Chengdu J-20 pictures, analysis and speculation Part I

[saintkatanalegacy]

not completely different...

just different initial maneuver

 

[Deino]

Deino:
Let's do it logically.
First step, get the weight. you might not have the official data of the weight, but conjecturing its size is not so much difficult now.
A fighter with 22 meters length, almost 15 meters wing span, it will be no less than 19 tons for sure in terms of its layout seeming.
Second step, collect all of presented data of engine.
We all know thrust of AF-31 series engine won't beyond than 13 tons each, the WS-10 according to information from China merely is modification version of AL-31 combined with some F110 tech maybe, so its thrust will approach to 13 tons more or less.
Such power is distinctly insufficient, no matter this aircraft will be testbed or prototype.
So conclusion is this engine with seemingly different nozzle from AL-31 must be WS-10Kai

In general I follow Your logic ... but in closer detail it's not that simple.

First of all the Taihang is definitely NOT a AL-31F or FN simply modified with some F110 technology. It is an engine of its own - maybe based on the F110's core - but surely has nothing to do with the Russian one.

Besides that it is - esp. in mind of China's record on engine development - not that easy to develop simply a new WS-1X within a few weeks, months or even years ... and IMO even if both types are underpowered for that type, the J-20 surely could fly with both ... albeit not to the desired or foreseen performance; but simply for a testbed they would be sufficient.

As such the darker engine shown is clearly an AL-31F/FN … IMO we could end this debate here … but regarding the lighter one it is still a mystery. I won’t repeat my concerns why I still don’t think it is a simple painted AL-31F/FN, but otherwise I have to admit, that many details - especially the innere structure - do match that powerplant and clearly speak against the WS-10A or even an uprated Kai, G, bis, PLUS or whatever You like to call it.

Therefore my current conclusion – even one I don’t like to accept – is:
This is more likely a specialized or special-treated (painted) AL-31F/FN than a WS-10A

See also here: http://www.fyjs.cn/bbs/htm_data/27/1101/305600.html

But let’s wait and see.

 

[Ogami musashi]

not completely different...

just different initial maneuver

Those are not the same maneuvers at all; The mangoose is a full aoa Yaw translation; The transition is from level nose to high AOA nose with yaw; The SU-30 mki aerobatic is a barell roll that combines a bit of yaw from a nose down attitude;

In addition is was not really visible in the X-31 video, but when the plane did that maneuver it translated for several seconds in yaw;

You can see that better in this video from 1:05 and at the end the same ability is shown from distance:

http://www.youtube.com/watch?v=4eaGTU8BD7A&feature=related


If i took this example it is precisely because the SU-30 nor mig-29 OVT exibhited such ability because of drag, M.O.I and vectoring forces specs of those planes;

Again saying the obvious but putting a TVC on a plane doesn't make it equal to other TVC planes;

 

[overscan (PaulMM)]

Therefore my current conclusion – even one I don’t like to accept – is:
This is more likely a specialized or special-treated (painted) AL-31F/FN than a WS-10A

See also here: http://www.fyjs.cn/bbs/htm_data/27/1101/305600.html

But let’s wait and see.

Hmm, well, I did say so

I can't see a problem with equipping the first prototypes with AL-31F - it should allow a rapid test programme decoupled from the ambitious WS-15 engine. Salyut may be able to supply the higher thrust versions like the Series 42 which would be better matched to the airframe.

 

[saintkatanalegacy]

well... I really wouldn't be surprised if they ended up being the same engine

 

[rousseau]

Therefore my current conclusion – even one I don’t like to accept – is:
This is more likely a specialized or special-treated (painted) AL-31F/FN than a WS-10A
See also here: http://www.fyjs.cn/bbs/htm_data/27/1101/305600.html
But let’s wait and see.

Deino, since you can read Chinese, you should know Chinese forum where is the place released fake or fraud more than anywhere else. I don't mean all, but you'd better know who than what.
Variant engine can be fitted on different or same nozzle which oght to be improved or modified.
It is looks like AL-31 more than WS-10, but I'd rather go opposite way.

 

[sferrin]

Could be the same engine with different "turkey feathers". Maybe they dressed them up with RAM or something.

 

[Deino]

Hmm, well, I did say so

Welll ... better late than never ! :-[

 

[saintkatanalegacy]

Could be the same engine with different "turkey feathers". Maybe they dressed them up with RAM or something.

same thought

notice how the saw tooth edges are raised

 

[rousseau]

accidentally, heard this also is a stable aircraft. ;D ;D ;D

 

[DWG]

at the end the same ability is shown from distance:

"created quite a stir at the Paris Air Show"

I was there, I was stirred. Had the whole busload of 777 and EFA FCS engineers pretty damn stirred in fact

 

[overscan (PaulMM)]

Sharpening on the possible weapons bays.

