More thoughts on 6th generation projects

This is a follow up on what we have seen with the recent unveiling of Chengdu and Shenyang’s 6th generation project. Let’s refer to them as J-36 and J-XX respectively for the rest of this entry.

I had a twitter space with Lei to discuss what we thought of the designs and other things we’ve seen, but I thought it would be better putting them into words.

It’s best to first start with this diagram from 2022 Zhuhai Air show:

The shape of aircraft looks very similar to J-36. Electrical architecture is clearly a very important part of designing an aircraft. By 2022, CAC likely had already frozen the general internal layout of J-36. How much space is provided for its electrical system is known, but the actual parts to be put in there are still to be developed.

For a modern 6th generation aircraft, you need exponentially higher amount of electric power generation and cooling to deal with all the power needed for radar, electronic warfare, IR sensors, computation farm, communication antennas, cooling, DEW and more as I discussed in previous blog entry. In fact, you can see from F-35 Block 4’s own upgrade plans, just how important the additional electric power is:

But the demand for J-36 is a lot higher. I would expect them to future proof the demand with support for greater than 1MW of power generation and cooling. While that may sound like a lot, one needs to consider that a 3 ton Yangwang U9 has to deal with similar level of cooling. If a U7 PHEV can generate 200 kW power with 2.0T engine, a 60T J-36 should be able to install 1MW electric generator. That along with high density, fast charge/discharge batteries will lead to efficient power generation & consumption as well as liquid cooling. All the electrical technology already exist and are improving. As China’s civilian sector continue to develop ever higher voltage SiC power platform, that will also lead to have compact and more efficient electrical systems. So as we have seen J-36 already taking off, the initial testing are to validate the flight envelopes and the extremely complex flight control system for this 3 engine, 3 intake and tailless design. The electrical system is being developed and likely tested in its own place. They will want to make sure that they use the latest and greatest electrical technology on J-36. The Chinese supply chain is moving so fast in these areas.

As I discussed in the other document, the power demand for RF applications is astronomical in a 6th generation aircraft. However, its power demand goes beyond that. For example, consider just this scenario where it has to control a bunch of UCAVs vs different adversaries targets.

In this case, it is in charge of gathering sensor data from all the UCAVs and crunch the data to figure out where all the enemy assets are. It is also in charge of leading the effort to organize electronic warfare against adversarial targets. It has done so in a consistent manner that makes adversaries see targets that are not there and for not seeing targets that are there. All this takes a lot of data transmission between UCAV & J-36 as well as serious amount of data crunching inside of J-36. It is unclear to me just how much computation is needed by J-36, but I would surmise many CPUs & GPUs. If we have something like 32 Ascend NPUs + 64 Kunpeng CPUs & associated memory chips & circuit boards, that alone would use 30kW of power. It’s quite possible that I’m underestimating things. A lot of computation is needed to run some very powerful AI models to figure out what type of emission tactics are needed to fool adversaries and not be fooled by adversaries EW tactics.

In the world of electronic warfare, higher power RF, better algo and faster crunching computation are what wins. You cannot get to all of this without significant interior space dedicated to electrical platform.

Then, there is the question of just how far J-36 can go. The rumor on Chinese social media is that it has 10000 km range and can easily do missions to Guam (about 3000 km from China). I would not be surprised if it can do missions like fly over to 1000 km from Alaskan air base, perform electronic attack, launch missiles and fly back. A SDF member calculated that J-36 has wing area as large as 170 square meter. That much wing area can carry serious amount of fuel. The flywing type of planform also allows for much lower drag and longer range vs aircraft of comparable size.

For those that think J-36 is a bomber and not a fighter. Just remember that the proposed NGAD would have similar dimensions to achieve similar type of range, payload, stealth and MUMT performance. A video from a year ago by Perun described an aircraft that’s very on point with what we see with J-36.

Another interesting part of J-36 is the presence of two caret intakes like F-22 as well as extremely high wing sweep angle (49.5 deg vs 42 to 43 for F-22/J-20 and 60 for SR-71). All of this fits really well with claim from prominent “Big Shrimps” that claim J-36 will be able to cruise about Mach2.0 and reach Mach 3.0. With next generation engines (one after WS-15), it may even be able to cruise at Mach 3.0. It will be able to do so by flying at very high altitude and thin air. While the initial prototype was flown with some uprated version of WS-10C (like J-20 2001 was with AL-31FN), the production version will initially be using WS-15 and then upgraded to true 6th generation engine later. WS-15 for J-36 is expected to have TVC. As such, J-36 is expected to be able to fly really high and fast and use TVC for greater maneuverability.

