plawolf
Lieutenant General
Nope, model making is a surprisingly precise undertaking. Flash and mould lines are nothing like that pronounced. You can see actual mould lines on the missiles running the length of them.
Chinese air to air missiles
- Thread starter tphuang
- Start date
PiSigma
"the engineer"
Actually the official AVIC models are very good and precise compared to the real thing. I have official models for J-10A and JF17 when my uncle still worked. The models are actually not plastic, they are metal, every detail is scrutinized by the original team.
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It just refers to your impulse within a specific range of time over the whole impulse graph of an object in motion. Instantaneous force would probably have been more precise but since we’re not talking about a single moment of force impulse came more naturally to me.
You guys seem to be conflating several considerations here regarding missile range and maneuverability.
Specific impulse is a measure of propulsive efficiency - simply put, the higher the more range you get out of a propulsion system, all else (weight, flight profile etc.) equal. Ramjets do well here compared to rockets because they do not need to carry along the oxidizer for their fuel, which is a big weight saving (though not a volume advantage, because of the empty air intake ducts). This can be used to carry more propellant, increasing burn time - ramjets which can be throttled improve this even further and that does mean better end game maneuverability.
Once the propellant has been used up, every turn bleeds energy that can no longer be recovered - this is where dual pulse (not strictly impulse) rockets come in. These have basically 2 independent rocket motors in series, the second of which can be ignited long after the first burns out. Think of it as a poor man's two-stage missile that does not jettison the first stage, this enables even a non-airbreathing missile to also perform its end game intercept under power.
Nonetheless, there are potential drawbacks to ramjet propulsion in terms of maneuverability. These are both, directly or indirectly, related to the presence of air intakes. On the one hand, they may encounter difficulties at high angles of attack and/or side slip, on the other they might require a bank-to-turn control scheme (Meteor is a bank-to-turn missile, SA-6 isn't). That is to say, the missile rolls into the desired direction of turn before actually turning, like an aircraft, which causes a small delay (worse *instantaneous* turn). Though the subsequent turn rate (*sustained*) of a properly designed bank-to-turn missile might actually be better.
So, ramjet = better range, pretty much unequivocally. Maneuverability-wise, it could go either way.
Specific impulse is a measure of propulsive efficiency - simply put, the higher the more range you get out of a propulsion system, all else (weight, flight profile etc.) equal. Ramjets do well here compared to rockets because they do not need to carry along the oxidizer for their fuel, which is a big weight saving (though not a volume advantage, because of the empty air intake ducts). This can be used to carry more propellant, increasing burn time - ramjets which can be throttled improve this even further and that does mean better end game maneuverability.
Once the propellant has been used up, every turn bleeds energy that can no longer be recovered - this is where dual pulse (not strictly impulse) rockets come in. These have basically 2 independent rocket motors in series, the second of which can be ignited long after the first burns out. Think of it as a poor man's two-stage missile that does not jettison the first stage, this enables even a non-airbreathing missile to also perform its end game intercept under power.
Nonetheless, there are potential drawbacks to ramjet propulsion in terms of maneuverability. These are both, directly or indirectly, related to the presence of air intakes. On the one hand, they may encounter difficulties at high angles of attack and/or side slip, on the other they might require a bank-to-turn control scheme (Meteor is a bank-to-turn missile, SA-6 isn't). That is to say, the missile rolls into the desired direction of turn before actually turning, like an aircraft, which causes a small delay (worse *instantaneous* turn). Though the subsequent turn rate (*sustained*) of a properly designed bank-to-turn missile might actually be better.
So, ramjet = better range, pretty much unequivocally. Maneuverability-wise, it could go either way.
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It look like lattice fins on the back, well, looking at them, the missiles look like R-77 missile...
Yeah I immediately thought of the r-77 missile the moment I saw it.... got no idea why it took so long for everyone to figure it out lol
The proportions of the midbody fins is quite different to that of R-77 which are wider, longer and with front and rear edges being much more perpendicular to the missile body, as are their relative size to the aircraft.
The rear fins also do not look like what one would expect the potato masher rear fins of R-77 to look like even if folded, in terms of individual geometry.
The angular bulges of the missile body (the yellow circles in the image highlighted) also are not present on R-77 either.
There's also the issue that if we do accept this is a proper and official AVIC commissioned model and with attention paid to details, the idea that they would have accidentally let the model accommodate R-77s be odd, bordering on outrageous.
There are basically two explanations:
1. Either the missiles themselves are not representative of anything specific and are just random stand ins that do not depict a future in development missile or real world missile in any form...
or,
2. The missiles are representative of the specific new BVRAAM that has been rumoured for the last couple years as being under development, a missile that was specifically to allow J-20 to carry six of ventrally.
Option 1 would basically have to assume that the official AVIC commissioned models are not of any particular credibility in terms of their details.
Option 2 would basically have to assume the opposite.
However in neither option IMO is there any reason to think that the missiles in the model are depicting R-77s, the differences are just too large.
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.
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.
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.
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.
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.