J-XX Fighter Aircraft

Re: J-xx

I would like to see how China reduces the heat signature emmited from the turbofans, as all images of the possible "J-XX" has their engine revealed with any cover...simular method to the US F-22 maybe...also materials must be specially made, thickness of the material must be precision and spot on, revolving internal launch rail is yet to be discussed, engine is still an issue even with the WS-10A in production...just wont cut it for a advance heaveyweight fighter...smaller SD-10 with clipped wings in order to fit inside the internal weapons bay....

yes....a very long list of what to do and test is still at hand...this will be the ultimate challenge for the PLAAF aviation industry history...seems the Chinese arent bothering with VTOL fighter pitty

Re: J-xx

The development of a valuable VTOL fighter is a really challanging, time and cost intensive project. Besides the fact the I think chinese aviation companies are currently pretty busy, I don't think the potential gains would justify the development resources needed.
The J-10 seems to be able to use pretty short runways, and China also seems to develop full scale carriers, so there's no necessity for a VTOL aircraft.

I think canards offer some usefull aerodynamic advantages that can outweight the potential RCS increase. At least as long as there's no TVC. Probably even then. Maybe for a LO aircraft it may be advantageous to have the canards moved to the same level as the main wing, to minimize visible surface from the frontal aspect. Finally I guess there will be an RAM coating on those anyway.
Btw, since all the ECDs have the canards above the main wing level, what would be the aerodynamic consequences of moving them to the same level as the wing?

Tphuang, you wrote in your blog about rumors that this 5gen fighter may now become a collaboration between SAC and CAC. Does that mean that those J-10 upgrades CAC was working on looked pretty promissing and may go straight into that "J-xx"? Wich in turn could mean that it would have some basic similarities with J-10?

Re: J-xx

Scratch said:

The development of a valuable VTOL fighter is a really challanging, time and cost intensive project. Besides the fact the I think chinese aviation companies are currently pretty busy, I don't think the potential gains would justify the development resources needed.
The J-10 seems to be able to use pretty short runways, and China also seems to develop full scale carriers, so there's no necessity for a VTOL aircraft.

I think canards offer some usefull aerodynamic advantages that can outweight the potential RCS increase. At least as long as there's no TVC. Probably even then. Maybe for a LO aircraft it may be advantageous to have the canards moved to the same level as the main wing, to minimize visible surface from the frontal aspect. Finally I guess there will be an RAM coating on those anyway.
Btw, since all the ECDs have the canards above the main wing level, what would be the aerodynamic consequences of moving them to the same level as the wing?

Tphuang, you wrote in your blog about rumors that this 5gen fighter may now become a collaboration between SAC and CAC. Does that mean that those J-10 upgrades CAC was working on looked pretty promissing and may go straight into that "J-xx"? Wich in turn could mean that it would have some basic similarities with J-10?

Click to expand...

I don't know, certain techniques might be. But I would expect the 5th generation fighter to be an entirely new deign. One thing is for sure, they are going with a heavy fighter (F-15/su-27 class) for the next generation. They can't achieve the same level of stealth as the Americans. So, the only thing they can do is to build a larger fighter with larger radar, more powerful EW suite and greater internal carriage.

Re: J-xx

tphuang said:

They can't achieve the same level of stealth as the Americans. So, the only thing they can do is to build a larger fighter with larger radar, more powerful EW suite and greater internal carriage.

Click to expand...

Why not go the opposite way? If you're going to operate near the mainland anyway, rely on ground-based radar or AWACS and a good datalink.

Build a small, fast maneuverable fighter that can intercept an F-22 quickly with the support of external tracking.

Re: J-xx

tphuang said:

I don't know, certain techniques might be. But I would expect the 5th generation fighter to be an entirely new deign. One thing is for sure, they are going with a heavy fighter (F-15/su-27 class) for the next generation. They can't achieve the same level of stealth as the Americans. So, the only thing they can do is to build a larger fighter with larger radar, more powerful EW suite and greater internal carriage.

Click to expand...

I was under the impression that SAC had a preference for an F-22 type aircraft while CAC had a preference for a lighter (but still dual engine) type aircraft. After all, that's the specialty of the two companies.

If they are going for a heavy fighter for the J-XX program, then it looks like we're not going to see a light stealth fighter at all. With the cancellation of "twin engined J-10", the J-10's will be upgraded up to a certain point, but not to the point of having a true stealth airframe.

A bit disappointing actually. I was hoping for a light air superiority fighter in the vein of J-10, but designed from the beginning for stealth.

Re: J-xx

If you have canards coplane wth the main wing their is some loss of lift on the main but on the other hand there are vortices running over the main wing too. The risk is having these vortices turn into turbulence which is why many co planar canard designs separate tthe canards from the main wing by sheer distance.

Re: J-xx

Wouldn't it be simpler for SAC and CAC simply to for go canards, just to reduce costs and design time, if nothing else?

And what exactly did the CAC proposal feature?

Re: J-xx

crobato said:

If you have canards coplane wth the main wing their is some loss of lift on the main but on the other hand there are vortices running over the main wing too. The risk is having these vortices turn into turbulence which is why many co planar canard designs separate tthe canards from the main wing by sheer distance.

Click to expand...

why forward canard,when the aircraft already got TVC.while this design can make aircraft ultra manueverity,but at high -G ,no pilot is able physcally survive.
the idea probably conceptual design.

Re: J-xx

crobato said:

If you have canards coplane wth the main wing their is some loss of lift on the main but on the other hand there are vortices running over the main wing too. The risk is having these vortices turn into turbulence which is why many co planar canard designs separate tthe canards from the main wing by sheer distance.

Click to expand...

Su-30 MKI's canards are not only coplanar but also very close to the main wing as seen . Actually they are just small fixtures which help during high AoA and hence are not canards in the conventional sense. With TVC, it doesn't need full-fledged canards anyway.

But larger controllable canards (as in Gripen, EF and J-10) can obstruct or somewhat divert the wind flow to the main wing, which is probably why they are at a different level from the main wing.

Re: J-xx

I thought the main reason that aircraft have canards was to increase the surface area of the wing, therefore, increasing the amount of lift it produces? Aren't supposed to make a small wing produce the amount of lift a large wing would?