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Chengdu J-20 5th Generation Aircraft News & Discussions

If I were you, I would ignore the troll. He repeats the same thing over and over again despite being presented with new evidence. He only posts after I put up a comprehensive analysis. Indians used to do it to me all the time.

They rehash the same old arguments from months ago to clutter the thread. This way no one will see my exhaustive analysis after spending hours collecting the information and presenting it in a streamlined manner.

Please ignore him or he'll clutter this thread again. Thank you.
YOU have done NOTHING of the kind. What you have done is simply look for and zero in on the opinions that you agree with. Nothing more. You ignored valid criticisms of your 'analysis', which is fine with me. The issue here is I present credible challenges for the readers to see.
 
Stop putting words in people's mouth.

Houshanghai did not compare J-20's RCS with that of the F-35 in his post. All he did was state the fact that the 207 institute was satisfied with the RCS readings and that the J-20's underside is smooth and similar to that of the F-22 in that respect. Where did he say that the F-35's underside was a negative and how did China figure into this?
Touchy...eh? My questions are just as valid as his without inserting anything.
 
If I were you, I would ignore the troll. He repeats the same things over and over again, despite being presented with new evidence.
This is a publicly accessible forum. Your 'evidences' are not exempted from challenges and especially if the challenges are valid.

http://www.defence.pk/forums/china-...craft-updates-discussions-23.html#post1934472

In the above, I pointed out where APA had to admit they used a flawed tool in their analysis. What I questioned are legitimate points for discussion as 'The Man' pointed out. When you used an inappropriate tool and exclude data, any result is immediately suspect and any interpretation from that suspect result are disqualified. That is not being unfair but valid peer review process. I have been through several peer reviews, formal and informal. Not one of my formal submissions were rejected. If you want to be taken seriously by knowledgeable and fair minded people, you need to address the points I raised about APA's flawed methodology. Else you are misleading people.
 
I certainly doubt the bumps and ridges on the F-35 create problems.. from my layman's point of view.. they arent angles from any "angle"..
And whilst the F-35 may never be as stealthy as the F-22.. for its required task... I think its enough.
Although I understand how an export F-16 may not have the "have glass" modifications.. how do you make a F-35 less stealthy???


On the subject of the J-20.. Kopp's analysis or not, it is clear that the jet is designed for LO. How much of it? it is a certainty that it's RCS is definitely less than that of existing 4.5++ gen jets. Now does it approach the F-35's?
Looking at it head on.. I can by comparison to the F-22 and f-35 see that it exhibits similar clean lines... and has similar shaping which should put its Frontal RCS close to if not equal to the F-35's. However.. looking at the sides of the jet, and those Canards I am inclined to think that any carefree microwave is going to bounce back to a waiting receiver when it hits those canards, or even the tiny gaps that will come and go when the jet's FBW system makes tiny corrections. The EF designers too claim that their RCS reduction technique for the canard works only head on, not when looked at from beyond a certain angle.

However, whether the above is accurate is true or not.. what matters in my view is how these advantages and disadvantages matter operationally.
If the J-20 is supercruising.. as an interceptor it still will be in my view(if armed with appropriate Long range AAM's, coupled with support systems that China is also manufacturing) as good or better as an interceptor than the F-35. simply because it can get into a fight faster.. provide greater kinetic energy to its missile shots.. and get out faster.

As a strike craft.. the J-20 may have the advantage of surprising a CAP(although it seems rather useless , since even if a CAP is shot down.. people know its shot down) and getting through to a target. Inside hostile airspace however, I am doubtful that the consistent threat circle concept applicable to jets such as the F-22 and F-117 may not apply here.. a radar may pick up the J-20 a lot later when its approaching from the front.. but probably quicker if its coming to its 2 or 10 o clock.

If the J-20 is equipped with Standoff weapons though. .. whatever advantages its LO .. even if partial give it, may make a big difference in a conflict.
 
