Chengdu J-20 pictures, analysis and speculation Part I

[saintkatanalegacy]

some are coincidences from the hundreds of fan arts

 

[PAK FA]

Any information about his name ?

nickname 'Yexu' rings some bells here (too complicated to explain), so he may be Russian
PAK FA, thanks for that info

No problem i hope the informartions is useful

 

[QuadroFX]

Is this real ... couldn't check at GE, since my internet at home has a complete break-down !

 

[Otaku]

Latest 'Ares' blog:

http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a2bbb8a32-8bf4-47c5-86c4-48f3c78e53c2&plckScript=blogScript&plckElementId=blogDest

Apparently Douglas Barrie's assessment cannot be uttered in the 'Other Place' (somewhere near heaven, apparently).

 

[JFC Fuller]

Has there been any word on the engines yet? That still seems to be the biggest mystery.

 

[TAKHISS]

From an article in the New York Times today...

"Staging the test flight of the long-secret J-20 while Mr. Gates was in Beijing amounted to an unusually bold show of force by China. But the demonstration also raised questions about the degree of civilian control of the Chinese military, as President Hu Jintao and other civilian leaders gave their American visitors the impression that they were unaware that the test had been conducted only hours before they received Mr. Gates at the Great Hall of the People.

A senior American defense official said that when Mr. Gates asked Mr. Hu to discuss the test it was evident to the Americans that the Chinese leader and his top civilian advisers were startled by the query and were unprepared to answer him. Photos of the flight of the radar-evading J-20 had been prominently posted on unofficial Chinese military Web sites a few hours before the meeting.

"The civilian leadership seemed surprised by the test," Mr. Gates told reporters on Wednesday morning in Mutianyu, during a visit to the Great Wall outside Beijing.

In remarks to reporters on Tuesday in Beijing, Mr. Gates said that Mr. Hu did acknowledge the test, apparently later in the same meeting, and that he assured Mr. Gates that it “had absolutely nothing to do with my visit.”

Asked if he truly believed that, Mr. Gates said, “I take President Hu at his word.”

They surprised by Mr. Gates' native question.In Chinese culture, a politician should be more stable.
"One's countenance betrays nothing seeing mountains fall and the earth splits"

In CPC,organization is the highest."Party commands guns" is party principles.the New York Times' article is a joke do not understand the generation

________________________________________________________________________________
Celebrate the successful first flight of the "project 718" "01" prototype fighter aircraft .

 

[Foxglove]

Has there been any word on the engines yet? That still seems to be the biggest mystery.

Chinese Military Aviation says one prototype is equipped with the AL-31F, the other, the flying one, with WS-1X. The X mark probably stands for 0. The series-produced J-20 is to be powered by WS-15 with 17t of thrust. The WS-10 installed on the J-20 supposedly has reduced RCS( serrated joint lines?) and IR.
Somebody here posted a drawing that illustrated the J-20 profile on Huitong's site for at least a year. It is indeed strikingly close to the actual aircraft, there's a difference though: the drawing shows an airframe with angular LERXes, the real thing has curved ones.

 

[TAKHISS]

验证机 is maybe a "prototype fighter aircraft",and maybe a "technology test aircraft".
???

 

[PAK FA]

In CPC,organization is the highest."Party commands guns" is party principles.the New York Times' article is a joke do not understand the generation

________________________________________________________________________________
Celebrate the successful first flight of the "project 718" "01" prototype fighter aircraft .

The article is not bad, in fact it is a really good way of mocking the Chinese lack of "knowledge about the J-20" it is logic, if civilians pretend to do not know, means they are not told by the military.

It is clear that no military program will be unveil like the J-20 was and later pretend they did not know or it was not intentional.
Only naive people are going to acept it.

 

[overscan (PaulMM)]

Has there been any word on the engines yet? That still seems to be the biggest mystery.

Chinese Military Aviation says one prototype is equipped with the AL-31F, the other, the flying one, with WS-1X. The X mark probably stands for 0. The series-produced J-20 is to be powered by WS-15 with 17t of thrust. The WS-10 installed on the J-20 supposedly has reduced RCS( serrated joint lines?) and IR.
Somebody here posted a drawing that illustrated the J-20 profile on Huitong's site for at least a year. It is indeed strikingly close to the actual aircraft, there's a difference though: the drawing shows an airframe with angular LERXes, the real thing has curved ones.

