Inst@Lev-sha:
Matters like materials, drag, and intake design matter as well. In practice, an eight-fold increase in thrust is needed to generate a doubling of speed provided that the other factors don’t cut things out. From what I’ve read the F-14D’s bigger problem was the fixed inlets; these were designed for the TF40 and didn’t generate enough gas velocity for the GE engines.
@Deino:
I mean the consensus on SDF is that the J-20 is just the Chinese version of the F-22, when even the F-22 is outmoded against F-35s in large numbers. Definitely, some of the arguments I use are recycled from the last time around, but the habit of groupthink on SDF isn’t healthy and it’s just creating a mirror image of Western partisans who play up their own planes.
The other thing I’ll point out is that discussing things for the purpose of discussing them is somewhat the point of a message board, isn’t it?
The age old argument is rather simple. On one hand, you have people who point to design documents about the J-20 and official communications and claim the J-20 must be an air superiority fighter because an air superiority fighter is sexy. The counter argument treat demonstrated performance by the J-20 (22.5-30 degree / sec instantaneous turn performance at around 1500-5000 meters) as more important and notes that the J-20 is currently underpowered,
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This tends to not to go anywhere because of entrenched biases. Skeptical Westerners tend to question the difference between the J-20 and the Iranian Qaher 313 stealth demonstrator; i.e, if the 313 is a fake, the J-20 must be as well. The China-watching community, often ethnic Chinese, treats the status of “air superiority fighter” as extremely prestigious and takes claims that the J-20 is not an air superiority fighter as an affront.
I’m pointing out, in contrast, that a heavyweight air superiority fighter in the age of stealth and advanced WVR missiles (even the Chinese PL-10 claims to be able to do 360-degree engagements) is an anachronism and that the Chinese, if they’re being reasonable, are not designing it for such purposes.
InstThere was a report a while back that the J-20 was able to cruise at Mach 2.5. However, this was quickly redacted and attributed to a typo.
On SDF, people are discussing the claim that the J-20 has beaten the top speed record in testing of any Chinese domestically produced aircraft. This roughly goes to Mach 2.3 to Mach 2.5, and implies roughly a Mach 2.7-2.8 top speed when the WS-15 becomes mature.
We also ended up having an interesting discussion, which I’d like to bring here, as to whether the J-20 should be characterized as a fighter-interceptor or an air superiority aircraft.
InstI’ll state that the Su-57 in Chinese service is a great opportunity to have an agile, attritional fighter conduct dogfighting duties that the J-20 would prefer to avoid for cost reasons.
InstThere’s a few pilot interviews that suggest that the J-20 has F-16- or J-10-level maneuverability subsonically (, but with superlative supersonic maneuverability. The latter makes sense, the J-20 has long-coupled canards, huge elevon actuators, and is slated to receive TVC. I’d also state that the most recent rumors state that the J-20 currently has a gun emplacement, but no gun.
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Where I’d disagree is whether an engagement need to progress from BVR to WVR, when one side is significantly faster. In the First Gulf War, the Iraqi MiG-25s, despite being obsolete and monkey-model, performed very well against the USAF and scored the sole US air-to-air loss in the last few decades. If you are maneuverable enough to quickly change direction, and fast enough to escape your opponent, you can hit and run slower but more maneuverable planes.
InstDid you follow the AVIC listing; i.e, they’re now listing WS-15 as a product in their stock exchange compliance sheet. At the very least, if the WS-15 does not show at Zhuhai, the WS-15 is definitely at an advanced stage, more advanced than PLA-watchers expected.
Gates not figuring out when the WS-15 would be released was probably based on intelligence estimates expecting the Chinese, as the United States did, to delay flight trials of their J-20 until the WS-15 was semi-ready, some time in the 2020s. However, if the WS-15 can IOC before 2020, that would be a major coup.
Of course, given how contentious our SDF argument has become, if the WS-15 is a no show, I’ll be in deep trouble.
Inst@Stealthflanker: Interesting figures. If you trust this information, and then add some extrapolations based on it (reputed 50% detection range vs 0 dBsm of 450 km on J-11/J-16), a KJ-3000 with the latest radar technology should be able to achieve 1150 km detection range vs 0 dBsm. Given that the F-35 is likely around -30 to -40 dBsm in UHF band, updated AEW&C should be able to detect a F-35 at around 154 km range, while an American E-2D should be able to pick up a J-20 around 200 km, which is within the range of a PL-15.
InstDoes anyone know about a hypothesis being floated that the F-35 uses metamaterials, but it’s tightly classified? It’d make sense; the F-35 shape-wise reaches -30 dBsm, but with metamaterials the RCS drops to -50 dBsm, exceeding the F-22.
