Chengdu J-20 5th Generation Aircraft News & Discussions

[帅的一匹]

Once again ... no fighter needs a thrust of +210kN for a climb and there was NOT that astonishing sustained vertical climbing. It was a brief climb after a high-speed pass and then banking out ... but I know I'm still sticking in the sand !

WS15 is not operational, that's for sure. I think WS10b also can make J20 do the sustained vertical climb. No one knows whether J20 open its afterburner in the show or not. You can't see it clear in the video. Exaggeration is not necessary. And some fancy story of WS10 with AL31FN NOZZLE , I'm done with it. China has made huge progress, and I can feel the complacent and arrogant some members start to show. It's all BS.

If you can't accept the Fact, you can't make further progress.

 

[Deino]

First of all thanks a lot for this post and I really appreciate that as a starting point:

Let's continue looking at the facts. We've had two statements concerning the J-20 engines within the past few months. It's important to look at the direct quotes from the professionals. Other comments citing unnamed sources are a waste of time.
...
Both sets of statements are open to interpretation. Both men seem to agree that the WS-15 is under development. However, the statements concerning the J-20's CURRENT ENGINES appear to be contradictory.

Therefore I would suggest Mr @Asok to explain HIS own theory, probably in the same way I explained mine instead of calling it again and again as

…completely evidence-free, fact-free, and filled with hot-air, only.

PLEASE; What’s plain and simple Your theory? Sometimes You say already ‘2001’ was using the WS-15 engine, later it was only from ‘2011’ on .. then an interim hybrid-WS-10/WS-15-type … then again already now a +210 kN engine. Do Your at least have a consistent theory ??

IMO this would be most important since it would ease any further discussion … mine is on the table and as long as Yours is not, I think it is irresponsible and ridiculous, to the extreme to continue any further discussion.

Therefore I would again take this post as a starting point:

...What evidence do we have that this phantom engine is currently powering the J-20? It's important for both sides of the debate to provide supporting evidence to back up claims.

I would suggest – as typical in a scientific approach if You want to explain something and don’t know the real true – You need to weight probabilities and usually or often the most likely, most reasonable version to explain this mysterious issue is the closest to the truth until it is confirmed. So let us collect the pros and cons so that anyone can make up his own decision and let’s start with:

1. Deino’s uprated-AL-31FM2-based version-theory:

• We all know that CAC was and is still closely working with Salut. The first then still secret AL-31FN for the J-10 is a prime example. The J-10B/C are still using that engine and there are striking external similarities to both engines/exhaust.
• We know the M2 was a concurring project to power the T50 but lost against the 117 from Saturn. This engine was bench-test, but it is a true project, a development of an already established engine.
  
• The latest source from a respected Chinese authority clearly stated “It will not take a long time for our fifth-generation combat plane to have China-made engines," … IMO a clear confirmation, that until now it is powered NOT by a Chinese engine. That’s plain and simple logic.
  
• We also know from other reliable sources, that the WS-15 is still not ready, just as @wanglaokan repeatedly noted. It will probably enter flight testing “soon” but to think it is already operational even in prototype form on LRIP-J-20s is impossible.
  
• So the 2012-date (reports on the M2) might indeed be a weak point in my theory – esp. time-line-wise – but IMO this fits nicely to reports that the prototypes were using regular AL-31FN, later switched to uprated series 2 and finally the LRIP-birds are using this new variant. Also the other issue that we lack reports from Russia can be IMO much more easily explained – maybe by a certain contractual clause similar to then then secret AL-31FN. It is a weak-pint, but anyway explainable.
  

2. And now on to that mysterious mega-Monster+210kN-WS-15-theory:

• IMO this theory contradicts to all we know on technical possibilities (it is not possible to plug&play certain items like core, fan and afterburner from three different engines from three different manufactors and mate them to a working engine.
  
• It contradicts to all we know on the WS-15’s development: How can this Frankenstein-monster-engine be already deliver more thrust than the final projected output the definitive WS-15 (180kN) should deliver?
  
• Timeline-wise it is impossible: We are hearing about a 14t WS-15B/IPE or whatever that is not operational yet (albeit close to) and the so far strongest engine delivers maybe +130kN, so a jump to +210kN is simply illogical. Why then continue development of the WS-10B/IPE or even WS-15 if such a beast is already operational?
  