425-yangwei.jpg



Yangwei, China's First Master Designer



2011-07-07 (China Military Article cited from strategypage.com) -- After years of trying to keep it a secret, China has confirmed that one of their aircraft engineers, Yang Wei, is actually one of those extraordinary designers who produces one successful design after another. Born in 1963, he graduated from college at age 19 and finished graduate school three years later. He soon went to work at the Chengdu Aircraft Design Institute, and a decade later was appointed director. So far, he has designed a working fly-by-wire system, as well as the JF-17, J-10B and J-20. He did not design the original J-10, but did design the most successful version, the J-10B, and provided important upgrades for other J-10 models. The new J-20 (a stealth design that is still in development) is less of a surprise now that it's known the Chinese have a genuine ace designer working on it.
Ace aircraft designers are rare, and those that do show up tend to create a number of exceptional designs during a few decades (or much less, if there's a war going on). For example, Russian designer Mikhail Simonov recently died (at age 81). He was responsible for the Su-24 bomber, the Su-25 ground attack plane and the Su-27 fighter. Starting during World War II, for example, one American designer (who was trained in Germany), Edgar Schmued, designed the P-51, followed by the F-86 and F-100 after the war. In Germany, Willie Messerschmitt designed the Me-109, Me-110 and the first jet fighter (Me-262) plus several others during World War II, and a few after the war.
j20-yangwei.jpg

J-20 Stealth Fighter
In China, Yang Wei appears to be the first designer in this tradition. He had nothing to do with the original J-10, the first modern jet fighter designed and built in China. That appears to explain the many problems this aircraft has had. The J-10 was an attempt to create a modern fighter-bomber that could compete with foreign designs. The experiment was not completely successful. Work on the J-10 began over twenty years ago, in an attempt to develop an aircraft that would be comparable to the Russian MiG-29s and Su-27s, and the American F-16. But the first prototype did not fly until 1998. There were continued problems, and it wasn't until 2000 that the basic design flaws were fixed. By 2002, nine prototypes had been built, and flight testing was going forward to find, and fix, hundreds of smaller flaws. It was a great learning experience for Chinese engineers, but it was becoming apparent that the J-10 was not going to be competitive with the Su-27s/30s China was buying from Russia. The J-10 looks something like the American F-16, and weighs about the same (19 tons). Like the F-16, and unlike the Su-27, the J-10 has only one engine. Yang Wei improved the J-10 considerably with his J-10B version.
But it was the JF-17 (also known as FC-1) that made Yang Mei's reputation. The JF-17 was developed by China in cooperation with Pakistan, which originally only wanted to buy 150 of them. All this came about because Pakistan could not get modern fighters from anyone else, and turned to China. At the time, China had nothing comparable to the early model F-16s Pakistan already had. The 13 ton JF-17 is meant to be a low cost alternative to the American F-16. The JF-17 is considered the equal to earlier versions of the F-16, but only 80 percent as effective as more recent F16 models. The JF-17 design is based on a cancelled Russian project, the MiG-33. Originally, Pakistan wanted Western electronics in the JF-17, but because of the risk of Chinese technology theft, and pressure from the United States (who did not want China to steal more Western aviation electronics), the JF-17 uses Chinese and Pakistani electronics.
J-2014511-07part.jpg
 
From Aviation Week in 2009: If you want to claim the "APA has got their models wrong, it probably wouldn't compromise security to explain why." Don't try to hide behind the argument of secrecy. The Chinese and Russians already have their own radar modeling software. "The worst argument against APA, though, is that of secrecy."

Since Lockheed or another reputable organization has not published a study to challenge the APA analysis in two years, we can only conclude the APA models are accurate.

Aviation Week has implicitly acknowledged the F-35's shortcoming by suggesting the F-35 is "stealthy enough to survive." However, that was two years ago, before the debut of the J-20 Mighty Dragon in 2011.

