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Chengdu J-20 5th Generation Aircraft News & Discussions

what are you trying to say... F - 22 is not stealthy ???? F-22 is inducted long ago.. whereas China working on proto..

F-22 stealthy or not, I don't know.

It had not been tested in real war or approved by 3rd party other than buyer and maker.

The RCS @ specified band of F-22 is classified, we don't know. They covered it as top secret and bubbles cannot "bang".
 
F-22 stealthy or not, I don't know.

It had not been tested in real war or approved by 3rd party other than buyer and maker.

The RCS @ specified band of F-22 is classified, we don't know. They covered it as top secret and bubbles cannot "bang".
F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.
J-20 is a later design. Learn mistake from the earlier and improve better.
not better... you are trying to achieve what US achieved already ... learn from mistakes? ??? no China just started working on Stealth ...
 
F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.
not better... you are trying to achieve what US achieved already ... learn from mistakes? ??? no China just started working on Stealth ...
Hey, you american?

F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.
not better... you are trying to achieve what US achieved already ... learn from mistakes? ??? no China just started working on Stealth ...
Indians envy china's economic rise, but console themselves by pointing outthat it is no democracy.

F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.
not better... you are trying to achieve what US achieved already ... learn from mistakes? ??? no China just started working on Stealth ...
india children suffering from shortage schools as government has low priority for education and health.

F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.
not better... you are trying to achieve what US achieved already ... learn from mistakes? ??? no China just started working on Stealth ...
A country which donot emphasize education will have no future.

F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.
not better... you are trying to achieve what US achieved already ... learn from mistakes? ??? no China just started working on Stealth ...
A country which donot emphasize education will have no future.
 
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Hey, you american?


Indians envy china's economic rise, but console themselves by pointing outthat it is no democracy.
Why you are after my nationality ... Neither I said China cannot make stealthy jet... I just said US did something which others are dreaming to achieve. .. got it
 
F-22 is designed for future wars...
No nation should bet on future (something like China south neighbor favorite).
You bet on future means you have no presents.

F-22 is designed for future wars... it's technology is classified. . let me ask you same question. . does China tested it's jet in real combat??? does China have real combat experience like USA.

We can not open a war in order to test weapons.
But US has, she has a lot. Why don't release the dog to field for future-proof?
 
Hey Gambit long time no see you. Still argue about stealthy B2, f117 and f22? Why old Gambit those stealthy air crafts got shot down, and USAF General claim them not stealth. F22 got shot by Syria, and B2 got shot down by Kosovo army with anti aircraft Sam no stealthy detector. F117 got shot down by Serbia with Sam no stealth detector. Those Sam brought down those air crafts have no stealth detector. You should be proud of the stealthy technology USA got for you. Ha ha ha.
 
Very good observation, sir. I wish I had thought of putting how/what they think of the subject -- that way.

To go a bit further, we all know by now that the corner reflector is a huge no-no in designing a radar low observable body, but as someone who have seen the -22 up close, I can say that there are plenty of corner reflectors on that jet. Minor ones. They are small enough that whenever exposed to radar and reflect, the energy level is not enough to raise the jet above a certain threshold.
The -22's many minor corner reflectors combined constitute a design flaw, but their individual effects as contributors to RCS are deemed tolerable based upon a certain radar detection threshold. We have to look at what these structures produce -- EM radiation -- via reflection more than the fact that they are X, Y, or Z type of structures. That is why I consistently uses the word 'radiator' as attempt to denote with greater precision what these structures are under radar bombardment. From a sensor specialist perspective, I do not care if the aerodynamicist call it a 'canard' or 'doohickey' or 'thingamabob'. If the structure produces EM radiation in one way or another, it is a 'radiator' to me and my radars.