As such I deeply beg @Asok to not only bash my theory as “irresponsible and ridiculous” but finally at first to explain HIS own theory and to explain why his theory should be more likely than mine.

If I missed anything I would be glad to be corrected or if arguments will be added…

So let the analysis begin …

Deino

 

[Asoka]

"What’s plain and simple Your theory? Sometimes You say already ‘2001’ was using the WS-15 engine, later it was only from ‘2011’ on .. then an interim hybrid-WS-10/WS-15-type … then again already now a +210 kN engine. Do Your at least have a consistent theory ??"

I say this:

1.) I believe, from the day one, since testing began,J-20 was using an engine with the WS-15 core, and various technologies from WS-10 and AL-31Fn, to create a quick prototype, so it could be flight tested, as early as possible, to flush out the potential problems, so the engineers have time to work on them. We could call it with various names WS-10X, WS-15 Prototype or Hybrid, since, engine model on J-20 was never officially disclosed.

What's important is that, it uses a WS-15 engine core, that has passed all performance evaluation criteria, during ground testing in 2005-2006.

2.) And later, starting No. 2011, it seems J-20's tail section has received noticable modifications, to accomodate a new engine, that is shorter and smaller. This lead me and other observer to suspect that a mature model of WS-15, with its own components, such as TVC nozzles, has installed for testing. Indeed, we have seen several pictures that clearly shown the nozzles could tilt slightly or moderately, in both sideway, and vertical directions.

3.) From the China Airshow video, J-20 has clearly demonstrated a sustain Vertical Climb, in front of thousands of spectators. It clearly shows there is no long flame shooting out of its nozzles. This leads to me to conclude that Afterburner was not used, and only Dry Thrust was used.

4.) I have shown that J-20's body, is at least 3-4 meters longer than F-22. And F-22's empty weight is listed as 19.7 tons. So, it is reasonable to assume J-20, is at least 2 tons heavier, than F-22, or weighting 22 tons. And if we assume it's fuel tank, is at least 1/3 full (which is reasonable and minimum amount), or carrying 4 tons of fuel, during the demonstration, then it must have at least +210kN of Dry Thrust to lift itself (26 tons) vertically, without AB.

As to Mr. Deino's Russian Engine "Theory".

1.) He has listed not one bit of evidence that any of the J-20 "are using IMO a dedicated, custom-made - maybe co-developed and co-manufactured - uprated, specialised or whatever version of the AL-31FN-family"

2. He has listed no evidence, whatsoever, that China has purchased such engine, and that Russia has delivered such engine for J-20 between 2011 and 2017. There was absolutely, no evidence, that China and Russia co-developed, and co-manufactured such engine. Indeed, why would Russia need China's help to develop a new variant of AL-31FN engine?

3.) What's even more damning to his "theory" was that J-20 was public flown on 2011, and AL-31FN-M2, was announced (not delivered) in 2012. And it was not reported that this version was ever tested, and completed and delivered to China. So how the hell, the CHinese managed fly J-20, with a not yet, exist engine.

4.) Mr. Deino has taken a strong and irrational position on this J-20 engine issue, while he is the Moderator of this J-20 thread. He has consistently accused me of groundless speculations and attempt to sabotage or derail this thread.

5.) While at the same time, he has not advanced one bit of evidence to "support" his theory. He arguments are completely evidence-free, fact-free, and logic-free that J-20 is using a Russian made AL-31FN engine. His "strongest evidence" is actually, the superficial similarity, between the nozzles of J-20 and AL-31FN. And from this he has drawn his unwavering conclusion.

This is the worst kind "groundless speculation" I have seen anywhere. And the fact, that it is coming from the Moderator of the thread, is simply mind-boggling.

5.) On three separate occasions, Mr. Deino, has threaten to delete all my posted, and ban me from PDF, because he don't agreed with my conclusion. I have swallowed this "insult" and apologized, because I feel I was too worked up with my arguments, and need to calm down.

6.) I simply trying to find the facts, here at PDF. I have learned a lot from all of you. Counter arguments made me dig deeper to find the hidden truth. I am quite often is very emotional with my arguments. But I don't get insulted, easily.