JSF News 2 - Stealth Questions Raised

"JSF News 2 - Stealth Questions Raised
Posted by Bill Sweetman at 1/7/2009 7:30 AM CST

The Air Power Australia team have produced an unprecedented report which asserts that the F-35 Joint Strike Fighter is much less stealthy than the F-22 - and in fact is comparable in radar cross-section (RCS), under some circumstances, to a conventional fighter in clean condition. APA's updated surveys of modern Russian radars - which are most likely to form the basis of the threat systems that it would encounter from the late 2010s onwards - have set the scene for this analysis.

The report is unprecedented because it's the first "civilian" use of radar scattering models to take a first-order look at an aircraft's RCS. It was the development of computer-based RCS models that opened the way to the development of stealth in the 1970s: the theory of scattering was well known but was too hard to apply to a 3-D shape without those tools.

The APA analysis will no doubt be countered by the JSF team in several ways. They'll argue that the APA team has an agenda. They will argue that the analysis is too crude to reflect reality; that anything it does show is not operationally relevant; and that the true picture is much more complex and (of course) secret.

The APA team does have an open agenda (as does the JSF team) but that does not mean that their data is bad.

The analysis is crude insofar as it doesn't make any detailed estimates of the effects of radar absorbent material (RAM). On the other hand, the doctrine laid down by Stealth pioneer Denys Overholser still stands: the four most important aspects of stealth are shape, shape, shape and materials.

On the other hand, the APA analysis is a lot more detailed than the cartoon representations in Lockheed Martin briefings. And more realistic than the claims of total invisibility made on JSF's behalf.

The APA team also makes the point that the F-35 doesn't look as much like an F-22 (or the X-35) as you might think. Those two aircraft both reflected a refined version of the F-117 shape - they are basically faceted designs, although they incorporate large radius curves and the lines between facets are smoothed. But the F-35 has acquired some very conventional-airplane-shaped lumps and bumps around its underside, not to mention the hideous wart that covers the gun on the F-35A. It's enough to raise questions.

DVcux.jpg


Of course, it's possible to argue that the F-35 meets its stealth requirements (which may or not be the same for all F-35s), and that it will be stealthy enough to survive - combined with situational awareness and tactics.

But that in turn depends on what the requirements are, and what threats it was designed against. (That's why stealth air vehicles are as diverse as they are, from the DarkStar to the AGM-129, while submarines look pretty much the same.) In the design of the F-22, for example, features such as 2-D nozzles, edges swept at 42 degrees, and high-altitude, high-speed flight were required to address that threat set.

More recently, the Northrop Grumman X-47B and Boeing X-45C designs have clearly been aimed at all-aspect, wideband stealth - although that's particularly important for an unmanned vehicle, which may not be as flexible in its response to a pop-up threat.

The worst argument against APA, though, is that of secrecy. Implemented on an experimental airplane 30 years ago, stealth is no longer covered by Arthur C. Clarke's principle that "any sufficiently advanced technology is indistinguishable from magic." Competitors and potential adversaries around the world have assuredly run F-35 models in simulations, in RCS chambers and on open ranges. So if APA has got their models wrong, it probably wouldn't compromise security to explain why."

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I explained the physics behind the compromise in stealth caused by "lumps, bumps, and warts" in an earlier post.

3. To save money, the F-35 has a compromised design of "‘hideous lumps, bumps, humps and warts’ [that] have appeared on the JSF to disrupt the shaping imperative." Also, the F-35 and the J-20 both share the round engine nozzles, which do not measure up to F-22 stealth standards.

Why are "hideous lumps, bumps, humps and warts" a problem? Recall your experience of driving on a rain-slicked road at night with your headlights turned on. Very difficult to see the road, right? The rain-slicked road is almost a perfect mirror. The beams (which are electromagnetic radiation like radar waves) from the car headlights bounce away from you.

However, if there are lots of "hideous lumps, bumps, humps and warts" in the road then you can see much better (like a radar receiver), because the car's lights are being bounced back into your eyes. For the same reason that you can easily see a bumpy rain-slicked road, it is much easier for a radar to detect a F-35 with bumpy surfaces.

