Re: Chinese Engine Development
On the wing-loading, you are almost definitely wrong, however. I've done my own measurements against the J-20's wing area, using a quadrilateral region including body lift, and the figures vary from 72m^2 to 78m^2, depending on what your guess of the wing area is. This is about 10% less than that of the Raptor, however, and for a larger airframe, so the J-20 can probably be expected to have relatively poor sustained turn rate compared to the Raptor and PAK-FA.
For what it's worth I did my measurements with a printout of a blown up satellite picture, a ruler, and protractor. There's going to be some measurement errors if course, but I found 79 m^2 to be a very low bound. I suspect one of the reasons we have discrepancies is because the satellite picture indicates a wingspan of 13.5+ meters for a length of around 20.5 meters. I trust this measurement of wingspan more than others because when I started I intended on cross referencing length, height, and wingspan dimensions with pictures from front, side, and bottom angles, and got discrepancies of the ratios of the major dimensions not only between different angles but even between different pictures of the same angle. I suspect this was caused by differences of geometric distortion and perspective of each picture. For example, pictures from the front suggested a wingspan of 12.5-13 meters, I suspect due to perspective, while pictures from the bottom suggested 14-15 meters, probably due to a pitch angle making the plane's length shorter relative to wingspan. I don't even trust paralay's estimates (which I believe are about 13.2 meters) over my own, in part because paralay did his estimates before we had an available satellite pic.
I also wouldn't be entirely certain that the J-20 must be a larger air frame than the Raptor. It could be less voluminous, or less dense. We simply don't know. For example, the J-20 has thinner wings than the F-22, which could have an effect on its mass. Then there's the assertion that has been made about how 3D printing will allow for much lighter structural weight than what forging and casting would allow.
Nor is a larger size necessarily indicative of poorer STR. The YF-23 was said to have had better STR than the YF-22, but it was a larger plane. This goes back to the importance of lift coefficient and L/D ratio of the design, which supersedes wing loading in determining performance. Then of course, as been mentioned, STR in which flight envelope? It's entirely possible for the J-20 to have superior STR at some flight envelopes and inferior STR in others.
With regards to IR, APG-77v1 would be able to track a -30 dBsm target at around 40km, but APG-81 on the F-35 would only be able to do so around 30km. Compare to PIRATE IRST, which can detect and track subsonic 4th gen fighters at 50km. In 5th gen combat IR tracking often occurs before radar tracking.
At 50 km you're technically entering WVR. For two aircraft merging at supersonic speeds that's only about a minute or two before intercept. And tracking doesn't guarantee lock.
And with regards to decoy stuff being fanciful; that's a bit un-Chinese, don't you think? If you consider the entire Chinese way of warfare it's based on misdirection and the use of minimal force. The West, especially the United States, might be attracted and addicted to the use of overwhelming force as its habitual doctrine, but decoys, attacking the opponent's decision process, and so on is fundamentally very Chinese.
Remember in Korea, to prepare for the 3rd Phase Offensive, the PAP spent a considerable amount of time to successfully fool the UN forces that the PAP was going to attack in the East when the attack actually came in the West.
Sure, but the scenario you're suggesting simply doesn't make any sense because pretending to be a less capable target in this case doesn't really achieve anything. For the J-20 in that scenario, pretending to be the less capable version actually MAKES it less capable because it will be coming into combat with lower potential energy. For example, if the opponent were the USAF (and the USAF is really the only adversary where this is really a concern), the USAF isn't throwing anything less than a team of F-35s or an F-22 or two no matter if the J-20 is using AL-31s or WS-15s, and they're not going to sandbag and come in with less PE just because the J-20 might be using Al-31s.
As far as imitating F-15s, the USAF is actually doing that, in a sense, with their F-15+F-22 combo tactics. The F-15 is the exposed radar emitter for F-22s, having greater radar range than the F-22s with their latest AESA upgrades. That functions as bait for enemy fighters; the point is that they don't realize that the F-15 is escorted by stealthier allies and that if they engage the F-15, they'll get ambushed and destroyed by F-22s.
As someone else said earlier, the decoy tactic itself is sound, but it makes little sense to build that tactic into your book of tricks and keep underpowered J-20s around, when you can employ similar decoy tactics with less valuable air assets like J-10s and J-11s and just upgrade those J-20s once better engines are available.
