Shenyang / Chengdu "6th Gen" Aircraft - General Discussion and Speculation

[Deino]

Neat

Here is the clear original one ... and please, at least make it clear, it is not real!!

 

[SspewixzzZ]

Seems a new vedio of J36 shows up...
I am wondering will 611 change their base in the future

 

[Elysium]

Those main gear wheels seemed too small. Was it ever determined if this was real?

View attachment 800774

I'm no expert but this feels off to me. I think it can be generally assumed the center of gravity for all aircraft is somewhere in the geometric midpoint of the 3 landing gears (and certainly forward of the rear 2, since otherwise it would sit on its ass). For me, it feels like the aircraft in the picture has far too much mass behind the rear 2 gears.
I might be completely wrong though.

 

[Nx4eu]

I'm no expert but this feels off to me. I think it can be generally assumed the center of gravity for all aircraft is somewhere in the geometric midpoint of the 3 landing gears (and certainly forward of the rear 2, since otherwise it would sit on its ass). For me, it feels like the aircraft in the picture has far too much mass behind the rear 2 gears.
I might be completely wrong though.

Are you looking at it through the lens of a traditional fighter jet? The nose on this aircraft is far larger, and thus far heavier than how it appears from this angle. From the side i suppose, the nose is deceptively small.

The landing gear placements seem completely fine to me, and we have in flight photos of the aircraft with the gears down, which seem to be in the same location. (Bottom image scaled assuming J-XDS is 20m long)


If you want to see an example of trippy looking gear placement, see YF-23 below:

That ass extends way far back.

 

[Deino]

Seems a new vedio of J36 shows up...
I am wondering will 611 change their base in the future

Where? … and Care to post?

Edit: this one?

https://h5.video.weibo.com/show/1034:5262398114955364

 

[Scott Kenny]

If you want to see an example of trippy looking gear placement, see YF-23 below:
View attachment 800851
That ass extends way far back.

Yeah, even the 1/72 plastic models required something like 2oz of weight in the nose.

 

[Not James Stockdale]

I'm no expert but this feels off to me. I think it can be generally assumed the center of gravity for all aircraft is somewhere in the geometric midpoint of the 3 landing gears (and certainly forward of the rear 2, since otherwise it would sit on its ass). For me, it feels like the aircraft in the picture has far too much mass behind the rear 2 gears.
I might be completely wrong though.

You can usually assume that the main gear are basically under the center of gravity.

 

[Deino]

An interesting comparison of the two known J-36 configurations: Above from one of the recent test flights one of the later prototypes vs. prototype 01 in the lower one as seen on 7. April 2025.

(via @琴石2022 from Weibo)

 

[barry bozo]

That's a impossible timeline, It'll take until 2027 optimistically to even get out of the prototype phase and then a few extra years of LRIP and operational testing before being inducted.

Based. At minimum, third engine implies a huge amount of power generation, and in combination with the dual operators I think its safe to assume they're planning to incorporate mass amounts of radars, comms, and primarily EW.

EW in 6th gen aircraft is a different can of worms than this reply requires, soI'll save it for another time. But with regards to all the new systems it will most certainly require, there's a very good chance most of those apertures and radars are simply just surrogates, and will remain surrogates until they are finished being developed. And from my experience, good mission systems do not come quickly. Hell, even B-21 flew with surrogate panels for a good while.

Sorry for the yap-fest, but yeah... 2027 is a pipe dream for a combat-ready variant unless they use J-20/J-35 mission systems, which means the only thing "6th gen" about it would be the OML.

 

[barry bozo]

We won't know for years. We also won't know for certainty that the troughs won't come back later. They seem to be developing the aircraft rapidly (aiming for the earliest IOC), so features could be chosen because they are technically or tactically more desirable or because they involve less development risk, more established technologies or more commonality with other programs (e.g. sharing systems which are being matured for the J-50/J-XDS). There are many possible explanations.

Definitely in agreement with this line of thinking. If they're aiming for the quickest way to verify the airframe performance (both kinematically and aerodynamically), then choosing to implement simpler features can get you in the air faster while you spend time building and developing the features you're actually desiring. Probably isn't cheap tho.

 

[Sferrin]

Definitely in agreement with this line of thinking. If they're aiming for the quickest way to verify the airframe performance (both kinematically and aerodynamically), then choosing to implement simpler features can get you in the air faster while you spend time building and developing the features you're actually desiring. Probably isn't cheap tho.

