What is up with the J-31?

[gunnut]

I don't see a thread on this. Seems like a shocking development. The Chinese has a copy of the F-35.

OMG OMG OMG WE ARE ALL DOOMED. DOOOOOOOOOOOMMMMED!!!

[DonBelt]

Hope they copied all the delays and cost over-runs too!

[Chunder]

Hope they just plug n play all that bait code left lying around and they've been hoovering up... lol.

Awww shucks.

[SteveDaPirate]

Sounds like the Chinese may have copied a few things such as the exterior shape in particular, but the J-31 is clearly significantly different than the F-35. Perhaps the most glaring is the fact that it is a twin engine design. It apparently uses stealth coatings as opposed to the F-35's fiber mat, but like the F-35C appears to be designed to operate off a carrier. Overall the J-31 looks like it is shaping up to be a very solid 4.5 gen fighter.

What I haven't seen from the J-31, and what is arguably the most important development of the F-35 program is the massive focus on better sensors and communication along with sensor fusion.

And let's not forget the trashcan sized laser that is in the works. The A and C models have a very convenient spot to drop it in where the lift fan would be on the B model. And the F-135 engine is clearly designed to offload significant power to that specific spot on the aircraft. If you want to look at significant developments on the F-35, I think the sensor suite and the upcoming laser will be a much bigger leap than just another stealth fighter.

[Skywatcher]

Sounds like the Chinese may have copied a few things such as the exterior shape in particular, but the J-31 is clearly significantly different than the F-35. Perhaps the most glaring is the fact that it is a twin engine design. It apparently uses stealth coatings as opposed to the F-35's fiber mat, but like the F-35C appears to be designed to operate off a carrier. Overall the J-31 looks like it is shaping up to be a very solid 4.5 gen fighter.

What I haven't seen from the J-31, and what is arguably the most important development of the F-35 program is the massive focus on better sensors and communication along with sensor fusion.

And let's not forget the trashcan sized laser that is in the works. The A and C models have a very convenient spot to drop it in where the lift fan would be on the B model. And the F-135 engine is clearly designed to offload significant power to that specific spot on the aircraft. If you want to look at significant developments on the F-35, I think the sensor suite and the upcoming laser will be a much bigger leap than just another stealth fighter.

There's also a photo of the J-31 in a wind tunnel from 2000-2002 (or rather, the larger design concept from SAC that lost out to the J-20, and the J-31 was subsequently based on). The MiG people also said J-31 was an indigenous Chinese design, and the Russians as a rule usually aren't too flattering to Chinese aviation.

[Stitch]

One thing that struck me is the fairly small size of the radome; not really a whole lot of room to house a decent AESA radar array in there. Looks like it's more suited size-wise to a ground-mapping radar, rather than an A-to-A radar (although, looking at it, the F-22's radome isn't much bigger).

[citanon]

One thing that struck me is the fairly small size of the radome; not really a whole lot of room to house a decent AESA radar array in there. Looks like it's more suited size-wise to a ground-mapping radar, rather than an A-to-A radar (although, looking at it, the F-22's radome isn't much bigger).

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I think this is still more at the development stage of the X-35 than the F-35. The outlines look too clean. By the time you get a working aircraft, you are going to have all kinds of weird bumps and apertures for things that actually let a multi-role fighter do its work.

Either they are going to spend years engineering those things in, or the J-31 and its cousin are going to be significantly less capable than the F-22 and F-35.

On the other hand, one can imagine the heartburn the Coalition air commander is going to have if a dozen or so of these things or the J-20 take off and head to god knows where. Then he has to task scores of F-35s to look for and defend against them, all the while cursing the name of Gates for killing the F-22. I would wager a fair penny that scenario is a significant part of the motivation for the Chinese stealth fighters.

[Stitch]

Then he has to task scores of F-35s to look for and defend against them, all the while cursing the name of Gates for killing the F-22. I would wager a fair penny that scenario is a significant part of the motivation for the Chinese stealth fighters.

Yeah, I would much rather go up against a J-20/21 in an F-22 rather than an F-35; the F-35 may have a (slightly) better sensor suite, but the F-22 has the muscle to back it up.

[citanon]

Yeah, I would much rather go up against a J-20/21 in an F-22 rather than an F-35; the F-35 may have a (slightly) better sensor suite, but the F-22 has the muscle to back it up.

To be honest I think the real issue is how much real-estate each F-35 can cover versus F-22. With the supersonic dash speed and high altitude perch of the latter, you'd need fewer aircraft to do an effective defense or search, freeing up sorties for offensive operations.

[Stitch]

To be honest I think the real issue is how much real-estate each F-35 can cover versus F-22. With the supersonic dash speed and high altitude perch of the latter, you'd need fewer aircraft to do an effective defense or search, freeing up sorties for offensive operations.

Yes, I can see an additional 15,000' being relevant (50,000' for the F-35 vs. 65,000'+ for the Raptor).

[Jimmy]

I really think you guys are putting a lot of stock in the stealth capabilities of a country that's releasing its first attempts at the tech.

[SteveDaPirate]

I really think you guys are putting a lot of stock in the stealth capabilities of a country that's releasing its first attempts at the tech.

The fact that they are still using the stealth coatings rather than the fiber mat seems like it will be a real pain to maintain.

[Double Edge]

The fact that they are still using the stealth coatings rather than the fiber mat seems like it will be a real pain to maintain.

I read somewhere that the bolts need to be tight (whatever that means) otherwise it gives off a bigger radar signature.

[Jimmy]

Well bolts need to be tight otherwise everything falls apart. But they need to be countersunk for aerodynamics and to avoid reflecting radar.

[FJV]

For this plane the Chinese will have to make similar design trade offs anyone will have to make when developing a stealth aircraft.
(You allow one aspect of the plane to be worse, in order to improve another aspect of the plane)

Likely their stealth technology is not as good as the US's so those trade offs will be more severe and problematic.
So the aspects of the plane the choose to be "not as good" may be worse than those of an US stealth design making the same trade off.
Also the aspects of the plane the choose to be "improve" may be not as good as those an US stealth design making the same trade off.

IMHO this is about all the airplane fanboys cannot handle about of design trade offs with regard to stealth.

The really nasty suprise will be that the Chinese and Russians will have plane with similar characteristics as US stealth planes as a benchmark to test and train their air defense against.
The missile installation has to be able to track a J-31 at a range of 200km in order to track a F-22 at a range of 100km kind of stuff.
So when the shit hits the fan, they will know how to handle a stealth aircraft.