J-20 5th Gen Fighter Thread V

[weig2000]

Yes. It's called Song Wencong's original design study, *as well as* the stated requirements for the J-XX program, which we've known about now for more than a decade.

Clearly Blackstone doesn't know that, nor does he care to know. All he does is to provoke with the same silly comment, or sometimes pose it as a seemingly (and loaded) "innocent" question to others.

I have started to feel that Blackstone isn't really interested in the answer or truth - he clearly lacks the knowledge and refuses to learn. I don't even think he is sinister. He is just being childish, poking to get attention and response from adults, or to see the adults quarrel among themselves. For that, he is quite successful, I'll have to admit. Even Deino felt the urge to take the bait. ;-)

 

[Blitzo]

Clearly Blackstone doesn't know that, nor does he care to know. All he does is to provoke with the same silly comment, or sometimes pose it as a seemingly (and loaded) "innocent" question to others.

I have started to feel that Blackstone isn't really interested in the answer or truth - he clearly lacks the knowledge and refuses to learn. I don't even think he is sinister. He is just being childish, poking to get attention and response from adults, or to see the adults quarrel among themselves. For that, he is quite successful, I'll have to admit. Even Deino felt the urge to take the bait. ;-)

I'm willing to give Blackstone the benefit of doubt in some ways, because some of that information he might not have been around for or maybe he didn't pay attention at the time.

But at the same time, I do think he needs to realize that the centre of gravity and authority for talking about Chinese military aviation in many respects (including J-20) does not reside in English language defence media or "analysts" anymore (if it ever did at all) and instead now lies with a collection of experienced China defence watchers on forums like this (for English at least).

 

[cloyce]

This video (1:02) says it uses domestic engines, is it reliable?

 

[manqiangrexue]

This video (1:02) says it uses domestic engines, is it reliable?

Ah, I see this is where the rumors came from. Yes, what he said could easily be interpreted as saying that "...now, it is using domestic engines and can satisfy basic combat requirements though it will be much improved with WS-15." However, it is also possible to interpret that statement as, "...now, if it were to use domestic engines, it could satisfy its basic combat requirements but it could be further enhanced by WS-15." In Chinese, the "if" may be implied without directly saying. That leaves room for doubt and cannot be regarded with certitude that it is currently flying on domestic engines. Although he is definitely saying that current domestic options are fully matured for powering J-20 (no actual dependence on foreign engines), so it can be implied that it is not necessity that drove J-20 to use an AL-31 variant but some other circumstance such as convenience or price.

 

[Hyperwarp]

What about copying the 117 engine? China can't produce its own, so its options are limited. Su-35 buy allows it to reverse engineer the Russian engine.

Again, 117 is the engine of the PAK-FA. The Su-35S has the 117S which produces at least 500N less.

People are over-estimating PRC's ability reverse-engineer (RE) high-performance turbofans. This is not like REing an air-frame, RADAR or a missile. The Russians are confident that PRC cannot RE the 117S and even if they do it'll take long time and may not even reach the level of the 117S. Trying to RE something like the 117S will take years maybe more.

The other argument I keep hearing is that the Su-35S is just a proxy and CAC is going to magically fit the 117S the moment the Su-35S lands in China. Even that is a major stretch. You can't just plug-in the 117S into the J-20. Unless NPO-Saturn passed classified information of the 117S to CAC back when the J-20 was in design phase, there is no chance CAC can just fit the 117S into the J-20. J-20 will have to go through modifications, and if intake requires a major redesign, things will get very messy. The reason SAC could interchange AL-31F with WS-10 in the J-11B is because they had access to both the Su-27 and the AL-31F along with the technical manuals and they had years to do that. As far as we know, there has been no connection what-so-ever between NPO-Saturn and CAC. CAC's long time partner has been MMPP-Salut. It is much safer to use a custom Salut made engine even if it is not up to the 117S standard.

If the WS-15 flops, by that time the 117S will also be of no use. By that time the Russians will be using the "Type 30" engine and CAC can buy an engine better than the 117S directly from Salut though it'll still be inferior to the "Type 30".

 

[b787]

117 is not accessible to China. Its only for the PAK-FA and in an emergency mode can produce 147kN at the expense of MTBO. Combat mode is less. About 142kN - 144kN.

The 117S the Su-35S has can produce max thrust around 142kN, combat mode max about 138kN -

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And you've said yourself, J-20 is going to be quite large and heavy. There is no guarantee 117S will give it any supercruise capability. Actually, I'll go out on a limb and say "IT WON'T".