Please don't misquote Huitong.

Leaked images suggest that two different engines were installed (separately on two prototypes?)

Note the question mark.

 

[overscan (PaulMM)]

Its interesting to speculate on whether J-10B will enter production with essentially similar systems as a high/low mix or if it was just a one-off demonstrator for the J-20 technologies.

Interesting how in today's China, you can now buy souvenirs for the J-20 already. Times have changed

 

[Sundog]

Interesting how in today's China, you can now buy souvenirs for the J-20 already. Times have changed

Is that official swag, or just made by third parties? I'm guessing it isn't official, since the writing is in english. It would still be cool to have the patch in my patch collection, though.

 

[Lauge]

Interesting how in today's China, you can now buy souvenirs for the J-20 already. Times have changed

"J-20. Defender of Peace - Vanguard of Victory"....Hey, I'd want one ;D

Regards & all,

Thomas L. Nielsen
Luxembourg

 

[overscan (PaulMM)]

According to Chinese internet forums, this is a bunch of test pilots celebrating the first flight of Project 718 Prototype 1 ("J-20").

In first pic the guy second from right is indeed the J-10 test pilot Lei Qiang, apparently the J-20 test pilot Li Gang is the short guy fifth from right. So if you were scaling J-20 based on him, you might want to revise your estimates

 

[Deino]

Is this real ... couldn't check at GE, since my internet at home has a complete break-down !

Surely in 2008 there was no J-20 ... but the picture itself looks real

http://img.fyjs.cn/Mon_1101/27_143222_d98755c57330e15.jpg

???? Any my internet is still down at home.

 

[F-14D]

Compilation of some videos of the J-20 flight here:

http://www.youtube.com/watch?v=V9rvBLxGs-8&feature=player_embedded


First part we've mostly seen before (except it's in 720p), but it gets real interesting at 2:13 where the writing starts to be translated. At 3:12 there's an artists' drawing showing the bay doors open with an interesting description of the airframe and at 3:23 there's a pic of the 'chute deployed.

 

[flateric]

your thoughts? thanks to 41° for his PS skills that I don't have...

 

[JFC Fuller]

The article is not bad, in fact it is a really good way of mocking the Chinese lack of "knowledge about the J-20" it is logic, if civilians pretend to do not know, means they are not told by the military.

It is clear that no military program will be unveil like the J-20 was and later pretend they did not know or it was not intentional.
Only naive people are going to acept it.

No its an awful article. Civilian politicians knowing very little about military affairs is fairly standard, take the whole of Europe as an example.

 

[overscan (PaulMM)]

For my money, looking VERY closely at the closeup photos, the J-20 engine looks like an AL-31F nozzle painted silver. The relative lengths of the petals and shroud, the number of petals, all the same.

The zigzag line could just be painted too. If so, hats off to Chengdu, it made me think the nozzles were LO configured from the lower res piccies

This would, incidentally, put paid to the multiple engines/multiple aircraft theories.

 

[Deino]

Agreed ... could be !

But why should CAC paint these pedals ?? ... only to fool us ???

I don't know if You trust him, fut a friend of mine closely related to AVIC confirmed me that the prototype flew with completely new indigenious engines.

Let's wait and see ...

Deino

PS ... still off-line at home

 

[RAJ47]

Surely in 2008 there was no J-20 ... but the picture itself looks real

http://img.fyjs.cn/Mon_1101/27_143222_d98755c57330e15.jpg

The image is of 11 Jan 2011.
Extremely difficult to PS satellite imagery.
You can see the arrangements made for visiting dignitaries in red, buses carrying the guests and the chase plane etc.
The size on image is length 21.3m, wingspan 14.5m approximately.
I will try to attach some corelated images soon.

 

[frank]

I was looking thru some watched items in my eBay account & found one way down (ending in a couple of weeks) that I've been watching off & on for a couple of months, definitely prior to the J-20's unveiling, & it takes these folks several weeks to make a model, but here is a search for Shenyang J-XX showing what these Phillipines model makers had been selling as the J-XX for some time now. Most of these same sellers, OTOH, are still offering display models of the PAK FA, which is still based an earlier inaccurate depiction, so I never bought one nor gave this J-XX much thought, until now. http://shop.ebay.com/?_from=R40&_trksid=p3984.m570.l1313&_nkw=shenyang+j+xx&_sacat=See-All-Categories

 

[RAJ47]

Here is the satellite image with ground pics from the net.

