J-21/J-31 Chinese 5th Generation Stealth Fighter

J20!

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The overall design matters. You are making it too simple.
It is simple. Maybe you misunderstand me...

The J31's underside is smoother, thus stealthier(shaping wise) than the F35's underside. I'm not referring to the design as a whole(materials included)Even F35's weapons bays are two very prominent bumps under its fuselage, almost reminiscent of PAK FA's short range AAM bays. Whereas J31 has a flat, center-line weapons bay completely flush with its fuselage.

Remember that the F35's lumps and bumps are the main reason Carlo Kopp believes the J20 has better stealth shaping than the F35. And J31 is basically F35 without the distortions all along its sides and underside. One has better shaping than the other.

Let's not forget though, that this is only the first flying prototype, and X35 didn't have F35's bumps either, so maybe J31 will get fatter and lumpier as it matures through development as the F35 did.
 
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p2prada

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It is simple. Maybe you misunderstand me...

The J31's underside is smoother, thus stealthier(shaping wise) than the F35's underside. I'm not referring to the design as a whole(materials included)Even F35's weapons bays are two very prominent bumps under its fuselage, almost reminiscent of PAK FA's short range AAM bays. Whereas J31 has a flat, center-line weapons bay completely flush with its fuselage.

Remember that the F35's lumps and bumps are the main reason Carlo Kopp believes the J20 has better stealth shaping than the F35. And J31 is basically F35 without the distortions all along its sides and underside. One has better shaping than the other.

Let's not forget though, that this is only the first flying prototype, and X35 didn't have F35's bumps either, so maybe J31 will get fatter and lumpier as it matures through development as the F35 did.
The B-2 does not have a flat underside either.


Same for YF-23, said to be more stealthy than the YF-22.


And even PAKFA.


Rather this concept of lumps and bumps being unstealthy may be a product of superstition, quite like canards are not stealthy rhetoric.

Kopp may not have the latest testing rigs for measuring RCS. He deals with computer simulations with assumed physics laws that may not be completely accurate. For all we know these lumps and bumps could make the aircraft even more stealthy by forcing the incident waves to reflect in multiple directions compared to a flatter surface which may reflect in only one direction.

Specular reflection


Diffused refection


You can probably say a controlled diffusal of reflection may contribute greater to stealth than the simpler specular reflection. This is just my opinion, but at the same time we don't really know these aspects well enough to either accept it or discard it.

That's why it is not as simple as you stated.
 

tony4562

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PAK-FA at this stage does not really qualify as a stealth fighter. The only stealthy feature it has is the nose, nothing else.

With that being said, comparing stealthness between J31 and F35 right now is nothing more than an exercise of futility. If I were forced to make a bet, I would probably put my money on F-35 cause US after all has whole lot more experience in designing stealth objects than anybody else does.
 

Yijiuliuer

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PAK-FA at this stage does not really qualify as a stealth fighter. The only stealthy feature it has is the nose, nothing else.

With that being said, comparing stealthness between J31 and F35 right now is nothing more than an exercise of futility. If I were forced to make a bet, I would probably put my money on F-35 cause US after all has whole lot more experience in designing stealth objects than anybody else does.
What is the difference between T50 and PAK-FA? Just one prototype with two designations I believe.
btw, I wonder why the Indians came up with such a name, since anything related to PAK has been considered as pejorative or taboo, they name the plane PAK-FA.
 

tony4562

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What is the difference between T50 and PAK-FA? Just one prototype with two designations I believe.
btw, I wonder why the Indians came up with such a name, since anything related to PAK has been considered as pejorative or taboo, they name the plane PAK-FA.
PAK-FA is russian abbreviation for Prospective Airborne Complex of Frontline Aviation, india has nothing to do with it. T-50 on the other hand is the name of the prototype that should evolve into PAK-FA.

The indian designation is FGFA , short for 5th genration fighter aircraft, apparently a very imaginative name.
 

Yijiuliuer

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They, I mean the Russian should really stick to Sukhoi - 40 or something like it, PAK-FA does not even ryhme right.
 

p2prada

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PAK-FA at this stage does not really qualify as a stealth fighter. The only stealthy feature it has is the nose, nothing else.
Hehe! Ok.

They, I mean the Russian should really stick to Sukhoi - 40 or something like it, PAK-FA does not even ryhme right.
PAKFA is a project name. Even your J-20 and J-31 will have such a name.

