China’s J20 Stealth Fighter: Made in America...via Belgrade

[below_freezing]

Not guaranteed does not equal to assurance of otherwise. Look at China's map. Now understand that an air defense radar has at best a couple hundreds km of effective coverage. Now guess how many stations will you need to actually overlap each other in order to have no gaps.


Yes...I have been saying that long before you are a member of this forum.


Yes...I have been saying that long before you are a member of this forum.


Yes...I have been saying that long before you are a member of this forum.

Try something I do not know.


There goes that 'long wavelength' thingie again...You are wrong...They are not 'quite detectable', whatever that mean. The odds of detection increases with increasing wavelengths, but at the cost of target resolutions, such as altitude, speed, and heading. Increased odds does not mean guarantee.


By what do you mean 'optimized'? I usually see people squirm whenever they are asked to detail the 'what' of this 'optimized'. From my experience, the word is often used by people who do not know what they are talking about.


No...The B-2 is not 'optimized' against 'long-wave' freq. These goes that useless word again.

Bottom line is this...An F-117 at night and at below the radar horizon, it can hit Beijing without Chinese air defense radars even registering an 'anomaly'.

What a joke. And the J-20 can bomb the white house to kill Obama since US air defenses share the same weaknesses and aren't even as dense.

 

[gambit]

What a joke. And the J-20 can bomb the white house to kill Obama since US air defenses share the same weaknesses and aren't even as dense.

Not with those flip-flapping canards...

 

[tanlixiang28776]

Not with those flip-flapping canards...

Unless its dogfighting the Canards will be kept aligned and you know that. Is the Canard the only thing you can come up with? The prototype JSF had canards too so they can't have been too bad for stealth.

 

[gambit]

Unless its dogfighting the Canards will be kept aligned and you know that. Is the Canard the only thing you can come up with? The prototype JSF had canards too so they can't have been too bad for stealth.

That is not how canards work. Either they are fixed or they are active flight control elements. If canards are the only things I can come up with, and I have far more related experience in aviation than you boys do, what do you have other than speculations on the J-20's relative comparability to the F-117 or even the F-22? Zilch, other than speculations.

 

[applesauce]

That is not how canards work. Either they are fixed or they are active flight control elements. If canards are the only things I can come up with, and I have far more related experience in aviation than you boys do, what do you have other than speculations on the J-20's relative comparability to the F-117 or even the F-22? Zilch, other than speculations.

is the USAF less experienced than you also? they went far enough as to make actual prototypes of VLO planes featuring canards even if they eventually dropped it it does mean that its workable, maybe not F-22 level of signature but workable with careful management. and please let us know more about these "other" things you can come up with.

and what do you have other than "speculations on the J-20's relative comparability to the F-117 or even the F-22? Zilch, other than speculations". what allows you to say it cant fly over Washington? and what do you have other than "speculations on the" F-117's capabilities against modern sam systems such as the S-300 and the HQ-9 and lets not say it will avoid them as these systems are mobiles and their locations strictly secret and of course Beijing will be covered by the best china has

 

[gambit]

is the USAF less experienced than you also? they went far enough as to make actual prototypes of VLO planes featuring canards even if they eventually dropped it it does mean that its workable, maybe not F-22 level of signature but workable with careful management.

This is where the issue of canards are so misleading when it comes to radar cross section (RCS) control. In designing a complex body where we want to have equal importance between aerodynamic necessities and low RCS, it is possible to have an active flight controls elements in the fore of this complex body but we have to do so with the understanding that under certain conditions, the body's RCS may rise above a certain threshold because of those active FLCS elements.

Take a look at these examples...

Nowhere in them will you see the airliners' passenger windows. But does that mean they do not exist? The dominant energy spikes are from corner reflectors and I think everyone here should know about them by now since I have spoken enough of them. The final RCS value is a sum of many smaller RCS values so even if we can do 'something', either physically or virtually, to remove the larger physical structures that created those high energy spikes, smaller physical features such as passenger windows will still make the aircraft rise above a certain threshold. The graphs will just have a more uniform distribution of 'bumps'.