 

[QuadroFX]

Maybe this photo is not from Google Maps?

 

[Otaku]

Yip, they painted the nozzle silver, and (irregular) sawtooth pattern. The sawteeth in the unpainted, preceding stage appear real though.

 

[Deino]

And what makes You sure on that ?? ... only Your wish that they haven't a working Chinese engine yet.

Come on guys ... I know the problems surrounding CHinese engine development quite well, but why should they show the prototype during a nearly public first flight but paint the engine pedeals in silver ? To impress the VIPs and PLAAF top brass ... to fool us ? Isn't it much ore likely that this is - as repüorted by several CHinese sources - an uprated version of the already operational WS-10A ... maybe the WS-10G that is reported to be delivered in two test-specimen already in 2008. I really can't think that the guys at CAC would be so foolish with a fake-effort ... they actually have much different problems to solve than to initiate that PR-gag.

Deino

PS Foto reportedly from today ... and following Your theory they pulled the paint off again !?

 

[overscan (PaulMM)]

I have no axe to grind on the engine of the J-20. Its perfectly possible its fitted with WS-10 or WS-15 engines. Until someone presents proof either way, you can only go on what is visible. Aside from the colour of the outside, in geometric terms it looks like an AL-31F nozzle. Now maybe thats because the WS-10G happens to have very similar geometry in its nozzle to the AL-31F. Maybe that is complete coincidence, or maybe the nozzle is derived from the AL-31F.

"Painting the nozzle silver" doesn't have to be an act of deception. It could be a special type of IR suppressing paint, it could be radar absorbent, it could just be that Chengdu wanted it to look shiny and futuristic for the photos.

I don't see any physical evidence of different engines in the photos unless WS-10G and AL-31F share identical external dimensions, down to the number, shape and size of the petals on the afterburner.

 

[overscan (PaulMM)]

And what makes You sure on that ?? ... only Your wish that they haven't a working Chinese engine yet.

Come on guys ... I know the problems surrounding CHinese engine development quite well, but why should they show the prototype during a nearly public first flight but paint the engine pedeals in silver ? To impress the VIPs and PLAAF top brass ... to fool us ? Isn't it much ore likely that this is - as repüorted by several CHinese sources - an uprated version of the already operational WS-10A ... maybe the WS-10G that is reported to be delivered in two test-specimen already in 2008. I really can't think that the guys at CAC would be so foolish with a fake-effort ... they actually have much different problems to solve than to initiate that PR-gag.

Deino

PS Foto reportedly from today ... and following Your theory they pulled the paint off again !?

Well, its possible. Maybe the paint doesn't stay on well under the effect of heat

1) You don't actually know when the photo was taken.
2) It is unclear, and you can hardly see the nozzles anyway.
3) Maybe they are testing two different engines - maybe the first flight showed issues with the other one.

You can't say "there are two prototypes" or even "it uses WS-10G" based on the images seen so far. You can say there might be two prototypes, or it might use WS-10G. Given that noone has seen a picture of WS-10G, identifying it in a picture is going to be tricky.

A lot hinges on the status of this aircraft. Is it a pre-production aircraft, as the J-10 prototype was? Or is it more like the EAP or 1.44, a technology demonstrator?

 

[Deino]

Agreed ... but it seems highly unlikely that they change the powerplant while they prepare the 1. flight and since the first picture ws leaked on 22. December, we've seen both types of nozzles. As such - to admit IMO - I daubt that they reengine the prototype or even paint or polish the nozzles regardless the reason ... and the reasons you mention would only be interesting during operatrional testing and not for a first flight.

As such - again IMO - i think its more likely that there are already two prototypes with different engines similar to the ATF-demonstrators which both tested both engines. Another possibility is that the AL-31F/FN powered bird is the actual first prototype - maybe a sign or hint that the program is much further advanced than we think - and the WS-1X powered one is the second bird. Again I agree with You I can't say this "IS" the WS-10G ... IMO it's not even a WS-10, since the inner structure is different.

Yet another possibility could be an AL-31F/FN development. Remember that Saturn developed for the first time a special version upon request for the J-10 and not much was known before that ... so, maybe Saturn was again contracted to develop a special version ... would also explain the posibilities of being re-engined.