7.) And NO intend is to insult to Mr. Deino. I do find him an able and dedicated Moderator, quick to restore order, when the discussions got off topic, make sure no foul language was used. This forum is actually, a million times, more civil than other forums, I have visited. In no small parts, thanks to Moderators like Mr. Deino.

7.) So apologize again, if I have hurt anybody's feeling.

 

[Deino]

First of all THANKs for Your reply even if You again avoided to answer the specific questions and second PLEASE leave out any insults on my role as moderator since they are completely irrelevant to my theory:

Anyway, You still missed to answer these points see below; instead You really think:

1.) it is possible to create a quick prototype based on the WS-15 core, and various technologies from WS-10 and AL-31Fn, as early as possible ??

2.) ... to later accommodate yet another shorter and smaller engine, that is IYO a mature model of WS-15??


So we are again at my questions You ignored to answer:

2. And now on to that mysterious mega-Monster+210kN-WS-15-theory:

• IMO this theory contradicts to all we know on technical possibilities (it is not possible to plug&play certain items like core, fan and afterburner from three different engines from three different manufactors and mate them to a working engine.
  
• It contradicts to all we know on the WS-15’s development: How can this Frankenstein-monster-engine be already deliver more thrust than the final projected output the definitive WS-15 (180kN) should deliver?
  
• Timeline-wise it is impossible: We are hearing about a 14t WS-15B/IPE or whatever that is not operational yet (albeit close to) and the so far strongest engine delivers maybe +130kN, so a jump to +210kN is simply illogical. Why then continue development of the WS-10B/IPE or even WS-15 if such a beast is already operational?

To admit.... You call my arguments "completely evidence-free, fact-free, and logic-free" but Yourself are avoiding all questions, suggesting a technology leap that is plain impossible and contradicts everything we know otherwise So I'm out; let the others decide ... but if You once again question my ability to moderate this forum only since You don't like my theory, then it's enough.

Deino

Deino

 

[gambit]

...plug&play-add an AL-31-component to a WS-10 core and even more still the WS-15 is not ready.

I am watching this engine debate -- smiling...

There are three levels of maintenance: Organizational, Intermediate, and Depot.

http://navyaviation.tpub.com/14292/css/Maintenance-Levels-And-Types-Of-Maintenance-12.htm

Each military may have slightly different labels, but essentially they are the same.

Organizational is at the unit level, aka 'front line'. At this level, there are severe limits on what mechanics are allowed to do to a jet engine. Usually, that means non-core components are LRUs. They are those items that are attached to the outside of the engine casing.

Intermediate is when the engine is shipped off the base and sent to a 'back shop' where the engine can be taken apart under conditions that are safe for reassembly. The core where all the inner compressor blades and their stages are repairable at this level.

Depot is where the engine is literally taken apart down the nuts and bolts. Everything is reconditioned if possible, or discarded.

So just because the F-111 and the F-14 initially shared the same engine -- TF30 -- that does not mean the Intermediate guys can swap out the cores between the engines that came from each aircraft. The base performance of the TF30 maybe identical, but once a particular TF30 engine is assigned to the F-111 or the F-14, that version of the TF30 will be tuned to match the flight capabilities of the appropriate aircraft. This engine will go from the F-111 base, to the back shop to be overhauled, then back to an F-111 base again. Does not have to be same F-111 base, just any F-111 base. But never to the Navy. The core maybe common, but if the core must be changed, as in taking the core from a Navy TF30 and install it into a USAF TF30, only the Depot level is authorized to make that change. They have all the information originating from the design stages. The Intermediate guys can do the job but only if they are authorized to do so by Depot and under strict instructions. The Organizational mechanics will never be allowed to go this deep.

What this means is that taking an engine from one design to use in another design is not a casual endeavor. A common core maybe common only in design and not in materiel and associated components that are unique to a jet. The F135 came from the F119 but that does not mean Organizational and Intermediate can, on their own, swap parts between the two. FADEC parameters are different between the F-22 and F-35. So just because the engine can make fighter design A go vertical without AB, that does not mean it can do the same for fighter design B. If it was that easy, we would not have so much jet engine designs in our inventory.

But hey...Do not expect the Chinese guys to take what I said seriously...

