Shenyang FC-31 / J-31 Fighter Demonstrator

taxiya

Brigadier
Registered Member
No I haven't. When I said if the photos ... I'm referring to the CGI ones obviously.
Ok, as SinoSoldier showed in post 5631, the door opening is real (I believe). The CGI I meant was the weapon launching sequence GIF. But this photo does not necessarily mean J-31 can not do something like F-35 does, after all this is only version 1.0. It is not a big deal to reinforce the inside of the doors with thicker ridges to hold a missile. The current mechanism seems too weak though. We will have to wait and see.
 

Air Force Brat

Brigadier
Super Moderator
Because J-31 was not designed to accommodate side bays because of considerations for space and price perhaps? Side bays would have taken room from main bays while adding huge complexities, time in production, and cost. It was never designed to be a dog-fighter and likely won't make an exceptional one even with WS-19s. So why compromise. Internal bays seem to be a monumental task. KF-X is now officially decided to not have internal bays at least for the first model. J-20 is currently the only stealth fighter with total bay volume that more or less matches F-22. J-31 missions will hardly ever require two SRAAMs. Any such requirement can be filled by the handful of other fighter types available to PLAAF. Weren't stealth fighters always been designed for the sniper/ door opener/ force multiplier role? The shoot and scoot guerilla tactics, sometimes visible often not, sources of enemy frustration. J-20 side bays are more useful as a PR tool than actual use. Exposing J-20 to WVR air to air combat would be such a silly risk to take. Everything from Hornet to Rafale and Typhoon have successfully "taken out" F-22s in exercises. IIRC some claimed the Su-30MKM have "gunned down" F-22s in their exercises back in 2016?

You start out strong with a great argument against side weapons bays, (the main reason is this is a small airframe, the exact same reason the F-35 does NOT have them)!

Then you get onto some unfathomable argument that the FC-31 won't make a good dog-fighter and blah, blah, blah.... you really don't have a clue about the FC-31, or for that matter the F-35..

Then you go for the grand finale that the side bays on the J-20 are for PR,,, (really Einstein???, you have an inside source at Chengdu? right???)

and then the "Piece de resistance", that the Rafael or Eurofighter are the equals of the F-22 and take them out frequently in exercises..

it really would be nice if you qualified your data, along with a notation that the F-22 jockeys have to practically beg people to fly against them, and when they do, they make very significant sacrifices in ROE, just to get the other side to come out and play.

You very smart, you do have good instincts, but then you get on a roll and "stuff" just comes rolling out?? I admit its very difficult to come up with accurate, detailed information on the internet,,, but I wish you would stick to realities, and what is "known information"
 

plawolf

Lieutenant General
Contrast that with how the F35’s bay doors open to allow them to hang missiles on the doors.

It might be technically possible with a little compressed air directional ejection assist, but that seems very technically complex and risky to do.

I have not seen any photos of the F35 carrying AIM9s internally. So even redesigning the entire bay will be unlikely to allow internal carry for PL10s.

SRAAMs are typically railed launched instead of drop launched as BVRAAMs are. That means the missile engine ignites with the missile still on the launch rail.

That powerful back blast will take a much higher design tolerance to withstand (more weight and cost), and you are also likely to have other issues if you got other missiles still in the bay from the funnelled back blast hitting those.

Without side bays (which there is just no room for without going to F22/J20 sizes) the J31 may not even be able to internal carry any SRAAM, which will put it at a decisive disadvantage in a 5th gen vs 5th gen fight, where neither side might be able to detect and/or effectively engage each other until they are within WVR combat ranges.

This is a key reason I have been cold on the J31 from the get go.

The only way to add SRAAM capability without the major drag and signature penalty of external carriage might be PAKFA style semi-recessed carriage in the wings, with drop away covers; or stealth pods (maybe wingtip mounted and thus semi-fixed like conformal tanks, which will normally remain in place, but could be removed by ground crew without too much fuss).
 

Air Force Brat

Brigadier
Super Moderator
Contrast that with how the F35’s bay doors open to allow them to hang missiles on the doors.

It might be technically possible with a little compressed air directional ejection assist, but that seems very technically complex and risky to do.

I have not seen any photos of the F35 carrying AIM9s internally. So even redesigning the entire bay will be unlikely to allow internal carry for PL10s.

SRAAMs are typically railed launched instead of drop launched as BVRAAMs are. That means the missile engine ignites with the missile still on the launch rail.

That powerful back blast will take a much higher design tolerance to withstand (more weight and cost), and you are also likely to have other issues if you got other missiles still in the bay from the funnelled back blast hitting those.

Without side bays (which there is just no room for without going to F22/J20 sizes) the J31 may not even be able to internal carry any SRAAM, which will put it at a decisive disadvantage in a 5th gen vs 5th gen fight, where neither side might be able to detect and/or effectively engage each other until they are within WVR combat ranges.

