Shenyang FC-31 / J-31 Fighter Demonstrator

Deino

Lieutenant General
Staff member
Super Moderator
The biggest problem with the J-31 is that they went budget and skipped the EODAS. If they kept the EODAS, the J-31 could have been a nice F-35 clone to offset the F-35's capability.
Pardon, but why should an omitted EODAS - IMO barely useful or necessary in a factory financed demonstrator project - be "the biggest problem", when otherwise no decent engine is available, the PLA itself is at least officially not 100% committed and as such it's future simply insecure?
 

Inst

Senior Member
I don't like the J-31 platform, if the Chinese had to knock off an American aircraft, the YF-22 would have been a better choice. The F-22 / F-35 aerodynamics are old hat and force the J-31 to either outnumber its rivals or chase the F-35 in a tech race it has difficulty winning.

The J-31 lacking EODAS puts the J-31, likewise, in a situation where it's committed to outnumbering the F-35. The Chinese, if they have to go with a middleweight fighter, are better off using a pure stealth platform instead of just trying to match the F-35.

As to engines, the J-20 is intended to work with WS-10. The J-31 needs the WS-19 to work propoerly, which isn't a problem as the J-20 would hold the line for it.

As for other concerns, if the J-31 is cancelled I wouldn't care.
 

donnnage99

Just Hatched
Registered Member
The vertical stabs have a very high off centerline angle, almost like a V-tail, not so steep as the YF-23, but much steeper than the F-22/F-35, no doubt to cut RCS, although the FC-31 has a conventional horizontal stabilizer.
Having horizontal stabilizer is more reason to have steeper angle for vertical stabs as far as RCS is concerned, since you want to get as far away from creating a 90 degree angle cavity as possible.
 
I don't like the J-31 platform, if the Chinese had to knock off an American aircraft, the YF-22 would have been a better choice. The F-22 / F-35 aerodynamics are old hat and force the J-31 to either outnumber its rivals or chase the F-35 in a tech race it has difficulty winning.

The J-31 lacking EODAS puts the J-31, likewise, in a situation where it's committed to outnumbering the F-35. The Chinese, if they have to go with a middleweight fighter, are better off using a pure stealth platform instead of just trying to match the F-35.

As to engines, the J-20 is intended to work with WS-10. The J-31 needs the WS-19 to work propoerly, which isn't a problem as the J-20 would hold the line for it.

As for other concerns, if the J-31 is cancelled I wouldn't care.
the SDF "nonsense of the day post"

#1 while you are certainly entitled to your opinion, (opinions are like butt holes, everybody has one), I rather doubt AVIC really cares what you think? Its possible that AVIC might value the opinion of one or two of our posters?? Mr. Deino perhaps?? has an opinion that might bear some interest to AVIC, and an audience? he is often, though not always, polite enough to be encouraging and kind in his assessments?

I guess from your perspective, China should ask LockMart to build a plant in China??? LOL your could say that the F-22 was Dr. Songs Muse, and the F-22 inspired the good Dr. to build the ultimate Chinese fighter aircraft?
 
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Inst

Senior Member
Especially this part is most strange?!!



Either it is a typo and you meant YF-23 or it makes even less sense. :confused::p
YF-23, of course. You're looking at a compromised stealth canard supercruiser that's going to be complemented by a somewhat stealthier cheap plane. The YF-23 is stealthier than the YF-22 that replaced in, on a planform level, and the F-35 is a derivative of the YF-22 design.

The choice comes out to less stealth, stealthy, and stealthier, and if you want to complement a lower VLO design, you're better off choosing a high VLO design to compensate instead of simply trying to match the F-35.

Put another way, the F-35 goes subsonic and quiet to detect enemy fighters (flying mine tactic). The J-20 can do so, but not as well due to its size, but it's an expensive platform and every J-20 that does so is a sort of waste. The J-31 is going to end up fulfilling this role, but the J-31 can, at best, only match the F-35 in doing so. A J-31 based on the YF-23, on the other hand, can fulfill this role better than the F-35 without needing to resort to having better stealth materials technology.
 
I don't like the J-31 platform, if the Chinese had to knock off an American aircraft, the YF-22 would have been a better choice. The F-22 / F-35 aerodynamics are old hat and force the J-31 to either outnumber its rivals or chase the F-35 in a tech race it has difficulty winning.

The J-31 lacking EODAS puts the J-31, likewise, in a situation where it's committed to outnumbering the F-35. The Chinese, if they have to go with a middleweight fighter, are better off using a pure stealth platform instead of just trying to match the F-35.

As to engines, the J-20 is intended to work with WS-10. The J-31 needs the WS-19 to work propoerly, which isn't a problem as the J-20 would hold the line for it.

As for other concerns, if the J-31 is cancelled I wouldn't care.
Humm?, no doubt you also meant WS-15 as well for the J-20??
 

Inst

Senior Member
The J-20's design doc indicated that lateness of the WS-15 was something that was accounted for. Current rumor mills indicate a 2022 to 2024 timeframe for the WS-15 to be certified.

In other words, the J-20 is meant to work with the WS-10, not the WS-15, although the latter engine would dramatically improve the J-20's capabilities.
 

ougoah

Senior Member
Registered Member
Lol how does Inst know that YF-23 is stealthier than F-22? I mean it's never progressed beyond prototyping. While it may be possible that the shaping is indeed stealthier, there are MANY elements to VLO and even if we assume those are equal or superior to that of F-22, you need to PROVE to us that the shaping gives the YF-23 lower RCS alone if all other factors equal. This has always been internet rumour type quality content. Was never proven or officially disclosed.
 

Inst

Senior Member
Shaping-wise, the YF-23 was superior to the YF-22. But the YF-23 was a prototype and the F-22 was a finished product, which implies that the F-22 should be stealthier than the YF-22 and probably the YF-23.

But if the YF-23 were fully developed, unlike the F-22, the YF-23 had V-tails instead of tailfin / tail combo, and its edge-alignment was better.
 
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