J-20 not yet ready for export: Jane’s Defense Weekly

[Black Widow]

Its radar has more T/R modules than the F-22's AN/APG-77, its engine will have 180 kN of thrust, which also outclasses those on the F-22, and its canards will remain stationary during BVR combat which means they will simply act as another pair of airfoils and therefore will not contribute to RCS.

Every prototype aircraft is an "airframe" until they reach more mature stages of testing via incrementation.

@TR_modules: lol..
@outclass_F22: lol
@180KN engine : Ever heard of term Power to Weight ratio??

 

[longlong]

More T/R modules does not automatically equate to superiority. It depends on manufacturing quality and more important -- supporting software.

Of course it is.
Software is important, does not mean it is more important than hardware.
Whatever the software you used, you cannot change a 50' TV to 60' or a phone-camera to a DSLR.

You can always get more powerful (range and detail) on a bigger size AESA ---- say, with same module on F-35, you can always get a more powerful radar on F-22/15 , that is what they're doing now.

Your physical is specialized for anti-Chinese , does it really exist? 

You should ask that of the Chinese members here. They are the ones making outrageous claims.


Please do not try to pass yourself off as someone with credibility. You first claimed to have 'aviation experience' to try to shut down the Indians, then when challenged, you backtracked to 'aviation study', then when challenged further as to which discipline since aviation have many disciplines, you ran. Essentially, you are a liar, a pretender, a fraud.

But in being generous, I will school you...

In intention of RCS control, which includes RCS reduction of an existing design or designing for RCS consideration from the start, it is necessary to control...

1- Quantity of radiators.
2 - Modes of radiation.
3- Array of radiators.

The two boxes above illustrate the three rules nicely. Rules, not merely guidelines or suggestions, if the intention is to take RCS into consideration. The Sopwith Camel, the P-51, or the F-16 did not have RCS as consideration so the three rules do not apply. But the F-117, F-22, F-35, B-2, PAK, and now allegedly the J-20, have RCS as consideration so the three rules absolutely applies.

Each box have a fixed quantity of radiators and the same array of radiators. But box 2 (right) obeyed rule 2, which is to control the modes of radiation. Contrary to what Stupidboy said about the canards being the same as the tailplanes, just as canards affects aerodynamics differently than tailplanes, canards falls under all three rules and being WHERE they are, rule 3 applies so the RCS signature of the body with canards will be different from the body with the tailplanes even though two bodies may have the same quantity of radiators -- rule 1.

Different does not automatically equal to either higher or lower. Only Measurement can tell us. But experience have already hinted that with current technology, canards, as per rule 3, TENDS to increase total RCS per rule 2. SinusSoldered said that the canards being on the same plane as the wings and therefore would have no effects on RCS. It is a baseless declaration as each canard is a finite body and with any finite body, rule 2 applies.

When we -- on this forum -- see at least a couple of reputable sources that says a stationary body is effectively invisible to radar, then we can toss out the three rules and I will be the first in line to do so.

F-22 two wings is whale bigger than J-20 canards, you'd better go cut them off.

 

[gambit]

Of course it is.
Software is important, does not mean it is more important than hardware.
Whatever the software you used, you cannot change a 50' TV to 60' or a phone-camera to a DSLR.

You can always get more powerful (range and detail) on a bigger size AESA ---- say, with same module on F-35, you can always get a more powerful radar on F-22/15 , that is what they're doing now.

That is a ridiculous argument. You are talking about several generations of diverse hardware and evolution of the camera itself. We are talking about comparing similar hardware. The more appropriate analogy would be DSLRs between Nikon and Canon.

Your physical is specialized for anti-Chinese , does it really exist?

To the Chinese members here, it is established a long time ago that to challenge Chinese claims, many so absurd that they violate the laws of physics, equals to being anti-Chinese, no matter how polite and credibly sourced the challenge might be. 

F-22 two wings is whale bigger than J-20 canards, you'd better go cut them off.

I see post 26 went whooooooosh over your head.

 

[longlong]

That is a ridiculous argument. You are talking about several generations of diverse hardware and evolution of the camera itself. We are talking about comparing similar hardware. The more appropriate analogy would be DSLRs between Nikon and Canon.