This is a key reason I have been cold on the J31 from the get go.

The only way to add SRAAM capability without the major drag and signature penalty of external carriage might be PAKFA style semi-recessed carriage in the wings, with drop away covers; or stealth pods (maybe wingtip mounted and thus semi-fixed like conformal tanks, which will normally remain in place, but could be removed by ground crew without too much fuss).

Right Wolfie, enlarging those weapons bays would require a complete rework of nearly every structural part on the airplane, which Boeing proved is not that tough with the Super Hornet?? (that's not really true is it Boeing, but they pulled it off seamlessly and Shenyang is no less capable of up-scaling their baby bird...

I would imagine those doors will be reworked to hang a couple of smaller AAMRAM, which is the simple fix,, lots of very effective weapons are being downsized.

This bird has a bright future and is Mig-29K sized, the Army and the Navy will both be well served in the future by this airplane, and it is significantly farther along than other possible designs, that means something these days!
 

ougoah

Brigadier
Registered Member
You start out strong with a great argument against side weapons bays, (the main reason is this is a small airframe, the exact same reason the F-35 does NOT have them)!

Then you get onto some unfathomable argument that the FC-31 won't make a good dog-fighter and blah, blah, blah.... you really don't have a clue about the FC-31, or for that matter the F-35..

Then you go for the grand finale that the side bays on the J-20 are for PR,,, (really Einstein???, you have an inside source at Chengdu? right???)

and then the "Piece de resistance", that the Rafael or Eurofighter are the equals of the F-22 and take them out frequently in exercises..

it really would be nice if you qualified your data, along with a notation that the F-22 jockeys have to practically beg people to fly against them, and when they do, they make very significant sacrifices in ROE, just to get the other side to come out and play.

You very smart, you do have good instincts, but then you get on a roll and "stuff" just comes rolling out?? I admit its very difficult to come up with accurate, detailed information on the internet,,, but I wish you would stick to realities, and what is "known information"

I said "likely won't make an exceptional dog fighter" and J-31 was not designed as one. Neither of these are false because I've never claimed 100% certainty and judged its WVR abilities based on what we know about engine performance available for J-31, at the moment WS-13 or RD-33x are just not going to give it enough push. So I don't get your strong reaction to this. Stealth fighters weren't designed to be dogfighters, many the capabilities are engineered into it but only ever as a lower priority to their main roles. So yes 5th gens can be great dogfighters like the F-22 but they didn't start those projects aiming for WVR dominance.

My statement about J-20 side bays are related to my belief that side bays on stealth fighters are a tiny bit of an anomaly given they will all be instructed to avoid WVR fights when not absolutely necessary. Which means the vast majority of missions they fly will not require side bays. Remember J-20 side bays can only currently fire WVR missiles. So if side bays comes with a variety of costs and they are rarely useful, it ALMOST becomes more useful as a PR tool as in, look we can manage this too like the Americans and no one else has even come close or plan on doing this. If you reread what I wrote my choice of words were fair. I never said it is a PR exercise, more so that given the costs of side bays and how they may end up being rarely useful for what I'd expect J-20 missions to involve, those bays are probably more effective as morale boosts for the airforce and engineering teams than they are useful for their designed purpose. Of course this whole premise is built on my assumption that 5th gens are costly and very limited assets, to risk them in WVR fights or pushing them into WVR fights when they can turn and run would be unwise. Of course I don't know better but I'd say that's a fair assessment.

All said and done I think you just like writing these abrasive comments for fun. I guess it's normal for you to take things out of context and misrepresent the reasonable points other people try to make... even when they are not forceful and carefully chose their words so misunderstandings like this can be avoided. Have fun trolling the forums.

Oh and btw Typhoon, Hornet, and Rafale have all gunned down F-22s in WVR mock fights. The very clear point I was making with that statement was to show that 5th gens lose a great deal of their (very expensive) advantage when they get WVR. This relates to how side bays being associated with WVR means side bays should be less important a consideration, particularly when they may come at great compromises to other important considerations like performance and main bay space re J-31.
 

ougoah

Brigadier
Registered Member
Contrast that with how the F35’s bay doors open to allow them to hang missiles on the doors.

It might be technically possible with a little compressed air directional ejection assist, but that seems very technically complex and risky to do.

I have not seen any photos of the F35 carrying AIM9s internally. So even redesigning the entire bay will be unlikely to allow internal carry for PL10s.

SRAAMs are typically railed launched instead of drop launched as BVRAAMs are. That means the missile engine ignites with the missile still on the launch rail.

That powerful back blast will take a much higher design tolerance to withstand (more weight and cost), and you are also likely to have other issues if you got other missiles still in the bay from the funnelled back blast hitting those.

