Future PLA combat aircraft composition

Bltizo said:

The second is the less ambitious, "FB-22"-esque configuration where you just lengthen the aircraft and lengthen the weapons bay a bit so it can carry more of the same A2G weapons that the baseline fighter can carry, but is unable to carry larger diameter strike weapons that you would hope a dedicated strike aircraft could accommodate. This option would likely require far less resources than developing the first, more ambitious proposal, but it also delivers a far less capable strike aircraft, to the extent that one could ask whether pursuing this less ambitious strike variant is even worth it as opposed to just buying more normal J-20s alongside more H-20s and stealthy UCAVs instead.


I'm not inherently opposed to the idea of a strike variant J-20, but for both the "more ambitious" and "less ambitious" strike variant options I feel like there are better, more cost effective choices if you want either of their capabilities.
OTOH, if the money and aerospace industry resources is there to pursue everything as well as a strike variant J-20, then sure, go wild.

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I agree.

My view is that a new J-20 strike variant isn't worth it.

The J-20 airframe will always be constrained by the internal volume available whilst maintaining stealth.
As a frame of reference, the F-35 can carry 2300kg internally with another 6800kg externally.

A stealthy flying wing is way better in my opinion, and would be able to carry all that payload internally.

It also wouldn't have small control surfaces which can be detected by long-wave radar.
After all, the only reason you need those control surfaces is for manoeuvrability, which is not an issue for a bomb truck.

A flying wing isn't able to go supersonic, but it's not supposed to be a fighter.
It's supposed to slip in quietly, deploy a payload, and then slip out.
Going supersonic also creates a large infrared signature, which you don't want anyway.

So I do think "normal J-20s alongside more H-20s and stealthy UCAVs" is probably the way forward, rather than also adding a J-20 strike variant.

AndrewS said:

I agree.

My view is that a new J-20 strike variant isn't worth it.

The J-20 airframe will always be constrained by the internal volume available whilst maintaining stealth.
As a frame of reference, the F-35 can carry 2300kg internally with another 6800kg externally.

A stealthy flying wing is way better in my opinion, and would be able to carry all that payload internally.

It also wouldn't have small control surfaces which can be detected by long-wave radar.
After all, the only reason you need those control surfaces is for manoeuvrability, which is not an issue for a bomb truck.

A flying wing isn't able to go supersonic, but it's not supposed to be a fighter.
It's supposed to slip in quietly, deploy a payload, and then slip out.
Going supersonic also creates a large infrared signature, which you don't want anyway.

So I do think "normal J-20s alongside more H-20s and stealthy UCAVs" is probably the way forward, rather than also building a J-20 strike variant.

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The problem is that I see the J-20 as fundamentally inadequate for A2A roles against the F-35. The F-35 is a strike fighter, true, but how many J-20s do you need to counter a F-35? When you're looking at around 1200 F-35s deployed against China in the theater, you'd be better off having "strike" J-20s that can compete symmetrically with the F-35 in terms of A2A missile payload. 12 PL-15X/PL-12s, remember, translates to also 6 larger and more capable long-ranged missiles as well.

The underlying assumption that people seem addicted to making is entertaining the notion that the J-20 can somehow outmaneuver the F-35 and beat it there.

It can't. The F-35 is anemic short-ranged as a kinematic fighter, but the F-35 has very good instantaneous turn rates allowing it to dodge long-ranged missiles. Once you get to dogfight range, both fighters have EODAS and both fighters have HOBS missiles. Therefore you want to beat it BVR, and a bay size advantage and better sensors work well there.

Inst said:

The problem is that I see the J-20 as fundamentally inadequate for A2A roles against the F-35. The F-35 is a strike fighter, true, but how many J-20s do you need to counter a F-35? When you're looking at around 1200 F-35s deployed against China in the theater, you'd be better off having "strike" J-20s that can compete symmetrically with the F-35 in terms of A2A missile payload. 12 PL-15X/PL-12s, remember, translates to also 6 larger and more capable long-ranged missiles as well.

The underlying assumption that people seem addicted to making is entertaining the notion that the J-20 can somehow outmaneuver the F-35 and beat it there.

It can't. The F-35 is anemic long-ranged as a kinematic fighter, but the F-35 has very good instantaneous turn rates allowing it to dodge long-ranged missiles. Once you get to dogfight range, both fighters have EODAS and both fighters have HOBS missiles. Therefore you want to beat it BVR, and a bay size advantage and better sensors work well there.

