Inst@Jessmo23:
RCS simulation show that the J-20 is already comparable to both the F-35 and F-22 in terms of RCS at certain angles; the problem is broadband stealth and the ability of the J-20 to evade detection by E-2D Advanced Hawkeyes functioning in UHF. I don’t think that anyone except for certain fanboys believes strongly in the ability of China to defeat the United States in war at this stage; the best they believe in is deterrence; i.e, the war will be either bloody enough, risky enough, or both, that the United States cannot trivially push China around through the use of military superiority.
The corollary is that China needs abilities that are viable against the United States; with the J-20 and the BASM / ASBM China does have these abilities. You are also ignoring what I’m saying about AEW&C drones and observation drones; the United States is moving in that direction, as is China, but the distance between China and the United States in the drone warfare field is probably between 1-3 years; China is pretty close to state of the art. If the point is to maintain a kill-chain, the challenge is being able to keep communications active and prevent hacking; drones are cheap, highly stealthy, and difficult to shoot down.
As an aside, UHF E-2D Hawkeyes with powerful PESA can be defeated by interceptor missiles; i.e, the interceptor missile needs to be agile enough and long-ranged enough that the moment the J-20 reaches detection range, it can launch interceptor missiles, maneuver away from the E-2D, then go home. Interception is part of its mission and AEW&C hunting will be one of its specialties.
As far as Cuda missiles and other technologies goes; these aren’t radically superior or difficult technologies. China has a long-standing laser research tradition; they blinded US EW satellites as part of weapons testing. Cuda missiles are advanced, true, but they seem to work off rocket motor technologies, which most countries have mastered; the innovation is guidance, maneuverability, and the intent to kill the opponent via a kinetic kill instead of a detonation.
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About the WS-15 project, I think Latenlazy makes a good case for why the WS-15 project MAY, and I repeat, only MAY, be able to match latest-generation US engines in terms of thrust. On the other hand, from all available information it will not reach maturity before 2019 based on Western engine technology progression, and it is still possible that the WS-15 will fail to meet target thrusts.
If we’re talking about what’s probable:
-Availability and IOC before 2019 is extremely unlikely
-Range will be between 150kn and 180kn, depending on how well the project goes.
This isn’t to say that it won’t be 150kn, or that it won’t be 180kn, but both are equally likely given the information available; as news of delays or mishaps trickles out, we may expect 150kn instead of 180kn, but the present information suggests that there’s a range of possibilities.
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@Latenlazy; I’m glad you’ve finally come around to understanding why the J-20 needs TVC. It’s not because the J-20 really needs the additional maneuverability (it will help, definitely; if the J-20 is inferior to the F-22 the TVC will either allow it to partially bridge or meet the gap), it’s because the J-20’s aerodynamic formula is enough for a trivial conversion to a X-36 / Boeing 6th-gen style configuration, with canards in front, a delta-wing in the back, and no tailfins at all. If the J-20 reaches that level of maturity, I would say, excepting its lack of DIRCM jammer, it would possibly be the best 5th gen fighter due to reduced drag, increased stealth, and improved maneuverability.
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Lastly, most stealth aircraft have RCS spikes, but these are engineered so it’s towards the 90 degree angle; i.e, you’re never going to be able to keep a fighter on the 90 degree aspect angle. Most RCS spikes are also relatively mild, the 2001 J-20 according to Kopp is the only stealth aircraft that has a -10 to -0 dBsm zone in the frontal sector; the F-22 and PAK-FA seems capable of having -40 dBsm in the frontal sector, while the F-35 only has -20 dBsm in the frontal sector. You’ve just as well seen the polar chart as I have; it’s a huge area where you have frontal returns.
Perhaps Kopp will redo the RCS chart once the J-20 hits IOC, and with the adjustments to the LERXes and the refinements the J-20 might be comparable to the F-35 in the frontal sector.
