Chengdu J-20 5th Generation Aircraft News & Discussions

[UKBengali]

Maybe they wanted to avoid risk of not able to fit WS15 with current J-20 with WS10 engine design. Just look at J-10A vs B & C model differences. Many parts that are not in common and J-10A can't be modified into J-10C. Imagine if China already built many J-20 with WS-10, when J-20 with WS-15 came out with different design, there's less budget left to build more J-20 with WS-15.

Yes that would be the only reason not to maximise J-20 production now.

 

[obj 705A]

What would China lose by mass producing J-20s with WS-10 engines?

Nothing, they will lose nothing which is why it entered service and began mass production long before the WS-15 was any where near ready, they have all the money to build as many J-20s per year as they want, there are no financial or political limitations, the only limitation is how many production lines can actually produce a J-20.

 

[obj 705A]

Maybe they wanted to avoid risk of not able to fit WS15 with current J-20 with WS10 engine design.

If for what ever reason an existing J-20 cannot be upgraded with new engines then that will still not stop China from procuring them now, once the WS-15 is ready they can simply produce many more additional J-20s with WS-15.

 

[UKBengali]

If for what ever reason an existing J-20 cannot be upgraded with new engines then that will still not stop China from procuring them now, once the WS-15 is ready they can simply produce many more additional J-20s with WS-15.

I am not too sure about this.

Would China really want to be stuck with many hundreds of inferior J-20s with the WS-10 engines?
I would say maybe no as then they have wasted billions for maybe not that much gain while the WS-15 is readied.
China does not need many J-20s for India or Russia, just to face off Japan/USA and so maybe a lower number of J-20 may suffice in the meantime.
It all really depends if the WS-15 is “hot- swappable” with the WS-10 and no-one here knows the answer to that question.

 

[serenity]

WS-10 is already providing as much thrust as the most advanced upgraded Al-31 and F-110 series engines between 135 and 145 thousand newton. Second WS-15 program is aiming for around 180. 145 is not too far from F119 and the fuel expense is lower. F-22 have short range due to extremely high fuel consumption of F119 this engine is most fuel consumption rating of all modern high power engines. Much more than WS-10, Al-31, and even F135. WS-15 first did not achieve required fuel and thrust for the technology of the 2010s. So WS-10 is not weak or unsuitable. It is already giving J-20 same or better thrust to weight than something like Mig-29 or J-10. With WS-15 that can reach 180kN, the J-20 should have even better thrust to weight than F-22 and F-35 or Su-35 even.

People who think J-20 is underpowered with WS-10 is just reading the random western articles who have no idea what truth is. J-20's real weight will surprise all of them and its lift is excellent. WS-10 with 140kN can give J-20 with >1 thrust to weight which is slightly better than most 4th generation fighters. Consider that J-20 also does not carry weapons outside which further improve lifting surface efficiency and lower drag.

 

[obj 705A]

Would China really want to be stuck with many hundreds of inferior J-20s with the WS-10 engines?
I would say maybe no as then they have wasted billions for maybe not that much gain while the WS-15 is readied.

Those billions of dollars are like pocket change for a 14$ trillion, there are no financial restrictions on the number of J-20 to be aquired.

The only case in which China would have to hold off on acquiring as many J-20s (with WS-10) as they can is if there are financial restrictions that would force them to hold back till the WS-15 is available however outside of Gordon Chang's brain these financial restrictions do not exist, by that I mean China will be producing stealth fighters from this point till 20 years from now at the maximum poduction capacity.

 

[obj 705A]

And just to further clarify just how insignificant (from a purely financial point of view) spending some billions of dollars is for China:-
Let us assume the J-20 costs 120$ million, so aquiring 60 aircrafts per year would cost 7.2$ billion a year till the WS-15 is ready, do you know how much China makes in an hour? 1.6$ billion, so China needs just 4.5 hours to have enough money for 60 J-20s per year! If China was a person then he could take a 7.2$ billion bank note and then literally wipe his @$$ with it and through the banknote in the trash bin and it would still be absolutely nothing for him.

 

[UKBengali]

And just to further clarify just how insignificant (from a purely financial point of view) spending some billions of dollars is for China:-
Let us assume the J-20 costs 120$ million, so aquiring 60 aircrafts per year would cost 7.2$ billion a year till the WS-15 is ready, do you know how much China makes in an hour? 1.6$ billion, so China needs just 4.5 hours to have enough money for 60 J-20s per year! If China was a person then he could take a 7.2$ billion bank note and then literally wipe his @$$ with it and through the banknote in the trash bin and it would still be absolutely nothing for him.

China does not have unlimited resources and like all other countries it has to make choices.

If it does not urgently need hundreds of J-20s for imminent war with USA/Japan then it will not build them quickly if it will get stuck with inferior WS-10 engines for their lifespan. Those 10s of billions saved can be spent on other more urgent weapons that it deems to need.

