PLA next/6th generation fighter thread

[Blitzo]

That is demonstrated by the WS-15.

No it is not.

We would need to see them mass producing WS-15s at scale for a number of years, as well as having multiple VCE demonstrators having had ground runs for a number of years, for that to be closer to reality.

We're talking about 6th gen designs here. US needs to show a plane, any type of plane, that has a credible claim of having engines that can perform more than the Chinese equivalent. I agree the number of engines don't matter, them coughing up a design does.

If J-XD spawns with say requiring 3 engines on a 50t frame to power a laser while NGAD spawns requiring 1 engine in a F-35 sized platform to power a similar laser, then US has demonstrated superiority.

If the null hypothesis is that US is superior, then we will start believing in it the moment they show their NGAD (and it is superior to the J-XD in engines). If you take this as your hypothesis, you should have no issue with my above statement, the superior US will deliver a NGAD that does not have the same limitations as J-XD, assuming your, in my opinion very optimistic hypothesis, is true.

I don't see how you can disagree on that point.

We actually aren't talking about 6th gen designs, we are talking about 6th generation air combat systems, where the trend is to pursue more distributed, system of systems capabilities enabled by UCAVs/CCAs.
Part of the US reassessment of what they want from NGAD is exactly due to the question of how much they are offboarding sensors, weapons from the manned fighter to UCAVs.

The US NGAD could be a single engine F-35 sized aircraft carrying only four BVRAAMs, a basic sensor suite and a host of datalinks, powered by a slightly uprated non-VCE F135, and J-XD could be a three engined 50t monstrosity, and it would not change the calculus of where US and PRC engine technology and industry are respectively at, unless the PRC are able to demonstrate that the best engine they can design and produce is at least equal to that of the US.

In the above scenario, if the J-XD is powered by three engines that are high thrust VCEs and the US NGAD is a single engine F-35 sized aircraft powered by an evolved non-VCE F135 and the US has no further VCE projects in the pipeline intended for development, then that would be circumstances in which we could consider that J-XD's pursuit of three engines, and all being high thrust VCEs, is a reflection of J-XD capability rather PRC engine industry limitations.



Putting it another way -- the US NGAD manned fighter could be inferior in every respect (size, range, weapons, electricity generation) to a J-XD manned fighter using three engines, and it still wouldn't change the null hypothesis that the reason they needed three engines for J-XD was due to the Chinese aeroengine industry being incapable of designing and producing a sufficiently capable powerplant which the US was otherwise capable of doing.... until we see that the US and other global aeroengine leaders are similarly incapable and not intending to produce powerplants of sufficient capability (such as high thrust VCEs).

Is anyone entertaining the possibility of the third engine being a RDE or next generation engine of some sort?

I think entertaining the idea of a third engine is already a stretch, and entertaining something exotic like a RDE is a step too far beyond that.

 

[sunnymaxi]

Is anyone entertaining the possibility of the third engine being a RDE or next generation engine of some sort?

not possible..

WS-XX(??) is in development stages, material/components and manufacturing process successfully developed. so porotype stage might start soon.

only possibility is WS-15 being used in prototype.

 

[Index]

and it still wouldn't change the null hypothesis that the reason they needed three engines for J-XD was due to the Chinese aeroengine industry being incapable of designing and producing a sufficiently capable powerplant which the US was otherwise capable of doing....

We do not know they are capable of doing until they actually show it.

until we see that the US and other global aeroengine leaders

Besides China there isn't any comparable. Which other country has home made F135/WS-15 equivalent in service?

Again this is a very simple assumption: if there is a null hypothesis where US has superiority, they would surely not struggle to deliver an objectviely superior engined 6th gen. Just like they didn't struggle to deliver a superior (over the WS-10C J-20) F-35 during the 5th gen competition.

Holding our horses until that "F-35" moment emerges is entirely appropriate imho. If the null hypothesis is that US has superior aerospace industry, then it should be a given that the F-35 moment will come.

 

[Blitzo]

We do not know they are capable of doing until they actually show it.

Besides China there isn't any comparable. Which other country has home made F135/WS-15 equivalent in service?

Again this is a very simple assumption: if there is a null hypothesis where US has superiority, they would surely not struggle to deliver an objectviely superior engined 6th gen.

On the contrary, the evolution of future air based combat may well make the pursuit of a manned fighter different to what we previously envisioned -- large, heavily laden with sensors and weapons, might well not be decisive or necessary depending on the advancement and proliferation of unmanned assets. (I personally am not yet convinced, but seeing as we are talking about this hypothetical let's go with it)

If there is no need for a high thrust VCE for a large, heavily laden manned fighter then naturally they would not seek to develop it -- however that is different to assuming they are technologically incapable of developing it.

OTOH, if China goes with a large, three engined J-XD, then they should indeed be assumed to be incapable of developing a suitable engine that would enable a twin engine configuration to be developed, until proven otherwise.

Just like they didn't struggle to deliver a superior (over the WS-10C J-20) F-35 during the 5th gen competition.

Holding our horses until that "F-35" moment emerges is entirely appropriate imho. If the null hypothesis is that US has superior aerospace industry, then it should be a given that the F-35 moment will come.

This is a whole different discussion, because suggesting that F-35 is "not superior" to J-20 (even powered by WS-10C mind you) is a very big claim, and the validity of that claim entirely depends on what one is measuring -- individual aircraft, or key technologies each aircraft have been able to implement, industrial scale of each, etc.