You now don't want to compare the size, old man?


Don't cheat yourself, you may don't know the physics, but we know what you are trying to do.


Take a flashlight and turn off all the light, put your two high-glossy boxes on a table, then you will find the real rules.

 

[antonius123]

You should ask that of the Chinese members here. They are the ones making outrageous claims.

Some chinese members said that stationary canard contribution to RCS is insignificant, while you and your gang said otherwise.

So if you accuse they are wrong, you must prove that you are right.

Please do not try to pass yourself off as someone with credibility. You first claimed to have 'aviation experience' to try to shut down the Indians, then when challenged, you backtracked to 'aviation study', then when challenged further as to which discipline since aviation have many disciplines, you ran. Essentially, you are a liar, a pretender, a fraud.

But in being generous, I will school you...

In intention of RCS control, which includes RCS reduction of an existing design or designing for RCS consideration from the start, it is necessary to control...

1- Quantity of radiators.
2 - Modes of radiation.
3- Array of radiators.

The two boxes above illustrate the three rules nicely. Rules, not merely guidelines or suggestions, if the intention is to take RCS into consideration. The Sopwith Camel, the P-51, or the F-16 did not have RCS as consideration so the three rules do not apply. But the F-117, F-22, F-35, B-2, PAK, and now allegedly the J-20, have RCS as consideration so the three rules absolutely applies.

Each box have a fixed quantity of radiators and the same array of radiators. But box 2 (right) obeyed rule 2, which is to control the modes of radiation. Contrary to what Stupidboy said about the canards being the same as the tailplanes, just as canards affects aerodynamics differently than tailplanes, canards falls under all three rules and being WHERE they are, rule 3 applies so the RCS signature of the body with canards will be different from the body with the tailplanes even though two bodies may have the same quantity of radiators -- rule 1.

Different does not automatically equal to either higher or lower. Only Measurement can tell us. But experience have already hinted that with current technology, canards, as per rule 3, TENDS to increase total RCS per rule 2. SinusSoldered said that the canards being on the same plane as the wings and therefore would have no effects on RCS. It is a baseless declaration as each canard is a finite body and with any finite body, rule 2 applies.

When we -- on this forum -- see at least a couple of reputable sources that says a stationary body is effectively invisible to radar, then we can toss out the three rules and I will be the first in line to do so.

It is you who claim to have solid aviation experience and education but busted many times. Dont try to slender.

You havent answered my question at all.

I am not asking whether stationary canard has effect or not on RCS.

My question is: how much the contribution of the J-20 stationary canard on it's total RCS. Is it negligible or significant?

IF it doesnt contribute much, then you need to shut up.

 

[antonius123]

To the Chinese members here, it is established a long time ago that to challenge Chinese claims, many so absurd that they violate the laws of physics, equals to being anti-Chinese, no matter how polite and credibly sourced the challenge might be. 

Maybe some chinese members here claim some absurd statement, but why must you be racist?

By attributing some absurd claims (if any) as chinese physics is a racist action.

Dont forget that you and some indian members here were also claiming some absurds, but we dont call it as viet or indian physics.

 

[j20blackdragon]

There's actually nothing inherently unstealthy about canards. Trolls that parrot that tired old argument can't even explain why canards are unstealthy in the first place.

But if you want to nitpick about canards, I want to nitpick about the giant gaps around the F-22's inlets.

I also want to nitpick about the lumps and bumps all over the F-35's lower fuselage.

So where do you guys want to begin?

 

[Esc8781]

You should ask that of the Chinese members here. They are the ones making outrageous claims.


Please do not try to pass yourself off as someone with credibility. You first claimed to have 'aviation experience' to try to shut down the Indians, then when challenged, you backtracked to 'aviation study', then when challenged further as to which discipline since aviation have many disciplines, you ran. Essentially, you are a liar, a pretender, a fraud.

But in being generous, I will school you...

In intention of RCS control, which includes RCS reduction of an existing design or designing for RCS consideration from the start, it is necessary to control...

1- Quantity of radiators.
2 - Modes of radiation.
3- Array of radiators.