Like I already said we do not yet know whether the WS-15 is "hot-swappable" with the WS-10 and if it is then it loses nothing by building J-20s to maximum capacity now.

 

[UKBengali]

WS-10 is already providing as much thrust as the most advanced upgraded Al-31 and F-110 series engines between 135 and 145 thousand newton. Second WS-15 program is aiming for around 180. 145 is not too far from F119 and the fuel expense is lower. F-22 have short range due to extremely high fuel consumption of F119 this engine is most fuel consumption rating of all modern high power engines. Much more than WS-10, Al-31, and even F135. WS-15 first did not achieve required fuel and thrust for the technology of the 2010s. So WS-10 is not weak or unsuitable. It is already giving J-20 same or better thrust to weight than something like Mig-29 or J-10. With WS-15 that can reach 180kN, the J-20 should have even better thrust to weight than F-22 and F-35 or Su-35 even.

People who think J-20 is underpowered with WS-10 is just reading the random western articles who have no idea what truth is. J-20's real weight will surprise all of them and its lift is excellent. WS-10 with 140kN can give J-20 with >1 thrust to weight which is slightly better than most 4th generation fighters. Consider that J-20 also does not carry weapons outside which further improve lifting surface efficiency and lower drag.

Nope.

The public maximum thrust of the F-119 of F-22 is 156kN but it is likely to be much more than that. USA engine tech is absolutely superb and decades ahead of anyone else but maybe the UK. In 1990 the demonstrator engines they built for YF-22/YF-23 prototypes were already delivering 160kN.

Other thing to consider is that 5th gen engines have low-bypass ratios to deliver even greater dry thrust to allow "super-cruise" and so the public specs of the F119 have a dry thrust to wet thrust ratio of 0.7. With 4th gen engines like WS-10 this is more like 0.6.

Make no mistake the J-20 is severely compromised in aerodynamic performance till it gets WS-15 engine.

 

[ZeEa5KPul]

Those billions of dollars are like pocket change for a 14$ trillion, there are no financial restrictions on the number of J-20 to be aquired.

Exactly right. In addition, there's a lot of benefit in ramping up J-20 production now so that an ecosystem of parts suppliers can be set up and expanded.

China does not have unlimited resources and like all other countries it has to make choices.

This just doesn't cut the mustard. You were given an analysis of how trivial this cost is and your response is a banal platitude, that's inadequate.

 

[UKBengali]

This just doesn't cut the mustard. You were given an analysis of how trivial this cost is and your response is a banal platitude, that's inadequate.

No it is not "trivial" the cost of making 100s of J-20s with WS-10 engines that may not be swappable with Ws-15s.

I repeat no country has unlimited resources and there are always choices that need to be made.

China needs to spend more on health as an example away from defence.

 

[ZeEa5KPul]

No it is not "trivial" the cost of making 100s of J-20s with WS-10 engines that may not be swappable with Ws-15s.

Why are you assuming they're not swappable in an MLU? And it is a trivial cost for a $14 trillion economy as @obj 705A pointed out. I'd also add that the $120 million is probably ludicrously overestimating the cost of the J-20, which would come down with scale. The most important thing is to establish the facilities to produce J-20s at scale, even if they have to be done with WS-10Cs for now.

 

[UKBengali]

Why are you assuming they're not swappable in an MLU? And it is a trivial cost for a $14 trillion economy as @obj 705A pointed out. I'd also add that the $120 million is probably ludicrously overestimating the cost of the J-20, which would come down with scale. The most important thing is to establish the facilities to produce J-20s at scale, even if they have to be done with WS-10Cs for now.

I am NOT assuming at all.

Read through all my posts.

Like I already said if they are "hot-swappable" then China can make as many as they can produce with WS-10 engines. If fact I would not be surprised if the WS-10 and Ws-15 are indeed "hot-swappable" or can be swapped out with minor work.

 

[LKJ86]

I am not too sure about this.

Would China really want to be stuck with many hundreds of inferior J-20s with the WS-10 engines?
I would say maybe no as then they have wasted billions for maybe not that much gain while the WS-15 is readied.
China does not need many J-20s for India or Russia, just to face off Japan/USA and so maybe a lower number of J-20 may suffice in the meantime.
It all really depends if the WS-15 is “hot- swappable” with the WS-10 and no-one here knows the answer to that question.

China had built many hundreds of J-10A and J-10S that can't be upgraded to the standard of J-10C, instead of waiting for J-10C.

 

[UKBengali]

China had built many hundreds of J-10A and J-10S that can't be upgraded to the standard of J-10C, instead of waiting for J-10C.

Totally different as J-10 is a 4th gen fighter and AL-31F and WS-10C are similar in performance.

AL-31F maximises performance of J-10 whereas WS-10 limits aerodynamic performance of J-20.