InstThere’s a rumor on Pakdef that the WS-10 is finally mature enough for the J-10C, but I’ll believe it when I see it. The big problem with the WS-10 is that there’s minimal incentive; the WS-10 project has gone on for so long and for so poorly it might not be mature by the time the WS-15 is ready; which is what happened with the F-14; the second-generation turbofan was ready before the first-generation turbofan was fully mature; i.e, it’s possible that a WS-15 derivative could be used instead for the J-10C or J-10D instead of a “fixed” WS-10.
What matters isn’t just where dBsm peaks. It’s how much area those peaks take up. Furthermore, you’re trying to extrapolate from a rather imperfect simulation, especially given that the peak is where the radar is, which would have to involve other complex treatments and LO design aspects anyways, since that part needs to be radar transparent.
If you’re looking at the same simulation applied to the T-50, you don’t see the same 0-degree DBSM peak. What’s more, there’s a large field or area where you see a large 0-degree DBSM peak at, so the J-20, at least according to Carlos Kopp, has adequate stealth in some angles but terrible stealth in others. To begin with, the J-20 seems to have stealth characteristics similar to the F-35; since the F-35 is projected to have -20 dBsm at 0-degrees, but somewhere off centerline it has -40 dBsm, so this sort of thing isn’t totally impossible.
InstIf you just want to do panda-baiting, or perhaps I’m spelling the b8 phoneme wrong, why don’t you make fun of Chinese members’ genital endowments instead? It saves time and mental effort.
That said, if you seriously want to study the J-20, look up arguments from both sides; for instance, I usually think that Chinese posters are overly sanguine about the J-20’s capabilities, while Western and pro-Russian posters can be often too sanguine… in the sense of being negative about capability. As usual, the truth is often in between, even if sometimes it can be skewed heavily to one side.
If you’re going to argue about the J-20 as a strike instead of an interceptor craft, look up the description of why the F-22 is unsuitable for strike, then look up the dimensions of the J-20’s weapons bay. I strongly suggest you do the research before you come to a conclusion, even if the research is often strenuous as much useful information is only available on Chinese websites or as translations from Chinese websites.
In general, you’re too ill-informed on the subject to be able to credibly debate the point; it has nothing to do with your ability or intelligence, it’s just that you haven’t spent sufficient time reading up on things (if you’re talking about J-20 as part of an ASBM kill-chain, look up satellite tracking, which can be downed by American ASAT weapons, or for that matter, low-RCS surveillance drones, which can’t be downed by American ASAT weapons). If you follow the media long enough, and this has nothing to do with whether it’s pro-Chinese, anti-Chinese, pro-American, anti-American, liberal or conservative, you’ll notice that the media often gets facts wrong and you need a cohesive multi-source collation of source materials before you can get anything near the truth.
InstActually, the US stole British industrial technology as well; the US’s primacy, aside from kicking Amerindians off their land and committing imperial aggression against its neighbors (Mexico), is also based on industrial espionage of protected British technologies.
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Jessmo23’s arguments seem like little more than trollbait; they consist of little more than waving a made-in-China American flag and going “America, **** yeah!”.
That said, I agree with Andraxxus regarding the status of WS-15; if we map a Western engine-development project onto the WS-15, it almost definitely will not be ready before 2019. I think the reason the DoD miscalculated on the J-20 project maturity was because being able to use AL-31 or WS-10s was built into the J-20 project design, and a J-20 with limited T/W can perform certain combat roles for China, even if it’s not as fully capable as a F-22, T-50, or even a F-35 (talking sensors and other subsystems, of course).
I would not be confident than the WS-15 would only be a 160+ kn range engine, however. It’s too soon to tell without better information; the WS-10 project was essentially the Chinese equivalent of the TF-30, which was the first-generation American turbofan. They had no experience at all with turbofan technology, and like the TF-30, the engine was, despite an arduous development route, never quite fixed, dooming the F-14 to semi-effectiveness until the F-100s were installed. It is possible that the WS-15 project, despite the late time schedule, will be able to achieve effectiveness, simply because it’s no longer the Chinese first-generation project, the WS-10 was their trial by blood and fire and through the arduousness of its failure the Chinese now have experience, not only with what works, as in the case of the Spey WS-9 turbofans that are license-produced, but also with what doesn’t work.
