The J 31. Who wants it ? Anyone ? Even the China fans fully admit the 31’s short comings. The concept is a good one. 2 engine F 35 sized fighter. But its reputation is in the gutter.

Rumor wise PLAAF and PLAN DOES NOT want J-31. It is now said to be purely an export product designated FC-31. Even the JF-17/FC-1 is made by Chengdu (CAC) and not Shenyang (SAC). Confidence in SAC among PLAAF/PLAN is rumored to be pretty low, but SAC is said to have a lot of high-powered people including former military top brass supporting them. The fact that they got themselves in to the J-20 program as a subcontractor after handsomely losing out the J-XX competition is scary. Don’t forget even with the Russians, the relationship with CAC and SAC are complete opposites. CAC has had long-term and apparently good relations with Russian industry including access to AL-31FN series 3 engines (~138kN). Compare that to SAC who has an embargo imposed by the Russians for engines. Some J-20 design & tech might have been absorbed by SAC when producing J-31. You can see multiple similarities.

Interesting attempt even if for my feeling You cut the radome of the J-15 a bit too much. If You look at several images as the one attached, the grey part between canopy and radome is nearly twice the length of the radome itself even without the pitot. In Your image it is only about a bit longer han the part from canopy to radome.
Anyway it clearly shows that the J-20 is never 23 m long as claimed by some self-proclaimed specialists and even if my first try was surely not correct and only a rough estimation, it is only 1 m more but still more than 1,70m less than the alleged 23m.

Therefore just as latenlazy suggested I would love to see his own attempt with a similar image or a better one if available. There’s simply no way to reach 23m as he claims … and by the way I never suggested anything on 18m.

Deino

You maybe right. I tried super-imposing. Difficult to align the edges due to blurring. But you might have to add another 5px to 8px to the J-15 length. Revised calculation comes about 21m for J-20.

[ATTACH=CONFIG]248746[/ATTACH]

Indeed the Tail-boom is shorter in the J-15 compared to the J-11B. So the length assigned for the J-15 should be around the Su-33 and not the Su-27. So around 21.185 for the J-15. Now comparing with the satellite image, the J-20 will be between 21.0m – 21.5m.

Edit: If we deduct the length of the shorter tail-boom then the length of the J-20 will be below 21m (20.8 – 20.9)

[ATTACH=CONFIG]248730[/ATTACH]

Glad we are in agreement that the original “analysis” was poor because of the poor quality image, and especially biased and poor measuring.

fanboys like to take things at face value, especially when it favors their pre-determined biased views, like Foxmulder

Good job on the picture. Now we have TWO people confirming that the J-20 is as big as the Flanker.
I took your picture and flipped the J-20 to make an easier side by side comparison with the J-15.

It is 1 or 2 pixels LONGER. But I’m not going to nitpick.
it is more or less the same size as the 22 meter J-15. So most outlet’s claim of 23meter was not baseless

[img*]http://i.imgur.com/RG8mctU.jpg%5B/img]

From that satellite image and if the Flanker length of 21.93m is without the pitot tube, then yes, J-20 will be around 22m. Even if we ad 5 – 10 pixels for the J-15 tail-boom it still won’t make much of difference.

Without Tail boom – ~22.2m
With Tail boom (+5px) – ~21.7m
With Tail boom (+10px) – ~21.34m

So at-least, from that satellite image they are roughly the same length give or take 50cm. The only question is the Flanker’s length. Is 21.93m with or without the pitot?

[*IMG]https://upload.wikimedia.org/wikipedia/commons/thumb/4/47/J9VI-IIprojec…]

was on a J 20 fanpage. They claim the J 20 is a variant of the cancelled J 9. I disagree.

J-9 is a series of designs. There were multiple wind-tunnel models tested in the 70’s. What you attached is the J-9VI-1. The wind-tunnel model that reassembles the J-20 is the J-9VI-2. The one that resembles the J-10 is the J-9VI-3. This doesn’t mean that Chengdu did not have any consultation with MiG or any other firm. They would have have had a lot of consultations, tech-acquisitions since the 90’s from companies and research institutes in Russia and beyond. But Chengdu had carried out many research work in the 60’s & 70’s by themselves after the split with the Soviet Union.

Let me give it a shot. I can’t get 23m. Problem is the resolution is extremely poor. It is hard see the J-15 tail boom. So I excluded the tail-boom. Another thing, what is the J-15 length without the pitot tube? Pitot tube won’t be visible at all at this resolution.

[ATTACH=CONFIG]248681[/ATTACH]

So with more powerful engine, would it need a major redesign?

Must be the case. Very least, wouldn’t a WS-15 class engine require inlet design changes? :confused:

Chinese aircraft in general just look very long. the J-20 compared to pak-fa or f-22, the j-10 compared to f-16 or gripen, or the j-8 compared to the f-4.
the only normal looking one is the jf-17.

Its a design philosophy. They have to compensate for having weaker engines compared to the rivals/competitors. Result is longer, narrower fighters. J-10 and J-20 follows this pattern. J-20 itself won’t reach its true potential until the WS-15 with 3D TVC is available.