Chengdu J-20 5th Generation Aircraft News & Discussions

[j20blackdragon]

Let me just clear up this whole issue about canards.

People need to understand that the entire airframe reflects radar. That means the main wings of every aircraft will reflect radar. The F-22's all-moving stabilators will reflect radar. And the J-20's canards will reflect radar.

So the question here is NOT whether canards are stealthy or unstealthy. The correct question to ask is whether the canards are planform aligned.

This is how planform alignment works:

Notice in the above diagrams that the F-22's stabilator (horizontal stabilizer) is clearly shown to be reflecting radar energy. But because the leading and trailing edges are swept at an angle, the radar energy is reflected at an angle and away from the enemy radar receiver assumed to be in front of the aircraft.

These same principles apply to the J-20's canards.

As for gambit, that guy is either ignorant or trolling. Most of the stuff he says is either incoherent or just plain misinformation. My suggestion is to ignore him.

 

[gambit]

Let me just clear up this whole issue about canards.

People need to understand that the entire airframe reflects radar. That means the main wings of every aircraft will reflect radar. The F-22's all-moving stabilators will reflect radar. And the J-20's canards will reflect radar.

So the question here is NOT whether canards are stealthy or unstealthy. The correct question to ask is whether the canards are planform aligned.

This is how planform alignment works:

Notice in the above diagrams that the F-22's stabilator (horizontal stabilizer) is clearly shown to be reflecting radar energy. But because the leading and trailing edges are swept at an angle, the radar energy is reflected at an angle and away from the enemy radar receiver assumed to be in front of the aircraft.

These same principles apply to the J-20's canards.

As for gambit, that guy is either ignorant or trolling. Most of the stuff he says is either incoherent or just plain misinformation. My suggestion is to ignore him.

Planform alignment is one component among many in how to design a radar low observable body. But here is where you, with your non-experience in aviation, is lacking. Planform alignment is not necessary, or a reduced requirement, if the first rule of radiation control is observed.

Again, the rules are:

- Control of QUANTITY of radiators.
- Control of ARRAY of radiators.
- Control of MODES of radiation.

The ideal radar low observable body is the sphere, after that it is the ogive. The sphere does not have any protrusions, other than from microscopic surface imperfections, for the first and second rules to take effect.

The ogive...

...With a shape that give sort of an edge will have rule 3 more applicable than rule 2. We cannot control its shape. So if we take all the OTHER basic bodies: cube, pyramid, cone, etc., we will see that since we cannot manipulate them, we have to compensate for rules 1 and 2 somehow, such as absorber. But once we introduce protrusions on to any of the basic shapes, including the sphere and ogive, then planform alignment comes into play.

In radar detection, we do not see a wing as a wing but as a radiator. Same for the canards and this is where you guys rooting for the J-20, and none of you have any aviation experience, are looking at the issue the wrong way. The J-20 planform is not as refined as the F-35 that you sneered at.

As for me, I taught ALL of you what you know about radar detection and 'stealth' without venturing into the 'classified' region. But despite the foundation that I gave you, it looks like integration of components is still problematic for all of you.

 

[longlong]

And how do those gaps affect the J-20's radar cross section. We want reasonably technical observation, if not hard data.

So the gaps on J-20 are acceptible by you. I tell why, not because of the bullish*t stealth rules and laws, it because F-22/35 have those gaps.

For your information, J-20 has less gaps than the failed F-22 and worse than failed F-35.

How can you say the F-22 is a 'failed project' ? Because of the quantity produced ? And how can you say the F-35 is also a 'failed project' ? Because of its development problems ? What make you think the J-20 does not have its own development problems ? Going by your simple minded thinking, I can say that by virtue of the J-20 came from the MIG 1.44, which was never mass produced, that mean the J-20 is already a failed project.

Even you can answer why they are failed.
Copy of not from 1.44, J-20 is always J-20.
All post-Iphone phones looks like iPhone, you oldman from 1960's don't know they're IOSed or androided.

Let me just clear up this whole issue about canards.

People need to understand that the entire airframe reflects radar. That means the main wings of every aircraft will reflect radar. The F-22's all-moving stabilators will reflect radar. And the J-20's canards will reflect radar.

So the question here is NOT whether canards are stealthy or unstealthy. The correct question to ask is whether the canards are planform aligned.

This is how planform alignment works:

Notice in the above diagrams that the F-22's stabilator (horizontal stabilizer) is clearly shown to be reflecting radar energy. But because the leading and trailing edges are swept at an angle, the radar energy is reflected at an angle and away from the enemy radar receiver assumed to be in front of the aircraft.

These same principles apply to the J-20's canards.

As for gambit, that guy is either ignorant or trolling. Most of the stuff he says is either incoherent or just plain misinformation. My suggestion is to ignore him.