That's pretty much the definition of a prototype. Think YF-22/23.

 

[barry bozo]

That's pretty much the definition of a prototype. Think YF-22/23.

I understand that. Where I'm diverging from the "prototype" train is that if you were truly only trying to evaluate the airframe design itself (OML, S&C logic, propulsion), then you typically wont bother with combat-related apertures and systems since it would be a waste of your time and resources. Those are already designed, integrated, tested, and analyzed with great accuracy on the digital front, so there's no need for them on a traditional "prototype". I'm sure there's exceptions, but I digress.

In short, their iterative approach to developing the J-36 is different that the traditional demonstrator/prototype - EMD - LRIP path (at least at face value). They seem to be blurring the first two phases into one.

 

[Avimimus]

Sorry for the yap-fest, but yeah... 2027 is a pipe dream for a combat-ready variant unless they use J-20/J-35 mission systems, which means the only thing "6th gen" about it would be the OML.

That's pretty much the definition of a prototype. Think YF-22/23.

Unless the surrogates work... or you have immediate surrogate, interim, and final systems planned... and being developed and prototyped simultaneously.

Thinking about surrogate systems... what happens if you scale the Type 1475 / KLJ-5 with more T/R modules?

With three engines you have at least 50% more power to work with. If the other aircraft systems haven't become more power hungry, then it doesn't scale linearly (i.e. the radar could have >75% more power to work with in actuality). If your thrust-to-weight ratio is a bit more than you need you could eventually draw more power from the shafts and produce even more electricity.

So, even if you are just using WS-15 without tweaking them for more power generation - you still end up with a radar that could be close to twice as powerful, on a supersonic platform that should have better low-observability characteristics than the J-20.

One could use five year old technology as 'surrogates', but the equipment into production using just J-20 systems with some modest expansions - and still end up with much greater capability.

In short, their iterative approach to developing the J-36 is different that the traditional demonstrator/prototype - EMD - LRIP path (at least at face value). They seem to be blurring the first two phases into one.

Yes, that is the speculation as to how they could speed up timelines. Also potentially putting multiple LRIP variants into production in parallel (e.g. J-20 has used three different engines - so it seems like current Chinese approaches are not opposed to having multiple development variants in production/service if it speeds development).

 

[barry bozo]

Unless the surrogates work... or you have immediate surrogate, interim, and final systems planned... and being developed and prototyped simultaneously.

When I say surrogate I meant more of a non-functional surrogate panel, which are used in applications like this. If you have radar built into the OML of an aircraft, blank surrogates are used (sometimes/usually with weights added for proper mass properties/flight dynamics since the MS are usually still in development at this point. So from the outside it looks no different than the real thing.

Thinking about surrogate systems... what happens if you scale the Type 1475 / KLJ-5 with more T/R modules?

I'm on the same page here though. When it comes to Non-OML systems (like an AESA in the nose), they are more likely to have functional surrogates since they can be a drop-in alternative for testing purposes. But do you really need them?

Some of them are required from a flight safety standpoint, so no quarrels there. But you (cool plane manufacturer) already understand how your mission systems operate within your weapons system through digital analysis. So if your main goal is just doing airframe design verification and S&C logic (which is likely given the uniqueness of tailless aircraft), then combat-purposed systems aren't necessary anyway.

But these newer aircraft have a lot of equipment built into the OML . If you look at B-21 as a newer example, there's numerous radars and such molded into the OML. That's mainly what apertures/equipment I'm referring to with regards to my previous comments

 

[Sferrin]

I understand that. Where I'm diverging from the "prototype" train is that if you were truly only trying to evaluate the airframe design itself (OML, S&C logic, propulsion), then you typically wont bother with combat-related apertures and systems since it would be a waste of your time and resources. Those are already designed, integrated, tested, and analyzed with great accuracy on the digital front, so there's no need for them on a traditional "prototype". I'm sure there's exceptions, but I digress.

In short, their iterative approach to developing the J-36 is different that the traditional demonstrator/prototype - EMD - LRIP path (at least at face value). They seem to be blurring the first two phases into one.