Point being ,is that the many nationals of respective nations when promoting their aircraft see it as a shape or a combination of shapes. They then assume that this shape(or the combination of shapes) has a RCS that is done by adding 1+1+1=3.
When the reality is far from that as you have stated here countless times and discussed.
There was this whole discussion on turning conventional aircraft stealthy, all sorts of stealth pods, RAM coatings and so on where discussed but at the end no one bothered to think whether the weapons hanging off it will generate their own RCS based on the totality of their surface and the interactions it has with itself and the aircraft wings.

This is my favourite reference to that. This shot is taken from the National Geographic documentary on the Horten XIII and the team from Northrop Grumman (those that built the B-2 if some did not know) who remade the aircraft for a RCS test. This was the first time I suppose that one was able to see modern RCS modelling techniques. The model was bombarded with VHF,UHF and L Band to simulate those days of Radar, but the principles of EM apply the same.

The model went up on a pole and the results are below. The two images show how electromagnetic energy radiates across the aircraft as it is rotated against an emitter. Here at a side pose, the energy return is lower due to the position of the surface(s) of the aircraft.
Capture.png


One the aircraft is taken at full frontal exposure the energy return spikes around the areas that are reflecting the most energy.
Capture2.png


Now there is on thing to notice, this sort of method gives us the advantage to see how exactly the energy spikes across a certain area. for e.g. you dont see a red outline of the cockpit instruments with the stick and seat and everything, but a combined red blur that is the combination of electromagnetic energy being reflected back to the receiver.

What it tells you is that by fixing the seat of the aircraft the designers may reduce the intensity of the red blur by a bit, but perhaps not by that much. If they do the same to the inlet, the reflected energy may dissipate but it wont do so if you just fix one area by applying RAM or otherwise. It has to be a combination of factors(compromises) to get the RCS of the red area down to say orange or dark yellow levels.

This is what @gambit has been trying to say here, and I have also taken cues from him to say elsewhere. The RCS is not a single shape(s) or design idea but a combination of all these factors. Just putting weapons in a pod will not fix the aircraft nor will adding Canted tails.

Now lets come back to the J-20, I am sure that the J-20 went through a similar procedure. The designers of the J-20 might have(as we calculate a guess) seen similar red areas for the aircraft with the cockpit, the intakes and the Canards over a full 360 degree sweep. They would then start looking for design ideas(compromises) that reduced those red areas; they could coat the cockpit with RAM, they would change intake shape and coatings, the would design algorithms built into the FLCS that manages the Canards to change position to minimize its energy return and avoid red spikes in favour of yellow or light yellow ones. The same sort of compromises go into aircraft such as the F-22, F-35, PAK-FA .. and are a reference to all those trying to come up with ideas to reduce RCS of conventional aircraft such as the F-15(F-15SE) or the JF-17.

It is important to always look at something with an open mind and always look for the most technical explanations possible as long as it is not technical loghorroa( Diarrhoea of useless information).

If you still have your doubts, take a look at this. What if someone someday was able to get something like this to fly without the extra bits on the top.. a Sphere aircraft so to say? What do you think the RCS of this massive thing will be? You would be surprised that it will near the RCS of the B-2(or less if done properly).
heart-of-Gold_610.jpg

@sandy_3126 @Dillinger @Armstrong @Aeronaut @Bilal. @Chak Bamu
 
Point being ,is that the many nationals of respective nations when promoting their aircraft see it as a shape or a combination of shapes. They then assume that this shape(or the combination of shapes) has a RCS that is done by adding 1+1+1=3.
When the reality is far from that as you have stated here countless times and discussed.
There was this whole discussion on turning conventional aircraft stealthy, all sorts of stealth pods, RAM coatings and so on where discussed but at the end no one bothered to think whether the weapons hanging off it will generate their own RCS based on the totality of their surface and the interactions it has with itself and the aircraft wings.

This is my favourite reference to that. This shot is taken from the National Geographic documentary on the Horten XIII and the team from Northrop Grumman (those that built the B-2 if some did not know) who remade the aircraft for a RCS test. This was the first time I suppose that one was able to see modern RCS modelling techniques. The model was bombarded with VHF,UHF and L Band to simulate those days of Radar, but the principles of EM apply the same.

