H-20 bomber (with H-X, JH-XX)

Brumby said:

I do not understand where you are trying to take your conversation.

There are pop up targets within denied airspace that are time sensitive. 4th gen platforms will not be able to execute those mission sets due to their questionable survivability against heavily defended targets. It is not just an issue of cost. Btw, SDB-II are used not because it is cheap but they serve their purpose. They are not dumb bombs with REKs. I am not aware that China has a product equivalent to the SDB-II You will need to educate me on that.

The piece I don't understand is why the need for a JHXX. The FC-31 or a J-20 fitted with air to ground capabilities could conduct those roles. Anyone?

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Range and payload type restrictions.

I do not believe these types of missions will be assigned to only these sorts of air platforms. Artillery bombardment is far cheaper and effective if you can move assets into range. If the whole railgun project finds success, a combination of artillery and missiles will be used against static ground targets. Air has the versatility and speed of delivery factors going for it but like you said, the questionable survivability is there. Overwhelming defences require comprehensive saturation.

There is most certainly a place for a higher speed, low RCS striker. The gap is huge between H-20, J-20/J-35 with J-16 and JH-7A thrown in.

ougoah said:

Range and payload type restrictions.

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OK. Go on. Please elaborate.

Maybe i should be more specific. Is the JHXX meant to be a replacement of the JH-7?

Brumby said:

OK. Go on. Please elaborate.

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I'm assuming it's accepted that J-20 and FC-31/J-35 bays are not deep enough to hold serious air to ground ordinance. Even if they are, they will be limited to smaller types. Haven't seen Chinese stand off weapons in a J-20.

Both J-20 and FC-31 look like they're optimised for air to air from wing sweep geometry and wing ratio compared to low speed, low altitude optimised designs.

ougoah said:

I'm assuming it's accepted that J-20 and FC-31/J-35 bays are not deep enough to hold serious air to ground ordinance. Even if they are, they will be limited to smaller types. Haven't seen Chinese stand off weapons in a J-20.

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If you build platform with internal bays you will bound to have load out limitations. Why would JHXX be any different to the J-20? Do you reckon it is easier to integrate weapons then to build a new platform bedside the cost?

ougoah said:

Both J-20 and FC-31 look like they're optimised for air to air from wing sweep geometry and wing ratio compared to low speed, low altitude optimised designs.

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Do you seriously believe that platform will be a hurdle when it comes to adopting standoff weapons? If you need a VLO platform we are talking about smaller ranges and form factor should not be an issue. Just think this through.

Specifically regarding the discussion about weapons bay sizes -- obviously all stealthy aircraft have a fixed volume in terms of their weapons bays, and different aircraft can have different bay volumes.

For a hypothetical JH-XX, the idea that such an aircraft would be designed from the outset to have weapons bay of a certain volume that happens to be larger than that of J-20's weapons bay is pretty sensible. A hypothetical JH-XX could certainly be able to accommodate larger munitions compared to what a J-20 can carry.

Of course this doesn't mean J-20 can't carry standoff munitions -- if specific munitions are designed to be carried inside the geometry and volume of J-20's weapons bays then of course J-20 can carry standoff munitions of a certain range and payload.
However, for a hypothetical JH-XX with a larger weapons bay volume, it means it can carry standoff munitions of greater range and payload.


The specific difference in range and payload between a standoff munition that "maxes out" a JH-XX's weapons bay volume vs a standoff munition that "maxes out" a J-20's weapons bay volume would obviously depend on just what the difference in bay volumes between the two aircraft are.


Edit: this entire conversation is a bit meaningless unless each side states what their vision of a hypothetical JH-XX actually is. Specifically, MTOW. Giving an MTOW of their vision of JH-XX will basically answer any questions about what the difference in payload and performance it may have versus say a J-20.

The immediate requirements for island chain ranges are in complement of Chinese naval power projection to those waters against dynamic targets. I'm not limiting JH-xx to these roles. The anticipated arenas can vary to Himalayas, Koreas, Russia - Vladivostok, to Taiwan, and within Chinese mainland borders. So the range considerations with existing weapons is not the complete picture. Versatility comes with the "blank canvas" JH-xx which should aim to fill the gaps between H-20's utility and the inherent restrictions placed on J-20 and J-35 (whatever SAC's fighter is) i.e. air superiority fighter designs. I doubt China will go with the do everything JSF model but that's pure speculation simply because China does not have the carriers needed to position multirole strike fighters. Unless it builds J-20 and J-35 bases everywhere close to where they anticipate the fight to be, they're going to need a stealthy platform without the range-payload sacrifices a J-20/J-35 striker will have.