Yes. . .just like the YF-22/23. They had stuff like this for that:

 

[barry bozo]

Yes. . .just like the YF-22/23. They had stuff like this for that:

View attachment 801197

That is for systems that were in development for the F-22 (production) variant. The YF-22/23 didn't have provisions for them on the prototype aircraft because its exactly that, a prototype. You wouldn't even need surrogates in the OML for apertures because there's no intention of putting any on the demonstrator/prototype. I was saying its a waste of time/resources to put it on a demonstrator, not to have them in development at all.

I must've not been very clear with what I was saying so apologies for the confusion.

The point I was trying to make is that the J-36 must be more than a simple demonstrator since it has aperatures for mission systems that would otherwise not be required for a simple proof of concept prototype, meaning there's an intention to swap real ones in later if they didn't already have them produced. But given that they've already made big changes to nozzles and inlets, it can't be full blown EMD either, so it's a weird in between.

Given that information, my other point was that those apertures likely contain surrogates since they are still early in development, because you'd otherwise be forfeiting potential development time on your MS equipment by having them ready this early on.

 

[Blitzo]

The point I was trying to make is that the J-36 must be more than a simple demonstrator since it has aperatures for mission systems that would otherwise not be required for a simple proof of concept prototype, meaning there's an intention to swap real ones in later if they didn't already have them produced. But given that they've already made big changes to nozzles and inlets, it can't be full blown EMD either, so it's a weird in between.

Regarding the bolded part, I think the changes described are not necessarily incompatible with EMD.

Given the amount of time elapsed between the first prototype and second prototype was fairly short (10 months), and the fact that third prototype (and possibly fourth prototype) have not greatly changed since the second prototype, imo there should be a high index of suspicion that the differences between the first and second prototypes were intended to occur well before the first prototype flew.

That is to say, I suspect the first prototype may have adopted a much earlier and perhaps less risky configuration in those specific parts mentioned (nozzles, inlets, and also rear landing gear) to enable the first prototype to fly and risk reduce the aircraft, while always intending to swap those elements out from the second prototype onwards.


It's a marginally different way of doing EMD, but given how well circumscribed the changes made were, and given how fast subsequent prototypes were produced and flown (and lack of major changes from prototype 2 onwards), it feels like the whole thing was very deliberate, rather than say, prototype 1's initial flight testing being fed into prototype 2 during construction and then changing things on the fly.

 

[Avimimus]

There is also the very real possibility that there were potential merits to more than one option (e.g. LO trough vs. thrust vector nozzles) and the decision was simply to build both in parallel so they could be tested. The same goes with the landing-gear configuration - it could be the case that both were approved simultaneously.

We can't even rule out that the first prototype we say isn't actually a testbed for a potential follow-on variant, and the other prototypes are closer being LRIP for an interim design. In other words, we could have everything backwards.

There is just too little information to be absolutely certain either way.

 

[Blitzo]

There is also the very real possibility that there were potential merits to more than one option (e.g. LO trough vs. thrust vector nozzles) and the decision was simply to build both in parallel so they could be tested. The same goes with the landing-gear configuration - it could be the case that both were approved simultaneously.

We can't even rule out that the first prototype we say isn't actually a testbed for a potential follow-on variant, and the other prototypes are closer being LRIP for an interim design. In other words, we could have everything backwards.

There is just too little information to be absolutely certain either way.

That is technically "possible" but imo not "probable" simply on the basis that subsequent prototypes after the initial airframe seem to have been consistent in their design features.

If we see a subsequent prototype with similar features to the first airframe, then the likelihood of your suggestion certainly shoots up a fair bit.

 

[Avimimus]

That is technically "possible" but imo not "probable" simply on the basis that subsequent prototypes after the initial airframe seem to have been consistent in their design features.

If we see a subsequent prototype with similar features to the first airframe, then the likelihood of your suggestion certainly shoots up a fair bit.

I agree.

Of course, the quality of our data assumes that there is only one test site - doesn't it?

I always felt the program looked a bit too mature for there to be one test site. That said, maybe engineering tools (CFD etc.) have just gotten more advanced.

 

[VTOLicious]

Jump to 22:55 for 6th gen related stuff...

View: https://youtu.be/j5NYNEneiOM?si=jQQkQcrGaRZzDytC

 

[TwoTribes]

New image.

 

[EmoBirb]

The test flight regime, simply based on what we see (and there's possibly much more we don't see) is just incredibly impressive. CAC and SAC are really putting a lot of effort into keeping the development timeline tight.

 

[snne]

The test flight regime, simply based on what we see (and there's possibly much more we don't see) is just incredibly impressive. CAC and SAC are really putting a lot of effort into keeping the development timeline tight.