The two boxes above illustrate the three rules nicely. Rules, not merely guidelines or suggestions, if the intention is to take RCS into consideration. The Sopwith Camel, the P-51, or the F-16 did not have RCS as consideration so the three rules do not apply. But the F-117, F-22, F-35, B-2, PAK, and now allegedly the J-20, have RCS as consideration so the three rules absolutely applies.

Each box have a fixed quantity of radiators and the same array of radiators. But box 2 (right) obeyed rule 2, which is to control the modes of radiation. Contrary to what Stupidboy said about the canards being the same as the tailplanes, just as canards affects aerodynamics differently than tailplanes, canards falls under all three rules and being WHERE they are, rule 3 applies so the RCS signature of the body with canards will be different from the body with the tailplanes even though two bodies may have the same quantity of radiators -- rule 1.

Different does not automatically equal to either higher or lower. Only Measurement can tell us. But experience have already hinted that with current technology, canards, as per rule 3, TENDS to increase total RCS per rule 2. SinusSoldered said that the canards being on the same plane as the wings and therefore would have no effects on RCS. It is a baseless declaration as each canard is a finite body and with any finite body, rule 2 applies.

When we -- on this forum -- see at least a couple of reputable sources that says a stationary body is effectively invisible to radar, then we can toss out the three rules and I will be the first in line to do so.

Gambit, do you have any experience in MATLAB, XPATCH, and RAM2d etc computational electromagnetic coding? Were you required using these codes in your career?

 

[gambit]

Some chinese members said that stationary canard contribution to RCS is insignificant, while you and your gang said otherwise.

So if you accuse they are wrong, you must prove that you are right.

When they said 'insignificant', they opined and they did it baselessly. As for me, I never said otherwise. I always said 'Measurement', as in no one can say either way until Measurement data is available, which is unlikely. But when I challenged the Chinese here, I do it with posts like this one...

https://defence.pk/threads/fundamen...ts-of-rcs-reduction.73549/page-3#post-4919945

Not one from the J-20 camp, including frauds like you, have ever supplied the readers with reasonably detailed explanation on the foundation of the subject under discussion. And what I explained in there is only the tip of the subject.

The three steps for radar cross section (RCS) data are:

1- Prediction
2- Modeling
3- Measurement

With computers, we can swap 1 and 2, but Measurement will always have the final word,, meaning Measurement of the full scale body is always done last after Prediction and Modeling to either confirm or deny, meaning prove wrong, what 1 and 2 speculated.

So when the J-20 made a claim, intelligent and not so gullible people will see it as a baseless opinion, but when I made my claim and I do it with posts like that one, what I opined will be seen as more credible.

It is you who claim to have solid aviation experience and education but busted many times. Dont try to slender.

Busted by whom? Not one of the J-20's supporters ever showed how I am wrong and when they said they did, it turned out they have a deeply flawed understanding of basic knowledge to start. Worse, they convinced themselves that what they know is correct despite being showed otherwise.

You havent answered my question at all.

I am not asking whether stationary canard has effect or not on RCS.

My question is: how much the contribution of the J-20 stationary canard on it's total RCS. Is it negligible or significant?
I have answered your question in its many variants before...

...With the above illustration.

On a complex body like an aircraft, EVERYTHING contribute, whether the structure is fixed or movable.

It is hilarious to watch you guys criticize the PAK's surface as being rough because it would contribute to RCS, but dismiss the J-20's canards as 'insiginficant' to RCS contribution. Rough surfaces contains visible to microscopic structures, so if these small structures, from panel gaps to fasteners, contribute to RCS to the point of criticism, why not the canards? But under 'Chinese physics', the J-20's canards are insignificant but the PAK's rough surfaces are 'significant'.

What the above illustration hinted at is that ALL structures, major or minor or microscopic, can raise the aircraft's RCS to above a certain threshold, and I know the Chinese members here have a difficult time grasping the concept of a threshold, and once that threshold is breached, it does not matter if the aircraft have canards or not, it will be detected.

That said, the foundation of the subject of RCS control have the initial statement that we should limit the QUANTITY of radiators (structures), after that, we should control the modes of radiation off structures and control the array of radiators to limit interference, especially constructive interference which tends to amplify and concentrate energy levels for the seeking radar.