Brumby said:

If you build platform with internal bays you will bound to have load out limitations. Why would JHXX be any different to the J-20? Do you reckon it is easier to integrate weapons then to build a new platform bedside the cost?

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I'd imagine JH-xx will be far larger than J-20 or its predecessor JH-7. I just assume (unfairly perhaps) that it will have deeper and longer bays and a design that allows for speedy transition but also low speed handling and low altitude flight. Variable geometry is still useful today. Stealth or not, flying low and having the ability to exploit terrain is important. Fighters are designed more towards making use of potential energy and trading fuel-altitude-speed-energy and making these shifts on moments notice to adapt against changing circumstances. Strikers are traditionally going to exploit low altitudes and often low speed handling is a must have. I don't think J-20 is designed for terrain following, low speed handling at all but I'm a structural engineer and not an aeronautical.

Brumby said:

Do you seriously believe that platform will be a hurdle when it comes to adopting standoff weapons? If you need a VLO platform we are talking about smaller ranges and form factor should not be an issue. Just think this through.

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Yes I do. Simply because it will be easier otherwise. So it's always better to have more room than it is to work against a certain limit. For that reason alone, it is a hurdle relative to the alternative. I think I have thought this through but then again I'm a moron compared to you.

At the thread - I feel I have to repeat that I believe if such a JH-xx is even technically achievable and financially viable for PLA and PRC, I am assuming it will be large enough to carry more payload - heavier and greater volume, over greater distances. After all that is the performance capability gap so it makes sense if they do deliver some new platform, it fills this gap. That alone distinguishes it from stealth fighters and strategic bombers.

Talking about IR and future radar detection is moot because you can apply that to J-20 H-20 or whatever. It is a separate matter. If detection and firing solutions become so good as to totally erode VLO advantages and the utility therefore purpose of JH-xx, then it may have an impact on whether or not such a platform is ever developed or how it is developed to overcome those challenges. It's a separate point to the capability gap.

Bltizo said:

Specifically regarding the discussion about weapons bay sizes -- obviously all stealthy aircraft have a fixed volume in terms of their weapons bays, and different aircraft can have different bay volumes.

For a hypothetical JH-XX, the idea that such an aircraft would be designed from the outset to have weapons bay of a certain volume that happens to be larger than that of J-20's weapons bay is pretty sensible. A hypothetical JH-XX could certainly be able to accommodate larger munitions compared to what a J-20 can carry.

Of course this doesn't mean J-20 can't carry standoff munitions -- if specific munitions are designed to be carried inside the geometry and volume of J-20's weapons bays then of course J-20 can carry standoff munitions of a certain range and payload.
However, for a hypothetical JH-XX with a larger weapons bay volume, it means it can carry standoff munitions of greater range and payload.


The specific difference in range and payload between a standoff munition that "maxes out" a JH-XX's weapons bay volume vs a standoff munition that "maxes out" a J-20's weapons bay volume would obviously depend on just what the difference in bay volumes between the two aircraft are.


Edit: this entire conversation is a bit meaningless unless each side states what their vision of a hypothetical JH-XX actually is. Specifically, MTOW. Giving an MTOW of their vision of JH-XX will basically answer any questions about what the difference in payload and performance it may have versus say a J-20.

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As true as this is, I think we can go a step further. Ignoring sensor and counter-stealth developments and assuming making some aircraft stealthier has a significant benefit in every way that isn't taking a direct compromise, I think it's possible to speculate on features. Why would PLA spend billions and decades developing overlapping capabilities where no redundancy is necessary. We're not talking about a single point of failure in this system and the same units of hardware replace the destroyed ones.

Therefore weapons bay must be larger otherwise what would be the bloody point. Range is longer again what would be the point if you can't even get to the places to complement other strike methods if they manage to get there? Stand off weapons are not necessarily a replacement. Delivery platform determines range of deployment and energy. It can even deliver from unexpected directions that a J-16 launching the same weapon could not. So if they can't manage these things, would they bother? Especially when other areas are in desperate need of funds?

I don't see artillery (whatever the platform), drone strikers, fighters, strategic bombers, cruise missiles, Stand offs from J-16/JH-7A can do any of the things this theoretical JH-xx can. All of those are limited in more than several ways such a JH-xx is not. So the versatility and speed of reaction already make it more than worthwhile on paper. The only real question is whether it can be done to this level and made stealthy enough.

ougoah said:

As true as this is, I think we can go a step further. Ignoring sensor and counter-stealth developments and assuming making some aircraft stealthier has a significant benefit in every way that isn't taking a direct compromise, I think it's possible to speculate on features. Why would PLA spend billions and decades developing overlapping capabilities where no redundancy is necessary. We're not talking about a single point of failure in this system and the same units of hardware replace the destroyed ones.