@ Latenlazy: reread Kopp’s article on the J-20 RCS. It’s a polar diagram in 3D; the different colors and intensities don’t represent RCS diffraction, what they represent are the level of RCS for a given angle. The J-20 does, like the F-35, have an RCS peak towards 0 degree frontal. It, at least with the P2001, has a significantly brutal RCS peak, at around -0 dBsm. Perhaps this problem has been fixed with the P2010 series, but the baseline is pretty nasty as they come.
Insthttps://www.youtube.com/watch?v=u9nOMfa40FY
0:11 to 0:17
The video I posted for 360 might be incorrect, though, but I definitely recall STR being around 20 degrees/sec.
About the DSI-claim, the important thing is that I’m not saying that the J-20 is going to be capable of Mach 2.5 supercruise under the present engine system. It might max out around Mach 2.5 speed, but it will likely be capable of Mach 1.2 supercruise with the present engines. Not the best, but good enough, and with later engine upgrades, the DSI may be adjusted.
There is also serious research on DHI or diverterless hypersonic inlets, so I wouldn’t be confident that DSI is not scalable to high-mach speeds. As mentioned before, the J-20 does not look optimized for low-speed maneuver, so sacrificing low-speed performance may be acceptable.
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About your arguments over lift; the point is that with greater generated lift while maintaining low drag, the aircraft becomes capable of more high-altitude performance, where both lift and drag decrease. By having more lift, the J-20 will need less AOA to maintain altitude and thus will generate less drag, and by having more lift, it will be able to do this at higher altitudes, creating correspondingly lower drag for higher speeds. With sufficient altitude, a wide DSI might not be a problem; since the air is already so thin that the engine can operate effectively at higher altitudes.
InstTheir estimate is with the probe included; don’t make it like the time you misread Kopp’s chart showing that the J-20, in the 2001 implementation, had a terrible 0 degree RCS.
With regards to the WS-15, it’s all fascinating and such, but given China’s terrible track record with engine technology, it’s best to count on the WS-15 when it hits IOC. Otherwise, the J-20’s going to be running Russian engines until kingdom come.
InstBy the way, is JSR on a lot of people’s ignore lists? Wikipedia claims the empty weight of the F-15E is 14.5k, and the empty weight of the F-18E/F is 14.5k as well.
Inst@Deino, I think the figures given by the VT estimates are high, but I used their figures (78m^2, 34,000 kg), because they’re Western and they look like a high estimate so they’re less likely to be disputed. For instance, the F-22 supposedly has 4200 kg of Titanium, the J-20 is about the same length * wingspan as the F-22, and the J-20’s designers claim that 3D printed titanium reduced the weight of titanium by 40%. The F-22 is about 19200 kg empty, taking off about 1800 gives you about 18000 kg, which is 500 kg lighter than the VT estimate, and honestly I would not be surprised if the J-20 were 17500 kg.
Besides, I’m more likely to be on your ignore list; you always scream at me for taking threads off topic at CDF and SDF when I try to talk about the J-20’s shortcomings.
InstInitial J-20 will be crippled in the engine department anyways, so it will only rarely breach M2 and the wingsweep is already sufficient for transonic / low supersonic supercruise. Also, compare the sweep of the Concorde at M2.2 cruise to existing aircraft; the wing sweep is sufficient evidence at least of emphasis on high-speed performance.
Inst135 KN yields .8 T/W with 34000 kg, which is worse than .86 T/W on the F-35A but better than the .75 T/W on the F-35C. In the former case, there’s a significant wing loading advantage, in the latter, there’s still a notable wing loading advantage.
@ Y-20 Bacon:
Media is often known to be wrong; if you want to understand a subject, read a book, if you want accurate journalism, read the books written by the journalist and then read the reviews and criticism of the book. It’s enough that you can make significant amounts of money betting against media bias and media errors.
