InstWe did this before and complained about it before; the known nearby object is the J-10 in the satellite picture, and if you go by a 15.49 length without pivot tube or a 9.75m wingspan for 19 pixels you’d get about a 19.4 or 19.3 m^2 length and a 13.2 m^2 wingspan. In any case, that’s about a .67 ratio between wingspan to length, which is worse than the F-22 which is a .75 ratio between wingspan and length, and about the same as the F-35.
http://farm8.staticflickr.com/7177/6978113113_12a9d72bc2_k.jpg
You assume that the Paralay diagram is internally consistent, and you use the Paralay diagram to give you a wing area, including body lift (which is what the F-22 does to calculate body lift and wing loading; let’s be fair), then you scale it to the current known dimensions.
http://paralay.net/jxx/255.png
You get a figure of approximately 69, 70 m^2, or something around that environs, which is MUCH higher than the strategy page estimate of 63 m^2.
Weight estimates then go between the F-22, which is about its size, but with less wingspan, and a scaled up F-35. That would be between 30 metric tons loaded to 32 metric tons loaded; you end up with higher than 400kg/m^2, which is rather high for a prototype stealth fighter and is actually worse than the F-35C variant.
InstAre we still playing this interceptor game? Wing area is approximately 68,69 m^2 (length 19.36m, satellite pictures and J-10 length without pivot tube). The aircraft, if scaled from the F-35C, is about 30,400kg loaded.
This comes out to 440kg/m^2 wing loading.
It looks a bit high, but then you have to note that the Chinese don’t really seem to get sustained turn rates and many of their aircraft tend to have high wing loadings. It’s not necessarily a bad thing; the YF-23 had better wing loading, thus better sustained turn rates, than the YF-22, and was rejected for having poor instantaneous turn rates. Same applies to LCA Tejas; it looks as though it should be ridiculously maneuverable due to sub-300 wing loadings, but it’s actually a clunker due to being delta-winged without LEVCONs or canards.
InstThey share a Canard LERX Delta layout.
I believe the Canard LERX Delta is the most unique aspect of the Rafale, aerodynamically speaking, although the intake design is also fascinating.
Long-coupled canards vs Close-coupled canards is another factor, as is the fact that the J-20 will have a far higher wing loading than the Rafale due to requirements to reduce drag for extended range.
There’s also the difference in vertical stabilizers; the J-20 has slanted all-moving vertical stabilizers.
InstThe Chinese are adherents of the SRBM approach to ground attack, though. SRBMs would carry a heavier warhead than CMs and impact at much greater velocities. While unguided, a few SRBMs would yield greater results than a cost-equivalent deployment in CMs.
Regarding Rafale low-flying operations, part of the issue will be that AWACS need to be taken down. While you may be able to avoid ground-based radar systems by flying low, AWACS in the sky will be able to detect you against the ground and their fighter escorts would be able to attack you from an altitude advantage.
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One interesting thing at the moment is that I’m trying to calculate the actual thrust to weight of the J-10. Some figures seem to be giving lower than previously estimated counts; for example, one source gives a “normal take-off weight” of 12400 KG. That’s lower than predicted.
I also have an empty weight of 8860 KG, and all of these are from official sources.
http://img200.imageshack.us/img200/5589/j10statsnov2.jpg
http://i47.tinypic.com/2wq5oqv.jpg
Assuming it’s at full fuel, and then calculating for 60% fuel capacity on the combat zone, then we get 11000 kg.
Adding 600 kg for two SRAAMs and two MRAAMs, we’d get something like 11600 KG, which actually allows for sub 300 wing loading and 1.06 t/w with a 122 kn engine.
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Even using a 13000kg take-off weight figure, you’d still get 333 wing loading, although you’d be saddled with a .96 thrust to weight ratio with the AL-31F.
InstStrictly speaking, the Rafale does not use an AESA. It is still on the RBE2 PESA and the AESA is planned for future iterations.
Oh! It turns out the Rafale C is due for 2012.
Regarding the small radar size, afaik, Dassault wasn’t expecting future wars to emphasize BVR to this degree, and optimized the nose for WVR maneuverability.
It’s not that Dassault is stupid, they just made a different optimization choice compared to the Eurofighter program.
InstThe fastest way to break-up a Rafale cuddle-party (there are ruder synonyms) is to bring up how crappy the radar is.
SURE! Sure! With fully up-to-date AESA, or revolutionary AESA technology, the Rafale could match other AESAs in capability, but the problem with the Rafale is that the nose cone is just too small for a decent AESA!
And I think we’ve already seen pictures of the RBE2-AESA. The modules have been counted and we see something around 900 modules. Very inadequate.
What exactly is the aperture size comparison between the Rafale, the J-10B, and the F-16 anyways? I’m told the Rafale made a big mistake during the design process by opting for a small nose cone, but the F-16 with AESA and the J-10B nose cones aren’t that large either. The Rafale is supposed to be unusually poor when it comes to that.
Aerodynamically, of course, the Rafale is superior to all other 4/4.5 generation multi-role fighters in its class the Indians may face.
Compared to the J-10B, the Rafale is ahead through better attention to the intakes, usage of LERXes instead of the simple canard – delta wing configuration (look at the J-20, it copies the Rafale’s canard – LERX -delta wing configuration, if you would be generous, you could say the J-20 is a stealthified Rafale), and superior wing loading.