If it is about reveres-engineering the 117S, that could take years. Maybe more than 5 or even 10 years to correctly ground-up reverse-engineer AND IMPROVE a high-performance turbofan. This is assuming they can reverse engineer it in the 1st place. Even if they are planning to use the 117S installed on the Su-35S, you can't just plug and play. They'll have to redesign parts of the J-20 possibly even the intake geometry to accommodate the 117S, not to mention integrating the 117S TVC system with FBW will require lot more testing and put the program further back. And they have to do all this by importing 24 full-blown Su-35S worth billions? WTH!? You know how inefficient that sounds?

Current J-20 will have to sacrifices both super-cruise and super-maneuverability thanks to the lack of the WS-15 and TVC. But, trying to cram in the 117S NOW will add a new set of problems. If CAC had designed the J-20 specifically with 117S in mind then it would have been possible. But CAC never had connections with NPO Saturn. CAC has ONLY been working with MMPP salut. Reverse-engineering the 117S might be part of a contingency plan if the WS-15 fails. But the J-20 will never reach its full potential without the WS-15 or similar engine.

You are pretty wrong, the 117S, is an engine designed to be fit on regular Su-27s airframes, same is the Al-31F-M2, there is no need for structural modifications, the Su-35, is the same Su-27 airframe improve it, Al-31F-M2 was the losing engine for the Su-35 and PAKFA bid, these engines can be retrofitted to the Su-27 family, but 117S is designed for the air superiority version

 

[latenlazy]

Again, 117 is the engine of the PAK-FA. The Su-35S has the 117S which produces at least 500N less.

People are over-estimating PRC's ability reverse-engineer (RE) high-performance turbofans. This is not like REing an air-frame, RADAR or a missile. The Russians are confident that PRC cannot RE the 117S and even if they do it'll take long time and may not even reach the level of the 117S. Trying to RE something like the 117S will take years maybe more.

The other argument I keep hearing is that the Su-35S is just a proxy and CAC is going to magically fit the 117S the moment the Su-35S lands in China. Even that is a major stretch. You can't just plug-in the 117S into the J-20. Unless NPO-Saturn passed classified information of the 117S to CAC back when the J-20 was in design phase, there is no chance CAC can just fit the 117S into the J-20. J-20 will have to go through modifications, and if intake requires a major redesign, things will get very messy. The reason SAC could interchange AL-31F with WS-10 in the J-11B is because they had access to both the Su-27 and the AL-31F along with the technical manuals and they had years to do that. As far as we know, there has been no connection what-so-ever between NPO-Saturn and CAC. CAC's long time partner has been MMPP-Salut. It is much safer to use a custom Salut made engine even if it is not up to the 117S standard.

If the WS-15 flops, by that time the 117S will also be of no use. By that time the Russians will be using the "Type 30" engine and CAC can buy an engine better than the 117S directly from Salut though it'll still be inferior to the "Type 30".

If the WS-15 does flop, do not be surprised if China gets its hands on the Type 30. That said, I'm doubtful that the WS-15 will flop.

 

[b787]

You're spot on here son, and I am in 150% agreement with you, and furthermore, I still do NOT believe China is going to thow away money to buy SU-35s, when they have NO real interest in OVT, and they build better Flankers anyway??? just my honest opinion?? if I'm wrong about the SU-35s I will issue a public apology and retraction. Brat

tell me where is the post stall in any J-20 video? TVC is not only for improving poststall, it improves turns rates, reduces drag and improves stealth and range, tell me why the Japanese Russians and Americans use TCV nozzles and China does not? why the US does not sell the F-22?

 

[b787]

Ohh come on ! And they lay these newly acquired engines right down onto an 3D-printer and voila, they have enough engines ???

- The Chinese have engines that are working ... at least for the Flankers, so please STOP this sort of argument.
- How long will it take to "copy" these engines ... and in parallel the latest news are quite positive in regard to the WS-15.
- By the way - and not only You, but also B787 - these is NO way China will get the 117 ! This engines is solely restricted for the T50. The engine in question is the 117S and this is a different beast. Simply get it.
-





In return: Just look at the fuselage .. is there anything that supports Your theory the J-20 is NOT designed for supercruise ??


To admit this endless forth and back on the same points is already boring !

So I am out.
Deino

the engine used on PAKFA is classified, the 117 and 117S one denomination only is official, the 117S is an official denomination, 117 is a Forum given denomination, taken as by logic, since people say 117 is a derivative of the engine, it is not an official denomination, only given by most forums and some Media outlets, but is not given by the maker and the United Engine corporation or United aircraft corporation which are official sources

 

[Hyperwarp]

Anyway, we will know the answers to this mystery in a year or 2. So make sure you bookmark these posts . If we eventually find out that the current LRIP J-20 is only powered by the basic AL-31F (122kN) and the engines in the PLAAF Su-35S suddenly start disappearing and re-appearing in the J-20, then I'll tender b787 an apology and admit my error.

So until, then I'll withdraw (eject) from this specific topic .