That said, we can point to the multiple record of Su-35 sales claims; i.e, it’s been done many many times and we are still no closer to an actual deal. Until both sides announce that a deal has been finalized and agreed to, it’s just more fluff on our hill of fluff.
InstTo summarize, at this stage of the discussion, we cannot know that the J-20 has supercruise capability, but it is likely to at least have transonic supercruise under some practical combat regimes. It is more unlike that with the AL-31s, it will have good supersonic supercruise, i.e, Mach 1.5 or Mach 1.8, but not wholly impossible.
The key piece of information missing is the coefficient of drag, or at least the understanding of coefficient of drag, since the VT study shows clearly a decent estimate of drag, but without being familiar with the drag of other similar aircraft, we can’t assert a judgment.
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The J-20 is an interceptor / air-superiority hybrid, that needs to achieve three roles, rated in order of difficulty.
First, it needs to be able to intercept enemy AEW&C and tankers; that’s to say, it needs to be able to passively detect AEW&C emitters at ranges where the AEW&C can’t detect it, supercruise or just afterburner in, launch XVR missiles, then afterburner out.
Second, it needs to be able to kill F-35s in BVR; that is to say, it needs to be able to spot the F-35 outside of the F-35’s NEZ, launch sufficient dogfight missiles while using its speed to put the F-35 into its NEZ, then supercruise out.
Third, it needs to be able to kill F-22s in BVR or WVR; it doesn’t matter if it has a negative K:D ratio, it just needs to be efficient enough at it to be able to attrition the F-22s, which are capped at ~191, including test airframes.
The first is definitely doable under present regimes; it has a big radar so it should be able to detect UHF-band or L-band emissions by AEW&C at long ranges, the second is not impossible, but questionable, because the F-35 is highly stealthy and when supercruising, the J-20 will be an obvious infrared opponent, while the third is possible, but highly unlikely, because of the F-22’s stealth. The sole advantage the J-20 has over the F-22 is that it has an integrated IRST, which the F-22 lacks, and in CMANO it seems to have allowed the J-20 to beat the snot out of the F-22, which I think is unbelievable.
InstDisagree; supercruise = f(lift, drag, power). For wing loading, the J-20 is perfectly competitive, at least according to your figures, but at the same time we have to know what the level of drag is with the J-20’s engines. The aspect ratio suggests that the J-20 is designed for low drag, and I think the VT sims can give you an estimate of coefficient of drag, how does that compare to other aircraft?
Another aspect is that 5th gens with internal carriages have significantly less drag when loaded than 4th gens with external stores. The F-35, for instance, is reputed to be less maneuverable than the F-16 without stores but more maneuverable with stores due to internal carriage.
Clean Su-35, which has somewhat more powerful engines than the J-20 while having less wing area, is capable of supercruise, as is the Typhoon and perhaps the Rafale. If the J-20 is designed to minimize drag, aside from its canards and quadruple tailfins, while retaining excellent lift, it stands a reasonable chance of supercruising under WS-10 / AL-31s.
Supercruising, anyways, is in large part a question of drag and thrust, not simply a question of lift.
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@ DSI, both Lockheed Martin and the Chinese have been working on DSI inlets for scramjets. I’m not sure if these are narrow / small enough that they would be completely incapable in subsonic regimes, but at the same time, the J-20 only needs around Mach 2 support with its DSI.
About the MiG-23MLD; it’s possible, if you wanted to fight at WW1-style dogfights there are few aircraft that outperform a Zero, and newer aircraft tend to be optimized for progressively faster flight regimes, but at the same time I’ve shown you vids of the J-20 moving at 22.5 deg/sec for 360 degree turn and 30 deg/sec for 180 degree turn under certain regimes. Turning performance for most aircraft tends to rise up to a certain speed, usually subsonic, then begin to subside as the speed increases.