The J-20's canards raised red flags and they are legitimate concerns base upon sound technical foundation.

IF it doesnt contribute much, then you need to shut up.

May be you and the Chinese members here should take that 'shut up' advice. You guys are the ones trying to downplay the canards and does it carelessly while I criticize them on solid technical grounds.

 

Gambit, do you have any experience in MATLAB, XPATCH, and RAM2d etc computational electromagnetic coding? Were you required using these codes in your career?

MATLAB.

I was never involved in any exotic endeavours like designing 'stealth' fighters. I designed, executed, and monitored field tests for various 'low altitude low RCS semi-autonomous' penetrators. We used MATLAB to analyze flight maneuvers when the penetrator try to escape radar detection.

 

[JohnyD]

It requires the amount of money, we don't have.

and the tech that Chinese dont have...
Moreover, evolution of chinese stealth jets will take at least a decade and dont expect IAF wont have a fitting or superiror tech by then...

 

[Informant]

It's one thing to develop a plane on your own, from scratch much ontop of that a stealth plane. It''s an achievement for the Chinese. No one is claiming their J-20 is going to be better than the Raptor. But what is with the smug Indian attitudes here, it's downright abhorring and mocking for something they are a paying partner. Not a development party.

@gambit could you please elaborate on the MATLAB work I am a huge fan of your knowledge plus MATLAB is heaven for guys like me! Any tips on RCS reduction methodologies or links. Thanks!

 

[Kompromat]

and the tech that Chinese dont have...
Moreover, evolution of chinese stealth jets will take at least a decade and dont expect IAF wont have a fitting or superiror tech by then...

It doesn't matter, nor will it come to that as we won't be able to buy them in the first place.

 

[gambit]

@gambit could you please elaborate on the MATLAB work I am a huge fan of your knowledge plus MATLAB is heaven for guys like me!

MATLAB, like any high level computing languages like Perl or Python or PHP, is great for quick and dirty data processing without requiring the organization hiring professional software specialists. The MATLAB version of today is ten times better than the version I used back in the mid to late 90s when I was in aviation after ten yrs in the USAF. Back then, the Internet did not exist as we know it today, so information on it was scant, but to give you a sampler of what MATLAB can do in the radar detection business, give this a read...

http://www.mathworks.com/help/phased/examples/designing-a-basic-monostatic-pulse-radar.html

The MATLAB codes that I worked with, and I did not write most of them, had to do with analyzing vehicle performance under full environmental influence. Basically, the air vehicle was assigned an approach corridor and inside that air corridor, pretty much like how air traffic controller would direct his area of responsibilities, there would be EW obstacles. The vehicle would have limiters, such as altitude and air speed, and we would receive either recorded or real time data on how it respond to those EW threats while under those limiters. Prior to the testing day, we would insert those EW threats into the codes and print out the projected responses on paper, yes PAPER. On the testing day, we would compare the vehicle's performance under real world conditions versus our projections. Any differences from projections, depending on a set percentage, would warrant investigations. But the bulk of the codes were already established by others before me.

My job, started out as low man on the totem pole as the proverbial saying go, was the usual code verification and constructing the tests. Later I grew into designing the tests themselves but essentially, my job was to design a test based upon requests, construct its parameters, conduct the test, evaluate the results for any errors that were testing regime based, give an initial opinion on how the test vehicle performed, then send the whole package back to the requesters. We were in Florida for a reason: Water is extremely problematic for any radar sensor based airborne penetrator. The lower the altitude, the greater the odds of environmental influence, which in this case is water, and when combined with EW threats, it was not surprising that often the test vehicle failed to match projections.

My investigation would be limited only to ensure that our test constructions did not matter in either success or failure. A constructor factor would be the local airport, for example. If local air traffic was heavy on the testing day, potential contaminant signals exists and I had to make sure that is reflected in the codes and recompile the projections -- on the fly if necessary. Later, the client could consider that factor to be heavy EM traffic, but non-EW based, over enemy target area that would affect his vehicle, for example. If unpredictable EM signals were not noted, the test could lead the designers astray when confronted with out of projections performance. The client would not understand why did his vehicle executed a pitch down maneuver that was as violent as when confronted with a EW signal. If civilian radar signals were noted, the client could redesign his vehicle to recognize such and reprogram his vehicle not to respond at all, or respond not so violently. Then there would be new testing. And so on...