They got their requirements and program management in order and pressed ahead aggressively, assuming they were still playing catch-up and that the US was still ahead of them in 6th gen fighter efforts like it had been with the F-22; when in reality the Americans were initially not as serious, and half a decade later were reevaluating not only their requirements but also their industrial and fiscal capabilities since everything had changed so quickly... This is why these birds will begin entering official service around the same time real F-47 prototypes (not subscale X-planes!) start flying...

 

[TomcatViP]

Don't forget that they are probably more radical in their approach as less efficient in their design.

We talked in length about the choice of deleting verticals or not with GCAP. This applies here.

 

[Sferrin]

New image.

They got their requirements and program management in order and pressed ahead aggressively, assuming they were still playing catch-up and that the US was still ahead of them in 6th gen fighter efforts like it had been with the F-22; when in reality the Americans were initially not as serious, and half a decade later were reevaluating not only their requirements but also their industrial and fiscal capabilities since everything had changed so quickly... This is why these birds will begin entering official service around the same time real F-47 prototypes (not subscale X-planes!) start flying...

Doesn't hurt to have something to look at. Ten years ago.

https://aviationweek.com/defense/northrop-grumman-outlines-6th-generation-fighter-study

 

[Ainen]

Would be interesting if 4th and 5th generation situation will repeat itself, and US will roll out something else entirely.

 

[Sferrin]

Would be interesting if 4th and 5th generation situation will repeat itself, and US will roll out something else entirely.

4th gen in the US was pretty much what you got is what was being talked about. ATF. . not so much.

 

[Scott Kenny]

Would be interesting if 4th and 5th generation situation will repeat itself, and US will roll out something else entirely.

In terms of general capabilities I think what the 6th generation needs to have are pretty consistent.

Not like how most people thought 5gen was going to be "much greater maneuverability" (Typhoon/Rafale) and not stealth (F-22)

 

[Ainen]

In terms of general capabilities I think what the 6th generation needs to have are pretty consistent.

Not like how most people thought 5gen was going to be "much greater maneuverability" (Typhoon/Rafale) and not stealth (F-22)

If I understand the story correctly, it can be summarized as Lockheed Martin convincing US DOD that instead of reasonable signature reduction you can go all the way to LO without sacrificing too much... and US happily keeping that knowledge for themselves for long enough to screw over everyone else.

Need to reduce signature itself was well understood and consistent(pre-stealth ATF was probably way better/more ambitious signature vise than future eurocanards), the trick was how much was actually achievable. Broadly speaking, Europe/Soviets went for sub 1m clean, US pre ATF were, say 0.1-0.5 clean, but result was more towards 0.01 combat. Which is entirely different quality.

Or, how since late 50s through mid 1960s the general wisdom was that bigger radar, missile and speed is the way. When Vietnam and middle east shown that's not the way world works, it was not secret, but US turned to new direction decisively and faster than anyone else.
As a result, inertia got old world Mirage F1, Mig-23/27, Viggen and Tornado ADF.

Basically, Chinese 6th are very obvious direction of going forward, we knew it for decades. But US overturned the chessboard, twice.

 

[Scott Kenny]

Basically, Chinese 6th are very obvious direction of going forward, we knew it for decades. But US overturned the chessboard, twice.

I'm not sure there's another flip of the chessboard possible.

The only really big surprise that's come out of F-47 has been that it is only the size of an F-22 MTOW, not a battlecruiser like J-36 or like I was expecting F-47 and FAXX to be.

 

[Ainen]

I'm not sure there's another flip of the chessboard possible.

The only really big surprise that's come out of F-47 has been that it is only the size of an F-22 MTOW, not a battlecruiser like J-36 or like I was expecting F-47 and FAXX to be.

Well, that's the point.
if it's obvious, you can't overturn the board.

 

[Scott Kenny]

Well, that's the point.
if it's obvious, you can't overturn the board.

ATF versus Eurocanard supermaneuverability relied on someone recognizing Ufimstev's equations as important. The only group that has openly admitted how much those equations mattered was Lockheed.

Remember, that paper was openly published.

BAE and Dassault could have used it. Didn't. At least not until well after Typhoon/Rafale designs were frozen.

 

[Avimimus]

Basically, Chinese 6th are very obvious direction of going forward, we knew it for decades. But US overturned the chessboard, twice.