 

[Deino]

Exactly what I - at least meant and - tried to explain: You cannot use via plug&play certain components and et voila develop just for the quick use for the prototypes a new engine, redesign it within a few years and again voila it is more powerful than the anything already in use and future projected ones.

But YES, it's me who is disillusioned, illogic, plain irrational ...

 

[Ultima Thule]

First of all thanks a lot for this post and I really appreciate that as a starting point:




Therefore I would suggest Mr @Asok to explain HIS own theory, probably in the same way I explained mine instead of calling it again and again as



PLEASE; What’s plain and simple Your theory? Sometimes You say already ‘2001’ was using the WS-15 engine, later it was only from ‘2011’ on .. then an interim hybrid-WS-10/WS-15-type … then again already now a +210 kN engine. Do Your at least have a consistent theory ??

IMO this would be most important since it would ease any further discussion … mine is on the table and as long as Yours is not, I think it is irresponsible and ridiculous, to the extreme to continue any further discussion.

Therefore I would again take this post as a starting point:



I would suggest – as typical in a scientific approach if You want to explain something and don’t know the real true – You need to weight probabilities and usually or often the most likely, most reasonable version to explain this mysterious issue is the closest to the truth until it is confirmed. So let us collect the pros and cons so that anyone can make up his own decision and let’s start with:

1. Deino’s uprated-AL-31FM2-based version-theory:

• We all know that CAC was and is still closely working with Salut. The first then still secret AL-31FN for the J-10 is a prime example. The J-10B/C are still using that engine and there are striking external similarities to both engines/exhaust.
• We know the M2 was a concurring project to power the T50 but lost against the 117 from Saturn. This engine was bench-test, but it is a true project, a development of an already established engine.
  
• The latest source from a respected Chinese authority clearly stated “It will not take a long time for our fifth-generation combat plane to have China-made engines," … IMO a clear confirmation, that until now it is powered NOT by a Chinese engine. That’s plain and simple logic.
  
• We also know from other reliable sources, that the WS-15 is still not ready, just as @wanglaokan repeatedly noted. It will probably enter flight testing “soon” but to think it is already operational even in prototype form on LRIP-J-20s is impossible.
  
• So the 2012-date (reports on the M2) might indeed be a weak point in my theory – esp. time-line-wise – but IMO this fits nicely to reports that the prototypes were using regular AL-31FN, later switched to uprated series 2 and finally the LRIP-birds are using this new variant. Also the other issue that we lack reports from Russia can be IMO much more easily explained – maybe by a certain contractual clause similar to then then secret AL-31FN. It is a weak-pint, but anyway explainable.

2. And now on to that mysterious mega-Monster+210kN-WS-15-theory:

• IMO this theory contradicts to all we know on technical possibilities (it is not possible to plug&play certain items like core, fan and afterburner from three different engines from three different manufactors and mate them to a working engine.
  
• It contradicts to all we know on the WS-15’s development: How can this Frankenstein-monster-engine be already deliver more thrust than the final projected output the definitive WS-15 (180kN) should deliver?
  
• Timeline-wise it is impossible: We are hearing about a 14t WS-15B/IPE or whatever that is not operational yet (albeit close to) and the so far strongest engine delivers maybe +130kN, so a jump to +210kN is simply illogical. Why then continue development of the WS-10B/IPE or even WS-15 if such a beast is already operational?

As such I deeply beg @Asok to not only bash my theory as “irresponsible and ridiculous” but finally at first to explain HIS own theory and to explain why his theory should be more likely than mine.

If I missed anything I would be glad to be corrected or if arguments will be added…

So let the analysis begin …

Deino

you are so assuming sir there is a possibility J-20 is using specialized and interim version of WS-10/ core of WS-15 for the development of J-20 but i would agree with you on that point that "Ws-10/core of WS-15 was not install from beginning installing WS-10/WS-15 combination in the later stages, specially on the LIRP Birds, i believe Chinese senior members like @cirr, @ChineseTiger1986, @wanglaokan and @Beast rather than you, its not plug and play thing sir they specially develop interim and specialized version WS-10 for the development of J-20 because they know main power-plant is in development, you are just speculating sir

Exactly what I - at least meant and - tried to explain: You cannot use via plug&play certain components and et voila develop just for the quick use for the prototypes a new engine, redesign it within a few years and again voila it is more powerful than the anything already in use and future projected ones.

