Chengdu J-20 5th Generation Aircraft News & Discussions

[ptldM3]

Don't care if you don't appreciate what has been said is to the point and scientifically proven. I don't need to repeat what Martain2 has already explained in detail in reference to pak-fa's overall huge rcs and design.

To start off with pak-fa complete design is non stealthy. Let me port what Martain2 posted nothing better than to re-posted which is to the point. So pak-fa team actually did not work that hard to design a stealth prototype lets see if in later stages their brains growup.

1. Circular exhaust.
2. Infrared-search-and-track ball on the nose.
3. Canopy frame,
4. Gaps around the inlets.
5. Various unshielded intakes and grilles.
6. Limited use of composites for now. Eventually, 40% of the aircraft will be made using composites.
7. Many surface intersections and flight-test probes that increase the radar signature.

So russians need to work hard to come up with a refined revamp design.

One ill informed person taking the words of a well know liar and hypocrite. Your beloved Martian has been caught contradicting himself more times than I care to count and sadly you have fallen for it. On one occasion he claimed that the F-22’s gaps between the engines were ‘stealthy’, but on the other Martian claimed that identical gaps on the pak-fa were not stealthy. And as for the IRST argument, it is weak, to say the least especially when the J-20 has countless curved, round or spherical protrusions--but according to J-20 fan boys these rules do not apply to the J-20.

Martian and blind followers of the barf that comes out of his mouth still can not digest that something as the F-15 SE has the same frontal RCS as the F-35-with its framed canopy, intakes and all. The F-15 SE as well as other ‘LO’ aircraft take everything that you believe about ‘stealth’ and throws it into the trash where it rightfully belongs.

 

[danger007]

Default Re: J-20 5th Generation Aircraft: Updates & Discussions

At Gambit, I don't understand why you keep making moronic arguments.

J-20 canards are made of RAM-coated composite materials (which makes it stealthy) and it is carefully shaped to deflect radar. Su-30 and T-50/Pak-Fa IRST is a giant sphere of metal, glass, and electronics.

You can't seem to understand the difference.

Also, saw-toothed edges are designed to bleed radar energy away from the direction of the emitter. The IRST is simply a giant sphere that reflects substantial radar energy back to the emitter. I've already provided a citation from "How Does Stealth Technology Work?"

It is obvious you don't understand basic stealth technology.

@Martian2


Does you have knowledge on Stealth technology. You are making every one laugh on you by your nasty arguments. do you think Russian engineers don't have knowledge than an ordinary web digger....... good to know about Chinese physics.. I guess F-22 is a 4th gen jet according to chinese while it is 5th gen jet to the rest of world. keep continue.....

BY the way thread is about J-20 only and you are turning it into J20 vs PAK-FA/T-50/F-22/ F-35 you are not even leaving Su-30 and rafale also....

 

[j20blackdragon]

Martian and blind followers of the barf that comes out of his mouth still can not digest that something as the F-15 SE has the same frontal RCS as the F-35-with its framed canopy, intakes and all. The F-15 SE as well as other ‘LO’ aircraft take everything that you believe about ‘stealth’ and throws it into the trash where it rightfully belongs.

Not this propaganda again.

Boeing has backed down from previous statements comparing the frontal-aspect radar cross-section of the F-15SE to an international release standard for the F-35.

However, Jones confirms that Boeing's original briefing chart - claiming the F-15SE provides frontal-aspect stealth offered by fifth-generation fighters - remains accurate.

Boeing unveiled the F-15SE in March 2009. The redesign adds conformal weapons bays, stealth techniques, fly-by-wire and canted tails to the F-15E configuration, providing a "first-day-of-war" stealth capability.

Lockheed and F-35 programme officials, however, have criticised Boeing's assertions that the F-15SE offers equivalent front-aspect stealth as the JSF, and denied that an international release standard exists for F-35 stealth characteristics.

