see my reply in blue:

Some people are unable of nuances.
Has the Chinese been building high tech fighter jet for more than 60 years accumulating experience, industrial capabilities etc ? No.

uh-yes, Starting 50s and 60s USSR gave them extensive assistance in aerospace industry. They were building Mig-17/19/21/Tu16/An-12/An-24/Il-28 by end of 1960s. and had their own design/ derivatives in the pipe line.
so, yeah…
They have been building high tech jets for more than 60s years.

US, Russia, France, UK are the only one to have been building jets from A to Z for decades. China is pretty new to the game and has already been seen copying Russian’s jet on large scale.

is the J-8 a copy of any russian jet? what about Q-5? remind you those two programs were started back in late 50s early 60s, not even when their license production of soviet jets was fully digested. and what about J-10? is that a copy of something?

So maybe with the J20 they have acquired enough skills building aircrafts to have been able to implement their own ideas, but still, because they learnt how to make a plane from the russian, and because their industry is still in the process of cacthing up with Russia and the West they aren’t in a position to inove yet.

20 years from now if they keep the same investment then maybe.

Example they have introduced the J-11 around 1995 which no matter what you say is a reverse engineered Su 27 with some minors modifications with worse avionics than the Russian’s. The J10 which could have the strongest claim as totally indigenious fighter as no more credibility. Between Israeli and Russian nobody knows who was the most involved…

sure it is a Su-27 with revamped structure, new chinese radar and cockpit avionics, new chinese engines, new fbw hardware and software… your point is?
that program was mandated by the PLAAF and basically they can’t deviate. from the requirement, J-11 as any one who has their head screwed on right can see now, was the not full capability of chinese aerospace, by a long shot.

There is no shame in learning. But I might laugh out loud if you tell me that the very first time China might make a fighter on its own with an industry still lagging at least 10 years behind even Russia in some area they are going to blast the F22 out of the sky !

and J-10 is a lavi clone blah blah blah, for crist sake for all intends and purposes J10 program finished 10 years old. and you guys still hasn’t wrapped your head around the fact.
go read the project pilot’s account and those who were involved in that program, sure people gave help, the chief project pilot went to cal-span/grippen effort and flew on mirage also, now you can toss the swedes/americans/french in the list.

Why do you think Russia is so angry and is menacing to stop supplying quite a few things to China starting with engines for its JF 17 ?

oh could it be india has something to do with PAK fielding JF17. could it be JF-17 is rather export competitive?

If Chinese are so inept why should the russians be fearful and agnry??

I thought we have past the denial stage. apparently not.

you know back before WWII, people were also typically very dismissive of Russian and Japanese aerospace/military industry.
Any thing they come up with must be a derivative or a copy of a western design. that assessment was true… until it wasn’t true any more.
there is no singular moment where the copier became innovator. it is a process.
it is utter foolish to dismiss their capability, especially facts are staring at us in the face.

I’m not speaking of sciences in general. I’m speaking strictly in the areas of aircraft design/VLO shaping/RAM, avionics/AESA radar and T/R modules/IRST/sensor fusion, engine technology, etc… The most sophisticated operational aircraft they’ve built to date, is the J-10, and much/most of that came from the Israeli work, on the Lavi. They’ve had quality control issues on some of the reverse engineered Flankers. They’ve yet to equal the AL31, much less F100/110/119, in fighter engines(even the PAK FA’s won’t have their representative engines for 8-10yrs). This is why I’m skeptical of them suddenly having breakthroughs in all of these areas.

you ain’t see nothing yet… 😎

this one?

yup. one of them.

do we have any swedish viewer here? 🙂

clearly this J-20 thing is a stealthrized version of Viggen!

Is there out right espinoage in aviation world ? you bet.
Is there copying with out license in aviation industry? heck-yes.
Is there taking inspiration from others who had gone before you? who-doesn’t?
Is the chinese only one doing this? I have one word for you: Echelon.

But at end of the day the engineering solution has to be the maker’s own. and they should be judged by that effort alone.

I found judging others by their suppsed historic patterns extremely narrow minded, short sighted and racist. Americans/Russians/Brits/French/Japanese… and chinese included!

The appearance of DSI on the JF-17 was not totally coincidental, no ? Industrial espionage was a known fact, with multiple suppliers of the F-35 later on found to be totally compromised, with all data stolen and servers hacked.

If you trace their R/D effort through open pubs , you would know that DSI was first filed as a public patent by LM.

As far as I know they already had a r/d effort with wind tunnel studies etc. when the F-16 DSI effort was mounted in US.

Why do you think they can not advance anything on their own with out espionage efforts?

Does the logic goes like this: “They are biologically in-ept so they can not work out the problem on their own, so anything similar must have been the result of espionage.”
I find these attitude extremely racist.

I remember see stuff like this: before WWII broke out in pacific USN pilots and western military observers opinioned that those damn Japanese are bad pilots and has naturally bad eye-sight therefore they can not be a airpower?

bunch of thanks!

and what people thinks of team of CAC designers – is that the same team that did J-10?

Song Wencong is 80 (let his years last forewer) – well, our Mikhail Simonov is 81
Xue Chishou? Su Longqing? I think they should be involving the best for 4Gen fighter?

welcome.
Yang wei is head of 611. His background is from flight controls/control law. and as far as I can tell he is the chief designer on this program.

His original assignment was put together the piloted simulation lab, then went on to really productionized the china’s first digital flight by wire system for fighters, in form of J-10.

and he headed J-10S (twin seater) and the FC-1 program.

I do not know if Xue and Su is involved. I assume they would be involved also by default.

It is similar looking, i even fine the top view of the plane’s wing similar to Rafale, however that does not matter a bit in how the plane will fly.

All the talk of zig jag and serrated edges on prototypes and tech demonstrator’s, the X-32 demonstrator had very few of them, yet was the solution boeing came up with.
As long as the manufacturer satisfies the requirements of a air force with out going over the budget everything is fine.

I guess people must have ‘mine is bigger’ contests, they can be fun.

see my comment above.
the prototype you mentioned is not the final solution.

I hate to say this but it appears that you clearly don’t know much about steath design mate…:diablo:

It IS pretty hard to make toothed doors actually, especially aerodynamically. Early test flights of YF-23 got at least one of the big toothed doors bend or torn then they have to increase the number (thus decrease the size) of the tooth. That could also explain why J-20 have relatively small tooth on the bay doors to begin with.

Apperantly IMO J-20 is almost ready for all aspect RCS and IR test, which is much earlier than T-50 judging from all the information we get so far…

tooth size has to do with what frequency range you want to optimize around. Gear door flutter is fairly common event…even for commercial a/c development. failrly complex requirement given that door is never meant to be as a aerodynamic surface. mismatched aeroloads and stiffness req’t is the issue here.