J-36 is a high value asset. It is likely very hard to bring down. By flying really high and at very fast speed, it becomes even harder for adversaries to detect and missiles to chase down. It can also use very powerful EW to cause missiles to miss as well as Direct Energy Weapon for emergency targeting of incoming missiles to bring threats down. And that is assuming the adversaries can even get past the CCAs that accompany J-36. As you can see from above, the entire formation falls apart once the central node J-36 is taken out. None of the CCAs or other manned aircraft have the level of computation required to process all the data and coordinate Electronic attack at the same level. As such, it is critical to not lose J-36s. CCAs are attritable. The central node is not. PLAAF is likely to already experiment this with J-20S. J-36 is likely to similarly have 2 seats and coordinate battle formation at a much larger scale.

It is also important to note that J-36 itself carries very large internal weapon bay, which means it can carry some very long ranged AAM. Since it will be flying very high in the air at high altitude, it can launch long range missiles that lose less energy traveling long distance. This will allow something like PL-17 to have longer NEZ. This could allow J-36 to be comfortably behind CCAs launching missiles that can bring down adversarial aircraft from much farther out. It can bring down targets much farther out and long before it can be detected by them.

All of this brings us to the next question of just how will it be used. I have seen a lot of arguments from people online calling it fighter bomber or even bomber. In many ways, I think that’s an extremely old way of thinking. By its nature, any 6th generation aircraft system is very multi-role. The central node (J-36 in this case) is the brain of the system, but the actual weapon capabilities is supplied by all the other nodes that accompany it.

For example, if you are doing B-21 hunting in Sea of Japan after noticing it took off from Alaska, you may want to be bringing WZ-9 UAVs with its large airborne anti-stealth radar system in your grouping.

We’ve seen recent flights of this extraordinary looking UAV. Although it is not stealthy, it certain has lower signature than KJ-3000 and lower cost. With J-36 around, it can operate closer to frontline and detect incoming B-21s with longer wavelength for rest of the fleet to key in on narrow beam for weapon grade tracking.

If you are doing missions out to Guam, you can pair J-36 with a whole bunch of GJ-11s.

The longer range and lower signature of GJ-11 will allow this group of aircraft to get closer to Guam. Help coordinate attacks on target that. It can aid ground launched DF-26s as well as LACMs launched from H-6K (from further out) by providing significant electronic attack to confuse air defense of where the incoming missiles are coming from as well as launching its own Anti-radiation missiles and ground attack missiles. It is also possible for J-36 to carry a lighter hypersonic missile. Although I don’t know if that makes sense in practice. Either way, PLA already has significant fire power to these areas. A fleet of J-36s and GJ-11s will only make it significantly harder for defenders.

Another possibility would be an attack against a large carrier group close to edge of the Second Island Chain. You can bring along J-36s and CCAs to deal with incoming F-35Cs and Super Hornets that are performing DCA (defensive counter air) operations. It would allow H-6Ks and H-20s to launch hypersonic missiles from behind the offensive formation as well as incoming hypersonic aerial vehicle like MD-22 (that have 2IC range). The missiles from MD-22 would be very fast and long range due to the high speed of aerial vehicle.

All of this can be coordinated with DF-26/27s. Again, once you have stronger close-in EW pressure as well as multi-axis and multi-threat attack, it becomes significantly harder to defend. The interception probability of defense comes down. Sure, you can overwhelm defense with just more missiles than air defense, but hit probability of anti-ship missiles against strong defensive electronic warfare is probably lower than people think. You want to increase that probability by weakening the defense.

As you can see, J-36 brings significantly increased fire power due to its range, large interior space, large internal weapon bay, all aspect stealth, high speed and altitude flying as well latest electrical technology. However, it cannot do these missions alone. It is a true force multiplier. But force multipliers need a supporting cast. So, the accompanying manned and unmanned aircraft (especially the latter) will be quite critical here. They will need to be able to keep up with J-36 in range, all around stealth and cruising speed. As such, they will need to be far more capable (and likely larger) than what we have right now. They will also need to have significant interior space for powerful radar and EW. We will also need significantly improved AI so that they can maneuver intelligently as well as manned aircraft. All of this development will take significant time and resource to achieve. That is what to keep your eyes on next.