceable. Stuff isn't plug and play especially aircraft engines, look at how long integration with J-20A is taking. WS-15 is in production for nearly 2 years by now yet we still haven't seen confirmed sustained production of J-20A at CAC. Also, unless you haven't been listening to CAC's head engineers word. In his vision 6th generation is literally built on the electronics while advanced aerodynamics and stealth is only a relatively small part of it. So basically you are suggesting to chuck out everything that actually makes this aircraft so advanced and have it enter service effectively as a empty shell. I'm not sure why some members here are so eager to rush J-36 into service even when it's not ready, at this point I feel like to some people one upping the Americans is more important than actually having a fully functional aircraft. If that's the case then we are no different than the Soviets and the Russians. I'm still very much onboard with letting development run it's course and have it enter serial production once it's ready.

 

[AndrewS]

That's just not how this works, if you read my post you'd see that some systems might be specifically designed for VCE and quite literally be non functional without it. Cooling issue is not a trivial concern, look at the F-35 it's not even at original design specs with the latest upgrade due to F-135 being underspeced and had been facing constant thermal management issues. J-36 with WS-15 would face the same problem but 10 times worse. FYI the third bypass stream is what gives VCE such massive thermal management capability and it's non replaceable. Stuff isn't plug and play especially aircraft engines, look at how long integration with J-20A is taking. WS-15 is in production for nearly 2 years by now yet we still haven't seen confirmed sustained production of J-20A at CAC. Also, unless you haven't been listening to CAC's head engineers word. In his vision 6th generation is literally built on the electronics and advanced aerodynamics and stealth is only a small part of it. So basically you are suggesting to chuck out everything that actually makes this aircraft so advanced and have it enter service effectively as a empty shell. I'm not sure why some members here are so eager to rush J-36 into service even when it's not ready, at this point I feel like to some people one upping the Americans is more important than actually having a fully functional aircraft. If that's the case then we are no different than the Soviets and the Russians. I'm still very much onboard with letting development run it's course and have it enter serial production once it's ready.

We had this sort of discussion six months ago below. The paper uses a large twin-engine stealth fighter (presumably the J-20 with WS-10 or Ws-15 engines) as the reference point.

Chengdu next gen combat aircraft (?J-36) thread

https://x.com/Hurin92/status/1874139288407072779 Thanks to Hurin's work. He listed some design details. If you want a complete version, please refer to the original paper. @siegecrossbow posted very important chat about J-36 chief designer.. if you actually read last few pages of this thread...

www.sinodefenceforum.com

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We're still looking at 400 KW of cooling capacity. So we can expect a J-36 (with 3 engines) to exceed the J-20 in terms of cooling capacity.

And think about AWACs such as the E-2, E-767 or E-737.
They use 2x 150KW electricity generators as standard

So there is enough electricity with WS-15 engines to function.

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And at higher supersonic speeds, the only way to get rid of waste heat is by dumping into it the fuel. A third airflow in the VCE is simply not available for cooling

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Sure, a VCE could add a lot more cooling and thermal management at subsonic speeds
But then, the worse case scenario with WS-15 engines is the radars refreshing the radar picture less frequently, or potentially tracking fewer targets.

But a J-36 equipped with WS-15 engines should still outperform the J-20 in terms of sustained electricity usage.
And the J-36 radars themselves are way bigger than on the J-20

 

[sunnymaxi]

That's just not how this works, if you read my post you'd see that some systems might be specifically designed for VCE and quite literally be non functional without it. Cooling issue is not a trivial concern, look at the F-35 it's not even at original design specs with the latest upgrade due to F-135 being underspeced and had been facing constant thermal management issues. J-36 with WS-15 would face the same problem but 10 times worse. FYI the third bypass stream is what gives VCE such massive thermal management capability and it's non replaceable. Stuff isn't plug and play especially aircraft engines, look at how long integration with J-20A is taking. WS-15 is in production for nearly 2 years by now yet we still haven't seen confirmed sustained production of J-20A at CAC. Also, unless you haven't been listening to CAC's head engineers word. In his vision 6th generation is literally built on the electronics while advanced aerodynamics and stealth is only a relatively small part of it. So basically you are suggesting to chuck out everything that actually makes this aircraft so advanced and have it enter service effectively as a empty shell. I'm not sure why some members here are so eager to rush J-36 into service even when it's not ready, at this point I feel like to some people one upping the Americans is more important than actually having a fully functional aircraft. If that's the case then we are no different than the Soviets and the Russians. I'm still very much onboard with letting development run it's course and have it enter serial production once it's ready.