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For the F-35 to get those instantaneous turn rates it needs to run as clean as possible with internal weapons only and a reduced fuel load.

On short range engagements the fact the J-20 can launch an IR missile at the F-35 more quickly is important. The F-35 does not have the side bays with the exposed missile IR sensor so I think it will be highly disadvantaged in short range combat no matter what EODAS or HOBS capability it has.

A larger aircraft like the J-20 can pack a larger diameter radar. Also FWIW I think the F-35 does not use GaN radar yet and considering how new the aircraft is and how large the fleet will be an upgrade is likely way off into the horizon if ever for most aircraft. China allegedly has a lead in GaN radar so it can likely leverage this by making a radar which not only has more surface area but has more power per unit of area as well.

Inst said:

Problem with your proposals is, as you've stated, a strike variant of a stealth aircraft is basically a completely new plane; you'd need to redesign the fuselage to pack a greater weapons bay, and you'd need new stealth and aerodynamic testing given the change in configuration. Therefore the full J-20 mod would be more suitable because you'd be paying for semi-new development anyways.

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Question is at that point why not just go for a clean sheet design with more longevity more appropriate for the role at that point...?

The other point I keep on making is that a strike J-20 would be a far more capable A2A platform than the current J-20. Put another way, we can't stuff PL-XX/PL-16s into the J-20 due to bay length restrictions. But being able to do so would greatly enhance the J-20's interception capabilities, and interception is a key mission of an air superiority aircraft; air superiority aircraft are defined by their poor strike abilities.

Likewise, if the J-20 opens its bays, it's going to compromise its stealth and make it vulnerable. Better to launch 12 missiles instead of 6 missiles when it hangs the Sword of Damocles over its head. A greater missile load-out, and a more flexible missile load-out, is the way to go.

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I have nothing against increasing magazine size, but literally developing a new variant of an aircraft that is structurally different and larger with one of the driving goals to increase magazine size doesn't seem like a cost effective use of resources.

First, I don't see why you believe launching 12 missiles versus 6 missiles would somehow mitigate that "weakness" (which frankly is not even a weakness -- every stealth fighter has to open its weapon bays to launch missiles, after all).
You don't launch all your missiles simultaneously, you still have to ripple launch them, and unless your fighter has very spaced out weapons bays, you'll still have to ripple launch your 12 missiles one by one in the same way you ripple launch your 6 missiles one by one, so you're going to spend twice as long with your weapon bays open if you're launching 12 missiles versus 6.


All this is of course academic because developing missiles that allows you to carry more of them in the weapons bay is a much better solution -- we've known for over a year now from yankee that a new BVRAAM with similar performance to PL-15 is in development that will allow J-20 to carry six in the ventral bay.
We can all anticipate improved variants of PL-10 and Cuda or Perengine equivalents to be in development as well, to further increase effective magazine size.
As guidance, propellant and flight control systems further converge, I expect the sizes of missiles to shrink further while capability is retained or even increased relative to the world's competitors.

In the longer term, pursuing offboard sensor/shooter loyal wingmen type UCAVs as supplemental AAM trucks is an alternate solution to the same goal of increasing your force's magazine size.


All this said, I have nothing inherently against the idea of a strike variant J-20, I just think there are better solutions to approach the same problem and goal.
Compared to H-20 and future stealthy strike and loyal wingman UCAVs, IMO a strike variant J-20 is far from a "must have".

Inst said:

The underlying assumption that people seem addicted to making is entertaining the notion that the J-20 can somehow outmaneuver the F-35 and beat it there.

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I'm not sure who has entertained that notion -- the best way to defeat opfor fighter aircraft, stealth or otherwise, is to have your system of systems achieve superior situational awareness, positioning and networking, to enable you to engage them in BVR before they can engage you.
It's the same for J-20.

Nobody in the last few decades has developed a fighter aircraft with the goal of entering WVR as the primary way of defeating an opfor's fighter.

Inst said:

The problem is that I see the J-20 as fundamentally inadequate for A2A roles against the F-35. The F-35 is a strike fighter, true, but how many J-20s do you need to counter a F-35? When you're looking at around 1200 F-35s deployed against China in the theater, you'd be better off having "strike" J-20s that can compete symmetrically with the F-35 in terms of A2A missile payload. 12 PL-15X/PL-12s, remember, translates to also 6 larger and more capable long-ranged missiles as well.