The model went up on a pole and the results are below. The two images show how electromagnetic energy radiates across the aircraft as it is rotated against an emitter. Here at a side pose, the energy return is lower due to the position of the surface(s) of the aircraft.
Capture.png


One the aircraft is taken at full frontal exposure the energy return spikes around the areas that are reflecting the most energy.
Capture2.png


Now there is on thing to notice, this sort of method gives us the advantage to see how exactly the energy spikes across a certain area. for e.g. you dont see a red outline of the cockpit instruments with the stick and seat and everything, but a combined red blur that is the combination of electromagnetic energy being reflected back to the receiver.

What it tells you is that by fixing the seat of the aircraft the designers may reduce the intensity of the red blur by a bit, but perhaps not by that much. If they do the same to the inlet, the reflected energy may dissipate but it wont do so if you just fix one area by applying RAM or otherwise. It has to be a combination of factors(compromises) to get the RCS of the red area down to say orange or dark yellow levels.

This is what @gambit has been trying to say here, and I have also taken cues from him to say elsewhere. The RCS is not a single shape(s) or design idea but a combination of all these factors. Just putting weapons in a pod will not fix the aircraft nor will adding Canted tails.

Now lets come back to the J-20, I am sure that the J-20 went through a similar procedure. The designers of the J-20 might have(as we calculate a guess) seen similar red areas for the aircraft with the cockpit, the intakes and the Canards over a full 360 degree sweep. They would then start looking for design ideas(compromises) that reduced those red areas; they could coat the cockpit with RAM, they would change intake shape and coatings, the would design algorithms built into the FLCS that manages the Canards to change position to minimize its energy return and avoid red spikes in favour of yellow or light yellow ones. The same sort of compromises go into aircraft such as the F-22, F-35, PAK-FA .. and are a reference to all those trying to come up with ideas to reduce RCS of conventional aircraft such as the F-15(F-15SE) or the JF-17.

It is important to always look at something with an open mind and always look for the most technical explanations possible as long as it is not technical loghorroa( Diarrhoea of useless information).

If you still have your doubts, take a look at this. What if someone someday was able to get something like this to fly without the extra bits on the top.. a Sphere aircraft so to say? What do you think the RCS of this massive thing will be? You would be surprised that it will near the RCS of the B-2(or less if done properly).
heart-of-Gold_610.jpg

@sandy_3126 @Dillinger @Armstrong @Aeronaut @Bilal. @Chak Bamu
@gambit .... m.phys.org/news/2012-12-quantum-stealth-material-invisible.html#&ui-state=dialog

is it possible to use quantum stealth for fighter jet..
 
The foundational rules for designing a radar low observable body are:

- Control of quantity of radiators.
- Control of array of radiators.
- Control of modes of radiation.

From a sensor specialist perspective, I do not care if the aerodynamicist call it a 'canard' or 'doohickey' or 'thingamabob'. If the structure produces EM radiation in one way or another, it is a 'radiator' to me and my radars.

The large forward-facing gaps around the F-22's inlets to divert boundary layer air are radiators. That's a violation of your first rule. The J-20 has DSI and doesn't have these gaps.

Kit0Igw.jpg


The three forward-facing cavities on the F-35 are radiators. First rule violated again. Neither the J-20 nor the F-22 have these cavities.

R6p8Bqi.jpg


Inlets are cavities too. However, a properly designed stealth aircraft will have long and deep serpentine inlets to induce multiple radar bounces along the RAM coated inlet walls. But in the shallow cavities shown above radar energy goes in and bounces right back out. Any comments?:rofl:
 
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@Oscar thats quite understandable but having said that we also have a model of RCS reduced aircraft in the form of F-15SE or later blocks of F-16s, to name a few. Even in gen 4.5 we see RCS reduction measures put into the design. Then why is it such an absurd idea when speaking of JFT?
 
