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

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Captain
FairAndUnbiased said:
A cruise missile bomber akin to a stealthy Tu-22M would be a game changer in WestPac. It would be able to provide yet another way of putting hostile naval groups at risk, serving as a recon platform, and gaining technical experience in improving the performance of large planes.
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The big question is still payload. If you go supersonic, you sacrifice range since supersonic flight is extremely fuel intensive, or alternately you sacrifice payload as the space that'd otherwise be devoted to a bomb bay ends up being used for fuel storage.

Another point to be made is that the JH-XX is more interesting for the J portion than the H portion; i.e, the first generation of stealth fighters (F-22, Su-57, J-20) were intended to kill 4th and 4.5th generation fighters by triumphing BVR through superior stealth and sensors. When you see the second generation of stealth fighters like the F-35, however, what you see more is a fighter that is willing to sacrifice aerodynamics for payload (i.e, better missile loadout, being capable of destroying counter-stealth radars) and greater stealth (so that it can see the enemy first and launch datalinked missiles at it); or in other words, more designed for stealth vs stealth warfare.

Hopefully, the JH-XX will be a representative of the second generation, as in, it'll be a key support aircraft for J-20s by carrying the heavy PL-21 for it, a large radar that might be designed for counterstealth, and EODAS systems of sufficient size and power to neutralize the F-35. And hopefully it'll have a pure enough stealth that even when unescorted by J-20s, it'll be able to pose a major threat to F-35s.
 
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Looks like the nose is still going to be X-band / Ku-band from the appearance. They could go the J-16 route and stuff L-band modules in there, but it won't even be as good as the UHF radar on the E-2D. I'm disappointed.
 
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vincent said:
It look nothing like Su-34
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Russian_Air_Force_Sukhoi_Su-34.jpg


But it does, doesn't it? The radome has the same wide shape, although the Su-34 is closer to a duckbill and the proposed JH-XX is closer to a sparrow's beak. The JH-XX looks as though the radar will be significantly more powerful than the Su-34, but would it be a proper counterstealth radar?
 
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sinophilia said:
You can tell all that from a picture taken with a Soviet-era microwave of something we don't even know is the actual plane?
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It's a band thing. Stealth tends to degrade and fall apart at low bands on fighter aircraft; bomber aircraft can have purer stealth shaping without this vulnerability.

Bands are dependent on antenna sizing, which determines the module sizing. The more modules you have, the more precise your beamforming, and implicitly the greater your range (the more modules, the more concentrated the beam and thus the greater distance), although module count implicitly creates an issue of diminishing returns.

A relatively small radome, as on the purported JH-XX pics, imply there's not enough space to put in a ton of UHF modules, as with the large PESA on the E-2D (although the E-2D is properly a question of phase shifters). It means that to get precise tracking from the limited number of modules you have available, you'd want to go to L-band instead, and L-band is less effective as a counterstealth radar than a UHF-band radar.
 
vincent

vincent

Grumpy Old Man
Staff member
Moderator - World Affairs
Inst said:
Russian_Air_Force_Sukhoi_Su-34.jpg


But it does, doesn't it? The radome has the same wide shape, although the Su-34 is closer to a duckbill and the proposed JH-XX is closer to a sparrow's beak. The JH-XX looks as though the radar will be significantly more powerful than the Su-34, but would it be a proper counterstealth radar?
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Might as well say all planes looks like the ones created by the Wright brothers, or the F-22’s cockpit looks like the Su-27’s
 
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My biggest issue with what information we seem to be getting for the JH-XX program is that it sounds like a 2-engined design, as opposed to a 4-engined design. A 4-engined design with middleweight engines gives you a superheavyweight fighter, but it also gives you something that can approximate a B-21 in its bombing capabilities. Yes, you sacrifice range and stealth compared to an actual B-21, but you gain speed, as well as something that can actually conduct traditional air superiority missions adequately.

With the JH-XX looking 2-engined, the aircraft looks more like a heavy F-35 counterpart (i.e, improved stealth over the J-20) than a rough analogue of the B-21 that is also designed for "second generation stealth fighter warfare". It might be able to par the F-35s, but it won't be able to decisively outclass it.

Remember, the big advantage of being JH, as opposed to J, is that you can sacrifice high-AoA performance and maneuverability, which the J-20, despite my denigration of its maneuverability, cannot do. The gain, on the other hand, is in having purer stealth; i.e, a JH-XX can engage the F-35 on its own paradigm (stealth uber alles) and win.

Likewise, if we're looking at the micromissiles paradigm the USAF is trying to develop, the F-35 is highly suited for it, since its heavy payload can be converted to carry many interceptor missiles, dogfight missiles, and anti-missiles. The J-20, since it has a relatively anemic payload (more optimized for air-to-air like the F-22), can't. The JH-XX, on the other hand, can.

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Perhaps the only real limitation has to be the engines. A proposed 4-engined JH-XX would require WS-19, but even the WS-15 is not yet ready. A 2-engined JH-XX more focused on a cruise-missile carrying role only requires WS-13, RD-93, or WS-10/15.

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There is no Chinese counter for NGAD, nor is there likely to be before 2035. The NGAD program is ahead of schedule and has already taken its first flight. It might IOC or LRIP in the 2025-2030 timeframe. Better and more advanced fighters than the J-20 are needed to provide partial counters to NGAD.
 
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vincent said:
Might as well say all planes looks like the ones created by the Wright brothers, or the F-22’s cockpit looks like the Su-27’s
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Aircraft ultimately all look like each other because they have common functions. The choice of the duckbill radome is similar to the choice of the sparrow radome on the JH-XX. They're both highly longitudinal radars, probably because the radar is tilted at an angle to improve stealth as well as to improve tracking of ground targets.

That said, the radome size on the Su-34 is about 2 meters. Applying a typical 25% reduction, we'd expect 1.5 meters radar aperture. If the JH-XX is about the same, the radome power on the JH-XX would be about 50% greater than on the J-20.

If the Chinese opt to use GaN here, you could see 2.66x the detection range, or about 1200 km detection vs 0 dBsm. vs -40 dBsm like the F-22, you'd be looking at 120 km detection range (sufficient to cue J-20 EODAS / EOTS), or 67 km detection vs -50 dBsm as on the F-35. Maybe L-band as opposed to X-band might cut opponent stealth by 10 dBsm, which might provide workable detection ranges, although it's still ever so thin a margin compared to a true counterstealth radar.
 
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