 

[chuck4]

Looking at the photo above, I find it hard to believe this thing is just a technology demonstrator. Who the hell puts night formation light strips on a technology demonstrator? These strips suggest this plane is not only a real prototype, but one which is already quite close to the production item.

I think I also agree this plane was meant to be fast and as stealthy as the Chinese can get it while remaining cautiously conservative in aerodynamics, engineering, and power plant trickery. This would be pretty much what one expects from a country designing it's first 5th generation fighter without having first accumulated a whole lot of prior modern fighter design experience.

I suspect it was intentionally designed to be serviceable but not go out on a limb as far as maneuverability is concerned because of lack of confidence engendered by inexperience. I think the chinese wants to avoid being so ambitious that it's inexperienced design team would take far too long to make it serviceable. This was a mistake the Indians made with LCA Tejas.

 

[Abraham Gubler]

Looking at the photo above, I find it hard to believe this thing is just a technology demonstrator. Who the hell puts night formation light strips on a technology demonstrator?

Someone who wants to fly a technology demonstrator in formation with other aircraft? While you may be right about it not being a one (or two) off demonstrator I don’t think formation lighting is going to be either here nor there in making this determination.

I think the chinese wants to avoid being so ambitious that it's inexperienced design team would take far too long to make it serviceable. This was a mistake the Indians made with LCA Tejas.

The Indians are cursed more by a rampart impeding bureaucracy than inexperience in a rather modest design effort like the LCA. Any limitations in the design of the J-20 probably have a lot more to do with limitations in access to technology.

 

[chuck4]

I think the Chinese are likely not short on the fundamental technology they need to attempt to build a hypermaneuverable fighter. They just lack the experience and confidence to anticipate the likely aerodyanmic and operational pitfalls of a really aggressive design, so they would fear falling flat on their faces if they were to cut metal on any such design, resulting in a probably unexceptably long design cycle and perhaps an ultimately unsatisfactory production plane. There is more to a good fighter than technology. They have enough technology. They lack the know how. Compare how many X-planes the US built, not to mention production planes modified to be technology testbeds, and how many chinese equivalent there have been. They lack experience.

 

[kcran567]

I think the Chinese are likely not short on the fundamental technology they need to attempt to build a hypermaneuverable fighter. They just lack the experience and confidence to anticipate the likely aerodyanmic and operational pitfalls of a really aggressive design, so they would fear falling flat on their faces if they were to cut metal on any such design, resulting in a probably unexceptably long design cycle and perhaps an ultimately unsatisfactory production plane. There is more to a good fighter than technology. They have enough technology. They lack the know how. Compare how many X-planes the US built, not to mention production planes modified to be technology testbeds, and how many chinese equivalent there have been. They lack experience.

To me the plane looks like an attempt to get some type of stealth capability into the air. Not built to be agile, very large, some stealth shaping, and j-20 is years behind in engine technology and materials.

Overall probably the least capable of the "big 3" f-22, t-50, and this. But it is a capability. It looks like a stealthy, supercruising offensive striker built for head on engagements of targets in the air and ground/sea with long range frontal intercept of targets.

Probably using a good amount of technology gained by study of existing tech, and obtained info on tech needed i.e. stolen, bought, and borrowed tech thrown together into this platform.

 

[kcran567]

Any ideas for names? How about the Chengdu j-20 Black Panda ;D

thats what it look like to me, or a big overweight Ninja.

 

[chuck4]

Years behind in engine technology, probably. Years behind in material technology, hard to say. Whether it is the least capable of the big three is also hard to say. It could well split the difference between F-22 and T-50 in stealth, match the latter in electronics, and be longer legged and carry a heavier armament than either. It does seem to lack enough lifting surface and thrust to weight ratio to match T-50 and F-22 in sustained agility. But large deflection on those canards could well give it very high instantaneous maneuverability and high level of post-stall controllability. If it carries a much heavier fuel load, then it may effectively be faster than either by being simply being able to supercruise for longer. The shaping and layout of this fighter seems to resemble early Lockheed concepts that later evolved into the JSF.

I would speculate that the following aspects of the aircraft would be changed before service entry:
1. The underwing fairings for flap and aileron actuators would either be blended into the wings or disappear all together.
2. The main gear would be changed to fold rather than retract forward to make space for longer side weapon bays
3. The canards, vertical tail and wings will become larger.
4. Engines will be changed

 

[rousseau]

The enhanced pic overscan posted reminds me of a famous angle view of this

 

[Deino]

For those who like the J-20 as a nice wallpaper !!

http://www.top81.cn/top81bbs/thread.php?cid=1&rootid=2760445&id=2760445

Deino

 

[saintkatanalegacy]

....