The underlying assumption that people seem addicted to making is entertaining the notion that the J-20 can somehow outmaneuver the F-35 and beat it there.

It can't. The F-35 is anemic short-ranged as a kinematic fighter, but the F-35 has very good instantaneous turn rates allowing it to dodge long-ranged missiles. Once you get to dogfight range, both fighters have EODAS and both fighters have HOBS missiles. Therefore you want to beat it BVR, and a bay size advantage and better sensors work well there.

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You don't want to compete with F-35s symmetrically with more J-20s.

Instead, add more disposable UCAVs which will launch the extra A2A missiles that you need.
And more UCAVs to act as your offboard sensor platforms.

This negates your argument about a larger bay size and better sensors being a key advantage for a strike-variant J-20.

Well I think a strike variant J-20, or the mythical JH-XX, might make sense for a couple of reasons.
In case China decides to adopt a first strike strategy they might need to attack targets beyond the first island chain quickly.
They might also need to attack naval strike groups beyond the first island chain before they get into range of the Chinese mainland.

For this you would want a supersonic or hypersonic aircraft with long range and the capacity to carry missiles large enough to sink ships or destroy airbases. Neither the J-20 nor the H-20 fit into this attack profile. In theory you could develop box shaped cruise missiles which could have bomblets for airbases or an optional tactical nuclear warhead to hit the naval strike groups. But the payload capability and range would be limited.

My issue with the loyal wingmen concept is that it works great for aerial defense but on a long range mission you will have loads of problems. You'll have more aircraft you need to refuel and China already has quite limited aerial refueling capabilities to begin with. You'll have highly vulnerable and slow air refueling platforms flying over the first island chain. And you'll have decreased sortie rates for aircraft because you'll need to make multiple launches instead of a single one.

gelgoog said:

Well I think a strike variant J-20, or the mythical JH-XX, might make sense for a couple of reasons.
In case China decides to adopt a first strike strategy they might need to attack targets beyond the first island chain quickly.
They might also need to attack naval strike groups beyond the first island chain before they get into range of the Chinese mainland.

For this you would want a supersonic or hypersonic aircraft with long range and the capacity to carry missiles large enough to sink ships or destroy airbases. Neither the J-20 nor the H-20 fit into this attack profile. In theory you could develop box shaped cruise missiles which could have bomblets for airbases or an optional tactical nuclear warhead to hit the naval strike groups. But the payload capability and range would be limited.

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A stealthy, high speed (supersonic or hypersonic) strike aircraft with long range is certainly desirable, however the challenge is that if you want size, stealth, and speed, you end up with a rather challenging aircraft to develop. Not impossible, but it will cost significant treasure and effort and resources.

The idea of a JH-XX/theater stealthy bomber has been discussed for many years, and the possibility of the JH-XX concept being developed is still there, in fact we don't know if the PLA is actively pursuing it or not.

But what we do know is that they're definitely pursuing H-20 and that a stealthy, large, subsonic bomber is much less technically challenging with commensurately less risk, cost and resource demand.

If they had the funding and aerospace industry resources for it, then I'd say they should go wild. But in context of finite funding and resources, I'm not sure if a high speed stealthy bomber is very high on their priority list.

My issue with the loyal wingmen concept is that it works great for aerial defense but on a long range mission you will have loads of problems. You'll have more aircraft you need to refuel and China already has quite limited aerial refueling capabilities to begin with. You'll have highly vulnerable and slow air refueling platforms flying over the first island chain. And you'll have decreased sortie rates for aircraft because you'll need to make multiple launches instead of a single one.

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Not necessarily, it really depends on the size of the UCAV itself.
A UCAV can achieve the same combat radius as a manned fighter will being substantially smaller by virtue of being unmanned -- and if a UCAV is a similar size to a manned fighter then it will have far superior combat radius than the manned fighter.
The CONOPS of loyal wingman UCAVs certainly is not married or dependent on having a large aerial refuelling fleet.

It's a bit hard to follow the discussion going on in the J-20 thread, as some stuff is being written there, some is here. Still, I guess here it'd be less off topic.