PAKFA is called FGFA in India as already mentioned above.

AMCA is called NGFA or Next Generation Fighter Aircraft.

These are just regular project names.

YF-22 was part of the Advanced Tactical Fighter (ATF) and F-35 is called Joint Strike Fighter (JSF).

Shiphone was talking about J-31 being called AMF. I dunno, maybe it is Advanced Multirole Fighter or something in Chinese.
 

bhramos

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Second stealth jet puts China on path to top regional power,say expert



Beijing: China's second stealth fighter jet that was unveiled this week is part of a programme to transform China into the top regional military power, an expert on Asian security said on Friday.

The fighter, the J-31, made its maiden flight on Wednesday in the northeast province of Liaoning at a facility of the Shenyang Aircraft Corp which built it, according to Chinese media.

"This is the second entirely new fighter design that's emerged from China in the last two years, which suggests a pretty impressive level of technical development, and puts them ahead, certainly, of all their regional neighbours," said Sam Roggeveen, a security expert with the Lowy Institute in Sydney.

The Chinese military "has been extremely deliberate, well-funded and persistent, and it's starting to bear fruit", Roggeveen said.

"What you're now seeing since the early '90s is the slow emergence of a first-class regional military power."

China's Defence Ministry did not respond to a request for comment.

China's previous stealth fighter, the J-20, is a heavier aircraft and believed to be less manoeuvrable than the J-31.

China's military capabilities lag far behind those of the United States, but China is seeking aggressively to boost its strength, including launching its first aircraft carrier - purchased from Ukraine - in September.

The build-up is a worry for neighbours uneasy about China flexing its military muscle, especially in territorial disputes with Japan in the East China Sea and with Vietnam and the Philippines in the South China Sea.

"Just like the U.S. F-22 and F-35 fifth-generation fighters, the J-20 and J-31 will complement each other during future operations," Bai Wei, former deputy editor of the weekly Aviation World, told the Global Times newspaper.

"The J-31 is almost certainly designed with the intention to have the potential of operating on aircraft carriers, judging from its enhanced double-wheel nose landing gear and two big tail wings, which help increase vertical stability," Bai said.

China needs both the heavier J-20 and more nimble J-31 to defend its air space, Bai said.

The J-31 is a mid-sized fighter using Russian-made engines which will later be replaced by Chinese engines, the Global Times reported.

"The big Achilles heel for Chinese aerospace generally, and particularly for both of these two programmes, is engines," Roggeveen, a former analyst for Australian government intelligence and editor of the Lowy Institute's blog LowyInterpreter.org.

"They still rely very much on foreign technology, and their progress on developing domestic high-performance engines for combat aircraft has been frustrating and slow," he said.

While the J-31 and J-20 will add to China's offensive as well as defensive capability, "it will take many, many years" for them to enter service with the air force, Roggeveen said.

Second stealth jet puts China on path to top regional power, say experts | NDTV.com
 

farhan_9909

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Re: Second stealth jet puts China on path to top regional power,say ex

now china need to expertise the engine tech as well
 

Yijiuliuer

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Re: Second stealth jet puts China on path to top regional power,say ex

now china need to expertise the engine tech as well
Long way to go my deeper/higher/sweeter brother, design and techniques are easy to conquor, but material is where time and experience count a key parameter for success. we have a long long way to go and it won't happen in one night.
 

Drsomnath999

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shenyang 's J 31 is a smoother finish copy of F35 with twin engines.

Well it's development fulffills 2 purposes
1) naval stealth plane for china's future carriers

2) for targetting export customers exactly like US's F-35 (whther one country would buy it or not apart from our bankrupt neighbour :lol:) that's a different thing.

.
 

farhan_9909

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shenyang 's J 31 is a smoother finish copy of F35 with twin engines.

Well it's development fulffills 2 purposes
1) naval stealth plane for china's future carriers

2) for targetting export customers exactly like US's F-35 (whther one country would buy it or not apart from our bankrupt neighbour :lol:) that's a different thing.

.

Good to know that every where you guys are concerned about Us
 

sayareakd

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money is not the key word in relationship between china and Pakistan.geo-politics play a key role with essential national interests in it.
true Pakistan has already given its sovereignty to USA, China, UAE and NATO, so i wont be surprised if they offer something to China in return.
 

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