J-20... The New Generation Fighter II

Asymptote said:

No, you don't use TVC like that. If you turn so aggressively to incur such massive increase in drag, it is almost certain you will snap the pilot's neck or pilot will lost conciousness. TVC is almost always use in conjuction with conventional flight control surfaces. The flight control surfaces makes up 50% of the maneuverability, and the TVC enhance it and takes up the other 50%. It is sort of like 2WD (two-wheel drive) vs 4WD (Four-wheel drive).

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I would say control surfaces and the aircraft's aerodynamic design contributes a much larger percentage to maneuverability than TVC. Otherwise, putting TV to JH-7A will possibly make it more maneuverable than the J-10A.

Asymptote, I think we agree. But TVC is payed for in extra weight, aerodynamic losses in the jet pipe and complexity, perhaps leading to slightly smaller control surfaces and attendant drag advantage. As always, you have to investigate the probability that one concept or another is the better one.

Asymptote said:

I agree with you.

The latest Comac ARJ21 and Comac C919 for example, still largely use western avionics, engine, flight control system, etc etc. The only thing that's made and designed in China of these supposedly "indigenous designed" aircrafts are the airframes.

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That might have more to do with getting Western certification than the capability (or the implied lack of) of indigenous components.

Quickie said:

Try watching some video of those acrobatic maneuvers and you'll understand what I meant. It's nothing like a sustained turn or an instantaneous turn which you normally see fighters perform. Right after the acrobatic maneuvers, the pilot will have to immediately recover his aircraft from stalling or possible stalling, and regain flying speed before the aircraft gets to the point of no return and falls to the ground. In the meantime of doing so, the aircraft is virtual sitting duck.

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Well, I think with just the canards and vertical stabilizers (all moving tail-fins) - the J-10 and J-20 have a huge weakness in turn rate in yaw direction because the aircrafts have to rely on the only vertical control surface (in J-10's case, in J-20, two vertical control surfaces only) to do that.

Just imagine how much more improvement it can offer if TVC is installed on J-10 or J-20 - the TVC nozzles deflected sideways in conjunction with the control surfaces will dramatically make the J-10 and J-20 far more agile than they currently are.

delft said:

Asymptote, I think we agree. But TVC is payed for in extra weight, aerodynamic losses in the jet pipe and complexity, perhaps leading to slightly smaller control surfaces and attendant drag advantage. As always, you have to investigate the probability that one concept or another is the better one.

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There is another point of consideration in favor of TVC over conventional control surface. The control surfaces (flaps) create discontinuity in the shape of the aircraft (edge alignment ) - compromising its stealth potential. That's why if you look at F-117 and B-2, they minimize the control surface from the frontal aspect, while F-22 and PAK FA adopts "Leading Edge Flaps" (but not full canards) to improve maneuverability.

I think if you look at 6th generation fighter design, they are trying to further minimize the control surfaces usage, and probably relies even more on TVC.

I think if you look at 6th generation fighter design, they are trying to further minimize the control surfaces usage, and probably relies even more on TVC.

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uh... there are no sixth generation in production or development beyond early concept art just yet. the Next Generation Tactical Aircraft of the USAF and USN Next Generation Air Dominance concepts are slated for sometime in the 2025–2030 time span assuming development starts sometime in the next two too five years, At this point the only requirements know for such a craft as defined by Air force magazine october 2009 article are "extreme stealth; efficient in all flight regimes (subsonic to multi-Mach); possible “morphing” capability; smart skins; highly networked; extremely sensitive sensors; optionally manned; directed energy weapons." the only concept images yes lack vertical structures however those are so early as too be pre-developmental.

Asymptote said:

Well, I think with just the canards and vertical stabilizers (all moving tail-fins) - the J-10 and J-20 have a huge weakness in turn rate in yaw direction because the aircrafts have to rely on the only vertical control surface (in J-10's case, in J-20, two vertical control surfaces only) to do that.

Just imagine how much more improvement it can offer if TVC is installed on J-10 or J-20 - the TVC nozzles deflected sideways in conjunction with the control surfaces will dramatically make the J-10 and J-20 far more agile than they currently are.

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Yaw is only important for instantaneous turn rates, but in this day an age, with HMS cued high off broadside missiles, how important instantaneous nose pointing is has become questionable, especially since you incur huge drag when you turn your nose too much. TVC assisted extreme yaw pitching will result in exactly the kind of excessive energy and speed bleed that everyone, including yourself, acknowledges is a bad idea.

For sustained turn rates, yaw is irrelevant since pilots would turn their plane and pull up into the direction they wish to turn in, where the plane's turn rate is much better and a pilot could better brace themselves to take more Gs.

Like I said before, it seems in current time frame China starting to be able to do very advanced airframe designs - which parallels its civilian aircraft developments. It still needs substantial help in sub-systems and engines in both civilian and military sectors. An example is the recent news just few days ago that AVIC is still seeking partners from western business jet manufacturers for co-development of its industry.

Chinese Fighter Group Seeks Bizjet Partners
Chinese Fighter Group Seeks Bizjet Partners | AVIATION WEEK

If China is capable of doing everything itself, why would AVIC be asking for partnership? China is certainly not short of cash right now (in fact it is flush with it - look at the recent aggressive buying spree of western aviation companies - eg. Future Advanced Composite Components (FACC) and Cirrus Industries....etc), so we can rule out finance is certainly not the reason for the desire of a partnership.

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That's nonsense. AVIC is a huge organization that encompasses many effectively independent companies and it only betrays ones ignorance to confuse AVIC with CAC.

