Shenyang FC-31 / J-31 Fighter Demonstrator

SinoSoldier

Colonel
Strangely enough, China would be imbecilic not to put the J-31 into at least limited service. It's essentially an F-35 knockoff, the primary opponent of the J-20. The J-31, if upengined and gold-plated for DACT purposes, would make a great pseudo-F-35 for the J-20 to practice with. It is an aircraft designed for purer stealth than the J-20, and can help train J-20 pilots to dominate the F-35.

Not to mention that it could still be useful as a "low" 5th generation aircraft.
 

Iron Man

Major
Registered Member
Strangely enough, China would be imbecilic not to put the J-31 into at least limited service. It's essentially an F-35 knockoff, the primary opponent of the J-20. The J-31, if upengined and gold-plated for DACT purposes, would make a great pseudo-F-35 for the J-20 to practice with. It is an aircraft designed for purer stealth than the J-20, and can help train J-20 pilots to dominate the F-35.
Wow, how can you even make this claim with the large number of photos from every angle that we now have of the J-31?

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Skipping the obvious difference of one vs two engines, which alone would alter the entire design of the plane past the air intakes, you also have a smoother underbelly on the J-31 with much smaller wing roots than the F-35. The horizontal stabilizers on the J-31 are shaped differently and are much smaller while its vertical stabilizers are much bigger and also shaped differently. The wings are also shaped differently with the J-31 having a greater taper towards the sides (less clipped); the wings also sit more forward on the fuselage than on the F-35. the air intakes are shaped differently, with the J-31's being more flared outwards than the F-35's. The dorsal spine is more pronounced/less blended on the J-31. The nose undercarriage sits significantly more forward on the F-35. Looking from underneath you can tell that even the design of the nose section is different, especially as it tapers to its most forward point. They look roughly like each other, but saying the J-31 is a knockoff of the F-35 is as accurate as saying the Toyota Corolla looks like the Honda Civic. Close, but no cigar.
 

ougoah

Brigadier
Registered Member
I guess people will see the strong similarity in the shape of the radome, intake position and DSI intakes and believe it's a 1:1 carbon copy. In reality the designs are close and Chinese engineers did have a look at how the Americans approached the problem of designing for VLO. I will wager that other future players in VLO will come to the same conclusions in optimal designs and come out with exactly the same overall designs IFF they can even do it in a few decades. Chances are it'll just be China and USA (maybe S.Korea). Even Russia failed to come up with a properly shaped stealth fighter. Let's see how their next gen bomber and interceptor looks when they are revealed. China is great at copying, stealing, reverse engineering... whatever you want to call it, great ideas and modifying them accordingly. Haters can hate but ALL humans have been doing this for millenia so they can hate on all Chinese people for doing it and dwell in their misery all they want. We'll make our money and build up our empire while they suffer in jealousy and lose out after believing in their false superiority and silly pride. Reinventing the wheel and making it square like the Indians.
 

Iron Man

Major
Registered Member
I guess people will see the strong similarity in the shape of the radome, intake position and DSI intakes and believe it's a 1:1 carbon copy. In reality the designs are close and Chinese engineers did have a look at how the Americans approached the problem of designing for VLO.
Only the amateurs who don't like to bother with the details. I'll wager an actual designer would come to a different conclusion. At best you can say the J-31 is "inspired by" the F-35, as it probably was. The external shape is generally similar, but that is where the similarities end. The radome is certainly not a carbon copy; all of the stealth fighter nose sections are very similar but none are identical. The intake position is also similar among the J-31, J-20, F-22, and F-35; all are side (as opposed to chin) intakes that begin at the rear of the cockpit. The DSI was pioneered by the J-20, not the J-31, so nothing was needed to be taken from the F-35. When I think of "carbon copy" I think of the J-11B or the Y-8, and even then the Chinese versions incorporate some changes and improvements.

China is great at copying, stealing, reverse engineering... whatever you want to call it, great ideas and modifying them accordingly. Haters can hate but ALL humans have been doing this for millenia so they can hate on all Chinese people for doing it and dwell in their misery all they want. We'll make our money and build up our empire while they suffer in jealousy and lose out after believing in their false superiority and silly pride. Reinventing the wheel and making it square like the Indians.
Yes China like all countries has copied, stolen, and reverse engineered.... except in this case. People like to point to the terabytes of data stolen from some Lockheed Martin subsidiary many years ago as evidence of J-31 copying the F-35, except that even if it was China who did the stealing, all the stolen material was deemed to be unclassified. There is no direct or even indirect lineage of the J-31 from the F-35 like there was the J-11B from the Su-27.
 

Inst

Captain
You concentrate on the differences between the F-35 and the J-31, but I concentrate on the similarities. If you compare the two in terms of silhouettes, they're actually quite similar. Both have swept-back tailfins, both use horizontal stabilizers, etc...

The disadvantage of the J-31 is primarily in its lack of IR sensors. Its advantage lies in its lighter construction and presumably better maneuverability, having a wing area 25% larger than the F-35, and being slated to TVC, which the F-35 will never have.

The J-20 is a good match for the F-35, stealth vs stronger radar, maneuverability versus subsystems, but the J-31 vs the F-35 leaves the J-31 pilot maneuverable, but blind. The J-20 can expect to jam the F-35's radar based simply off its larger radar aperture, but if the J-31 has an advantage, it's relatively small and could turn into a disadvantage due to the difference in technology levels.

That said, don't behave like a snowflake. There's way too many similarities between the F-35 and J-31, but I think Bill Sweetman did praise the latter by saying it's a "fixed" F-35.
 
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