He is well known troller of this forum, you have to live with it.

 

[gambit]

So the gaps on J-20 are acceptible by you. I tell why, not because of the bullish*t stealth rules and laws, it because F-22/35 have those gaps.

For your information, J-20 has less gaps than the failed F-22 and worse than failed F-35.

You cannot tell me 'why' simply because you do not know a damn thing about these issues. You probably can barely tell the difference between a hammer and a screwdriver.

Even you can answer why they are failed.
Copy of not from 1.44, J-20 is always J-20.
All post-Iphone phones looks like iPhone, you oldman from 1960's don't know they're IOSed or androided.

How are the F-22 and F-35 are failures ? Based upon what criteria ? You cannot even understand the basics I taught you.

 

[longlong]

Planform alignment is one component among many in how to design a radar low observable body. But here is where you, with your non-experience in aviation, is lacking. Planform alignment is not necessary, or a reduced requirement, if the first rule of radiation control is observed.

Again, the rules are:

- Control of QUANTITY of radiators.
- Control of ARRAY of radiators.
- Control of MODES of radiation.

The ideal radar low observable body is the sphere, after that it is the ogive. The sphere does not have any protrusions, other than from microscopic surface imperfections, for the first and second rules to take effect.

The ogive...

...With a shape that give sort of an edge will have rule 3 more applicable than rule 2. We cannot control its shape. So if we take all the OTHER basic bodies: cube, pyramid, cone, etc., we will see that since we cannot manipulate them, we have to compensate for rules 1 and 2 somehow, such as absorber. But once we introduce protrusions on to any of the basic shapes, including the sphere and ogive, then planform alignment comes into play.

In radar detection, we do not see a wing as a wing but as a radiator. Same for the canards and this is where you guys rooting for the J-20, and none of you have any aviation experience, are looking at the issue the wrong way. The J-20 planform is not as refined as the F-35 that you sneered at.

As for me, I taught ALL of you what you know about radar detection and 'stealth' without venturing into the 'classified' region. But despite the foundation that I gave you, it looks like integration of components is still problematic for all of you.

Since those magic engineer can control the quantity, array, modes of radiation well on two giant wings of F-22/35, why so difficult on two small canards?

Hi, troller, your $%$ rules are jokes to me: yours rules followed F-22/35, not F-22/35 followed the rules.
Anything F-22/35 have, they are okay.
Anything F-22/35 don't have, they are wrong.

You cannot tell me 'why' simply because you do not know a damn thing about these issues. You probably can barely tell the difference between a hammer and a screwdriver.


How are the F-22 and F-35 are failures ? Based upon what criteria ? You cannot even understand the basics I taught you.

Okay, restart the demolished F-22 lines and send F-22 to Afghanistan, Iraq, Syria, Ukraine, S.Korea, dock them to Europe.
Send F-35 to time machine dated 2000 and fuc* the F-35 one more time.

 

[gambit]

Since those magic engineer can control the quantity, array, modes of radiation well on two giant wings of F-22/35, why so difficult on two small canards?

Hi, troller, your $%$ rules are jokes to me: yours rules followed F-22/35, not F-22/35 followed the rules.
Anything F-22/35 have, they are okay.
Anything F-22/35 don't have, they are wrong.

This is exactly what I mean when I said the Chinese members here simply do not have the smarts to debate this subject.

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.

These rules are not meant to be applicable against individual structures, such as a wing or the cockpit, but against the CONCEPT of the design. What a dope you are.

What this mean is that if I want to design an aircraft that is radar low observable, because this is an aircraft, it must have wings, meaning wings are unavoidable. So if my design have two wings, two rear horizontal stabs, and two rear vertical stabs, I should stop adding on similar structures, ergo: Control of quantity of radiators. Same for any external stores such as missiles. If I enclose the missiles, I just followed the same rule: Control of quantity of radiators.

The F-22 and F-35, the two 'failed' aircrafts according to you, an Internet Chinese who have no aviation experience, each have six major flight control structures. The Chinese J-20 have eight major radiators: pairs of wings, horizontal stabs, vertical stabs, and lower fins. It does not mean the J-20 somehow 'violate' the first rule. It simply mean the J-20 did not follow that rule as well as the F-22 and F-35 did. You cannot 'violate' those rules. You can only follow them to varying degrees.

Okay, restart the demolished F-22 lines and send F-22 to Afghanistan, Iraq, Syria, Ukraine, S.Korea, dock them to Europe.
Send F-35 to time machine dated 2000 and fuc* the F-35 one more time.

We are still waiting for that 'high Chinese IQ' to show.

 

[Genesis]

This is exactly what I mean when I said the Chinese members here simply do not have the smarts to debate this subject.

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.

These rules are not meant to be applicable against individual structures, such as a wing or the cockpit, but against the CONCEPT of the design. What a dope you are.