The base model MiG-23, however, is shown to be capable of completing a 360 degree turn in 24 seconds, as opposed to 16 with the J-20. The MiG-23MLD is much improved, however, so I don’t know how well it would perform in comparison.
InstJo: Latenlazy and others are right about the long-coupled canards, though. Look at the airframe; it only looks close-coupled because there’s a LERX extending the main wing to the canards; and speaking of LERXes, there’s even a lerx in front of the canards.
That said, here’s a question for everyone, does this forum hate the F-35 more or the Chinese more? I mean, I absolutely agree that the J-20 has inferiorities to other 5th gen air superiority fighters; for instance, it could be less stealthy than the F-22, its avionics could be worse than the F-22, it’s less maneuverable than the T-50, but if you say it’s less maneuverable than the F-35 you might as well argue that a Mitsubishi Zero, in a truly fair fight, could beat the stuffing out of the J-20.
InstSo their pilots can get laid, you know. Very few people join the Air Force because they want to pilot a transport or a bomber; the F-117 bomb truck was intentionally designated as such to attract air force fighter jocks who didn’t know they were walking into a bomber.
@ mig-31:
DSI doesn’t necessarily mean the aircraft can’t supercruise, for instance, there are claims that the F-35A can supercruise around Mach 1.3 under certain weight conditions that are combat impractical. The point of DSI is that it’s non-adjustable, DSI can be optimized for a specific Mach number, above and below which performance begins to suffer, but that Mach number can be supersonic.
The reason I assume that the aircraft is built for speed is because of the high aspect ratio of the aircraft; the ratio of wingspan to length is higher than in many other aircraft, and the sweep of the wings is higher than in the PAK-FA and the F-22, not to say the F-35.
There is also a design document by Song Wencong, a senior Chinese designer, talking about how to use and modify a LERX-Canard-Delta to achieve supercruise, stealth, and supermaneuverability while being hobbled by inferior engines.
About the wing loading, as mentioned before, the J-20 has less internal volume than the PAK-FA, and even high estimates of the J-20’s 100% fuel weight is around 34,000 kg. Assuming 78 m^2 wing area, that comes down to 425 kg/m^2, which is still superior to the F-35; if the weight is lower and it’s closer to the F-22 (length * wingspan is roughly the same as the F-22), it can have around 375 kg/m^2. In either case, it’s better than the F-35A, which has an incredible 600 kg/m^2 wing loading at 100% fuel.
About the AESA jamming; any sufficiently advanced and powerful radar is capable of jamming by focusing its beam on enemy radars. The F-22’s radar can be upgraded for similar features, and the J-20 can have jamming built into its radar as well.
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In general, I just don’t see why the J-20 is double or triple inferior; if you look at the size of the airframe it cannot be relied upon to defeat the F-35 through sheer numbers; its physical mass is greater and Chinese aircraft, like the old J-10 at 27 million for the rough equivalent of a F-16, no longer have significant cost advantages over Western aircraft.
The main questions are, will the engine mature on time? Will the sensor loadout be mature on time; i.e, when the Chinese went after US EODAS systems, F-35’s EODAS was not mature and its 360-degree view was pretty buggy. Chinese coders will have to fix their own implementation of EODAS to get it to work. The J-20’s AESA is also going to be either the first or second generation of Chinese AESA, will the Chinese AESA be sufficiently advanced to compete with the F-35 and F-22?
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That said, one other problem is IR emissions. The J-20, if it supercruises, will get picked up by the F-35’s EODAS, and even when it’s subsonic, it’s a larger airframe than the F-35, and its engines will, even when underpowered, have more power than the F-35 and thus emit more. The F-35 will necessarily be darker and harder to see in IR because it’s built for subsonic. If people expect TOPCOAT to factor in, well, so many F-35 subsystems got hacked and it’s not impossible for the Chinese to come up with their clone or equivalent without TOPCOAT.