I could be wrong, but as far as I know, MATLAB was the best, if not the only high level language, that would allow quick on-the-fly simulations while the testing was on-going. With today's laptop PCs that is ten times more powerful than the stuff we had back then, who knows what testing engineers are doing now.

I always worked with at least one engineer from the requestor/client and usually he is at least on the vehicle development team, and sometimes we even had the vehicle designer himself. Never had a 'herself', though. Anyway, his job would be to make sure the vehicle would fly and repairs if necessary. Often, he would be accompanied by technicians that he supervised.

Am not going to name any specific vehicles I worked with. Most of them were experimental in the sense that they served as test vehicles for sensors, navigation, or flight controls systems. Some were jets, some were prop jobbers. Some were manned, but most were unmanned. Some flew for several hundreds km, some just did a pop up maneuver and the test ended. None were destructive but we did had a few crashes, one from lightning because the requester specified 'heavy meteorological influence', so I waited for the weatherman to predict a summer t-storm, but no one expected a bolt from Zeus.

Any tips on RCS reduction methodologies or links. Thanks!

Sure...Give this a try...

https://defence.pk/threads/fundamen...ts-of-rcs-reduction.73549/page-3#post-4919945

 

[antonius123]

When they said 'insignificant', they opined and they did it baselessly. As for me, I never said otherwise. I always said 'Measurement', as in no one can say either way until Measurement data is available, which is unlikely. But when I challenged the Chinese here, I do it with posts like this one...

https://defence.pk/threads/fundamen...ts-of-rcs-reduction.73549/page-3#post-4919945

Gambit, everybody here already know that object will contribute RCS no matter how low it is. So your rebuttal is useless and a troll in nature.

What they mean "insignificant" is relatively compared to other shape/parts (airduct gap, round nozzle, perpendicular fin, etc).

Therefore what they are expecting from you is: your explanation + evidence why static canard on J-20 contribute RCS significantly, or more compared to bump, gap, round nozzle on other fighter plane (Pakfa, F-35). Some member has elaborate that to you, but you still dont respond properly yet.

Your pdf explanation why object contribute RCS is useless.

Not one from the J-20 camp, including frauds like you, have ever supplied the readers with reasonably detailed explanation on the foundation of the subject under discussion. And what I explained in there is only the tip of the subject.

Then why fraud and troller like you think that you have supplied adequate explanation and evidence on our query?

The three steps for radar cross section (RCS) data are:

1- Prediction
2- Modeling
3- Measurement

With computers, we can swap 1 and 2, but Measurement will always have the final word,, meaning Measurement of the full scale body is always done last after Prediction and Modeling to either confirm or deny, meaning prove wrong, what 1 and 2 speculated.

So when the J-20 made a claim, intelligent and not so gullible people will see it as a baseless opinion, but when I made my claim and I do it with posts like that one, what I opined will be seen as more credible.

Why you consider static canard on J-20 contribute RCS significantly or more compared to other shape/object on other fighter (gap on Pakfa, bump on F-35, round shape, etc)?

What I understand from chinese member here about their claim why static canard contribute RCS insignificantly is because static canard will be like small wing. So if you dont agree, we need to know the reason and evidence.

Busted by whom? Not one of the J-20's supporters ever showed how I am wrong and when they said they did, it turned out they have a deeply flawed understanding of basic knowledge to start. Worse, they convinced themselves that what they know is correct despite being showed otherwise.

You forget about your own claim which is demonstrating your clueless about the thing you claim in previous old thread? (air intake = nacelle ? LOL, travelling wave, 120 degree corner, a lot more which are busted already)

https://defence.pk/threads/j-20-5th-generation-aircraft-updates-discussions.111471/page-167

 

[conworldus]

and the tech that Chinese dont have...
Moreover, evolution of chinese stealth jets will take at least a decade and dont expect IAF wont have a fitting or superiror tech by then...

So I guess the J-20 is flying with non-existent tech. That must be something.