PLA next/6th generation fighter thread

[Blitzo]

Why would you assume there is a "sufficient" engine technology when no one else has demonstrated credibly what a 6th gen would be like? That seems to me uncharacteristically unconservative.

Because there are no indications that there is any 6th generation fighter project in the world that will have three engines, in what would be a huge deviation of design trends that is not something that would be omitted even in speculative concepts or early stage contractor models or program visions.

Two engines remain very much the null configuration -- if J-XD ends up with three engines, the natural assumption should not be that "this is a superior configuration" but rather "why did they have to choose this configuration".

The implication of them not being able to get the job done with two engines is that there's something about the J-XD that no other twin engined plane design can suffice.

That view would be reasonable, if we had evidence that PRC aeroengine technology has been demonstrated to be sufficiently competitive/capable with global peers.
But we very much have not yet reached a point where we believe or can assume PRC aeroengine technology is so comfortably qualitatively competitive with global peers that they are qualitatively to par at this point or in the immediate equivalent time point future.


Or to put it simply -- the idea of having three engines is not necessarily a sign of increased capability, if anything it would more likely be a reflection of a degree of technological backwardness.

 

[Index]

Because there are no indications that there is any 6th generation fighter project in the world that will have three engines, in what would be a huge deviation of design trends that is not something that would be omitted even in speculative concepts or early stage contractor models or program visions.

Two engines remain very much the null configuration -- if J-XD ends up with three engines, the natural assumption should not be that "this is a superior configuration" but rather "why did they have to choose this configuration".




That view would be reasonable, if we had evidence that PRC aeroengine technology has been demonstrated to be sufficiently competitive/capable with global peers.
But we very much have not yet reached a point where we believe or can assume PRC aeroengine technology is so comfortably qualitatively competitive with global peers that they are qualitatively to par at this point or in the immediate equivalent time point future.


Or to put it simply -- the idea of having three engines is not necessarily a sign of increased capability, if anything it would more likely be a reflection of a degree of technological backwardness.

No other country besides US has put 2 10 TwR range fighter jet engines into service. So China experiences an equal degree of technological "backwardsness" as US and less than anyone else.

The leader is the trend setter, I.e. Whoever puts out the first 6th gen. If US puts out a 6th gen first, it has 2 engines and has the same rough capability as 3 engined J-XD, then a credible discussion about limitations can be made. But this is far from what's happening.

The natural assumption when an industry leader tries a new thing is that it is done because it is the next generation step, unless indicated otherwise. China isn't UK or Turkey, it doesn't experience the need to compromise on designs, as evidenced by J-20, J-35 etc.

 

[latenlazy]

Since this thread is about 6th gen, who do you think leaked the 3 engine concept first for him to draw, or do you think Cute Orca is just trolling everyone?

I think Cute Orca is not that reliable and sometimes likes to post things for attention before they’ve fully vetted their information.

 

[ZeEa5KPul]

I think you have misunderstood what I wrote in my last post.

If J-XD has three engines, I am not saying it has any effect on our appraisal of what a 6th generation aircraft is like or what expectations three engines possesses.

I am saying that if J-XD has three engines, it does tell us where we can expect the Chinese aerospace industry to be, particularly in terms of aeroengine development and capability, because they would not choose to go with a three engine configuration if they possessed sufficient engine technology to enable a twin engine configuration instead (whether it's in terms of thrust, flight regime optimization, or electrical power generation -- which isn't inherently tied with engine thrust/engine count but it is also related to the aircraft's onboard generators and its cooling/thermal capacity).



If you want to argue that having three engines means that designers believe a key feature of 6th generation aircraft is additional power generation, my counter view is that it means they weren't able to get the job done with two engines (which would be a preferable configuration to three engines) or associated generators.

That implies the Chinese aeroengine industry is in a much worse place than even the most conservative estimates. No one here would argue they're the best in the world, but they're certainly not that far behind that they'd cripple the 6th gen design with something like a third engine, especially given how fast China is advancing. The much better play would be to wait for the engines to advance and mature, especially since NGAD is delayed/soft cancelled.

They were in a far worse place both in relative and absolute terms with the J-20 and they didn't cripple that design to accommodate weak engines. They just bit the bullet and flew the airframe they wanted in a nerfed configuration, and that's what we should overwhelmingly expect here.

I'll rephrase what Index said because I think the idea is correct: If the 6th gen design indeed has three engines, then that's an inherent feature of CAC's conception of a 6th generation fighter. It would have 3 engines even if China had the American engine industry.

That view would be reasonable, if we had evidence that PRC aeroengine technology has been demonstrated to be sufficiently competitive/capable with global peers.
But we very much have not yet reached a point where we believe or can assume PRC aeroengine technology is so comfortably qualitatively competitive with global peers that they are qualitatively to par at this point or in the immediate equivalent time point future.

How have we not? Is the WS-15 not a thing?