Boeing applies to export F-15SE to South Korea

Partners to Get Equal JSF Stealth

Posted by Amy Butler at 6/22/2011 9:17 AM CDT

JSF partners and customers will be able to have the same stealth characteristics as the U.S., according to Joe Dellavedova, the F-35 program office spokesman.

There is a caveat: "each partner will have the option to add 'unique' capabilities that may have minor LO characteristics," he tells Aviation Week. One example, he says, is the addition of a drag chute, an item Norway has eyed.

Such "capabilities may have minor implications on LO characteristics," Dellavedova says.

Partners to Get Equal JSF Stealth

 

[ptldM3]

However, Jones confirms that Boeing's original briefing chart - claiming the F-15SE provides frontal-aspect stealth offered by fifth-generation fighters - remains accurate.

Did you forget to highlight this part? Your own source is contradicting you

Taking some ESL classes wouln't hurt

 

[j20blackdragon]

People can decide for themselves with their own eyes.

F-15SE vs F-35:

 

[ptldM3]

People can decide for themselves with their own eyes.

F-15SE vs F-35:

In the real world things aren’t decided by looking at them, especially not by clueless Chinese adolescent girls. I will hold my trust in engineers not in what comes out of your mouth. The frontal area of any aircraft always presents the smallest RCS. The biggest contributors to an aircraft’s frontal RCS would likely be the cockpit and engines, with a treated canopy and shielded compressor face those two factors are now resolved. It’s also no surprise that the pylons were removed, canon hidden, and a number of other subtle changes made.

And since Chinese adolescent girls love to point out size as a factor, the F-15 is noticeably smaller/more narrower than the F-35. Essentially the F-15 is not much different from a frontal perspective when compared to the F-35, with minimal differences such as nose, and ‘serration’ other than that many of the same features and techniques that are found in the F-35 are also found in the F-15.

 

[conworldus]

In the real world things aren’t decided by looking at them, especially not by clueless Chinese adolescent girls. I will hold my trust in engineers not in what comes out of your mouth. The frontal area of any aircraft always presents the smallest RCS. The biggest contributors to an aircraft’s frontal RCS would likely be the cockpit and engines, with a treated canopy and shielded compressor face those two factors are now resolved. It’s also no surprise that the pylons were removed, canon hidden, and a number of other subtle changes made.

And since Chinese adolescent girls love to point out size as a factor, the F-15 is noticeably smaller/more narrower than the F-35. Essentially the F-15 is not much different from a frontal perspective when compared to the F-35, with minimal differences such as nose, and ‘serration’ other than that many of the same features and techniques that are found in the F-35 are also found in the F-15.

The F-15 is a heavy fighter.... Su-27 class fighter...
Length: 19.43 meters
Wingspan: 13.05 meters

F-35
Length: 15.67 m
Wingspan: 10.07 m

Please go home... I want to call you names but I don't want another warning from PDF.

No more hijacking this thread. ptlDM3, gambit, Martian... you three should have a private amateur discussion and stop pretending to be professionals because you simply do not have the knowledge.

Let's post more J-20 pictures and videos!!!

 

[ptldM3]

The F-15 is a heavy fighter.... Su-27 class fighter...
Length: 19.43 meters
Wingspan: 13.05 meters

F-35
Length: 15.67 m
Wingspan: 10.07 m

Please go home... I want to call you names but I don't want another warning from PDF.

No more hijacking this thread. ptlDM3, gambit, Martian... you three should have a private amateur discussion and stop pretending to be professionals because you simply do not have the knowledge.

Let's post more J-20 pictures and videos!!!

I was referring to the frontal profile not length or width. And before you go around accusing me of hijacking, I only replied to 2 members both of which started the off topic and provocative posts. Go and find one post where I deliberately mentioned anything off topic for no apparent reason. All of my posts are replies, in fact if no one would mentioned anything ridiculous about the pak-fa or F-35 or F-15 I would have no reason to post anything in this worthless thread.

 

[marshall]

I think you take this personally. I don't know how big the IRST probe appears to a radar, but on the other hand you have to think in terms of the russian engineers having a tiny bit of brain too.

