Chinese AAM


Bltizo

Lieutenant General
Staff member
Super Moderator
Registered Member
IMO you are reading too much into a plastic model, the yellow bits could just be casting connectors or flow channels used for casting. Like those little plastic bits in model plane sheets which keep all the parts connected to the sheet so none of them fall off.

I mean, the whole point is that this is an official AVIC commissioned model where the details deserve careful consideration.

If this was just a random model on eBay or Taobao made by nobody then this amount of scrutiny would be a waste of time and completely inappropriate.


There have been many models made of J-20 over the years, some with details that were obviously different to the real thing, some depicting the aircraft with a ventral bay carrying six missiles as well. But those models were not given any consideration or serious thought at all because they were not official.
 

ougoah

Colonel
Registered Member
Dual pulse on PL-15 is much better than single boost like AIM-120, PL-12, R-77 etc. Of course if all factors remain same. Ramjet is much more complex and EXPENSIVE than the pretty effective and decent solution that is dual pulse. In fact I'm willing to bet many new developments will be making use of dual pulse.

Making staged AAM is ridiculous. Not even long range AAMs use rocket stages. The cost per missile will almost double considering you got to do a hell of a lot more engineering to get everything else to perform equally well despite having multiple stages. So no, dual pulse isn't a "poor man's" multistage missile. It's a poor man's air breathing AAM but it is almost as effective. Certainly much more effective (ceteris paribus) than having only a single boost. Well it's all a matter of range and energy.

Now how cheap can we make ramjets. The PLA uses many air breathing air to surface and surface to surface missiles. A long range (much longer than Meteor) ramjet/scramjet powered missile should be the sweetspot for an air breathing AAM. Soviets used such missiles to target larger aircraft and of course surface targets/ships. And yet we've seen PLAAF test a very long and slim long range missile rather than go down the development path of a modern Kh-31P or whatever the anti-radiation version is.
 

Totoro

Captain
VIP Professional
While I am not saying the model shown is necessarily inaccurate, I will personally wait for further images, of the real missile or real J-20, to be able to make a decision on the likelihood of that particular missile design and load configuration.

That's not to say 3 missiles in a bay is unlikely in the future, it will most probably happen at some point, and there already are unsubstantiated rumors about it, but certain elements in that model just don't scream as credible until corroborated by images of the actual thing.

Firstly, i have yet to see a high speed AAM missile that's been fielded anywhere in the world, with folding fins. While it may seem like a logical thing to do, obviously there are drawbacks to that solution, otherwise everyone who has stealth jets would also use such missiles. (weight and added drag are among them) That doesn't mean such missiles can't happen in the future, and it doesn't mean China won't be the first country to field such a missile - but I personally won't use an image of a tabletop model plane to make my decision on it. (R-77 does not have folding fins, as the control lattices are just that - lattices. Not fins. No one else uses that solution on an AAM and even the russian newest missile has reverted to fins, rather than lattices)

Secondly, not to use a staggered arrangement of missiles when 3 missiles are in a bay is wasteful and probably unlikely. There are two options, really. One, to have long missiles which take up most of the length of the bay, which would preclude staggering the position of the middle one. But for that to work and still have room for 3 missiles, the missiles themselves would have to be quite narrow.

Second option would be to have a shorter missile, not by much, and certainly still longer than an amraam, so the staggered arrangement can be accommodated. That would also mean missiles themselves could be made wider, which is pretty important for various front section subsystems. Bigger cross section usually means more capable seeker, fuze, warhead, etc. Staggered arrangement would make any folding fins and the drawbacks coming with those unnecessary.

Bigger cross section also means more drag, but that ties into a discussion of what the new smaller missiles would be all about. If it is to completely replace PL-15, then suffering more drag and thus having shorter range might not be acceptable. But personally, I find it more likely that the new missile would serve alongside the PL-15. That it's really a custom made solution for the stealth planes, to be able to carry more missiles in missions against other stealth jets. So in missions requiring chase of tankers for example, four PL-15 might still rather be used, instead of 6 new missiles.