But YES, it's me who is disillusioned, illogic, plain irrational ...

No plug and play sir specially develop for a development for J-20 not for mass production, its possible as @gambit said sir look yourself

"The core maybe common, but if the core must be changed, as in taking the core from a Navy TF30 and install it into a USAF TF30, only the Depot level is authorized to make that change. They have all the information originating from the design stages."

 

[帅的一匹]

you are so assuming sir there is a possibility J-20 is using specialized and interim version of WS-10/ core of WS-15 for the development of J-20 but i would agree with you on that point that "Ws-10/core of WS-15 was not install from beginning installing WS-10/WS-15 combination in the later stages, specially on the LIRP Birds, i believe Chinese senior members like @cirr, @ChineseTiger1986, @wanglaokan and @Beast rather than you, its not plug and play thing sir they specially develop interim and specialized version WS-10 for the development of J-20 because they know main power-plant is in development, you are just speculating sir


No plug and play sir specially develop for a development for J-20 not for mass production, its possible as @gambit said sir look yourself

"The core maybe common, but if the core must be changed, as in taking the core from a Navy TF30 and install it into a USAF TF30, only the Depot level is authorized to make that change. They have all the information originating from the design stages."

They will use the experience they gain from developing WS15 to improve WS10 engine. There is no WS10 engine with WS15 core, it's a absurd cliam without solid prove. Same as WS10 engine with Al31F nozzle. Even though, only three countries on this planet can produce turbo fan engine with thrust beyond 140KN, China is one of them.

you are so assuming sir there is a possibility J-20 is using specialized and interim version of WS-10/ core of WS-15 for the development of J-20 but i would agree with you on that point that "Ws-10/core of WS-15 was not install from beginning installing WS-10/WS-15 combination in the later stages, specially on the LIRP Birds, i believe Chinese senior members like @cirr, @ChineseTiger1986, @wanglaokan and @Beast rather than you, its not plug and play thing sir they specially develop interim and specialized version WS-10 for the development of J-20 because they know main power-plant is in development, you are just speculating sir


No plug and play sir specially develop for a development for J-20 not for mass production, its possible as @gambit said sir look yourself

"The core maybe common, but if the core must be changed, as in taking the core from a Navy TF30 and install it into a USAF TF30, only the Depot level is authorized to make that change. They have all the information originating from the design stages."

They will use the experience they gain from developing WS15 to improve WS10 engine. There is no WS10 engine with WS15 core, it's a absurd cliam without solid prove. Same as WS10 engine with Al31F nozzle. Even though, only three countries on this planet can produce turbo fan engine with thrust beyond 140KN, China is one of them.

 

[Ultima Thule]

They will use the experience they gain from developing WS15 to improve WS10 engine. There is no WS10 engine with WS15 core, it's a absurd cliam without solid prove. Same as WS10 engine with Al31F nozzle. Even though, only three countries on this planet can produce turbo fan engine with thrust beyond 140KN, China is one of them.


They will use the experience they gain from developing WS15 to improve WS10 engine. There is no WS10 engine with WS15 core, it's a absurd cliam without solid prove. Same as WS10 engine with Al31F nozzle. Even though, only three countries on this planet can produce turbo fan engine with thrust beyond 140KN, China is one of them.

thank you sir for your correction sir, one more question sir is J-20 using a version of WS-10 or it is using Al-31FM2 as @Deino sir suggesting

 

[帅的一匹]

thank you sir for your correction sir, one more question sir is J-20 using a version of WS-10 or it is using Al-31FM2 as @Deino sir suggesting

I'm not sure the one in the fly test stage, I only know they are replacing it with WS10b. WS15 faced some technical glitch a while ago, but it is solved.

 

[gambit]

No plug and play sir specially develop for a development for J-20 not for mass production, its possible as @gambit said sir look yourself

It maybe possible, and given the current technology, it may even be workable all around. But my point is that the combination between airframe and propulsion is an intricate one to the point that a common engine core between engine designs is quite irrelevant.

Yes, if you can use the core from one engine of one aircraft to design the propulsion system of a newer platform, that would be great. But in no way does that equals to identical performance once the new aircraft is flight tested.