For the Rafale to be beaten by the J-10B, the J-10B would have to exploit BVR advantages, which only come into play once the AWACs get shot down (like I said before, Indian Novator, Chinese PL-21), and more than that, the J-10B would have to take advantage of its likely lower cost, due to being a single-engined platform compared to the Rafale.
On an RCS basis, both the Rafale and J-10B are sub 1m^2 RCS platforms when clean.
The Rafale also has a highly superior engine to the J-10B, at least until the rumored WS-10Gs come online, which is to say, never, as the WS-10 project has been delayed to hell since day one.
InstHow does the Rafale’s poor radar fare into this? The Eurofighter is expected to get a 1500 element AESA. The Rafale, at last report, can only sport a 900 element AESA. This is the worst AESA in any 4.5th or 4th gen fighter available. If the AWACS start popping once PL-21s and Novators start getting traded, won’t the Rafale be at a disadvantage due to poor BVR detection performance?
InstI’m referring to this picture.
via Pinko on CDF:
InstAgreed, but also keep in mind that the shadow can be a bit tricky. Also, it’s dependent on how people decide which pixel should count it ends and begins. It’s best to corroborate by posting your pixel choices.
Maybe, but I liked the first image with the truck and the J-20 and J-10 the most, because trusting the J-10’s known length is way better than trusting a truck’s :P.
I have to go with the picture where the J-20 and J-10 take about approximately the same position; that basically kills all debate over its size.
So, um, back to discussing whether or not the J-20 is primarily a striker, an interceptor, or an air superiority fighter?
InstLatenlazy:
The pixel via satellite method gives you roughly a minimal error of about a third of a meter. It gets more fuzzy when you include the fact that it’s hard to determine the exactly where the plane starts and ends due to low resolution.
Still, I think we’re reasonably accurate with the satellite method and that should have been preferred over the truck method before we had better figures from the big shrimps.
InstI can make an argument for a bit of extra length; if you use Paralay’s diagram as I’ve previously suggested, you can see that if you use the distance from the back of the wing to the back of the canards as a measuring stick, it extends to roughly the same distance as from the back of the canards to the front tip of the plane.
So I’m still sticking with the 20.5 figure, although I distinctly do not like that particular picture as it is too hard to make out where the wing ends and where the canard ends.
As far as bomb bay area goes, the bay size is approximately 2 meters long if you use the Paralay diagram. That’s strangely larger than the weapons bay size on the F-22.
The way this works out is that if the J-20 has a greater vertical depth than the F-22, it can expand the width of the main weapons bay, but put the SRAAM weapons bay in a position above the main weapons bay, instead of putting it roughly parallel to the main weapons bay.
On the other hand, the PL-12s are larger missiles than the AMRAAMs, and I’m not sure how they’re going to fit in the PL-21 BVRAAMs.
InstIf you look at the satellite photos the reason I prefer it is because you don’t have variant scale. You have two aircraft, one of which has a known length, on approximately the same distance from the camera, which is located on a satellite.
http://www.flickr.com/photos/digitalglobe-imagery/5347525358/sizes/o/in/photostream/
Determine the length of two lines, running from the start of the J-20 to the end of the J-20, and from the start of the J-10 and the end of the J-10.
Compare the length of the two lines, using the Pythagorean theorem.
If you don’t know where the two lines start and end, well, you have paralay’s diagram to work on, which is to scale, but not necessarily of the correct length. Overlay it over the J-20 in the picture, then use that to determine the end-points of the J-20.
The J-10 is easier to determine.
The figure I’m currently getting is 125%. That gives out 20.5 meters.
InstThe reason LQ satellite photos are superior to HQ close-range photographs is because you don’t have to deal with the effects of perspective on the relative size of the photograph.
We are not looking for small details here; we just need to know the pixel of the J-10 in the picture, and the length of the J-20 in the picture. Once we have both, we compare and scale. The figure at 133% is ~21m, the figure at 125% is 20.5m.
Big shrimps, or people in the know, on the Chinese forums give the craft a length of 20.6m.
It’s corroborated.
And as I’ve mentioned, the length of the aircraft doesn’t matter when it comes to wing area. It’s the ratio of the size of the aircraft to wing area that determines wing loading, because the weight of the aircraft is a function of its size. In any case, the J-20 is about 15% smaller in wing area for size than the F-22, and about 5% smaller in wing area for size than the T-50.
The aircraft has taken some modification for speed over maneuverability, but it’s not likely to be that much, considering the fully movable tailfins, the ventral fins, the canards, the lerxes, the body lift, and the TVC.
InstFirst, you can calculate the size of the J-20 based off satellite pictures. The effects of perspective on a satellite picture are effectively nil due to the long distances involved.
We have a picture of the J-20 near a J-10. You compare their two relative sizes and you get something around 20% more that of a J-16, which is about 20 meters. Using pictures where the J-20 and the J-10 are in the same point, you get about the same figure.
Second, the scale of Paralay’s pictures simply does not matter. The wing area is a function of size, true, but relative wing area is size-independent. If you somehow say the J-20 has 23 meters, then the total wing area, neglecting the canards, is 97 square meters. If the length of the J-20 changes, the wing area changes alongside it, so the length doesn’t matter when you’re discussing the wing-loading of the aircraft.
InstCambered upper surface?
Not as extreme as that on the F-35, but check.
Our dearest Kitchen Sink fighter; incorporating virtually every feature under the sun and hoping it sticks.
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