Technology wise, the new missile will likely share its electronics with the next variant of PL-15 then. So it's not like future PL-15 would be behind in that department.
 

Tirdent

Junior Member
Registered Member
Making staged AAM is ridiculous. Not even long range AAMs use rocket stages. The cost per missile will almost double considering you got to do a hell of a lot more engineering to get everything else to perform equally well despite having multiple stages.

Yup, too expensive, but it has been considered (KS-172, AIM-152 AAAM).

Now how cheap can we make ramjets. The PLA uses many air breathing air to surface and surface to surface missiles. A long range (much longer than Meteor) ramjet/scramjet powered missile should be the sweetspot for an air breathing AAM.

Manufacturing cost for a ramjet is not that different from a rocket - neither has any moving parts. It does make flight control development more challenging, for the reasons outlined earlier (but that stops being a financial drain once you complete testing).

Firstly, i have yet to see a high speed AAM missile that's been fielded anywhere in the world, with folding fins. While it may seem like a logical thing to do, obviously there are drawbacks to that solution, otherwise everyone who has stealth jets would also use such missiles. (weight and added drag are among them) That doesn't mean such missiles can't happen in the future, and it doesn't mean China won't be the first country to field such a missile - but I personally won't use an image of a tabletop model plane to make my decision on it.

R-33/R-37 top side fin pair, for semi-recessed carriage in x-attitude under the MiG-31. Plenty of high-speed SAMs too, including some of the fastest outright (9M82, 9M96, Standard Missile family). It's expensive and might make stable separation difficult (fins can only pop out once clear of whatever obstacle requires them to be folded in the first place) but it's an established solution.

Aerodynamic stability during separation is probably the crucial problem, rather than speed, which is why it's much more common in SAMs (TELs are to all intents and purposes stationary during launch).
 
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Tirdent

Junior Member
Registered Member
Secondly, not to use a staggered arrangement of missiles when 3 missiles are in a bay is wasteful and probably unlikely. There are two options, really. One, to have long missiles which take up most of the length of the bay, which would preclude staggering the position of the middle one. But for that to work and still have room for 3 missiles, the missiles themselves would have to be quite narrow.

Second option would be to have a shorter missile, not by much, and certainly still longer than an amraam, so the staggered arrangement can be accommodated. That would also mean missiles themselves could be made wider, which is pretty important for various front section subsystems. Bigger cross section usually means more capable seeker, fuze, warhead, etc. Staggered arrangement would make any folding fins and the drawbacks coming with those unnecessary.

Another consideration is the aspect ratio of the flying surfaces. Long chord strakes make staggering just as difficult as a very long missile, because the offset required to align the fins of one missile with the fin/strake gab of its neighbour becomes prohibitively large. Try staggering R-77s, the package would be almost 1m longer than the individual missile! Of course, this is exactly the situation we see in this model (assuming the strakes aren't also folding), and fortunately the span of low aspect ratio strakes is often compact enough that staggering becomes unnecessary.

Not all missiles lend themselves to such an arrangement, and with the serpentine inlet duct encroaching on the top of the weapons bay in the forward section there might not be sufficient depth to stagger this particular design.
 

PiSigma

"the engineer"
One thing I forgot to mention is that the official models is always suppose to show known information. So I find the fact this model shows 6 missiles in the central bay surprising.

I got my j10A model when the J10b came out. Basically there is nothing new on j10A that can be learned from a model.

I wonder if the j20 can always take 6 missiles in the central bay but they just showed 4 on displays......
 

gelgoog

Captain
Registered Member
I thought dual-pulse air to air missiles were basically staged? Perhaps I am wrong but.
It does add complexity and failure modes when you add staging to any rocket but it's not impossible.
 

silentlurker

Junior Member
Registered Member
I thought dual-pulse air to air missiles were basically staged? Perhaps I am wrong but.
It does add complexity and failure modes when you add staging to any rocket but it's not impossible.
Pulsed rockets are simpler than staged rockets, you don't have seperate nozzles for each section, and each section doesn't detach after fuel is spent. There is more complexity compared to simple solid rocket motor, but not that much I think.
 

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