Shenyang FC-31 / J-31 Fighter Demonstrator

latenlazy

Brigadier
I thought J-20 was similar in size and might even be a little smaller than some of the Flankers... Might be slightly smaller than J-15, but should be comparable?

Weight, especially with the structural reinforcements needed for landing (and eventually catapult), would be a problem for the J-20. Let's say the J-20's current weight is the same as a J-15's (it will probably be north of that though). That weight will only go up for the base design to function on a carrier.
 

Quickie

Colonel
I thought J-20 was similar in size and might even be a little smaller than some of the Flankers... Might be slightly smaller than J-15, but should be comparable?

Most of us heard too many of the comments that the J-20 is big and, I guess, are somehow influenced to automatically assume it's a bit too big for carrier operation.

In the videos, I recall the takeoff distance of the J-20 isn't any noticeably different from the J-10A and the JF-17. I seem to recall, in one of the videos, the J-20 even has the shorter takeoff distance than the J-10. My guess is, with more powerful engines, the J-20 could just turn out to be capable of operating off the carrier afterall. If not off the skijump, then it could possibly operate off the catapult.
 
Last edited:

thunderchief

Senior Member
It would be a risky move, but SAC could fund the project's development while it's looking for buyers.

It would be almost suicidal . SAC would have to go into large debt . And if the China doesn't buy the plane , who would ? Maybe few dozen for Pakistan and other countries , not enough to cover huge expenses .
 

latenlazy

Brigadier
It would be almost suicidal . SAC would have to go into large debt . And if the China doesn't buy the plane , who would ? Maybe few dozen for Pakistan and other countries , not enough to cover huge expenses .

It could be a scheme where SAC goes into large debt and force the PLA to buy XD. Seriously though, we don't know how much it would actually cost for SAC to develop the project on its own. It seems like the only reason we even got to see a prototype was because SAC had already invested so much into the design, and it's possible that SAC can do the rest on the cheap using less than state of the art subsystems, or through built in subsidies of being within the larger AVIC conglomerate. Given that SAC is not a Lockmart, I would argue self funding while looking for buyers is a possibility.

Most of us heard too many of the comments that the J-20 is big and, I guess, are somehow influenced to automatically assume it's a bit too big for carrier operation.

In the videos, I recall the takeoff distance of the J-20 isn't any noticeably different from the J-10A and the JF-17. I seem to recall, in one of the videos, the J-20 even has the shorter takeoff distance than the J-10. My guess is, with more powerful engines, the J-20 could just turn out to be capable of operating off the carrier afterall. If not off the skijump, then it could possibly operate off the catapult.

Again, need to point out that structural reinforcement needed for carrier operations will exact an additional weight penalty on the design. It's not simply about how big the J-20 is, but how big it will be after you modify it for carrier operations. Making the design work for a carrier is certainly doable, but I doubt it's practical.
 

thunderchief

Senior Member
It could be a scheme where SAC goes into large debt and force the PLA to buy XD.

Well , that could be their tactics ;)

Seriously though, we don't know how much it would actually cost for SAC to develop the project on its own. It seems like the only reason we even got to see a prototype was because SAC had already invested so much into the design, and it's possible that SAC can do the rest on the cheap using less than state of the art subsystems, or through built in subsidies of being within the larger AVIC conglomerate. Given that SAC is not a Lockmart, I would argue self funding while looking for buyers is a possibility.

I don't say it would cost as much as F-35 or F-22 to Americans , but compare it with PAK FA and we are still talking about billions - just to get IOC . They could use cheaper avionics , even the engine , to cut cost . But what would be the point ? Main cost of the development is actual shaping of the plane to get minimum RCS with maximum maneuverability. If you did that it would be waste of effort to get skimpy on details (having fifth generation plane with fourth generation avionics and engine )
 

latenlazy

Brigadier
Well , that could be their tactics ;)



I don't say it would cost as much as F-35 or F-22 to Americans , but compare it with PAK FA and we are still talking about billions - just to get IOC . They could use cheaper avionics , even the engine , to cut cost . But what would be the point ? Main cost of the development is actual shaping of the plane to get minimum RCS with maximum maneuverability. If you did that it would be waste of effort to get skimpy on details (having fifth generation plane with fourth generation avionics and engine )
If that's the case, then the money seems already to have been spent. Besides, SAC doesn't have to sell a product that performs as well on RCS than the PAK FA or the J-20 or the F-22. It could simply be better than the alternatives on the market.
 

thunderchief

Senior Member
If that's the case, then the money seems already to have been spent. Besides, SAC doesn't have to sell a product that performs as well on RCS than the PAK FA or the J-20 or the F-22. It could simply be better than the alternatives on the market.

Not really , because this is just a basic shape which would be changed and refined as things progress . It is hard to guess RCS of current prototypes , but I think it is somewhere in the range of 1 m² . Now they will try to find "radar leaks" and correct potential problems with aerodynamics , hoping to reduce RCS to at least 0.0001 m² range in frontal sphere . We can only guess what sort of RAM materials will they use (especially for cockpit ) and for all important bandpass radome in the nose (problem of the radar in nose is main stealth spoiler ) .

For a potential market , J-31 would have to be better than latest generation of Chinese and Russian 4gen planes ( Su-30 , Su-35 , J-10 , J-11 ... ) and cheaper than PAK FA .
 

latenlazy

Brigadier
Not really , because this is just a basic shape which would be changed and refined as things progress . It is hard to guess RCS of current prototypes , but I think it is somewhere in the range of 1 m² . Now they will try to find "radar leaks" and correct potential problems with aerodynamics , hoping to reduce RCS to at least 0.0001 m² range in frontal sphere . We can only guess what sort of RAM materials will they use (especially for cockpit ) and for all important bandpass radome in the nose (problem of the radar in nose is main stealth spoiler ) .

For a potential market , J-31 would have to be better than latest generation of Chinese and Russian 4gen planes ( Su-30 , Su-35 , J-10 , J-11 ... ) and cheaper than PAK FA .

May not be that hard to achieve, at least in terms of R&D, since SAC is part of a bigger conglomerate.
 

SinoSoldier

Colonel
If that's the case, then the money seems already to have been spent. Besides, SAC doesn't have to sell a product that performs as well on RCS than the PAK FA or the J-20 or the F-22. It could simply be better than the alternatives on the market.

PAK FA and a reduced radar cross section certainly don't mix.
 
Top