 

[Deino]

That implies the Chinese aeroengine industry is in a much worse place than even the most conservative estimates. No one here would argue they're the best in the world, but they're certainly not that far behind that they'd cripple the 6th gen design with something like a third engine, especially given how fast China is advancing. The much better play would be to wait for the engines to advance and mature, especially since NGAD is delayed/soft cancelled.

They were in a far worse place both in relative and absolute terms with the J-20 and they didn't cripple that design to accommodate weak engines. They just bit the bullet and flew the airframe they wanted in a nerfed configuration, and that's what we should overwhelmingly expect here.

I'll rephrase what Index said because I think the idea is correct: If the 6th gen design indeed has three engines, then that's an inherent feature of CAC's conception of a 6th generation fighter. It would have 3 engines even if China had the American engine industry.

How have we not? Is the WS-15 not a thing?

In fact I think we are on a wrong way with the whole discussion here due to several reasons: First we barely know enough to be sure if there is already anything worth to discuss. Second, this artwork and its source is not conclusive in any way and that guy is known for posting similar stuff already before … and third: It would be indeed a „first“ overall to develop a three-engined fighter, so indeed of making strange conclusions like „the Chinese aeroengine industry is in a much worse place than even the most conservative estimates“ we should first find answers for the first two questions and then what conclusions can be drawn from it!

I would even go so far as- in case this artwork has any reality background in it, we are not looking at the J-XD 6th generation fighter, but maybe more at a supersonic striker, a stealthy supersonic-capable Theater bomber like this fancy concept we were discussing a few years ago from SAC. Just look at the Indicated canopy, which looks IMO at best like a striker‘s/bomber‘s canopy than a true fighter cockpit!

Just my two cents.

 

[ACuriousPLAFan]

I won't touch upon the validity or veracity of a triple-engine-equipped next-gen warplane (not just fighter aircraft), given how scarce the reliable information which we have access to at the present moment.

Let the bullets fly for a while (让子弹飞一会儿).

---

Recall that famed Academician Liu Daxiang (刘大响工程院院士) of the Chinese Academy of Engineering said this during the 2022 Keynote Report of China Aviation Industry Conference in late-November 2022, other than J-20A's WS-15 (directly translated):

Next generation (i.e. 5th-generation) low-bypass turbofan engine for use on fighters and bombers with TWR of 12-15... Have achieved key technological breakthroughs in their respective research and development progresses.

While I do agree that China's mastery in engine technology is still some distance away from the international leading standards (i.e. the US), I don't believe that China is absolutely that far behind them in this field at this stage of progress. We're in 2024 and not 2004, after all.

Going back to the presentation from December 2022, I have sufficient reasons to believe that the "5th-gen low-bypass turbofan engine" mentioned by Academician Liu is actually referring to the VCE/ACE meant to power China's next-generation J-XD.

Beyond the aforementioned TWR of 12-15 (which is a huge step-up from the current 4th-gen LBP turbofan engines' TWR of ~10) - What are the key performance parameters that we can expect from such engines?

Weight of the engine? Military (dry) thrust? Maximum (augmented) thrust? Turbine inlet temperature? Etc. I think these could be more useful for discussion/argument WRT powerplants for the J-XD.

 

[Gloire_bb]

That implies the Chinese aeroengine industry is in a much worse place than even the most conservative estimates. No one here would argue they're the best in the world, but they're certainly not that far behind that they'd cripple the 6th gen design with something like a third engine, especially given how fast China is advancing.

20t class fighter engines don't grow on trees. Especially given how fast this fighter has appeared, there's just no new engine like that.

China wants 50t class "fighter", if this term is still applicable. China has WS-10C.
Soon (but not yet) there will be WS-15. Those are close enough in size, power and airflow. Not hard to guess that since China has these two, it's again them.

It's nothing more and nothing less an aspect of speed of appearance of this fighter, barely a decade after J-20.

 

[Red tsunami]

Or to put it simply -- the idea of having three engines is not necessarily a sign of increased capability, if anything it would more likely be a reflection of a degree of technological backwardness.

I think the more likely scenario is that compared to US 6th gen, Chinese 6th gen MTOW is larger and has higher requirements for speed and other aspects (in the case of similar target engine thrust between the two).

Just like you can't say that compared to single engine medium fighters, twin engine heavy fighters are more likely to reflect a certain degree of technological backwardness.

 

[sequ]

I think the more likely scenario is that compared to US 6th gen, Chinese 6th gen MTOW is larger and has higher requirements for speed and other aspects (in the case of similar target engine thrust between the two).

To me it seems PLAAF wants to fight beyond the 1st IC and over Japan, preferably as close as possible to the 2nd IC to create as much stand-off distance as possible between the mainland and US (carrier) forces. For this they need range and thus lots of fuel and thus a large airframe.

 

[Deino]

And me again … IMO we should wait until we see something real to discuss - in case it really has or is - that large, that heavy or even uses three engines!

For now we have a cryptic artwork, some hints and rumours that at least doe not match to anything we expected …

Maybe it is all talk on nothing! … just wait a few more weeks.

PS … this seems to be the first hint!