 

[lcloo]

I don't know what engine J20 is using, but Wanglaokan's suggestion has much more weight in it because J20 and J16 are in similar weight class. One can assumed that both would be using engines of similar thrusts.

Thus if J16 is powered by WS10(A or B?), then the interim engines for J20 are WS10B is a safe bet, because you won't want to put a new engine which is not yet matured (or fully tested) on your most advance jet fighter.

Finally verdict will be official statement from AVIC or PLAAF, that time is yet to come.

 

[Asoka]

OK, I admit, I didn't answer the following questions of yours with detailed answers. It was 2AM in the morning here, when I read your post. Let me try here.

"IMO this theory contradicts to all we know on technical possibilities (it is not possible to plug&play certain items like core, fan and afterburner from three different engines from three different manufactors and mate them to a working engine."

I didn't say, China was used certain "plug&play" components to mated to the WS-15 core. I said, it used various mature and proven technologies "adapted" from WS-10 and AL-31FN. There is a difference here. China could manufacture all components of these two engines. So it is entire possible that Chinese Engineers could "adapt" their technologies to a new engine.

It was not a straight "plug & play". I don't know this is even possible. The different sizes and specifications of the components from three different engine, would be a big problem.

So I agree with you that such "plug & play" strategy is highly dubious. You got a point here, so your objection got some validity. But it was not a straight "plug & play". It can't be done, of course.

Between 2006 and 20011, there is enough time for China to "adapt" those proven technology to mate it with the new core.

"It contradicts to all we know on the WS-15’s development: How can this Frankenstein-monster-engine be already deliver more thrust than the final projected output the definitive WS-15 (180kN) should deliver?"

Yes, the "facts" or "truths" uncovered by us "contradicts to all we know on the WS-15’s development". That's because all we know was not firm or confirmed information in the first place. The first appearance of J-20 surprised everybody, including the CIA and Pentagon, which has a combined budget greater than $600 billions per year. They were surprised, big time. And the rate of progress of J-20 astonished the world too. It went from prototype, or technology demonstration to LRIP, in 6 years, far faster than F-22 and F-35, and T-50.

"How can this Frankenstein-monster-engine be already deliver more thrust than the final projected output the definitive WS-15 (180kN) should deliver?""

This final projected figure of 160-180kN is not an official figure. It's source of origin is dubious at best. I have searched all over the Internet to track this number down, and failed. It appeared suddenly, out of no where, and people stick with it, because it seems reasonable.

When I did my calculations, the final figure of 210kN surprised, the hell out of me, too. I never expected it. I was expecting a figure of 180kN. While, my assumption on J-20's empty weight of 22 tons, and carrying 4 tons of fuel, was not firm, but I don't see anything wrong, with my reasonings.

"Timeline-wise it is impossible: We are hearing about a 14t WS-15B/IPE or whatever that is not operational yet (albeit close to) and the so far strongest engine delivers maybe +130kN, so a jump to +210kN is simply illogical. Why then continue development of the WS-10B/IPE or even WS-15 if such a beast is already operational?"

"Timeline-wise it is impossible" So it is the timeline of J-20 itself. CIA expects China to have J-20, no sooner than 2020. And China beat it's estimates, by a full 10 years.

"We are hearing about a 14t WS-15B/IPE or whatever that is not operational yet (albeit close to) and the so far strongest engine delivers maybe +130kN, so a jump to +210kN is simply illogical. "

The core design of WS-15, is not related to WS-10's core, which was from the 1970's, Ge F110 engine. When the study for WS-15 core was initiated in early 1990's, WS-10 was not even bench tested.

Indeed, WS-10's design did not finalized till, 2005, and still many problem plagued it, many years afterward.

WS-15 core design, is entirely new, probably based on the Russian Yak-141's engine, the Soyuz R-79V-300, and developed with extensive assistances from former USSR's scientists, in the 1990s.

This WS-15 core passed all acceptance tests in 2005, after 15 years of intensive development. And the WS-15 project to produced a TWR engine of 10, for J-20 was officially launched, in 2006.

This practice of doing preliminary studies or research, then produce a engine core, then a final engine, and then an airplane to equipped it, was entirely new practice in China.