 

[pedrospe]

great j-20 wallpaper,thanks a lot deino.



regards


pedro

 

[Mike Pryce]

Analysis of the J-20:

http://www.flightglobal.com/blogs/the-dewline/2011/02/j-20-chinas-ultimate-aircraft.html

which I'd agree with for the most part (e.g. http://www.secretprojects.co.uk/forum/index.php/topic,11768.msg113800.html#msg113800 and http://www.secretprojects.co.uk/forum/index.php/topic,11768.msg113326.html#msg113326)

As it may be that the J-20 is a JH-7 replacement, maybe the much speculated engines are WS-9 Spey developments, to save on logistics costs. I should point out I am on strong pain medication regarding that thought though!

 

[quellish]

Analysis of the J-20:

http://www.flightglobal.com/blogs/the-dewline/2011/02/j-20-chinas-ultimate-aircraft.html

This is very much in agreement with some of the RCS reduction features that are visible on the aircraft. The J-20, I suspect, is intended to engage maritime targets protected by the Aegis system - or Aegis itself. Wether China can produce the physical materials of appropriate precision and maintainability to make this operational remains to be seen. It is no small set of problems to solve.

 

[kcran567]

If this aircraft has only limited stealth, yet can supercruise at M1.3-1.6 it can still be dangerous to carriers and air targets.

Even if it is already obsolete by a new generation of stealth detecting ground based and AESA radars like the F-35's.

 

[chuck4]

I think j-20 is primarily a air-air fighter, but it's design is constrained by staff requirement that it possess the range to supercruise out to Guam, and rely on such engine technology as the Chinese can deploy before 2020. It needs to out range the F-22 to keep the battle away from china. It won't be subject to rules of engagement that would force it to dog fight. If the requirements leaves it deficient in dog fighting capability, then that's what it takes. It seems pretty simple.

Any strike capability would be secondary. If I were the Chinese and I am interested in taking out aegis screens around carriers, I would develope supersonic stealth cruise missiles for the job. The Chinese have plenty of cruise missile development experience. Any defense a super cruising stealth plane can penetrate a super cruising stealth cruise missile can also penetrate. Stealth cruise missiles are much lower risk for the Chinese. If the J-20 is involved at all, it would be to further complicate the problems of carrier defense merely by it's mere potential stealthy presence.

 

[Wil]

Hello!

A new comparison between Su-27, J-20, T-50 PAK FA and F-22 Raptor, made by this humble servant. B)

or Click here.

For the J-20: ~21.90 m x ~14.40 m (provisional numbers!!)

Good Luck!

 

[saintkatanalegacy]

I think it's too big

 

[Deino]

Seems as Chinese new-year holydays are over ....

Pictures are from late January but posted today.

Deino

 

[Deino]

CORRECTION

Here's a link with all or at least most of the "new" J-20 pictures. Actually they were from the time around the 1. flight and only posted now.

http://www.top81.cn/top81bbs/thread.php?cid=1&rootid=2792845&id=2792845

Deino

PS intersting J-10 + J-20 comparison added

 

[RSF]

Nice graphic at the bottom which looks fairly accurate when compared with the photos of the J-20 with the J-10 chase plane in flight.

Speaking of size I recently came across a description of length of the J-20 putting it at 21.30m, or just under 70 feet. If this is accurate it appears that its slightly shorter in length then some have estimated in the west.


http://www.afwing.com/intro/Black4/black4-1.htm

 

[hesham]

Hi,

http://politeianet.wordpress.com/2011/01/13/chinese-stealth-fighter-j-xx-or-j-x-and-xxj/

 

[flateric]

http://www.secretprojects.co.uk/forum/index.php/topic,4349.msg36675.html#msg36675

 

[flateric]

ZT Feiyang BBS via zheng3pao

 

[lancer21]

Isn't this PS of an earlier picture, or ... ???

 

[dannydale]

I think it's pretty obviously shooped.

 

[Spring]

I think it's too big

Proportions are probably right, considering the comparison with the man standing, anyway there is a sure thing, the airframe is voluminous.

Either way if the J-20 is actually smaller, these intakes will be further smaller, the intake cross area of the F-22 andT-50 are significantly larger, so the big question is if the J-20 was designed to supercruiser.

And considering the chinese issues with their domestic engine development, is probably that the supercruiser requirement or goal was discarted.

 

[kcran567]

This thread seems to be slowing down a bit.

We need a few brave souls to try to get a few cockpit pics, that would make things interesting.

 

[Stargazer]

I think it's pretty obviously shooped.

What makes you think so?? ???

 

[saintkatanalegacy]

I think it's pretty obviously shooped.

What makes you think so?? ???

compare it to the previous picture of that

the side bays are gone

when I did the image analysis before, the serrated edges of the bays are gone in the bottom shots and was replaced by "blocks" and only the center line was left

this is an indication of heavy blurring