On the other side my contact at AVIC confirmed me - and I trust him at least more than some other media esp. from Russia which claim this to be a MFI-development - that this is anew CHinese powerplant. So long I admit I have no proof ... call it a bit of a feeling or to trust my sources ... but maybe it's too much of wishfull thinking.

We will see ....

PS: Besides the J-20 the J-10 1031 was also seen today in the same way as both H-6K prototypes at Xian ... and again operation Z-10 at Nanjing. I'm more than excited what will see even more from China this year.

 

[PAK FA]

An excellent analisys of the J-20
http://www.aex.ru/docs/3/2011/1/12/1258/
According to this analysis the main role of the J-20 is naval attack and interception.
The author bases his statemenst upon the center of gravity of the aircraft and the wing position, he says that the wing is too aft from the center of gravity by just looking at the wing and main landing gear position but also to a picture of the J-20 landing, he says that on the landing picture the J-20 is not flying with flaps deflected as in other fighters giving a relatively flat wing, this implies a high pitch down tendency on the design, flaps drooped down generate a pitch down force that can be used at roll , however also can increase lift at landings and take offs.
Some people point out the use of the vertical dorsal stabilizers to stabilize longitudinally the J-20 at landing.
This indicate it has not the maneouvrability of a fighter and is relatively stable longitudinally, using its canard mostly as a lift vector to balance the aft positioned wing.
This is s a result of a long fuselage with long inlet ducts.
He says the J-20 is optimized for a Mach 1.3-1.6 supercruise.

 

[Sundog]

An excellent analisys of the J-20
http://www.aex.ru/docs/3/2011/1/12/1258/
According to this analysis the main role of the J-20 is naval attack and interception.
The author bases his statemenst upon the center of gravity of the aircraft and the wing position, he says that the wing is too aft from the center of gravity by just looking at the wing and main landing gear position but also to a picture of the J-20 landing, he says that on the landing picture the J-20 is not flying with flaps deflected as in other fighters giving a relatively flat wing, this implies a high pitch down tendency on the design, flaps drooped down generate a pitch down force that can be used at roll , however also can increase lift at landings and take offs.
Some people point out the use of the vertical dorsal stabilizers to stabilize longitudinally the J-20 at landing.
This indicate it has not the maneouvrability of a fighter and is relatively stable longitudinally, using its canard mostly as a lift vector to balance the aft positioned wing.
This is s a result of a long fuselage with long inlet ducts.
He says the J-20 is optimized for a Mach 1.3-1.6 supercruise.

Based on his analysis, it's safe to say he isn't an aero engineer, because he really doesn't understand flight dynamics, much less aerodynamics if that's what he get's from what he saw in the pictures and videos.

For instance, it's obvious the vertical stabilizers are being used as airbrakes as they aren't as toed in at take off and what stability they add is going to be mostly in yaw, very little in pitch.

I am inclined to believe it is longitudinally stable due to the pitch angle on the canard, but that could be due to it being an all flying canard. I should do my calcs now that I have decent pics of the planform.

Also, this aircraft should be capable of supercruising at much higher than M=1.3 to 1.6, at least aerodynamically speaking, as it has one of the best fineness ratio's of any fighter out there. I could see it supercruising between M=1.8 and 2, but M=1.8 is where you start to see material limits, from a thermo standpoint. If it is limited to a supercruise of M=1.3 to 1.6, it will be because of the engines. I guess I should also check the capture area as well.

 

[rousseau]

To PAK FA:
This bird is weird ;D

 

[overscan (PaulMM)]

Rousseau prompted me to do a whole new sizing calculation based on side view comparison to Su-27.

I did this based on sizing engines to be roughly equal in diameter and sanity checking the size of the cockpit and landing gear.

Crunched the numbers and got - 20.05m. Thats almost exactly the same as my first calculation from J-10 and truck.

Either a freaky coincidence, or I'm getting close to to truth here.

 

[flateric]

Based on his analysis, it's safe to say he isn't an aero engineer, because he really doesn't understand flight dynamics, much less aerodynamics if that's what he get's from what he saw in the pictures and videos.

Karnozov? Yes, it's safe to say so.

 

[PAK FA]

I am inclined to believe it is longitudinally stable due to the pitch angle on the canard, but that could be due to it being an all flying canard. I should do my calcs now that I have decent pics of the planform.