The previous practice was, decided to produce a new plane, and decide to produce a new engine to go with it, and decide to produce a new engine core to go with the new engine. The engine and engine core was treated just like another component in the aircraft.

This lack of understanding of engine development cycle, that it tends to take far longer time, to produce the Airframe, did not sink in, till the late 1980's. And it plagued Chinese Aviation, resulting in numerous delays, and several cancellations.

So, the new practice, became, produce a new engine first, before the airplane. And produce the engine core first, before other engine components. They have understood, that if you produced a new and powerful engine core, you have got a new engine. And if you have got a new powerful engine, you have got a new airplane.

J-10 and WS-10 was a hard lesson. Both projects started at the same time, resulting in numerous delays. If there was no AL-31FN, and China have to wait for WS-10, J-10 is probably just finished testing, and not yet operational.

"so far strongest engine delivers maybe +130kN, so a jump to +210kN is simply illogical. "

It's simply astonishing and unbelievable, but not "simply illogical", like China's progress in other areas.

In year 2000, or 2005,

Who could believe China would have 30,000km of High Speed Railroad, by 2017?
Who could believe China would have world's fastest Supercomputer, by 2012, and world's first Exabyte Scale supercomputer, before the end of 2017?
Who could have believe China could produce a 5th generation fighter, by 2011 and operational by 2017?

Anyone say such ridiculous things, back in 2000 or 2005, would get lock up in a mental hospital.

So I can understand your astonishment and disbelief, that China produced an operational +210kN engine, by 2017.

You are not alone.

It is also jaw-dropping and unbelievable for CIA and Pentagon, and the rest of the world.

My estimate of a +210kN engine, is based heavily on the assumption, that it is at least 2 tons heavier than F-22, and carry, at least, 4 tons of fuel, with a flying weight of (19.7 + 2 + 4) of 26 tons. No one, is going to, allow me, to go near the plane, to find out, the actual weight, so my weight assumption, is a big "if".

And no one, except, the pilot and ground crews, knows how much fuel, the plane was carrying, during the demonstration. So I made the low ball estimate of 4 tons or 1/3 of a full tank. Standard practice is carrying a minimum of 40%-50% fuel, in an airshow.

Carrying a full tank, would lower the plane's performance, and lesson the "wow factor" on the spectators.

But, if the total flying weight, happens to be 22 tons (Empty weight + fuel), then the required thrust will still be 180kN, which is still a lot higher than 130-140kN range of WS-10b and AL-31FN variants.

This flying weight of 22 tons, is highly unlikely, because that would mean with fuel, J-20 is only 2 tons heavier than F-22's empty weight of 19.7 tons. And J-20 is a much longer and bigger plane than F-22. It's body length is at least 3-4 meters (9-12 ft) longer!!!

And this lower thrust value of 180kN would still disqualified WS-10b and AL-31FN to be J-20's engine.

This is my main point of the argument, not WS-15's total thrust is +210kN.

My main point is that, even the total thrust is just 180kN, it would still discount the possibility that WS-10 and AL-31FN could be J-20's engine.

"but if You once again question my ability to moderate this forum only since You don't like my theory, then it's enough."

BTW, I don't question your ability to moderate this forum, just thinking you are highly biased on this engine issue. I have expressed my appreciation and gratitude for your moderation, on several occasions. I understand this position is unpaid, and takes a lot of hard work and dedications.

So again, thanks for your hard work, to maintain order, here.

 

[Deino]

Thanks at least for a few answers ... however one important part is still missing:

If there is already such a hyper-engine, that delivers IYO much more thrust than the still unfinished WS-10B/IPE or whatever and more than the projected WS-15 ?? So why still all that fuss and not just manufacturing as many as possible of these engines and re-equip all Flankers and J-10s ?
Why is CAC still waiting for a reliable high-thrust version of the WS-10 is such a mega-engine is already available for thei J-20 ??

It all makes no sense; Your thrust calculation makes no sense, the timeline does not fit for a regular engine esp. if other engines of lower thrust still have issues and most of all it's technically impossible.

