Chengdu J-20 5th Generation Aircraft News & Discussions

[Ultima Thule]

My major is C4ISR, what do you think?

Its about RCS not whether its C4ISR platform or not

 

[Deino]

Guys ... can we stick to the topic plaese!

Not sure how far the RCS of an E-3 or C4ISR is relevant in a longer discussion?!

 

[dbc]

J-20 can surpass F-22 lift due to HUGE canard application and ventral fins. Our fighter is also quite light for its size and for stealth fighter. Around 18 tonnes according to whispers. Heavier than flanker but for stealth fighter, it is surprisingly light. According to them, done by new manufacturing processes and material processing and 3D printing some parts. Also our metamaterials for the skin is high end stealth unlike what Americans love to say. Our fighter is as stealthy as their's on F-35 and better than F-22. F-22 uses old stealth method of materials and paint. Already seen them breaking off and cracking only after 10 years and still they store them very preciously. Their F-35 matched our's with metamaterials latest generation stealth technology but their systems and engines are probably much better.

Where do you get this from? Photos of the J20?.

 

[Indos]

J-20 can surpass F-22 lift due to HUGE canard application and ventral fins. Our fighter is also quite light for its size and for stealth fighter. Around 18 tonnes according to whispers. Heavier than flanker but for stealth fighter, it is surprisingly light. According to them, done by new manufacturing processes and material processing and 3D printing some parts. Also our metamaterials for the skin is high end stealth unlike what Americans love to say. Our fighter is as stealthy as their's on F-35 and better than F-22. F-22 uses old stealth method of materials and paint. Already seen them breaking off and cracking only after 10 years and still they store them very preciously. Their F-35 matched our's with metamaterials latest generation stealth technology but their systems and engines are probably much better.

J 20 empty weight is 19.391 kg, but KFX/IFX is much lighter with 11.800 kg while it has longer range and more speed. J20 is also quite big, so it will likely to have bigger RCS. So your statement saying J20 is surprisingly light compared to another Stealth Fighter is not true.

 

[Deino]

Trumpeter's J-20 in 1/48

https://www.bilibili.com/video/BV1WD4y1D7YG

 

[zectech]

Only PL-xx maybe R-37 extended range have this sort of 300km range.

PL-XX do not fit in internal bay of J-20? Then use the same example above in putting PL-XX on external pylons for certain select missions. South China seas patrols with Island radar providing enemy stealth detection, is a possible scenario for using J-20s with PL-XX. Over India they would be useless, for stealth cover would be lost. Over Korea the same. Only over you own territory/open ocean can such a tactic be somewhat useful in certain cases.

 

[dbc]

F-22 lift coefficient is public, at least US Airforce boasted their number. J-20 designer made it, and surpass F-22. Those designer complained a lot, they initially thought this is mission impossible, but still made it eventually.

And the designer finally found F-22 is not as good as they boasted. It was old cold war tactic. Those designer has their channel to get the spec we don't know.

I can assure you, Chinese culture don't and hate boast, those designers can NOT lie on those sensitive issues.

Lighter is a relative number, it depends on the total weight. F-22 is designed with less than 60000 hydraulic press machine. To make it lighter, China built world biggest hydraulic press machine. Biggest Die forging machine.

Those kind of debate is meaningless. But I watched J-20 designer interview, they beat F-22 on many aspect.

So the J20 designer claims the J20 is more maneuverable and agile than the Raptor?

 

[vi-va]

So the J20 designer claims the J20 is more maneuverable and agile than the Raptor?

I didn't say that. But he said J-20 has better lift coefficient.

 

[dbc]

I didn't say that. But he said J-20 has better lift coefficient.

You said the J20 beat the Raptor in many aspects according to the J20 chief designer.
Lift coefficient is one but an Airbus A380 also has a better lift coefficient than the Raptor-so what?

 

[vi-va]

You said the J20 beat the Raptor in many aspects according to the J20 chief designer.
Lift coefficient is one but an Airbus A380 also has a better lift coefficient than the Raptor-so what?

I am out of this question.

 

[CAPRICORN-88]

F-22 lift coefficient is public, at least US Airforce boasted their number. J-20 designer made it, and surpass F-22. Those designer complained a lot, they initially thought this is mission impossible, but still made it eventually.

And the designer finally found F-22 is not as good as they boasted. It was old cold war tactic. Those designer has their channel to get the spec we don't know.

I can assure you, Chinese culture don't and hate boast, those designers can NOT lie on those sensitive issues.

Lighter is a relative number, it depends on the total weight. F-22 is designed with less than 60000 hydraulic press machine. To make it lighter, China built world biggest hydraulic press machine. Biggest Die forging machine.

Those kind of debate is meaningless. But I watched J-20 designer interview, they beat F-22 on many aspect.

You are absolutely right.
J-20 airframe is supposedly constructed using a very special alloy with lithium, titanium and aluminum. It is also very light in weight.