So, when talking about J-20 as a strike platform or when talking about a new plane for strike missions or using any other existing or planned (known) plane for strikes - the first thing to do, that might be useful, is to look at what missions are there, and what platforms are best suited for those missions.

1. Delivery of *heavy* cruise missiles against known targets. Meaning various fixed sites, but perhaps extending to currently non-mobile targets such as moored ships, parked vehicles/aircraft, deployed SAM sites etc.
I accentuate the word "heavy" as pretty much the same set of targets can and will be engaged by smaller munitions as well. The point of heavy cruise missiles is primarily added range. So those targets can be engaged from a very safe distance. The farther away a target is, the harder it is to actually engage anything else than fixed targets. That's because getting reliable and near real time information on relocatable targets so far away is usually quite problematic.

Air launched cruise missile in the class of Russian kh101 has ample range. Easily over 3000 km. US ALCM had similar range. AKD-10 is likely to feature very long range, closer to russian missile figures rather than sometimes mentioned 1500+ km.

With that sort of range - many targets will not require a stealthy launch platform at all. H-6K will suffice, very much.
There ARE some targets that might still require a stealthy launch platform, though. If one goes after Guam or Wake island, the carrier plane would first need to go out toward the first island chain, possibly even crossing that line sometimes. To do that and survive, a stealthy plane is certainly a better platform.
Yet, the whole mission is usually not something extremely time critical. After all, the targets are usually fixed sites. A subsonic H-20 would be a good fit for that job.

2. Delivery of even bigger missiles than 6-7 m long, 1m in width weapon. That category exists but it is a very, VERY niche category. Examples would be specialized anti-ship missiles, the kind USSR used. And to a lesser extent the Chinese YJ-12, which is still roughly in the heavy cruise missile weight/dimension category, though it does have a bigger wingspan. Another example of larger missiles would be various air launched ballistic missiles. The kind we're seeing being set up for H6K to be the launch platform. And H6K family of planes is perfect for it. Those planes' role is to extend the reach of the missile itself. It could just as easily be launched from the ground. But this way it probably enjoys several hundred km bigger range. In theory, if the plane could go a 1000 km away from the shore - the range could be even bigger. But in practice, getting reliable targeting data for targets so far away is again hard. Fixed targets would be more likely. And H6K would be a more cost effective solution, as long as it can enjoy fighter cover. Which means several hundred km out towards the first island chain. if a farther away launch point is needed, H20 would be a better choice. Though most likely that'd require a special launch harness, carriage underneath the plane, instead of inside it, and so on. Compromising stealth (though it'd still be much more stealthy than H6K) and potentially endangering a very expensive platform.

In my opinion it may not be worth it to even integrate such oversized weapons on H-20. If H6K can't handle the mission, then that mission might be better left to other, not aerial launch platforms altogether.

That also means that H20, and in turn all the other strike planes, smaller than H20, have no business being designed to carry anything bigger than a heavy cruise missile sized weapon.

3. Which brings us to the heavy antiship missile. Basically YJ-12 in its role, but not in its size. Instead, a different layout would likely be required. Perhaps something closer to brahmos? In any event, something that can be made more compact in terms of wingspan and overall width. While basic brahmos has folding wings in its ground launched variant, but NOT in its air launched variant, brahmos-m is a redesigned missile. When it is launched from a plane, it unfolds its wings. Overall it's a more compact missile, smaller even than YJ-12, so its range is limited to 300 km. But the full brahmos size is getting newer variants which are planned to achieve 500-600 km in range. An air launch would limit the need for a full size booster, thus the length of 8 meters might not be needed. In any case, a weapon that's designed from scratch to fit into H20 or some other plane, should be able to achieve 400-500 km range, with decent warhead, and still fit inside the AKD-10 size bracket. And do it all supersonically, like the YJ-12.

3b. Other large antiship missiles. These are notional categories. But something like air launched YJ-18, with only the terminal stage being supersonic, or something like LRASM, being subsonic all the way - are much easier to pack into planes. YJ-18 is basically the size of AKD-10, and LRASM could in theory fit into today's J-20. Or, if not, it wouldn't require a noticably bigger plane to fit a pair.