For the J-20's canards, they will be just like the airliners' passenger windows in that they will not stand out like those corner reflectors but they will be contributors that will make smaller 'bumps' like the ones above.

and please let us know more about these "other" things you can come up with.

Just did...

...and what do you have other than "speculations on the J-20's relative comparability to the F-117 or even the F-22? Zilch, other than speculations". what allows you to say it cant fly over Washington? and what do you have other than "speculations on the" F-117's capabilities against modern sam systems such as the S-300 and the HQ-9 and lets not say it will avoid them as these systems are mobiles and their locations strictly secret and of course Beijing will be covered by the best china has

I do not have such speculations. If I say the F-117 can fly undetected into China's electronic space, it is because I believe it and that conviction is based upon direct experience.

 

[S10]

.For the J-20's canards, they will be just like the airliners' passenger windows in that they will not stand out like those corner reflectors but they will be contributors that will make smaller 'bumps' like the ones above.

Northrop was comfortable enough to put forward a proposal for NATF with canard control surfaces. Certainly it will affect signal return, but they deemed it acceptable price to pay its intended benefit. The canard is not even in line with the wing, getting full reflection of both main wing and canard from the frontal aspect.

I do not have such speculations. If I say the F-117 can fly undetected into China's electronic space, it is because I believe it and that conviction is based upon direct experience.

Based on direct experience with a military that operated out of date sensors and suppressed by other support aircrafts. Based on the experience of security breach at the WH, I believe I could drive a monster truck in and slap the POTUS without being caught too. I think I got a pretty good chance of success too.

We all believe things we want to believe. Whether those opinions will prove true is another matter.

 

[gambit]

Northrop was comfortable enough to put forward a proposal for NATF with canard control surfaces. Certainly it will affect signal return, but they deemed it acceptable price to pay its intended benefit. The canard is not even in line with the wing, getting full reflection of both main wing and canard from the frontal aspect.

I have no problems repeating myself about this. Previous designs may incorporated canards but why are they not production model? The issue is not merely the interactions between diffracted signals onto other structures, the issue ALSO concern on whether that interactions will raise the aircraft above a certain threshold. You and the others are under the false impression that 'stealth' is a set figure or a line that is universal. That is not true. Technically speaking, there is no such thing as 'stealth' even if the word is casually used by engineers. If alternative designs that do not include canards are found to have a lower RCS value than those with canards, and even if all designs are below that certain threshold, which would anyone with common sense chose? The ones without.

 

[S10]

I have no problems repeating myself about this. Previous designs may incorporated canards but why are they not production model? The issue is not merely the interactions between diffracted signals onto other structures, the issue ALSO concern on whether that interactions will raise the aircraft above a certain threshold. You and the others are under the false impression that 'stealth' is a set figure or a line that is universal. That is not true. Technically speaking, there is no such thing as 'stealth' even if the word is casually used by engineers. If alternative designs that do not include canards are found to have a lower RCS value than those with canards, and even if all designs are below that certain threshold, which would anyone with common sense chose? The ones without.

No one here stated there is a figure to be considered LO, except you. Signal return varies according to multiple factors, and none doubted that canards would increase a plane's signature. The question is whether or not the added benefits of canard would justify its disadvantages. If both conventional and canard designs can satisfy requirement set forth by the military, which do you think they pick?

Obviously, Northrop put forward the proposal because they considered that it met NATF requirements. Same case with CAC presenting J-20 to Chinese military.

 

[gambit]

No one here stated there is a figure to be considered LO, except you.

Wrong...Nowhere have I ever stated such a figure. Usually I brought up the one meter square of a clean F-16 at 100km as a guide. I guess when all else failed, make up a false charge.

Signal return varies according to multiple factors,...

Que? Tell me something I do not know.

..and none doubted that canards would increase a plane's signature. The question is whether or not the added benefits of canard would justify its disadvantages. If both conventional and canard designs can satisfy requirement set forth by the military, which do you think they pick?

Obviously, Northrop put forward the proposal because they considered that it met NATF requirements. Same case with CAC presenting J-20 to Chinese military.

Bad argument. If a set of requirements are satisfied by competing designs, then it would not be a matter of canards or not because the canard-ed design was clearly done 'right' as far as meeting the low radar observability requirement. There would be no 'disadvantages' at all. It would be a matter of cost so no one would be able to say which would be chosen.