Finally, the F-35 was always intended to be an economy-model stealth fighter. The U.S. military will not redesign the F-35's round engine nozzles. The U.S. already has the F-22. There is no point in redesigning the F-35 until it looks like a F-22. There wouldn't be any cost savings.

If you want a more technical answer, the "lumps, bumps, and warts" create surfaces that are oblique (which are sometimes orthogonal from the perspective of an incoming radar wave) and increases the likelihood that the angle of reflection will equal the angle of incidence. Therefore, the stealth of the airplane with "lumps, bumps, and warts" has been compromised, because of the greater likelihood of detection.
 
And your own post contradict you. As far as the readers goes, they have yet to see anything from the Chinese members even half way close to post 333. I have no problems with their intelligence to see through your pseudo-technical blather.

On post 306 I have shown the readers on why physical optics (PO) is an inappropriate and inadequate tool for this project. That inadequacy was known even to the Iranians and no doubt to the Chinese. But here are the reasons why APA had to use PO.............

etc
etc
etc


Hey , sorry for jumping on the wagon too late, but now that I saw it, hey ... one of the same.

For once, Gambit, your understanding of APA's paper is .. well .. spotless.. I'd give it a first class grade.

I think you analysed the paper correct and although a kudos is out for you, well you'll agree with me you just used your extensive understanding of .... english ...

isn't that so? I didn't see any deep mysteries in that paper.

I agree it only verifies that the J-20 shows that the chinese understand about stealth shaping .. in a 2D POV (top,bottom, front rear,sides) as we can see.

incorporating this into a flying weapon.. well that is a tad harder now isn't it?
 
I see that more trolls are jumping in. Why can't we have two separate threads on the J-20?

This is the method that everyone agreed to on SinoDefence and Indian Defence. We, the Chinese members, would like to post new pictures, our new insights, and informative articles with new information in a J-20 thread. We don't care if the anti-China crowd want to badmouth the J-20 in their own separate thread.

However, we do OBJECT to the trolls (e.g. Gambit, PtldM3, Amalakas, etc.) constantly regurgitating the same old tired arguments and cluttering up our thread, which is meant to inform "guest" readers. The goal is to share our hobby of military watching, not to keep arguing endlessly with the anti-China trolls.

If the trolls are again permitted to keep posting endlessly after I (or another important Chinese member, like HouShanghai) post a new picture, article, or fresh insights then I will once again stop posting on this forum for many months. I don't like to waste my time and see my insightful posts buried three pages back within one day, where I (or a guest reader) have trouble finding it.
 
I see that more trolls are jumping in. Why can't we have two separate threads on the J-20?

This is the method that everyone agreed to on SinoDefence and Indian Defence. We, the Chinese members, would like to post new pictures, our new insights, and informative articles with new information in a J-20 thread. We don't care if the anti-China crowd want to badmouth the J-20 in their own separate thread.

However, we do OBJECT to the trolls (e.g. Gambit, PtldM3, Amalakas, etc.) constantly regurgitating the same old tired arguments and cluttering up our thread, which is meant to inform "guest" readers. The goal is to share our hobby of military watching, not to keep arguing endlessly with the anti-China trolls.

If the trolls are again permitted to keep posting endlessly after I (or another important Chinese member, like HouShanghai) post a new picture, article, or fresh insights then I will once again stop posting on this forum for many months. I don't like to waste my time and see my insightful posts buried three pages back within one day, where I (or a guest reader) have trouble finding it.
Sounds like someone does not like his ego to be challenged. The topic is about the J-20 and related DISCUSSIONS, not about the Chinese members here making claims, some reasonable, some outrageous, and be exempted from credible criticisms. Someone sent me a list of links of where you have been on the Internet promoting your arguments and you have been very busy. So far, not one of those places have challenged you the way I have here. That should tell the readers something.
 
Hey , sorry for jumping on the wagon too late, but now that I saw it, hey ... one of the same.

For once, Gambit, your understanding of APA's paper is .. well .. spotless.. I'd give it a first class grade.