Without side bays (which there is just no room for without going to F22/J20 sizes) the J31 may not even be able to internal carry any SRAAM, which will put it at a decisive disadvantage in a 5th gen vs 5th gen fight, where neither side might be able to detect and/or effectively engage each other until they are within WVR combat ranges.

This is a key reason I have been cold on the J31 from the get go.

The only way to add SRAAM capability without the major drag and signature penalty of external carriage might be PAKFA style semi-recessed carriage in the wings, with drop away covers; or stealth pods (maybe wingtip mounted and thus semi-fixed like conformal tanks, which will normally remain in place, but could be removed by ground crew without too much fuss).

Exactly and fair call on how the F-35 does it. Missile launch will be too risky particularly for hard turning launches of WVR missiles (highly likely scenarios). Best way to do it is either with drop away stealthy missile pods or drop away sheaths like what some suggest is how Su-57 hides WVR missiles. Far less risky than hanging them on the inside. I doubt we'd see a novel main bay door design for J-31.
 

ougoah

Brigadier
Registered Member
Ok, as SinoSoldier showed in post 5631, the door opening is real (I believe). The CGI I meant was the weapon launching sequence GIF. But this photo does not necessarily mean J-31 can not do something like F-35 does, after all this is only version 1.0. It is not a big deal to reinforce the inside of the doors with thicker ridges to hold a missile. The current mechanism seems too weak though. We will have to wait and see.

I think if that is how the final version will open doors, it does mean hanging missiles on the inside is out of the question. Missile launching is quite violent on the airframe. If the doors can handle this sort of stuff, they will still need to overcome the potential problems with failed launches or damaged mechanism. Managing these risks may mean it's just not worth pursuing that option when they can easily do stealthy pods or drop away pods.
 

Air Force Brat

Brigadier
Super Moderator
I said "likely won't make an exceptional dog fighter" and J-31 was not designed as one. Neither of these are false because I've never claimed 100% certainty and judged its WVR abilities based on what we know about engine performance available for J-31, at the moment WS-13 or RD-33x are just not going to give it enough push. So I don't get your strong reaction to this. Stealth fighters weren't designed to be dogfighters, many the capabilities are engineered into it but only ever as a lower priority to their main roles. So yes 5th gens can be great dogfighters like the F-22 but they didn't start those projects aiming for WVR dominance.

My statement about J-20 side bays are related to my belief that side bays on stealth fighters are a tiny bit of an anomaly given they will all be instructed to avoid WVR fights when not absolutely necessary. Which means the vast majority of missions they fly will not require side bays. Remember J-20 side bays can only currently fire WVR missiles. So if side bays comes with a variety of costs and they are rarely useful, it ALMOST becomes more useful as a PR tool as in, look we can manage this too like the Americans and no one else has even come close or plan on doing this. If you reread what I wrote my choice of words were fair. I never said it is a PR exercise, more so that given the costs of side bays and how they may end up being rarely useful for what I'd expect J-20 missions to involve, those bays are probably more effective as morale boosts for the airforce and engineering teams than they are useful for their designed purpose. Of course this whole premise is built on my assumption that 5th gens are costly and very limited assets, to risk them in WVR fights or pushing them into WVR fights when they can turn and run would be unwise. Of course I don't know better but I'd say that's a fair assessment.

All said and done I think you just like writing these abrasive comments for fun. I guess it's normal for you to take things out of context and misrepresent the reasonable points other people try to make... even when they are not forceful and carefully chose their words so misunderstandings like this can be avoided. Have fun trolling the forums.

Oh and btw Typhoon, Hornet, and Rafale have all gunned down F-22s in WVR mock fights. The very clear point I was making with that statement was to show that 5th gens lose a great deal of their (very expensive) advantage when they get WVR. This relates to how side bays being associated with WVR means side bays should be less important a consideration, particularly when they may come at great compromises to other important considerations like performance and main bay space re J-31.
 

plawolf

Lieutenant General
Ok, as SinoSoldier showed in post 5631, the door opening is real (I believe). The CGI I meant was the weapon launching sequence GIF. But this photo does not necessarily mean J-31 can not do something like F-35 does, after all this is only version 1.0. It is not a big deal to reinforce the inside of the doors with thicker ridges to hold a missile. The current mechanism seems too weak though. We will have to wait and see.

I just wanted to clear up that the F35 does not actually hang any missiles on its weapons bay doors, in case my earlier, poorly worded post was the cause of the confusion.

That F35 have a pair of normal launch rails, which pivots down when the weapons bays open, to create the necessary clearance for weapons deeper in the bay to be released.

It just appears that a pair of missiles are mounted on the inside of the weapons bay doors when that is not the case.
 
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