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Addition:
360-degree turn in 16 seconds or ~22.5 sustained:
https://www.youtube.com/watch?v=u9nOMfa40FY
This one ought to have a 180 degree turn in 6 seconds, or 30 degree ITR:
https://www.youtube.com/watch?v=yTIumPfiqXs
My point is that if you rate the F-35 above the J-20 in maneuverability, I want some of what you’re smoking. The F-35 by itself is also considered underpowered, if you consider that its large fuel weight results in T/W significantly below unity, especially in the case of the F-35Cs, which, while having respectable wing loading, have terrible T/W.
I do agree with many other posters, though, that WVR maneuverability doesn’t matter anymore with modern HOBS missiles (which the Chinese also have), and that fights SHOULD be determined BVR between stealth aircraft and the AEW&C they’re escorting, and the J-20 was designed for that. The weakness, as mentioned before, is still IR stealth, inadequate engines, and unknown sensor suite maturity.
InstOne thing I don’t get is why the J-20 is expected to be less maneuverable than the F-35 in certain regimes. Engine power is between 125kn to 135kn, if you consider the latest AL-31s provided by the Russians to the Chinese, thrust to weight could possibly be lower, depending on how much the aircraft turns out to weigh, but it has canards to compensate in subsonic regimes and has been shown to have around 20 degree sustained turn rate and 30 degrees instantaneous turn rate at low speeds. Not excellent, but good enough, if you compare it to the F-35.
I mean, if you want to bash the J-20 as mediocre, be my guest; it’s built more for high-speed interception and high-speed maneuverability and at the present time it’s crippled by immature engines, but I can’t figure out why you’re rating the F-35 above it. The main advantages the F-35 has right now is sensors, simply because they should be somewhat more mature than the J-20, and in the future its DIRCM laser, but in every other aspect I’m having a tough time seeing how the J-20 is inferior.
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Additions:
Let’s put it this way; if you want to say the F-22 with its superior 0 degree stealth and TVC is better than the J-20, be my guest, or that the T-50’s advanced TVC orientation + levcons can outmaneuver the J-20 in WVR, sure. The unimaginable thing is that you’re claiming that the F-35 is superior to the J-20 when both, according to estimates, are RCS -40 dBsm craft on off direct bore, the J-20 has a larger radar, is built for supercruise, and both have EODAS and IRST. The F-35 consistently loses in dogfights against 4th gens, the J-20 isn’t the most maneuverable aircraft but it’s competent compared to most 4th gens.
Other issues are, the J-20 seems to have a higher potential max Mach number (a Virginia Tech simulation by Americans using mostly accurate size estimates claimed that the J-20 will have max Mach 2.85 with proper engines and max Mach 2.1 with present engines), its wing area using Lockheed-style body lift is around 78-80 m^2, comparable to the F-22 and far superior to the F-35…
If you mean that magic missiles from Lockheed will shoot down the J-20 when fired from the F-35, I can believe that, or alternately that the F-35 has more advanced, if not larger radar and EODAS sensors, I can also believe that, but I can’t see how the F-35 is supposed to outmaneuver the J-20.
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Also, @ Y-20 Bacon, if you’re not trolling, the Su-35 deal has been rumored for almost 10 years. It may occur, it may not occur, but the Chinese and Russians have been making announcements back and forth about the Su-35 forever. Even if the technology is better than the Chinese technology (and I note, the Su-35 runs on PESA, the latest Chinese Flanker derivatives have AESA), the Chinese are not desperate enough to accede to whatever terms the Russians might have in mind.
This feels awfully like trolling, basically. The facts are out there about the J-20; it’s an okay airframe, it’s underpowered, it has a larger radar, its stealth abilities, according to projections, are acceptable, it has EODAS, its weapon bay is not optimal for a striker function, and it has canards. According to the measurements shown, as well as videos of the J-20, it has been shown to do a 360 turn in 18 seconds and a 180 degree turn in 6 seconds.
It may be complete target practice for the USAF, but that has more to do with its subsystems, the relative training levels of the PLAAF and the USAF, as well as cyberwarfare.
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