You're right, I absolutely take personal pleasure in this. There's a distinct difference between you/PtldM3, and this troll who has admitted to hanging out at Stormfront and AMREN, which are white power racist websites. He isn't here to debate like other hobbyists, plus exposing fakers is fun! lol For the record, I don't think the IRST or even the engine blades will be an issue, but not for the reasons discussed here so far.

coming to the canards, I don't think you are realising what you are saying.
in normal level flight, the primary control surfaces deflect only a little, there would be no point in limiting them anyway.
don't know how else to put it really

True, if only in level flight. When the J-20 and PAK FA/FGFA are eventually produced in numbers in the 2020s, the hypothetical radar grids that are being discussed today will probably exist in some form. This would probably consist of a combination of multi-modal radars, UCAV radar grids (X & L band), AWACs, etc...all datalinked and using much much more powerful onboard processing than we have today. The detection threshold will be an order of magnitude lower and the illuminating radars would be from multiple directions. Why not add an FBW mode for the canards to maximize the stealth?

 

[marshall]

Seriously.. you expect prototype to perform full fledged aerobatics. You think all critical maneuvers to be perform at public sites they would be far away from the population area just few flights over the air base can't be the conclusion.

Of course not, but there were some observers who were talking about the spectacular 02/27 test flight as if it was full of acrobatic stunts. I'm just pointing out the obvious.

 

[gambit]

The F-15 is a heavy fighter.... Su-27 class fighter...
Length: 19.43 meters
Wingspan: 13.05 meters

F-35
Length: 15.67 m
Wingspan: 10.07 m

Please go home... I want to call you names but I don't want another warning from PDF.

No more hijacking this thread. ptlDM3, gambit, Martian... you three should have a private amateur discussion and stop pretending to be professionals because you simply do not have the knowledge.

Let's post more J-20 pictures and videos!!!

And YOU do? I have yet to see anything remotely edukashional from you. But then again, I do not major in 'Chinese physics'.

 

[marshall]

You're the one who insinuated the non-faceted spheroidal IRST of the PAK FA could be larger according to the lambda rule not me. Nice try at role reversal there Houdini but no cigar. I suggested you had an interesting psychosis at some point but I didn't know it was this bad. LOL Those who have been paying attention know the history behind that statement.

Btw, if, as you suggest, the IRST's curvature already conforms to the lambda rule, what radar bands are you referring to exactly? The IRST looks to be somewhere between 22cm-28cm, typical fighter radar targets X-Band (2.5-3.75cm). Only the lower bound of X-Band somewhat applies and it wouldn't be effective because of the surface discontinuities of the IRST. It would have to be shaped more like a WOK, or better yet like the underwing protrusions of the J-20, for it to be reasonably stealth shaped.

This is outright stupid. If the diameter is 11x the wavelength -- in this case the cm -- why the hell would we need to make it larger? There is already specular reflection REGARDLESS of diameter. So enlarging the diameter to 12x or even 11.5x does not reduce RCS contributorship. The creeping wave already is negated at 11 or 10.5x.

On a non-spheroidal structure like the IRST device, the 10-lambda rule is still highly applicable even though the surface wave will meet a larger structure -- the fuselage. If the curvature is large enough, as in being 10x greater than the impinging wavelength IF it was a sphere, whatever surface wave behaviors that finally meet the fuselage and reflected off it, its energy level may be small enough to make that energy level statistically insignificant to the total RCS.

Get it?

It's interesting how you contradict yourself depending on whatever you are trying to prove. Here is that original classic again, remember to pay attention to the context, enjoy everybody...

I swear, your eyes are terrible. The T-50/Pak-Fa IRST probe is about the size of a pilot's head. What do you think will happen to a plane's radar signature when you stick a pilot's helmet on the plane's nose (like an IRST probe)? That's right. It's a giant radar reflector. You really are totally clueless.

In radar detection, paradoxical as it sounds, because of the 10-lambda rule, the larger the spheroid structure, it may be appear smaller to the seeking radar. Now go and look up my explanation of the 10-lambda rule.