 

[Asoka]

Thanks at least for a few answers ... however one important part is still missing:

If there is already such a hyper-engine, that delivers IYO much more thrust than the still unfinished WS-10B/IPE or whatever and more than the projected WS-15 ?? So why still all that fuss and not just manufacturing as many as possible of these engines and re-equip all Flankers and J-10s ?
Why is CAC still waiting for a reliable high-thrust version of the WS-10 is such a mega-engine is already available for thei J-20 ??

It all makes no sense; Your thrust calculation makes no sense, the timeline does not fit for a regular engine esp. if other engines of lower thrust still have issues and most of all it's technically impossible.

Thanks for your quick reply and more questions. Questions help me dig deeper and clarify my thoughts.

Why is China still making WS-10B/IPE engines to equip the J-20 and Flankers, if they got a more powerful WS-15?

Here is what I think:

1.) WS-15 is a new engine, which will still have its own issues and problems, years down the lines. WS-10 is already in service and matured.

2.) Being J-20's intended engine, equipping J-20 will be WS-15 highest priority. All other planes who want it, will have to wait after the orders for J-20 was satisfied.

3.) Because WS-15 is using new materials and new manufacturing process to boost it's Thrust. It will have production issue, to produces enough acceptable blades and other components, for a long time to come. Because the Compressor and Turbine, must be near perfect, the rejection rate for WS-10 blades are as high as 70%. That is for every 100 blades produced, only 30 will be accepted, or for every bladed installed, 3.33 blades will be rejected or wasted.

So, this production rate for WS-15 will be limited by this engine blade production rate. It will not be produced hundreds of copies per year, in the beginning.

And production rate of J-20, will be limited, by its engine production rate. The low production rate, (in the dozens, instead of hundreds, per year), of J-20, in coming years, will be a strong signal, that China has not totally mastered, the reliable production of WS-15.

4.) So, there will be no excessive WS-15 engine production capacity, for other airplanes, in the forceable future.

5.) Finally, because, WS-15, is a much more powerful engine, the airframes of J-10 and Flankers, must be redesigned and greatly strengthen, to handle this extra power, and the Digital Flight control system must be reprogrammed to incorporated this new engine.

And the planes, must be re-tested, all over again, like a brand new plane.

So, it is unlikely, that CAC will stop production of WS-10, and wait for WS-15 to equip the new J-10 and Flankers, coming down the production lines.

It will not be as simple as poop the new WS-15, into the new J-10 and Flankers, and tighten a few screws.

"It all makes no sense; Your thrust calculation makes no sense, the timeline does not fit for a regular engine esp. if other engines of lower thrust still have issues and most of all it's technically impossible."

So do your own very simple calculations, based on the method, I have shown, and see what numbers, you will come up with.

You don't have to post the result, if you think, it will embarrass you, and ruin your professional Journalist reputation. You can just do it, for your own benefit.

Look at the bright side.

If J-20, is using WS-15 ,and its thrust range is 180kN-210kN, not 160kN-180kn, as we previously believe, whoever report, this finding, first, on the mass medias outlets or website or newspaper or journal, will astonish the world.

He will be widely quoted and interviewed, for this military/aviation intelligence of the decade. And he will get a shot of world-wide-fame.

He will be laugh at, and disbelieved, at first, of course, but he will carefully present his simple, but solid calculations, to back him up.

I read a report that J-20 will be publicly display, on the ground in China, later this year. People will have a chance to take a close look at its engine.

So, potentially, journalists, have a six months window, to break this story, first, and astonish the world.

I agreed that +210kN upper range estimate is "iff", but the lower range of 180kN, is likely to be exceeded.

Because, to get a total thrust of 180kN, J-20 needs to have a flying weight of 22 tons (20 tons, empty weight + 2 tons of fuel, or some combinations like that)

It is incredible for J-20's empty weight, to be the same as F-22, despite its a much larger plane, with body length 3-4 meters longer.

And its also incredible, that any general will allow, his brand new 20 tons plane, to take off, with only 2 tons of fuel. I wouldn't allow a 10 tons plane, like F-16 to take off, with just 2 tons of fuel.

If it crashed, because of running out of fuel, its career ending, court martial, offense.

So, I stand with my estimate of 180kN - 210kN+ max. thrust range for WS-15.

It's likely to be higher than 210kN, because flying weight (26 tons) for this estimate, based the empty weight estimate of 22 tons and fuel of 4 tons, is still on the conservative side, IMO.