He is saying exactly the same, it is obvious from the Rafale picture at landing the Canard is deflect higher than the J-20 and the Rafale also has its flaperons deflected down more than the J-20.
He is saying the jet is an aircraft designed for supercruise.
I do not understand why you arrive to the conclusion it is stable or near stable and say he is wrong when he says the aircraft is near stable by the fact the canard is used as a big balance for the very aft wing.
By the way have you seen an YF-23 taking off?
http://wn.com/yf-23
you can see both the YF-23 and J-20 using the tails while at take off
http://www.youtube.com/watch?v=SlLGk6GiDuA,
on the YF-23 it has no canard, while the J-20 does, but is obvious that a V tail can give you pitch and yaw and a aircraft using canard will have less need of using its flaperons and V tail for take off.
Even the F-18 uses its V tail for take off

 

[Ogami musashi]

The example taken (rafale ,F/A-18, YF-23 and J-20) are totally different and can be used at comparision; It addition judging a plane's stability by its FCS laws on take off and, worst, on landing is nonsense; All of those planes (and surely the J-20) have special FCS gains for at least landing and often in take off conditions for the initial roll.

The rafale picture for instance, the plane is in landing FCS mode where the canards are there to add lift to the overall planform while in flight they are there to maintain balance and allow for boundary layer control at high AOAs;


The Yf-23 FCS on the ground was not optimized and first taxis revealed the FCS made too many corrections; Besides the V-tail use down rotation while the J-20 V t-ail are toed out (and they don't have the same angle)..

Only by seeing the plane in flight you can judge.

As for estimation of supercruise range...that very funny thing! I love all of those experts that have naked eye RCS-chamber/CFD-wind tunnel integrated capacities..

 

[PAK FA]

Only by seeing the plane in flight you can judge.

The question is what information you can really get as reliable for the J-20?
Engines at this moment is a mystery, the mission? still some people guessing, turn rates? nothing, performance nothing.
Most what we can guess is a bit of what the basic configuration let us see.
J-20 fans claim it already has TVC (without any evidence on the video it even moved and swivel the nozzles) it has already an engine of 17000kg, and so on.
That it will leave the F-22 as a relic of the past and the T-50 is not even a fifth generation and just a Flanker up date.
The Other side of the spectrum is those who think it is a fighter or a strike aircraft.
Frankly we know little but the basic configuration tells a lot about the aircraft, it is not an agile fighter, it is too heavy and big, it is stealthy with its limitations and probably it has AL-31s or WS-10 and still is underpowered. In my opinion it is a very stealthy aircraft but not as stealthy as the F-22, with more or less J-10 performance but with a lesser agility and probably it uses a lot of fuel in its current configuration.

 

[Ogami musashi]

You can't conclude anything from that; Mig 1.44 was meant to be in the same TOW than the supposed one of this plane (40 tons) and was meant to be maneuverable and agile.

Weight is not a problem as long as lift is here to compensate it; See the roll rates of F-22 which is an heavy plane (i recall the empty weight of a raptor is 19 tons) and the turn rates are visibly quite stellar..So you see you can make a big heavy plane which is agile;


Precisely why i told you basic configuration means nothing; we don't know anything about the canards+lerx interactions and as you said we don't know the engines in it.

I was only speaking of FCS actuation; If you want to speak about relaxed stability, you want to talk about an in-flight mode, not a landing or take off one;

And it is also important not to forget too much instability is the same thing that too little...The eurofighter is supposed to have an advantage because of this over the rafale in subsonic speeds too; reality is that no...because the FCS has trouble keeping the bird without yaw;

 

[Sundog]

I do not understand why you arrive to the conclusion it is stable or near stable and say he is wrong when he says the aircraft is near stable by the fact the canard is used as a big balance for the very aft wing.

I say it based on the fact that I know how to calculate it and was just waiting for a good planfrom pic to the aerodynamic center of the vehicle. I'll get around to it soon. I'm just very busy right now.

 

[sferrin]

I do not understand why you arrive to the conclusion it is stable or near stable and say he is wrong when he says the aircraft is near stable by the fact the canard is used as a big balance for the very aft wing.

I say it based on the fact that I know how to calculate it and was just waiting for a good planfrom pic to the aerodynamic center of the vehicle. I'll get around to it soon. I'm just very busy right now.

How do you know where the CG is?