InstThere is now a huge fight going on on SDF given interpretations of insider leaks, the Minnie Chan SCMP article, and so on, about whether the WS-15 will appear installed at Zhuhai this year, and whether it will be deployed on the J-20.
FYI, Deino, Blitzo, and latenlazy are vehemently against the notion as it goes against their current analysis, and they regard sources and source interpretation as either unreliable or just fradulent. Others are more enthusiastic, but the ultimate test will come down to what we see at Zhuhai.
InstYour stance is that the J-20 is a subsonic supermaneuverable air superiority fighter, or is implicitly such. You translated it by mistake because it defeats your argument, as the pilot report shows that the J-20 has excellent supersonic maneuverability, while its subsonic maneuverability is comparable to the F-16. That was a mistake, no matter how much you try to spin the F-16 to be aerodynamically superior to the Rafale et al.
InstAt LFMS: Even an F-4 using Pulse Doppler can detect and track an F-35, provided that the F-35 is close enough, although that may occur at the range where the F-4 might want to use guns, or the F-35 might just AIM-9X the F-4 out of the sky.
The importance of stealth is not that it makes planes completely invisible or invulnerable, but that it significantly reduces the detection and targeting range of enemy weapons.
Part of the entire stealth thing is that it’s touted by the Americans as their killer app. It’s not different than the US having a nuclear monopoly between 1945 and 1949, the Americans have nukes, no one else does, so when the Americans threaten you, you should cower. In practice, neither nukes nor stealth weapons are invulnerable (nukes make you look bad or trigger nuclear reprisal, stealth aircraft can be evaded with camouflage or shot down with major disparities in care between the two sides), but the psychological factor is still there and the Americans want to play it up.
Now, while it’s possible some American politicians and diplomats believe in the myth, the actual military planners know that there are ranges where stealth simply doesn’t work. For instance, to give a trivial case, you can destroy an F-22 while it’s parked on a tarmac, you can raid an F-35 forward base, and provided you can take the base fast enough, you can either destroy it or capture it. More practically, if you’re flying at extremely close distances to an S-300 battery, you are going to get detected and shot down.
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It’s simply a matter of math. -40 dBsm / .0001 m^2 RCS reduces radar ranges by .0001^.25 by deflecting the energy generated. A bistatic radar can reduce the amount needed, and low-band radars can exploit flaws in low-band stealth to reduce RCS, but more or less you can simply work off the -40 dBsm = 90% reduction in detection and tracking range. There is the matter of flicker (RCS varying immensely over small changes of angle), which the radar systems need to be proofed against, but a F-35 running too close to an S-300 it’s either ignoring, or doesn’t know it’s there, is defeatable.
Now, what you are saying is that the Russian IADS can deny airspace to the F-35 at far longer ranges than what I’m suggesting, and this is something I do not agree with.
InstThat’s my point, if the Russians wanted to knock out a F-35, they’d camouflage it so that the US and the Israelis wouldn’t know it’s there. Then, once the F-35 is visually detected in the target range, the S-300 turns on its radars while the F-35 is in targeting range, and the entire story looks awfully like the F-117 shootdown in Serbia. Then the F-35’s wreckage gets seized by the Syrians, and the RAM coating ends up in the hands of the Russians, and perhaps later on, the Chinese.
InstLMFS:
The S-400 system should be able to target F-35s within a 30-60 km range; these are generous ranges, of course. An ambush-type attack, using massive tunnel systems, could knock out F-35s, but this depends on the relative skill and elan of the attacker and defender and is not really a sure thing. But I don’t think the Israelis want to put up with calculating for that.
InstBecause S-300, S-400 systems make warfare more difficult. Moreover, the IsAF is not drowning its F-35s, it’s drowning in F-16s and F-15s. To handle S-300 and S-400, older IsAF aircraft need F-35s to lead the way and do SEAD, which is a major escalation, or older aircraft need to fly in WHILE being destroyable by S-300s. You don’t want to operate with a gun to your head like that.
Lastly, S-300s and S-400s have enough range to target civilian aircraft flying over Jerusalem. An itchy trigger finger amidst major hostilitiies can end up killing civvies, and Israel doesn’t want that. Besides dead Jews, it’s bad for business.
InstAnd the SR-71 Blackbird? Mach 3.3 at 80k feet? 300 kN of thrust?
Instmoon_light: strictly speaing, no. Attach specialized (non-air-breathing) rocket thrusters onto the aircraft, have them activate at 80k feet.
As to realistic action, we know quite well that the J-20 is slated to get TVC, so this maneuver won’t be strictly impossible.
In any case, you can see where we’re going with this, right?
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