4. Smaller cruise missiles. JASSM and the like. J-20 might or might not be able to cram some in. (I can't be bothered to look for my own analysis of imagery where I concluded J-20's weapon bay is very, very close in being able to fit such a weapon) In any case, either a slightly bigger bay (requirng a new plane or modified J-20) would be needed, or the weapon itself would be slightly smaller. Possibly then achieving only 80% of JASSM's range/warhead etc. Which would still be respectable. Especially with JASSM-ER's numbers. (Not sure if JASSM-XR will indeed retain the same outer lines)

5. Large bombs. Similar to US MOP and so on. These are very heavy but not that voluminous actually. A H6K should be able to carry a 10 000 kg bomb, if one is designed. H-20 should be able to carry those. Not sure it'd be worth sizing a notional JH-XX to carry one. Though it probably could fit one underneath, semi recessed.

6. various smaller bombs and missiles. That's a category that even today's J-20 can carry. H-20 would be able to carry those in droves. And any notational strike-modified J-20 or JH-XX would be able to carry in decent numbers.

To be concluded...

So what does all this tell me?
That the J-20, as it is, is already sized well to perform a large, large number of strike missions. Sure, right now it lacks the avionics. But if the production reaches such numbers that PLAAF can afford to use them for strikes too, then some J20 (or most) would likely be of the multirole variant. throwing out 2 JASSM or almost JASSM sized weapons is no small matter. Or 4 500 kg guided bombs. Or even a larger number of smaller bombs.

H-20 is, of course, likely to be sized to handle pretty much everything, except possibly MRBMs and soviet style antiship missiles. but the latter are likely to be replaced by brahmos sized missiles anyway.

Which leaves the issue of a possible plane in between the J-20 and H-20.

Now, there already are such planes. J-16. And JH7. And even H6 family. But they're all sort of vulnerable, if the mission calls for getting close to the target. Which a lot of missions would need - both for reliable targeting and for using weapons that don't cost an arm and a leg.

So the logic dictates that a stealthy platform will be needed. Now, there already are some drones out there. GJ-11 comes to mind. Not much is known about it, but it *may* be able to match J-20 when it comes to bomb volume/dimensions. Of course, unamanned planes come with their own set of issues. Re-targeting, chasing targets of opportunity and so on might lag behind the J-20's capabilities. Still, capability wise, GJ-11 doesn't bring much more to the table than existing J-20, save for possible added stealth and the fact it's somewhat dispensable.

One could just use more H-20, of course. The price tag factor is likely not a real issue. As any development of a completely new plane would cost so much that more H-20 could be justified instead. But subsonic H20 might simply not cut it in some instances. Deaths might be too frequent.

So why not have it unmanned? At that point - why not have another plane that's basically enlarged GJ-11? Or smaller H-20, whatever you want to call it. So it's still a subsonic flying wing, very stealthy, and designed to be unmanned. IF the whole unmanned thing can be made to work properly for 95% of the missions in the next 10 years - then that might be a real option.

But if crews are still preferred at that point - then a manned plane would be needed. A clean sheet design, supersonic JHXX, made to carry 6m missiles (likely not subsonic cruise missiles - as those would be better served by H20 launching them) would be expensive. Possibly similar to J20 development costs, though some subsystems could be used from it, so a bit cheaper. Still, that means likely a few hundred J20 worth. Or nearly a 100 H20 worth.

Making the plane a bit smaller, to comfortably carry JASSM sized weapons, possibly some midget sized brahmos style missile, and, say, 8 250kg bombs, would not make it much cheaper if it's a new plane. In that case, reworking the J20 in a completely new plane a la FB-22 might be more prudent. It'd still be costly, but not as costly. Probably a 100 J20 worth, or a few dozen H20 worth.

Some theoretical larger than GJ-11 UCAV would also be quite pricy to develop and buy. Possibly not much different than upscaled striker J20.

If there's a lack of conclusion to this text, that's intentional. There's simply so many options and possibilities. That we may or may not see a true medium sized strike plane.

Oh, and a last word: 8 to 9 meter long missiles are simply not needed. even the niche stuff like MRBMs on H6K are not crucial. H6K has a 7 meter long weapons bay. B-2 has similar weapon bays. B-21 is unlikely to have anything longer. Simply said, no one really needs oversized supermissiles anymore to be carried on planes, even if we're talking about intercontinental bombers. MRBMs on H6K are a niche weapon that only china uses. One can say that they simply used what was there - the old H6 which would be useless for anything else than stand off attacks, instead of developing a pairing of the plane and a missile from the get go.