@Oscar thats quite understandable but having said that we also have a model of RCS reduced aircraft in the form of F-15SE or later blocks of F-16s, to name a few. Even in gen 4.5 we see RCS reduction measures put into the design. Then why is it such an absurd idea when speaking of JFT?

Because in the case of the JF-17, the compromise will cost and time. Both of which undermine the very purpose of the aircraft.
 
It is your stupid-proud out-of-date aviation maintenance experiences confused you. That makes you don't know what you're talking about.

Stealth is nothing to do with manoeuvrability of an aircraft which is born to fly. Anything for stealth is at cost of manoeuvrability, and vice versa.

How to control the radiation and reflection? In1980's, its basic computer simulation, lab testing, and by bare-eyes plus imagination (Oops, that how F-117, B-2, F-22 had been made, they are too old). Now we have to rely on super-computer to balance between manoeuvrability and stealth.

0 of bare eyes, 0 of imagination (only thing you old guys are capable of).
Ooh, sorry, Chinese got the fastest and costliest computer right now and future.



Never pretend you are somebody and talk about the things you don't know----sure you have the right to do so on internet. Internet only, remember it. In real time, please shut up.

Anything is combined or assembled by individual parts. To you, two giant triangles are called "wings" and on F-22's body. To radar waves, they are two objects only.

How come two giant triangle are stealthy when they are called "wings"?
And two small triangle are non-stealthy when they called "canards"?
Aren't your two giant wings of F-22 are just "canards" in front of two H-stabs?



Above question is too difficult to your minus IQ score.
Your stupidity, and I said that kindly, is worth a one-point lesson...

Fundamentals of Stealth Design & Concepts of RCS Reduction | Page 3

I do not expect you to understand it simply because you are a stupid person, and I said that kindly. I made it a one-point lesson so that interested laymen who are smarter than you will learn something about this subject.

The large forward-facing gaps around the F-22's inlets to divert boundary layer air are radiators. That's a violation of your first rule. The J-20 has DSI and doesn't have these gaps.

Kit0Igw.jpg


The three forward-facing cavities on the F-35 are radiators. First rule violated again. Neither the J-20 nor the F-22 have these cavities.

R6p8Bqi.jpg


Inlets are cavities too. However, a properly designed stealth aircraft will have long and deep serpentine inlets to induce multiple radar bounces along the RAM coated inlet walls. But in the shallow cavities shown above radar energy goes in and bounces right back out. Any comments?:rofl:
Your stupidity, and I said that kindly, is worth a one-point lesson. See here...

Fundamentals of Stealth Design & Concepts of RCS Reduction | Page 3
 
Planes can be stealthy, but they are not immune to radar. To modern high powered radars, they are vulnerable. Just as M1A2 Abrams that has DU armor is still destroyed with 1 shot by an APFSDS round fired by another M1A2 tank.

does China have real combat experience like USA


Really? I'd like to see the US fight a real opponent instead of some 3rd world weakling. As a matter of fact, the US lost quite a number of planes in the 1st Gulf War. Coalition Fixed-Wing Attrition in Desert Storm
 
Planes can be stealthy, but they are not immune to radar.
Who said they are ?

To modern high powered radars, they are vulnerable. Just as M1A2 Abrams that has DU armor is still destroyed with 1 shot by an APFSDS round fired by another M1A2 tank.
Yeah...And I guess Chinese tanks cannot be killed.

Really? I'd like to see the US fight a real opponent instead of some 3rd world weakling.
Some experience is better than none. :lol:

As a matter of fact, the US lost quite a number of planes in the 1st Gulf War. Coalition Fixed-Wing Attrition in Desert Storm
As a matter of fact, China lost no planes in Desert Storm. Does that mean the PLAAF is the better air force ? I guess in your childish mind, it is.
 
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