What this mean is that if I want to design an aircraft that is radar low observable, because this is an aircraft, it must have wings, meaning wings are unavoidable. So if my design have two wings, two rear horizontal stabs, and two rear vertical stabs, I should stop adding on similar structures, ergo: Control of quantity of radiators. Same for any external stores such as missiles. If I enclose the missiles, I just followed the same rule: Control of quantity of radiators.

The F-22 and F-35, the two 'failed' aircrafts according to you, an Internet Chinese who have no aviation experience, each have six major flight control structures. The Chinese J-20 have eight major radiators: pairs of wings, horizontal stabs, vertical stabs, and lower fins. It does not mean the J-20 somehow 'violate' the first rule. It simply mean the J-20 did not follow that rule as well as the F-22 and F-35 did. You cannot 'violate' those rules. You can only follow them to varying degrees.


We are still waiting for that 'high Chinese IQ' to show.

What if the intention was to add maneuverability while reducing some stealth. Maybe the thinking is, radars would pick up both aircrafts roughly the sametime, so with more manuverbility, there be more survivability.

I'm no expert just putting my thoughts out there.

It's just baffling to me to think something so fundamentally wrong could be implemented by Chinese scientists. I mean we are designing a fifth gen, whether we are that good or not we are still doing it, tons of developed nations can't even do it for whatever reason.

 

[Beast]

What if the intention was to add maneuverability while reducing some stealth. Maybe the thinking is, radars would pick up both aircrafts roughly the sametime, so with more manuverbility, there be more survivability.

I'm no expert just putting my thoughts out there.

It's just baffling to me to think something so fundamentally wrong could be implemented by Chinese scientists. I mean we are designing a fifth gen, whether we are that good or not we are still doing it, tons of developed nations can't even do it for whatever reason.

Yup! If someone can make the world fastest super computer. I doubt they will screw up on this thing. Song wencong already mention in his study for adding the canard of J-20.

 

[Nitin Goyal]

which engine will be used in J20 ?

 

[gambit]

What if the intention was to add maneuverability while reducing some stealth. Maybe the thinking is, radars would pick up both aircrafts roughly the sametime, so with more manuverbility, there be more survivability.

I'm no expert just putting my thoughts out there.

It's just baffling to me to think something so fundamentally wrong could be implemented by Chinese scientists. I mean we are designing a fifth gen, whether we are that good or not we are still doing it, tons of developed nations can't even do it for whatever reason.

The canards are not a design flaw. There is nothing 'fundamentally wrong' about them. I have NEVER said the canards are either flawed or wrong on the J-20. Never.

The flaw here is in the thought process on your guys' part. I have to say that, no matter how uncomfortable it may be to you.

An aircraft is an exercise in compromises. The designer is not necessarily a master aerodynamicist or a radar expert or a propulsion guru. Rather, a designer is foremost a manager of ideas and compromises. He must have sufficient experience and knowledge in all major components of an aircraft to know when to call in an expert or guru, and when to tell these experts and gurus that they must accept compromises for the sake of the aircraft's mission. Look at the SR-71, for example. We had plans to turn it into a weapons platform when it was originally designed and built as a recon platform. The weapons idea was a terrible one and a good thing that it was scrapped.

Going back to the J-20 and its canards. If the designer's intent was to have exceptional agility and canards are necessary, he will have the aerodynamicist install the canards in spite of what the radar expert say about effects on RCS. If you insist on believing that the canards are a design flaw, then you have effectively placed the radar expert ahead of the aerodynamicist. This is where you guys went wrong in thinking. You might as well say the wings are design flaws since they are such large radiators.

From conception, you must have control of:

- Quantity of radiators.
- Array of radiators.
- Modes of radiation.

All rules are dynamic depending on the specific areas of the aircraft. When you install absorber to a leading edge or to panel edges where they meet and create small gaps, you just applied rule 3, for example. In other areas of the aircraft where radar bombardment is not possible, then you do not need to apply rule 3. Whatever structures and how they array themselves, as long as they are not exposed to radar, then you do not need to apply any rule.

The canards are NOT design flaws any more than the cockpit, wings, and engine intakes are. You just have to understand that if you install them, you will be less obedient to rule 1 than the designer who created the F-22. I do not know how I can explain this any more basic. It really is puzzling that none of you guys understand this.

 

[SQ8]

The canards are not a design flaw. There is nothing 'fundamentally wrong' about them. I have NEVER said the canards are either flawed or wrong on the J-20. Never.

The flaw here is in the thought process on your guys' part. I have to say that, no matter how uncomfortable it may be to you.