Your argument about the purchase of BizJet again only shows how little you know about some pretty basic business concepts. There are small libraries worth of books written about why companies would buy each other or go into joint ventures or seek partners.

Your own article points out that AVIC's moves is aimed at breaking into the civilian market and has absolutely zilch to do with military aircraft. It is frankly a pretty silly thing to say that AVIC's commercial ventures are aimed to help the J20, since there is very limited cross-over between the two fields, and any subsystems that have duel use potential are carefully controlled and vetted by the likes of the US states department anyways before being authorized to be made available to the PRC, that's only been the case for the last 20 years...

The rest of your posts are all like this - A lot of assumptions and theories are fundamentally undermined by a seeming lack of some very basic background knowledge.

TerraN_EmpirE said:

uh... there are no sixth generation in production or development beyond early concept art just yet. the Next Generation Tactical Aircraft of the USAF and USN Next Generation Air Dominance concepts are slated for sometime in the 2025–2030 time span assuming development starts sometime in the next two too five years, At this point the only requirements know for such a craft as defined by Air force magazine october 2009 article are "extreme stealth; efficient in all flight regimes (subsonic to multi-Mach); possible “morphing” capability; smart skins; highly networked; extremely sensitive sensors; optionally manned; directed energy weapons." the only concept images yes lack vertical structures however those are so early as too be pre-developmental.

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See : Boeing F/A-XX


"In late 2011, the Navy plans to analyze alternatives for the NGAD program with a technology demonstration phase beginning in 2013."

Meaning, it is already under development.

plawolf said:

Yaw is only important for instantaneous turn rates, but in this day an age, with HMS cued high off broadside missiles, how important instantaneous nose pointing is has become questionable, especially since you incur huge drag when you turn your nose too much. TVC assisted extreme yaw pitching will result in exactly the kind of excessive energy and speed bleed that everyone, including yourself, acknowledges is a bad idea.

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So, according to you, with HMS cued high off broadside missiles technology it has become absolutely no point in making aircraft agile? How about just making J-20 fly like a F-117? eg. a dump truck?

I don't believe TVC will result in excessive energy loss. Show me a paper that says so. If energy loss is as you said it would be, why are F-22, F-35, PAK FA are all incorporating TVC into their design??

That's nonsense. AVIC is a huge organization that encompasses many effectively independent companies and it only betrays ones ignorance to confuse AVIC with CAC.

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CAC IS PART OF AVIC incase you didn't know.
The point I am making about AVIC is that all the chinese aviation companies are grouped under this, all the research institutes and laboratories, factories, etc are on about the same technology level/generation. (Notice the emphasis on the underline part)

Your argument about the purchase of BizJet again only shows how little you know about some pretty basic business concepts. There are small libraries worth of books written about why companies would buy each other or go into joint ventures or seek partners.

Your own article points out that AVIC's moves is aimed at breaking into the civilian market and has absolutely zilch to do with military aircraft. It is frankly a pretty silly thing to say that AVIC's commercial ventures are aimed to help the J20, since there is very limited cross-over between the two fields, and any subsystems that have duel use potential are carefully controlled and vetted by the likes of the US states department anyways before being authorized to be made available to the PRC, that's only been the case for the last 20 years...

The rest of your posts are all like this - A lot of assumptions and theories are fundamentally undermined by a seeming lack of some very basic background knowledge.

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Personal attacks are not a convincing arguments, it adds nothing to your retort.
Explain to me why "civilian market and has absolutely zilch to do with military aircraft".
Give me plausible examples.

Like I mentioned in last paragraph, looking at the civilian aviation development tells you plenty about the military development. AVIC currently seems to be able to indigenously design airframes, while the rest needs to be imported. For example ARJ-21 programme is supported by 19 major European and US aerospace components suppliers, including General Electric (engine production),Honeywell (fly-by-wire system) and Rockwell Collins (avionics production).


Looking at the list of suppliers on the Comac C919 project will tell you the same thing. All things except airframes are imported.


This is fact. It shows lack of maturity and sophiscation in developing avionics to the western standard.

This is parallel in the military sector - If I am not wrong, even J-10 does not have FADEC (Full Authority Digital Engine Control) - it shows the lack of sophistication of Chinese aviation industries. FADEC has been around for the past 30 years since 1970s - starting with F-111 (3rd generation aircraft) and majority of the 4th generation (F14, F-15, F-16,F18) etc.. The technology eventually trickle down to civilian side and hugely benefit the civilian market. Boeing started using FADEC back in 1984 on Boeing 757.

So the military aviation industries is NOT completely separated from the civilian side. It benefits each other when technologies developed from one side can always cross over to other side. Currently, looking at the sophistication of chinese civilian aviation industry development can tell you a lot about the sophistication of the military aviation industry development. The two are the same (or at least not that far apart). This is especially true in China's case because most of the research and fundings are directed by state (centrally planned). There are very few companies in China that is capable of R&D independently in high sophistication comparable to the state funding level (or its western counterparts).
This is in contrast to the western (defense) conglomerates where they can independently fund, research, and develop the technologies require for their products.

Which only means AVIC is in need to catch up - and it has shown it is taking steps to do so by going the technology acquisition phase.

J-10 do have FADEC. As for AR-21 jet. Do you know civilian aircraft especially international jet has more strict requirement. That is why you see Russian so far has zero commercial jet making into euro and USA despite they have a robust military industrial. An AR-21 with US parts is easier to be accepted in Europe and US and international or An AR-21 with all Chinese parts is easier to be accepted in terms of perception, I think I need not tell u the answer.

And u also forget Y-20, an highly important large air transport is totally independent without foreign and prototype will makes it debut in next year.