 

[samsara]

You said the J20 beat the Raptor in many aspects according to the J20 chief designer.
Lift coefficient is one but an Airbus A380 also has a better lift coefficient than the Raptor-so what?

Moreover the A380 can even carry more loads, and have longer flight range.

 

[serenity]

PL-XX do not fit in internal bay of J-20? Then use the same example above in putting PL-XX on external pylons for certain select missions. South China seas patrols with Island radar providing enemy stealth detection, is a possible scenario for using J-20s with PL-XX. Over India they would be useless, for stealth cover would be lost. Over Korea the same. Only over you own territory/open ocean can such a tactic be somewhat useful in certain cases.

Yes PL-xx is too large for J-20. J-20 is more for operating in front and share data to J-16 and other fighters. AEWC aircraft and J-16 also share data with J-20. I don't think J-20 will be asked for carry any long range missiles. Only PL-12 improvements and PL-15 slim versions. It should carry 6 medium range not 4 because 4 is for the older larger PL-15.

J 20 empty weight is 19.391 kg, but KFX/IFX is much lighter with 11.800 kg while it has longer range and more speed. J20 is also quite big, so it will likely to have bigger RCS. So your statement saying J20 is surprisingly light compared to another Stealth Fighter is not true.

KFX and IFX is no even in prototype. Talk about 11.8 tonne weight after service. F-22 and F-35 true weight is secret but stealth fighter are much heavier that's why I said J-20 is light for its size and being a stealth fighter of that size. It is nearly F-22 weight. Lift is claimed by Chengdu engineers to be better than F-22's which they thought was excellent. This is believable but just claims. Believable because J-20 has huge canards for extra lift unlike F-22's arrangement its horizontal stabilizer does not add much lift at all due to flow of air after wings. Like F-35 and F-22, J-20 also incorporates a lifting body design. RCS depends on materials nowadays and how to manage the electronics and other spectrums of active and passive sensors. The aircraft itself relies all on metamaterials, workmanship, and good shaping. J-20 has good shaping and workmanship on surface and some official leaks also show some metamaterials even hinting next generation of materials can do things from children's imagination. Lockheed Martin already trialing some exotic things I bet and some videos they also hint at them. One is circuit one is invisibility to eye and of course all moving surfaces for much more variability in the geometry.

You said the J20 beat the Raptor in many aspects according to the J20 chief designer.
Lift coefficient is one but an Airbus A380 also has a better lift coefficient than the Raptor-so what?

F-22 vs Airbus then. So nothing truly but also for similar class fighters, then there is something. It doesn't matter much though because all depends on speed and altitude. F-22 has much better engines anyway.

 

[dbc]

F-22 vs Airbus then. So nothing truly but also for similar class fighters, then there is something. It doesn't matter much though because all depends on speed and altitude. F-22 has much better engines anyway.

The canard on the J20 generates both lift and drag which is further aggravated by the need to constantly negate pitching moment caused by the canard. This is one of the compromises of a close coupled canard design and hence the need to carry lots of fuel internally. Looking at the Lift coefficient in isolation is not the best way to compare aerodynamic efficiency of two platforms and hence my rather sarcastic remark about the Airbus A380.

Drag is the price paid to obtain lift. The lift to drag ratio (L/D) is the amount of lift generated by a wing or airfoil compared to its drag. The lift/drag ratio is used to express the relation between lift and drag and is determined by dividing the lift coefficient by the drag coefficient, CL/CD. A ratio of L/D indicates airfoil efficiency. Aircraft with higher L/D ratios are more efficient than those with lower L/D ratios.

 

[serenity]

The canard on the J20 generates both lift and drag which is further aggravated by the need to constantly negate pitching moment caused by the canard. This is one of the compromises of a close coupled canard design and hence the need to carry lots of fuel internally. Looking at the Lift coefficient in isolation is not the best way to compare aerodynamic efficiency of two platforms and hence my rather sarcastic remark about the Airbus A380.

Drag is the price paid to obtain lift. The lift to drag ratio (L/D) is the amount of lift generated by a wing or airfoil compared to its drag. The lift/drag ratio is used to express the relation between lift and drag and is determined by dividing the lift coefficient by the drag coefficient, CL/CD. A ratio of L/D indicates airfoil efficiency. Aircraft with higher L/D ratios are more efficient than those with lower L/D ratios.

J-20 is NOT a close coupled canard. All airfoils produce drag which is redundant comment. The canards presence offer the J-20 more lift than without canard. This is the point. J-20 has more lift with the canards than with conventional tail design.

Thank you for reminder of basic fluid mechanics. I know the relationship between lift and drag. Look at comment above. It is simple. The canards offer more lift. Can you prove then that J-20's canards gives penalty instead of giving us pointless comment. It's like I will say this larger engine offers more power to the car, and you return by saying power to weight ratio is the power output of the engine over the mass of the car. It is pointless without the numbers. I am saying canard offers J-20 more lift and of course there is some penalty in drag. This doesn't need to be said. Why will they go with canard design and ventral fins if the drag is too much compared to design advantages?