J-20 5th Generation Fighter VII


Junior Member
Registered Member
If what you are saying is true, the US would have prioritized F-35 over F-22. Which means F-35 would see service before F-22 did.
Pls read my post carefully.
I clearly said China chief adversary US is much more interested in South China Sea not mainland. US situation is different


"the engineer"
I think China made a mistake by prioritizing j20 over j31. US has no interest in going into mainland airspace and plenty of interest in South China Sea. The few number of J20 probably gonna sitting in rust in mainland seeing no actions other than some training.

All the while, China has no answer for US F35 on carrier or amphibious ship and its creating trouble in South China sea.

On top of that J31 is better option as carrier fighter.
On top of that J31 can be used for mainland air defense.
On top of that J31 can change geopolitics by exporting.

Many reasons J31 much more important than J21.
Looks like China screwed up again.
Wth are you talking about? The mission requirements for j20 and fc31 are completely different. J20 is designed to the goals and requirements determined by the central military committee. It's gone through 3 iterations before this current design was set. J31 is a private venture by 601, that's why it's not funded.

Don't tell me you are a pilot so you know how j20 is designed.

The plane actually exceeded what the original design requirements asked for.


Junior Member
Registered Member
Pls read my post carefully.
I clearly said China chief adversary US is much more interested in South China Sea not mainland. US situation is different
What make you think that J-20 is irrelevant in the US-China rivalry in South China Sea? What make you think that J-31 would fit China's need more than J-20 in this rivalry?

On US's point of view, F-35 is more suitable in the S.C.S rivalry, because the US is not a S.C.S country. It couldn't station any F-22s in the S.C.S region for long terms. If the US owns a lot of islands and colonies in SCS, it would have stationed F-22s there. However, the since the US is not, it will need to rely on allies and carrier forces. This is the reason why F-35 is more suitable for the US. Because it is both a carrier jet as well as a exportable air force jet. Because the US has made a rule of not exporting F-22s.

None of these points support the fact that J-31 works so much better in the S.C.S rivalry for China than J-20, that China should have prioritized putting J-31 into service before the J-20. China is not the US. China is a S.C.S country. It owns the single largest island in the middle of the S.C.S: Hainan Island. With J-20, PLAAF has enough reach to cover all of S.C.S, deploying the jet in Hainan, Guandong, and the newly built artificial islands. Had China prioritized J-31, the PLAAF would have ended up with a Jet with much short range and reach, and will have to rely on new CATOBAR carriers being put into commission. And that itself is a big constraint, because the carrier program are much more complex and time consuming than the J-20. Carriers could meet technological and training hurdles that could easily delay the commissioning of carriers for months and years. This will mean that China could be faced with a situation where it only has J-31, and without a carrier to fly the carrier based version.


Registered Member
I don't think others have mentioned the fact that China has not yet got a CATOBAR supercarrier capable of supporting enough units of J-31 (or whatever navy version will be). So when the PLA was pouring funding into J-20 rather than J-31, it didn't even operate a single training carrier like Liaoning let alone develop carrier aviation properly. This line of reasoning about hypothetical supercarrier J-31 is beyond ridiculous. Please think about the timing and where PLAN was when J-20 was being commissioned and developed. You're totally assuming PLAN has perfect carrier aviation techniques nailed down and has CATOBAR supercarriers operating. At least to present enough of a force with J-31s to totally counter USN and Japanese F-35s.

In any case, J-31 will have shorter legs for sure and J-20 coming from coastal bases will easily reach SCS, loiter, fight, and fly back. Even if all that requires two tanks, it would still be able to preserve VLO if they drop those tanks when coming closer towards the island chains. BTW those island airfields can also field J-20s when there are enough J-20s to go around. The issue isn't prioritising one over the other, and even then they made the correct choice!

I should add that export consideration is just about as much of a non-issue. If they can build export versions of J-31, why not for J-20? If you're suggesting the export version of J-31 will be identical more or less to PLA's, then what would stop that from being the case wrt J-20? If anything, not doing that implies the J-20's tech and abilities far exceed this thought experiment J-31 which would prohibit it from being exported. Anyway no country will buy J-31 unless it's super cheap. If it's super cheap, it's unlikely to be very capable. I cannot think of a single country that would realistically become a customer of a finished J-31 product that would cost around $100M.
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