The J-35A is not a spearhead fighter for China.
By 2030, there should be about a thousand J-20 in the Chinese Air Force, compared to a few hundred of the J-35A. And the J-20 is the "high" end aircraft of the two fighters.
In the Chinese Navy, the J-35 supposedly has a better radar than the J-35A used by the Chinese Air Force.
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At the Zhuhai Air Show, you can see multiple companies offering stealth materials for sale with glossy brochures and the technical specifications. You can see even Turkey and South Korea developing stealth aircraft.
Stealth materials just aren't that special anymore.
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When faced with an ultimatum, note that the UAE chose Huawei over the offer of 40 F-35.
In Saudi Arabia, we have the PLARF operating the Saudi DF-21 ballistic missiles. A notional F-35A order would presumably have a significant contingent of Chinese maintenance engineers as contractors.
Yes and all this makes the J-35 a spearhead, frontline fighter. It is literally the second best fighter China has in service and will be until 6th gen reach service.
We have PLARF operating Saudi DF-21 for good reason. We won't have PLAAF operating J-35AE. It also won't be difficult for the US to glean intel from PAF J-35s.
Stealth materials are so "unspecial" that only two nations on this planet have proven to have mastered them. TFX is a decade from service and KF-21 as well. We know from Chinese official sources say on video that the engineering and production of metamaterials that are applied to stealth aircraft only exist in the US and China. It hasn't been observed elsewhere and I haven't seen evidence that Russia, Turkey or Korea have applied those. Their fighters and 5th gen prototypes do not appear to have any of that "type" of coating that's apparent on the latest three 5th gen fighters - F35, J35 and J-20. Even the F-22 uses an older generation of material, possibly not even applying metamaterials. It is observably different and then we more or less have Chinese corroboration.
I am referring to stealth materials post F-22. F-117 and B-2 applied different treatments to their F-35. China leapfrogged the earlier generations of materials which were not metamaterial based. Metamaterial science and production currently only has limited application and no other nation has shown ability to produce them.
Particularly starting from the ten minute mark. There was an older vid on metamaterial scientists working in the US returning to China. That was a different context though but all the same. Clear hints are given on how out of reach synthesizing this stuff is. It's as exclusive if not more so than chip fab and lithography machinery.
Giving a piece to the US would expose the level however similar, further or behind it is compared to US equivalents and also how to perhaps overcome.