J-20 5th Gen Fighter Thread VIII

taxiya

Brigadier
Registered Member
It's noteworthy how the J-35 has a spine like the J-20A, and quite unlike the baseline J-20.
Because J-35, J-35A and J-20A are based on the same recent research outcome. That paper that circulated on the net was about J-35 but AVIC has dedicated research unit working on aerodynamic principles in the same way as Soviet Union, there is no reason that their research work is only used by SAC. This is one of the reasons that there is no reason to believe that J-20A is anything behind J-35A in terms of latest technology development.
 

GiantCanofWater

New Member
Registered Member
Do you guys know how the J-20 compares to the F-35 and F-22? Every time I see someone talk about the J-20 online they always say it’s RCS is the size of a dump truck and it would get eaten by an F-35. But I don’t understand, how do they even know the RCS?? Did they scan it themselves? I figured since China got the F-35 documents a long time ago its stealth should be close? Since you guys are more knowledgeable what are your opinions?
 

SinoAmericanCW

Junior Member
Registered Member
Do you guys know how the J-20 compares to the F-35 and F-22? Every time I see someone talk about the J-20 online they always say it’s RCS is the size of a dump truck and it would get eaten by an F-35. But I don’t understand, how do they even know the RCS?? Did they scan it themselves? I figured since China got the F-35 documents a long time ago its stealth should be close? Since you guys are more knowledgeable what are your opinions?
There's some open-source modeling that suggests the J-20's RCS is higher than that of the F-35, albeit still meaningfully lower than that of the Su-57. Said modeling only takes shaping into account, however, whereas in practice RAM will significantly reduce RCS, far beyond what can be achieved just via shaping.

Given that the J-20 was China's first VLO platform, one designed in the 2000s to boot, I admittedly do think it's plausible that its RCS is higher than that of its U.S. counterparts. How large the difference is, and how operationally significant said difference would be, is very much an open question.

The idea that it would "get eaten" by the F-35, however, is fanciful.
 

valysre

Junior Member
Registered Member
Every time I see someone talk about the J-20 online they always say it’s RCS is the size of a dump truck and it would get eaten by an F-35.
These people can judge the RCS of the J-20 by eye about as well as I can judge a person's IQ by the shape of their cranium. That is to say, not well. Although, if I knew that the cranium I was looking at belonged to one of these people, I'd be able to confidently say: 'low'.

Ignore them. China has a large number of supercomputers; they've surely spent at least a few thousand computation hours running RCS calculations on the J-20s shape. If they've settled on it, it can't be too bad. It at least must have challenged the detection capabilities of in-service radars in use at the time. So definitely not a dump-truck.

Remember, these are the same people who think that the B-1B has an RCS of less than 1 cm^2.

By the by, if any of these claims came from the r/LazerPig subreddit, do yourself a favor and stop going there. Nothing but trash there.
 
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latenlazy

Brigadier
But I don’t understand, how do they even know the RCS??
They don’t. Don’t believe everything you read on the internet. And try not to turn these threads into online clout contests. There is a difference between informed conversation for the sake of learning and information harvesting for the sake of collecting trophies and talking points to win dumb and pointless self esteem wrestling matches.
 
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tamsen_ikard

Senior Member
Registered Member
Do you guys know how the J-20 compares to the F-35 and F-22? Every time I see someone talk about the J-20 online they always say it’s RCS is the size of a dump truck and it would get eaten by an F-35. But I don’t understand, how do they even know the RCS?? Did they scan it themselves? I figured since China got the F-35 documents a long time ago its stealth should be close? Since you guys are more knowledgeable what are your opinions?

According to open source simulations of shaping, J-20 indeed has slightly worse RCS than F-35. Stealth is 90% shaping and the rest RAM coating. Moreover, J-20 is bigger than F-35. The bigger the plane, the bigger the RCS will be naturally. So, I think it can be reasonably said that F-35 has smaller RCS than J-20.

But because J-20 is bigger, it has more power, more space to have a bigger radar and bigger EW capabilities. It also has a bigger so I guess superior IRST.

So, even if F-35 has smaller RCS, there is strong chance J-20 will detect F-35 earlier or almost the same time.

BVR combat is ofcourse more than just who detects who first. It also depends on tactics, numbers, terrain and many other factors. J-20 also has a bigger missile bay which can hold bigger missiles with more Range/No Escape zone. So, that can also determine who can shoot who first.

There is also a final factor which is J-20 has a canard delta design with a very narrow wing. Which means it will have much better supersonic speed and manuverability. Which should mean it will be a better dog fighter and also better at dodging BVR missiles.

Overall, I consider J-20 to be superior AA fighter to both F-35 and F-22.

J-20 also has a bigger range than both. So, overall China basically min-maxed to the fullest with J-20, making some compromises but overall a superior plane when all factors are considered.
 
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