 

[latenlazy]

Putting it another way -- the US NGAD manned fighter could be inferior in every respect (size, range, weapons, electricity generation) to a J-XD manned fighter using three engines, and it still wouldn't change the null hypothesis that the reason they needed three engines for J-XD was due to the Chinese aeroengine industry being incapable of designing and producing a sufficiently capable powerplant which the US was otherwise capable of doing.... until we see that the US and other global aeroengine leaders are similarly incapable and not intending to produce powerplants of sufficient capability (such as high thrust VCEs).

Eh, I think this is overthinking things. AFAIK all “6th generation” engines are projected to have a 20-30% thrust growth from 5th generation engines. You can keep the same T:W ratio for 6th gen fighters with those thrust gains with a MTOW of 50 tonnes. To keep identical T:W ratio at 60 tonnes though you’d need a 50% margin gain from 5th gen engines. China could easily be keeping pace on engine power and still require a third engine if they want to be more ambitious about MTOW without sacrificing T:W ratio compared to the US. To field a bigger fighter than the US’s potential NGAD while maintaining the same T:W ratio would either require China to have much better engines than the US or to slap on more engines.

Personally I think “what if a third engine” sounds a lot like the kind of logic casual enthusiasts would use to try to make sense of the idea that the J-XD would be a big big fighter. I don’t see why the aircraft designers and requirements setters would go this direction though when they could easily adjust their requirements to stick with two engines and compromise elsewhere, such as with T:W ratio (like they did with the J-20s).

 

[sunnymaxi]

In the above scenario, if the J-XD is powered by three engines that are high thrust VCEs and the US NGAD is a single engine F-35 sized aircraft powered by an evolved non-VCE F135 and the US has no further VCE projects in the pipeline intended for development, then that would be circumstances in which we could consider that J-XD's pursuit of three engines, and all being high thrust VCEs, is a reflection of J-XD capability rather PRC engine industry limitations.

that the reason they needed three engines for J-XD was due to the Chinese aeroengine industry being incapable of designing and producing a sufficiently capable powerplant

i have read all your massages. and agreed with your general analysis.

but sir my opinion is slightly different, right now WS-XX is under development so i don't think so it is fair to say, PRC is unable to produce high thrust VCE. the fact is, they have successfully breakthrough in technologies like material/components and what we have seen in airshow like additive manufacturing and 3D laser printed alloys. these two process are next generation manufacturing process in Aero Engine industry.

the problem is, J-XD is emerging too early and intended powerplant is still years away.. just like J-20/J-35. this is because PRC Engine industry emerged just recently. you know better.

 

[Blitzo]

Eh, I think this is overthinking things. AFAIK all “6th generation” engines are projected to have a 20-30% thrust growth from 5th generation engines. You can keep the same T:W ratio for 6th gen fighters with those thrust gains with a MTOW of 50 tonnes. To keep identical T:W ratio at 60 tonnes though you’d need a 50% margin gain from 5th gen engines. China could easily be keeping pace on engine power and still require a third engine if they want to be more ambitious about MTOW without sacrificing T:W ratio compared to the US. To field a bigger fighter than the US’s potential NGAD while maintaining the same T:W ratio would either require China to have much better engines than the US or to slap on more engines.

I don't disagree here with what you've said -- but my view is a hypothetical three engine design means we should first err on the side of caution and assume that it is due to engine performance/technology/capability in future, rather than being more ambitious with MTOW, until proven otherwise.

Personally I think “what if a third engine” sounds a lot like the kind of logic casual enthusiasts would use to try to make sense of the idea that the J-XD would be a big big fighter. I don’t see why the aircraft designers and requirements setters would go this direction though when they could easily adjust their requirements to stick with two engines and compromise elsewhere, such as with T:W ratio (like they did with the J-20s).

That is also my view.

 

[latenlazy]

I don't disagree here with what you've said -- but my view is a hypothetical three engine design means we should first err on the side of caution and assume that it is due to engine performance/technology/capability in future, rather than being more ambitious with MTOW, until proven otherwise.

My version of erring on the side of caution is to not take the froth around this one seriously until we hear from someone more reliable

 

[Blitzo]

i have read all your massages. and agreed with your general analysis.

but sir my opinion is slightly different, right now WS-XX is under development so i don't think so it is fair to say, PRC is unable to produce high thrust VCE. the fact is, they have successfully breakthrough in technologies like material/components and what we have seen in airshow like additive manufacturing and 3D laser printed alloys. these two process are next generation manufacturing process in Aero Engine industry.

the problem is, J-XD is emerging too early and intended powerplant is still years away.. just like J-20/J-35. this is because PRC Engine industry emerged just recently. you know better.

Let's put it this way -- if J-XD is a three engine aircraft, for us to not assume it is pursuing a three engine design for reasons that are not due to future projected inability for future engines (let's call it WS-XX) to meet J-XD's needs relative to what other global aeroengine leaders can produce, we need to see:
- at minimum significant credible rumours and indicators that WS-XX is not technologically behind that of other aeroengine leaders, and
- J-XD being such a large aircraft or have requirement sets, which cannot be met by having two WS-XXs that are technologically competitive with global leaders, at any point during its expected production cycle.

If J-XD emerges with three engines and those two criteria cannot both be met, then I think we are obliged to defer to the most likely answer which is "it is three engined due to aeroengine industry limitations".

My version of erring on the side of caution is to not take the froth around this one seriously until we hear from someone more reliable

Stepping back a bit, I am skeptical at the idea of J-XD being three engined to begin with.

However, what I am saying is there are certain people who seem to view the idea of J-XD being three engined as a "good thing" while I am cautioning that if anything it may be a "bad thing" (if one wants to be more simplistic in the phrasing from a "muh PRC stronk" pov)

 

[THX 1138]

The J-XD and the H-20 are both under development.

What makes people think this 3-engine rumor refers to the J-XD and not the H-20?