Therefore weapons bay must be larger otherwise what would be the bloody point. Range is longer again what would be the point if you can't even get to the places to complement other strike methods if they manage to get there? Stand off weapons are not necessarily a replacement. Delivery platform determines range of deployment and energy. It can even deliver from unexpected directions that a J-16 launching the same weapon could not. So if they can't manage these things, would they bother? Especially when other areas are in desperate need of funds?

I don't see artillery (whatever the platform), drone strikers, fighters, strategic bombers, cruise missiles, Stand offs from J-16/JH-7A can do any of the things this theoretical JH-xx can. All of those are limited in more than several ways such a JH-xx is not. So the versatility and speed of reaction already make it more than worthwhile on paper. The only real question is whether it can be done to this level and made stealthy enough.

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I'm only pointing out that people here might be talking past one another a little bit if their visions of what a hypothetical JH-XX looks like (in terms of MTOW; i.e.: range, payload, endurance, speed, and also weapons bay volume) are not clearly laid out.

ougoah said:

At the thread - I feel I have to repeat that I believe if such a JH-xx is even technically achievable and financially viable for PLA and PRC, I am assuming it will be large enough to carry more payload - heavier and greater volume, over greater distances. After all that is the performance capability gap so it makes sense if they do deliver some new platform, it fills this gap. That alone distinguishes it from stealth fighters and strategic bombers.

Talking about IR and future radar detection is moot because you can apply that to J-20 H-20 or whatever. It is a separate matter. If detection and firing solutions become so good as to totally erode VLO advantages and the utility therefore purpose of JH-xx, then it may have an impact on whether or not such a platform is ever developed or how it is developed to overcome those challenges. It's a separate point to the capability gap.

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JH-XX is both technologically and financially viable for the PLAAF. This isn't an issue at all. I cannot think of any specific technological challenge that would be presented by the JH-xx that could be deemed "hard" for China. Anything you can think of ?
I can think of only one -
Dropping of a long hypersonic ALCM / ALBM / AshM from its internal bays. This would require some lengthy simulations on airflow interactions between the weapon and the aircraft. We don't want the payload to crash back into the aircraft as it is dropped, do we?
edit: And this isn't hard, exactly.
I'd like to point to the very first post of this thread by Deino

J-20 could certainly be used for strike missions within the 1st island chain as is. It could get better over time with fairly small changes, like implementing an optical sensor meant for air to grond work and laser designator under its nose, instead of the one used today which seems to be meant for air to air.

J-20's bays are fairly well sized, certainly not smaller than F-35's. But the issue with J-20 is that it's not going to be available in sufficient numbers. There will always be a bunch of them needed for defense all over China and, perhaps more so, a bunch of them needed for escort. We're talking easily 500-1000 planes for air to air missions. (Let's keep in mind they may be facing upward of 1500 F35/F22 around the 1000-15000 km distance mark by 2030 or so.

Self escorting is possible, (2+2 aams) but then the bomb loads are probably going be fairly poor. Perhaps 2 JSOW class weapons at best. And even then the air to air role may suffer due to excess weight and fewer missiles. It'd make a decent anti-ship striker though, if it had a weapon modelled after kh58ushke in regards to size/warhead/speed (but of course that's even more planes needed)

And stealth wise J-20 isn't what a JH-XX could be. Not only would JH-XX benefit from a decade more modern stealth fundations, but given it's role, it could be made even more inherently stealthy, as it could be a simple tailless delta wing, very much something like FB-22 was. It could have less control surfaces, less surfaces giving out radar returns. It could have engines buried deeper inside the fuselage and shielded from the top/down/sides, giving out smaller infrared return.
and it could, of course, have a bigger bomb bay. Imagine two bays, each 6 by 1.5 meters. (compared to J20's roughly 4.3 by 0.95 meters) That's enough for 4 missiles bigger than JASSM class. Enough for 30 small form 100 kg bombs. Enough for 12 500 kg class bombs. And probably enough room for 4 supersonic missiles (antiship or other) with a 300+ km reach. I'd still rate the antishipping mission as something somewhat less important for jh-xx than the ground strike mission.

Of course, all those weapons need to be developed alongside the plane, to take advantage of the new plane.