J-20 5th Generation Fighter VII

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zyun8288

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No one else has tried to do better because it’s an irrelevant exercise.

All his original analysis did was look at the external shape of the J20. But as anyone with even rudimentary understanding of stealth will tell you, everything from internal structures to the use of RAM and radar transparent composites all work together to give you the final outcome.
Agree. And the result is my point, all of those DT professionals can not do anything better than Dr Carlo did 10 years ago.

So can they still claim they know better about J20’s RCS?
 

Tirdent

Junior Member
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All his original analysis did was look at the external shape of the J20. But as anyone with even rudimentary understanding of stealth will tell you, everything from internal structures to the use of RAM and radar transparent composites all work together to give you the final outcome.

As such, while his work could provide a basement level worst possible case baseline for how stealthy the J20 was if China just made it out of standard untreated metal and only applied external shaping, so from a practical point of view is almost useless.

Anyone with a rudimentary understanding of stealth? Somebody like, for instance, one Denys Overholser?

Stealth: The Secret Race to Invent an Invisible Airplane said:
But for most of the airplane, especially the exterior, the key advance was not materials but rather geometry. As Overholser put it, the [four] most important factors for shedding radar were "shape, shape, shape and materials"

So who is this guy? None other than Ben Rich's right-hand man for RCS reduction at the Lockheed Skunk Works during development of the F-117. The famous discovery of Pyotr Ufimtsev's work which enabled the shaping of that aircraft to achieve hitherto unheard-of stealth characteristics was his.

About the same time, Overholser's opposite number at XST programme competitor Northrop, John Cashen, came to a similar conclusion, from a slightly different perspective:

Stealth: The Secret Race to Invent an Invisible Airplane said:
As a result of all his work on missile defense, Cashen had received a thorough grounding in radar scattering and radar cross sections. And he knew what many aircraft designers did not know because of classification: that radar scattering theory had already been applied to actual airborne craft, including the Mark 12 reentry vehicle and the SRAM missile - and, further, that those vehicles had achieved remarkable reduction in radar cross section not through radar absorbing material but from the shape of the vehicle itself.

And if you think about it logically, circumstantial evidence for this principle of shaping over materials abounds in the configuration and testing of modern LO aircraft. Tests for optimization of shaping are done with all-metal (no RAM, or even any effort to match the construction of the real airframe) models like this one:

Newark_MDC_MFVT.jpg
(MDD/BAe JAST/pre-JSF layout, if memory serves)

More to the point, if composite materials were so important, how come the majority-CFRP Typhoon does not achieve a lower RCS than the mostly metal F-117?

Typhoon_materials.jpg

F-117_TO_00-105E-9_Rev11_Segm12_Ch8_p39.png

While we're at it, why would you accept serious restrictions on major aerodynamic parameters such as wing/tail sweep angles (planform alignment) and structural design (internal bays, with all their weight penalties) if you could simply smother a conventional aircraft in RAM?

The fact of the matter is, shaping is the primary determinant of an aircraft's RCS, the objective being to concentrate reflection of incident RF energy into sectors too narrow for enemy radars to exploit. These spikes/hotspots (intakes, leading edges) are then treated with RAM to further improve survivability, but by analyzing the mere shape you can definitely deduce very valuable information about a LO aircraft! You can criticize the 3D model Kopp used as guesstimated and obsolete (IIRC it is based on the J-20 demonstrator configuration with different intakes, curved LERX and uncropped trailing edges), but the method is perfectly valid.

Last but not least, while he undeniably has biases and questionable opinions on certain subjects outside his area of expertise, Kopp is an RF engineer by education... Although I'd take his views on other aspects of fighter design with a large dose of salt, on the particular topic of stealth he is probably better qualified to comment than the vast majority of indeterminate "ex-military" people.
 
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by78

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parts shown again at Zhuhai, implied to be related to J-20.

51577813042_34d68d29e9_k.jpg

51579307989_ec249ecd22_k.jpg
 

Yodello

Junior Member
Registered Member
The J20 is such a beautiful Plane, and it looks quite menacing at the same time.
Despite what the naysayers say, the J20 gives the PLAAF the edge over all other Air Forces outside of the US Military, it also gives a chance to balance the Airpower against the US Military. Newer iterations, with incremental improvements, will make it even more powerful within half a decade to a decade.

Putting together the J20, along with the J16, J16D and the J10B and J10C, and also with the CATOBAR J15, the PLA Airpower is taking a monumental leap.
I believe that with the J16, the PLA has overtaken even the US in conventional Fighters.
All that is needed is to built the J20 in greater numbers, to achieve parity in stealth fighters

It is truly staggering, the level of qualitative and quantitative leap that China has taken in its Airpower. Too many people cannot grasp the reality and come to terms, or simply refuse to believe, the sheer strength and capability of the PLA Airpower. Even more astonishing and deserving of respect, is the fact that these are all indigenous, all built in-house.
 

Yodello

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The J20 is such a beautiful Plane, and it looks quite menacing at the same time.
Despite what the naysayers say, the J20 gives the PLAAF the edge over all other Air Forces outside of the US Military, it also gives a chance to balance the Airpower against the US Military. Newer iterations, with incremental improvements, will make it even more powerful within half a decade to a decade.

Putting together the J20, along with the J16, J16D and the J10B and J10C, and also with the CATOBAR J15, the PLA Airpower is taking a monumental leap.
I believe that with the J16, the PLA has overtaken even the US in conventional Fighters.
All that is needed is to built the J20 in greater numbers, to achieve parity in stealth fighters

It is truly staggering, the level of qualitative and quantitative leap that China has taken in its Airpower. Too many people cannot grasp the reality and come to terms, or simply refuse to believe, the sheer strength and capability of the PLA Airpower. Even more astonishing and deserving of respect, is the fact that these are all indigenous, all built in-house.
Just wanted to add...........

Even in terms of Naval surface combatants, with the Type 055 and the Type 052D, I believe the PLAN has equaled or surpassed the USN in terms of the Technological capability, and only the numbers remain to be ramped up.

Currently, I believe it is only the USN Nuclear Submarine fleet that is ahead of the PLAN.

Also, when the CATABOR J15 comes online, with it's full potential payload, it will suddenly become the most powerful carrier-borne Fighter. Add a smaller stealth Fighter alongside it, and it becomes almost insane.

Even in the Aircraft carrier department. with the Type 003, the PLAN has all the bells and whistles in terms of Technology, it is only the sheer number of USN Aircraft carriers that is currently giving the USN the edge.
I am wondering what it will be like 20 years from now...o_O
 
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Deino

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