Considering the context in which you are referencing the lambda rule, you could propose to the US Air Force that IRST probes should be made much larger...like 5 feet wide...this will make them more stealthy, according to you, since you posted this little factoid in the context of the above message from "Martian2" about a non-faceted spheroidal IRST. I'm sure you can convince China's communist government to finance your proposal to the US Air Force.

 

[marshall]

You don't understand the tactical requirement to minimize the effects of moving canards in a threat environment and are purposely pretending that canard movements cannot be reduced with corresponding compensatory adjustments from the other control surfaces. This is basic logic that any neophyte can understand.

Really? Then why bother with canards in the first place? Why not make those other flight control surfaces do the work that includes those compensatory actions?

Sigh! The canards negatively affect stealth, that's why they are a source of heavy criticism and the reason this idea of a canard stealth mode in the FBW even began. Your contention is some back-assward logic that the canards were put there to control negative stability rather than for any other reasons. Like I said, you lack tactical and strategic foresight and cannot conceive that there is a time, place and reason for everything. This is called "Strategy"...

strat·e·gy/ˈstratəjē/
Noun:

1. A plan of action or policy designed to achieve a major or overall aim.
2. The art of planning and directing overall military operations and movements in a war or battle.

So if the J-20 which is pretty much a delta winged design, which have inherent poor cruising speed maneuverability, and added canards to remedy that deficiency, you can bet your next decade's salary that the canards will not be 'locked' in place for ANY reason.

Yet another red herring, surprise! surprise! Fyi, your declaration that the canards are there only to compensate for negative stability is your personal guess and something you just threw in there so you can claim the canards function cannot be compensated whatsoever by the other control surfaces. All the control surfaces work together and the other control surfaces could compensate for less "severe" angling of the canards and vice-versa.

You then incorrectly and purposely quote a bogus accusation that I said the canards should be locked in place for such a FBW mode, something that is patently false and already proven false by message #1725. Like I've already said, you lack integrity and constantly resort to lies and deceptive use of out-of-context minutiae.

Fyi, the primary reason the J-20 has canards is because it was designed by CAC. Chengdu's primary strength where it is most experienced is with the delta canard layout with its most advanced fighter aircraft being the delta canard J-10B. The same developmental evolution is present with the PAK FA as derived from the family lineage of Sukhoi Flankers. If stability was the issue, the J-20 could simply have used a small LERX instead of having the delta wing so far back and using a canard. You quoted 10 pages of minutiae for a simple solution that could be summarized in 1 sentence Einstein. lol

 

[gambit]

It's interesting how you contradict yourself depending on whatever you are trying to prove. Here is that original classic again, remember to pay attention to the context, enjoy everybody...

You have not showed where is that 'contradiction'. Instead, you ended up showing everyone how you and your man are fools. If the IRST device is 'not stealthy', then so is the J-20's canopy since it is much much larger than the IRST device. But since you guys insisted that the ROUNDED canopy is 'stealthy', then how so is the IRST device 'not stealthy' when despite being rounded and much much smaller than the canopy? Your 'logic' does not hold up. This is real physics, not 'Chinese physics'.

 

[gambit]

True, if only in level flight. When the J-20 and PAK FA/FGFA are eventually produced in numbers in the 2020s, the hypothetical radar grids that are being discussed today will probably exist in some form. This would probably consist of a combination of multi-modal radars, UCAV radar grids (X & L band), AWACs, etc...all datalinked and using much much more powerful onboard processing than we have today. The detection threshold will be an order of magnitude lower and the illuminating radars would be from multiple directions. Why not add an FBW mode for the canards to maximize the stealth?

Now that is more stupidity.

It is true that the bi-static radar is 'stealth' greatest threat. But what is not true is that by the '20s such networks will be so widely deployed that it will render 'stealth' worthless. Even so, assuming that speculation -- wild as it is -- is true, then why the hell would the J-20 have canards in the first place given the usual decade long development time from test flight to volume manufacture?