The problem with overmatch is that it forces an arms race.

I am thinking that the board might have been genuinely overturned once again though.

The major trends:
1. Gallium nitride and networked sensors allowing long range shots (satellites are also part of this picture).
2. All aspect broad band stealth trying to deny those shots.
3. Considerations around volume (more platforms mean more distributed sensors, more targets, over more space) vs. price (more survivable platforms).

We don't exactly know how these will balance out.

However, it is enough to think that the F-22 may not be sufficiently networked and may have an older radar, and the F-35 may provide more volume but might not provide enough volume or survivability (i.e. might fall between the two), while 4th gen platforms may be even more vulnerable to long range shots (even if they can provide volume).

I don't think we can rule out the possibility of 6th gen platforms gaining a significant edge over 5th gen platforms. The F-35 design first flew over a quarter century ago... its design has been largely fixed since then (and just refined). The J-35 is only a dozen years old and the J-XDS... well, maybe two years old.

 

[lmaoxd]

The problem with overmatch is that it forces an arms race.

I am thinking that the board might have been genuinely overturned once again though.

The major trends:
1. Gallium nitride and networked sensors allowing long range shots (satellites are also part of this picture).
2. All aspect broad band stealth trying to deny those shots.
3. Considerations around volume (more platforms mean more distributed sensors, more targets, over more space) vs. price (more survivable platforms).

We don't exactly know how these will balance out.

However, it is enough to think that the F-22 may not be sufficiently networked and may have an older radar, and the F-35 may provide more volume but might not provide enough volume or survivability (i.e. might fall between the two), while 4th gen platforms may be even more vulnerable to long range shots (even if they can provide volume).

I don't think we can rule out the possibility of 6th gen platforms gaining a significant edge over 5th gen platforms. The F-35 design first flew over a quarter century ago... its design has been largely fixed since then (and just refined). The J-35 is only a dozen years old and the J-XDS... well, maybe two years old.

GaN in itself might not stay for as long as people think with Ga2O3 radars combined with diamond heat sinks(to solve the heat issue of Ga2O3) and a PIC based back end would make an insanely strong radar. We alr have significant research and prototyping into GA2O3 and PICs in isolation so might see such a radar at least enter prototyping by the end of the decade.

6th gens seem to be focusing more on payload capacity and capacity for oversized weapons(As seen by the larger IWBs even if they might not carry significantly more in tonnage. Personally i dont think the Gap btw 5th and 6th gen is going to be as large as the gap btw the 4th and 5th. 5th gen will still be competetive in the air but will eventually be relegated to more background/support roles while the more modern and larger 6th gens will form the main spear for CCA based combat and large payload deliveries.

 

[pagliacci]

Strange as it may seem, among China's aviation and weapon enthusiasts, the standout advantage of the sixth-generation fighter jet lies in its powerful power generation capacity.

 

[totoro]

A thought - Most PLAAF units today contain a single plane type. Though there are exceptions. With some flanker units having both J11B which has no atg abilities and J16, which is a multirole plane. And more importantly, there were rumors that J35s have been spotted operating (or at least being tested) in same units operating J20s.

Which leads me to believe that PLAAF might find it beneficial to use its both 6th gen type planes in the same unit. That it may become a standard deployment practice and that J36s will be escorting the smaller more maneuverable fighters often. Despite its size, more engines, sensors and percieved higher cost - I don't even think J36 is to be procured in significantly smaller numbers than the other 6th gen fighter. Even the mixed two type 6th gen units might operate them close to 1:1 or at least 1:2 - with additional J36s probably deployed for supporting older generation planes as well.

 

[tico]

A podcast released at the end of 2024 claimed that the J-36 features electronic warfare capabilities between those of the J-16D and large electronic warfare aircraft, undertaking a major role within the system.

He also stated that the J-20S was developed primarily for electronic warfare. It was not designated J-20D because it retains the full combat capabilities of the standard J-20. He drew an analogy to the cancelled U.S. EF-35 program, claiming the J-20S has electronic warfare performance on par with the J-16D. Personally, I find this unlikely. What do you all think?

 

[donnage99]

does a random conjecture from an internet podcast warrant any opinion?

 

[tico]

The guy leaked details about the J-36's first flight and its fundamental configuration in advance , and the tone they used didn't sound like a random guess at all.

does a random conjecture from an internet podcast warrant any opinion?