I think you analysed the paper correct and although a kudos is out for you, well you'll agree with me you just used your extensive understanding of .... english ...

isn't that so? I didn't see any deep mysteries in that paper.

I agree it only verifies that the J-20 shows that the chinese understand about stealth shaping .. in a 2D POV (top,bottom, front rear,sides) as we can see.

incorporating this into a flying weapon.. well that is a tad harder now isn't it?
Thanks...But as someone who have been through several formal peer reviews, it is not a big deal on how to be critical of any submission, especially when the subject infringes upon one's relevant experience. The peer review process is inherently hostile and the moment anyone make public his opinion on any topic, he should be matured enough to expect such hostility. It is nothing personal but very much professional.

For now, the current argument is that the secret for 'stealth' is no longer secret. I respectfully disagree. The secret for 'stealth' lies in the data and the more data gathered and exploited, the better the design that is appropriate for the goals. The US is the leader in gathering and exploiting those data.

The argument also said that advances in personal computing places the tools into the public domain. The 'stealth' people have no issues with that because they know full well the old computing adage of 'Garbage in. Garbage out.' applies regardless of the sophistication of the tools. I pointed this out back on post 306 of this discussion where despite 30+ years of computing advances, the Iranians themselves reaffirmed what E F Knott said before them: That Physical Optics ALONE is a totally inadequate tool for a complex body. This is not a state secret. And that mean APA's methodology and analysis are wide open to credible criticisms. No one need to reveal any trade or state secret to do that.
 
Here is proof that people don't want to read anti-China troll posts.

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The best anti-China troll is MIG-29/MIG-29MLD. SinoDefence gave him his own anti-China J-20 thread: "Discussion on J-20's aerodynamics, comparison with F-22 and some 'guesswork'"

Reference: http://www./air-force/discussion-j-20s-aerodynamics-comparison-f-22-some-guesswork-5603.html

With 1,469 posts, there are only 35,307 views. The view rate is 24 views per post.

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The troll-free J-20 Mighty Dragon thread has almost four times the viewership of the troll thread on J-20.

Reference: http://www./air-force/j-20-new-generation-fighter-iii-35-5600.html#post155027

The troll-free "J-20... The New Generation Fighter III" thread has 517 posts and 47,738 views. The view rate is 92 views per post.

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The public has spoken. They do not want to read a troll-infested J-20 Mighty Dragon thread.
 
I explained the physics behind the compromise in stealth caused by "lumps, bumps, and warts" in an earlier post.

If you want a more technical answer, the "lumps, bumps, and warts" create surfaces that are oblique (which are sometimes orthogonal from the perspective of an incoming radar wave) and increases the likelihood that the angle of reflection will equal the angle of incidence. Therefore, the stealth of the airplane with "lumps, bumps, and warts" has been compromised, because of the greater likelihood of detection.
More like you learned the basics of radar detection and 'stealth' from me. So give me something new instead of what you rehashed from my posts about the subjects.
 
Here is proof that people don't want to read anti-China troll posts.

----------

The best anti-China troll is MIG-29/MIG-29MLD. SinoDefence gave him his own anti-China J-20 thread: "Discussion on J-20's aerodynamics, comparison with F-22 and some 'guesswork'"

Reference: http://www./air-force/discussion-j-20s-aerodynamics-comparison-f-22-some-guesswork-5603.html

With 1,469 posts, there are only 35,307 views. The view rate is 24 views per post.

-----

The troll-free J-20 Mighty Dragon thread has almost four times the viewership of the troll thread on J-20.

Reference: http://www./air-force/j-20-new-generation-fighter-iii-35-5600.html#post155027

The troll-free "J-20... The New Generation Fighter III" thread has 517 posts and 47,738 views. The view rate is 92 views per post.

----------

The public has spoken. They do not want to read a troll-infested J-20 Mighty Dragon thread.
I challenge you to post your arguments on a more incredulous public: airliners.net. It would be amusing to see how far your arguments travels.
 

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