An aircraft is an exercise in compromises. The designer is not necessarily a master aerodynamicist or a radar expert or a propulsion guru. Rather, a designer is foremost a manager of ideas and compromises. He must have sufficient experience and knowledge in all major components of an aircraft to know when to call in an expert or guru, and when to tell these experts and gurus that they must accept compromises for the sake of the aircraft's mission. Look at the SR-71, for example. We had plans to turn it into a weapons platform when it was originally designed and built as a recon platform. The weapons idea was a terrible one and a good thing that it was scrapped.

Going back to the J-20 and its canards. If the designer's intent was to have exceptional agility and canards are necessary, he will have the aerodynamicist install the canards in spite of what the radar expert say about effects on RCS. If you insist on believing that the canards are a design flaw, then you have effectively placed the radar expert ahead of the aerodynamicist. This is where you guys went wrong in thinking. You might as well say the wings are design flaws since they are such large radiators.

From conception, you must have control of:

- Quantity of radiators.
- Array of radiators.
- Modes of radiation.

All rules are dynamic depending on the specific areas of the aircraft. When you install absorber to a leading edge or to panel edges where they meet and create small gaps, you just applied rule 3, for example. In other areas of the aircraft where radar bombardment is not possible, then you do not need to apply rule 3. Whatever structures and how they array themselves, as long as they are not exposed to radar, then you do not need to apply any rule.

The canards are NOT design flaws any more than the cockpit, wings, and engine intakes are. You just have to understand that if you install them, you will be less obedient to rule 1 than the designer who created the F-22. I do not know how I can explain this any more basic. It really is puzzling that none of you guys understand this.

Because the issue remains that people do not see RCS as waves on an electromagnetic spectrum and instead think of it as shapes and objects.

 

[longlong]

This is exactly what I mean when I said the Chinese members here simply do not have the smarts to debate this subject.

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.

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.

These rules are not meant to be applicable against individual structures, such as a wing or the cockpit, but against the CONCEPT of the design. What a dope you are.

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?

We are still waiting for that 'high Chinese IQ' to show.

Above question is too difficult to your minus IQ score.

 

[gambit]

Because the issue remains that people do not see RCS as waves on an electromagnetic spectrum and instead think of it as shapes and objects.

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.

On as complex a body as an aircraft, design flaws are inevitable. The issue is whether the flaw contribute to the system enough to adversely affect whatever principle it is that make up the aircraft. Let us take pneudraulics for example. A deficiency is when the pump can deliver 3000 psi for only 5 hr duration when the customer specified 8 hr duration. The jet can still fly, just not as long, and if the customer can live with that, he will take the jet. However, if he plans to incorporate the jet, with this deficiency, into his cargo delivery business, then the jet itself is a business design flaw because now he has to find some ways to make up that 3 hrs difference that he originally planned for. The hydraulic pump is deficient but does not affect the principles of pneudraulic operation, whereas the jet itself is a business design flaw because it cannot fly as long and as far as the business plan would like and will have an adverse effects on profitability.

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.

 

[longlong]

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.

On as complex a body as an aircraft, design flaws are inevitable. The issue is whether the flaw contribute to the system enough to adversely affect whatever principle it is that make up the aircraft. Let us take pneudraulics for example. A deficiency is when the pump can deliver 3000 psi for only 5 hr duration when the customer specified 8 hr duration. The jet can still fly, just not as long, and if the customer can live with that, he will take the jet. However, if he plans to incorporate the jet, with this deficiency, into his cargo delivery business, then the jet itself is a business design flaw because now he has to find some ways to make up that 3 hrs difference that he originally planned for. The hydraulic pump is deficient but does not affect the principles of pneudraulic operation, whereas the jet itself is a business design flaw because it cannot fly as long and as far as the business plan would like and will have an adverse effects on profitability.

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.

Your sick IQ thought F-22 is stealthy first, then applied all your the said theories.

Like you shoot first, then coil the hole with a score 10.

F-117 got wings, v-tails, your rules worked.
B-2 got wings only, your rules continue worked.
F-22 got wings, H-tabs, V-tails, your magic rules worked perfectly without minor flaws.
There should only have one of above 3 can be marked as Stealth to your radar for they are so different from the other two.

J-20 (compared with F-22, it minimised the main wings to canards, enlarged H-tab to wings) got canards, your rules fully kicked it out.

B-2 is real, F-22 is failed.

 

[danger007]

Your sick IQ thought F-22 is stealthy first, then applied all your the said theories.

Like you shoot first, then coil the hole with a score 10.

F-117 got wings, v-tails, your rules worked.
B-2 got wings only, your rules continue worked.
F-22 got wings, H-tabs, V-tails, your magic rules worked perfectly without minor flaws.
There should only have one of above 3 can be marked as Stealth to your radar for they are so different from the other two.

J-20 (compared with F-22, it minimised the main wings to canards, enlarged H-tab to wings) got canards, your rules fully kicked it out.

B-2 is real, F-22 is failed.

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