 

[S10]

Wrong...Nowhere have I ever stated such a figure. Usually I brought up the one meter square of a clean F-16 at 100km as a guide. I guess when all else failed, make up a false charge.

You were the one stating I and others believed there was a figure or line to be considered LO. Now you accuse me of making up a false charge?

Oh the irony....

Que? Tell me something I do not know.

Conventional layout was also present in J-20 program, not selected.

Bad argument. If a set of requirements are satisfied by competing designs, then it would not be a matter of canards or not because the canard-ed design was clearly done 'right' as far as meeting the low radar observability requirement. There would be no 'disadvantages' at all. It would be a matter of cost so no one would be able to say which would be chosen.

Your argument is invalid. There is no design without its perks and drawbacks. If a design met one particular criteria and the other exceeded the criteria, does not mean that the former is an overall inferior design. LO is not the only factor in J-20's selection, same with NATF.

 

[gambit]

You were the one stating I and others believed there was a figure or line to be considered LO. Now you accuse me of making up a false charge?

Oh the irony....

I have read enough about 'full stealth' or 'partial stealth' or variations thereof from all corners. Ironic indeed. The words 'full' and 'partial' is clearly based upon a figure or a line or at least a perception that there is a universal standard.

Conventional layout was also present in J-20 program, not selected.

Do not care.

Your argument is invalid. There is no design without its perks and drawbacks. If a design met one particular criteria and the other exceeded the criteria, does not mean that the former is an overall inferior design. LO is not the only factor in J-20's selection, same with NATF.

My argument is very valid in that it is based upon a set of requirements. If all competing designs meet requirements, in no way did I said that all are the same or perfect. The question is not about exceeding requirement. The question is about MEETING them, as in your words: 'set forth by the military'. Did you not say that? But even if one design exceed requirements, the cost of that excess may keep it out of contract.

 

[amalakas]

You were the one stating I and others believed there was a figure or line to be considered LO. Now you accuse me of making up a false charge?

Oh the irony....
.

I don't usually (if ever) rush in Gambit's defence, but he never mentioned a clear figure, he just said that some US designs are below the Radar threshold rejection region.

I can make a radar that detects rain drops (tiny aren't they?) (in fact we have these),

that radar would likely pick an F22 up.. would anyone be able to tell a supersonic "rain drop" from a real one ?
and besides .. it is the software that makes the radar return meaningful.. if the aircraft's signature cannot be classified by the software .. the plane might as well not be there...

 

[S10]

I have read enough about 'full stealth' or 'partial stealth' or variations thereof from all corners. Ironic indeed. The words 'full' and 'partial' is clearly based upon a figure or a line or at least a perception that there is a universal standard.

Where is this "full stealth" and "partial stealth" argument you've accused me of making?

Do not care.

I know what you mean. I get the same feeling whenever American officials say something.

My argument is very valid in that it is based upon a set of requirements. If all competing designs meet requirements, in no way did I said that all are the same or perfect. The question is not about exceeding requirement. The question is about MEETING them, as in your words: 'set forth by the military'. Did you not say that? But even if one design exceed requirements, the cost of that excess may keep it out of contract.

When the military set forth requirements for LO, does logic not dictate the design that exceeded the requirement have advantage over the one that only met it? It does not mean that the canard design was overall inferior, just in that particular criteria it is less capable compared to its competitor. Obviously CAC saw merits in a canard design, and so did Northrop when they bid for NATF.

 

[S10]

I don't usually (if ever) rush in Gambit's defence, but he never mentioned a clear figure, he just said that some US designs are below the Radar threshold rejection region.

I can make a radar that detects rain drops (tiny aren't they?) (in fact we have these),

that radar would likely pick an F22 up.. would anyone be able to tell a supersonic "rain drop" from a real one ?
and besides .. it is the software that makes the radar return meaningful.. if the aircraft's signature cannot be classified by the software .. the plane might as well not be there...

If you've read his post #83 carefully, he trumps up a charge that I and others believe there was a magical figure or line that is needed to be considered LO. I am still waiting for him to present the evidence where I said anything remotely about "partial" or "full" stealth.