Chief designer itself confirmed, J-36 final Engine will be VCE. its all depend on J-36 induction date, if mid 2030's then aircraft likely to enter in service with designated Engines.

1. AECC completed verification of key technologies of variable cycle Engine in 2018.

2. Liu Daxiang confirmed, next generation Low Bypass Engine for fighters with T/W ratio 12-15 have achieved key technological breakthroughs in materials in 2022 during Aviation industry conference.

back in 2025, it is likely we have already a prototype or prototype near completion. now its all depend on testing and verification of new material/components of VCE.. if first prototype pass initial test, then more units will manufacture for further testing and evaluation. so i would say, next 5-7 years if everything goes well.

if we check Patents/research papers, then AECC Shenyang too working on its own ACE/VCE engine. so it is safe to assume, we have two next gen projects ongoing.

 

[latenlazy]

That's just not how this works, if you read my post you'd see that some systems might be specifically designed for VCE and quite literally be non functional without it. Cooling issue is not a trivial concern, look at the F-35 it's not even at original design specs with the latest upgrade due to F-135 being underspeced and had been facing constant thermal management issues. J-36 with WS-15 would face the same problem but 10 times worse. FYI the third bypass stream is what gives VCE such massive thermal management capability and it's non replaceable. Stuff isn't plug and play especially aircraft engines, look at how long integration with J-20A is taking. WS-15 is in production for nearly 2 years by now yet we still haven't seen confirmed sustained production of J-20A at CAC. Also, unless you haven't been listening to CAC's head engineers word. In his vision 6th generation is literally built on the electronics while advanced aerodynamics and stealth is only a relatively small part of it. So basically you are suggesting to chuck out everything that actually makes this aircraft so advanced and have it enter service effectively as a empty shell. I'm not sure why some members here are so eager to rush J-36 into service even when it's not ready, at this point I feel like to some people one upping the Americans is more important than actually having a fully functional aircraft. If that's the case then we are no different than the Soviets and the Russians. I'm still very much onboard with letting development run it's course and have it enter serial production once it's ready.

The F-35’s cooling capacity issues have nothing to do with an absence of VCEs and everything to do with a failure to set appropriate requirements for future growth margins for an already volume constrained airframe. VCEs are only talked about as critical for the F-35 to expand cooling capabilities because they’re being offered as a workaround for that first order failure to set appropriate requirements.

There are many many ways to build cooling capacity into an airframe, and VCEs are not the most central factor to that equation. The J-36 has much larger volume and a third engine for a reason. The volume alone (especially the fuel fraction) provides much greater inherent heat sink capacity and the third engine provides much greater heat dumping ability. With or without VCEs the J-36 is already designed to have a much greater amount of cooling capacity than any other fighter in service or development today. If the J-36’s requirements are set to enable its primary system capabilities using WS-15s then the J-36 will perform fine with WS-15s. VCEs are not the critical enabler but the cherry on top here.

 

[Wrought]

DF-26s are way more expensive than a PL-17 or PL-17
CJ-10s are non-stealthy, slow and too easy to shoot down.

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At a distance of 2500km+, I don't see it being realistic for many Chinese tankers, AEW&C and navy ships to operate.

Hence what we see of the J-36 design philosophy so far.
It has multiple radars and IR sensors to compensate for the lack of AEW&C.
Plus huge range to compensate for the lack of tankers.

But with all-aspect stealth, my guess is that a J-36 is literally impossible to detect at a range of 300km.

And remember that on the opposing side, the J-36 is only facing a handful of airbases and carriers (floating airbases)

If you think J-36 design philosophy is to operate way out on its own instead of within an interlinked network, then you don't understand anything at all. Then again, you are also asking about SM-6, which was originally a SAM not AAM, so I guess that goes without saying.

The latest AAMs all have INS, GPS and mid-course guidance options.

Not surprising given that a JDAM guidance kit (with all of the above options) costs less than $30K, which is dirt cheap for a PGM

As the other guy pointed out, it's possible to modify missiles to service other roles, but expecting them to work just out of the box is ridiculous. There is a reason the AAM/AGM distinction exists and it's not because you are smarter than every air force in the world. Like he also said, you're just arguing for the sake of arguing. I'd advise cutting it out before Deino logs back in; he was already annoyed.