J-20 5th Gen Fighter Thread VI

[Inst]

I'm attacking your statement, which is false, and note that I have not claimed to attempt to use perspective distortion to determine the distance from the aircraft. Likewise, if we're talking about lens distortion, most modern DSLRs correct for distortion through software; in fact, it's become a minor scandal as people complain about DSLRs artificially enhancing their performance.

The work I have done is to try to calculate based on the J-20's length, ignoring perspective distortion, the turn radius shown in videos. Basically, if I were to claim that the J-20 can do 30 degrees sustained turn rate via visual analysis, you wouldn't care a fig because you're a PLAAF fanboy. On the other hand, since I'm showing that the J-20 is not maneuvering well in videos, you're taking issue with it because you need to believe that the J-20 is competent, when we know it's made design compromises because of its inferior engines.

The most you can say in defense of the J-20 is "we can't know that", but the evidence is sufficient for us to assume these factors. You guys seriously went off on a tangent about how "不错" means excellent through understatement when in Chinese, to say an object has an adjectival property, you use the adverb "很", or very, to imply a neutral statement.

I am not seriously disagreeing with your notion that outsiders are typically too negative on Chinese PLAAF capabilities, but neither do I agree with your inflated estimate of the PLAAF equipment.

 

[Inst]

Frankly speaking, it's not impossible that the J-20 is just a bad design necessitated by poor engines. Note that the discourse here has been heavy on the excuses: i.e, the J-20 hasn't shown its "real power" for security reasons and so on. Yet we're already willing to speculate that the J-20 made a stealth fly-by of the Korean peninsula undetected by American counter-stealth radars, which is implausible.

Let's put it this way. Tons of material about the F-22 is highly classified. Yet American pilots are not afraid to brag about 28 deg/sec STR, and there are many videos of an ultra-maneuverable F-22, even if we can safely assume the aircraft is not being pushed to its limits. Have we seen the same with the J-20? We definitely have videos of the J-20 making acrobatic maneuvers; we know the roll rate is excellent even without TVC, but none of the maneuverability videos have impressed; even at low altitude, which implies better maneuverability, we've rarely seen the J-20 exceed 18 deg / sec.

Of course, the jury remains out for want of better evidence. But with the evidence we have available, we can assume that the J-20 has been lackluster, relative to ultra-maneuverable Eurocanards, F-22s, and Russian aircraft, in the subsonic regime. It is possible that the J-20 will end up doing airshow tricks in the future, but this is what we know based on available evidence.

 

[ougoah]

Ok... so then I'll ask it: Is it really possible to calculate or estimate "anything" meaningless from that short blurred video??

It is a serious question and I'm not a technical guy, but from the maybe 5-7 seconds it seems more than eyeballing to make an educated guess.

And for me at least at seems as if a few are discussion as if their soul's future would depend on that outcome.

I simply don't understand that stuff ... but I'm willing to learn if one would explain.

Deino

Not really. Pretty obvious to anyone that these calculation cannot be done with any accuracy or reliability. Don't know why certain people even bother. Do they really think J-20's actual kinematic performance would be revealed by videos from such a secretive state? Even taking a clip that shows afterburners and deflection, we don't know initial velocity, altitude, weight (whether loaded with fuel or dummy weapons simulating bomb load etc). We have no frame of reference. We have no scale. On top of this we don't know speed up factor and how hard the pilot is pushing. So stop. You're embarrassing yourself with your assumptions.

I believe J-20 cannot be all that agile and maneuverable simply because it is currently not powered by ideal engines. I also don't really believe in significant enough weight reductions (could be totally wrong on that) to compensate for "lack" of thrust. If this is actually the case, performance will be enhanced with new engines and further upgrades. I could also be wrong on weight and there's another key variable. Don't know much about its aerodynamics but looks like it was designed for supersonic agility like the typhoon and raptor with its distant couple canards and lower drag owing to internal carriage. In any case, this fighter isn't designed as a close range dogfighter. Doesn't even have a gun currently so it shows this is not a priority. Agile and maneuverable or not, as long as it can supercruise and have decent supersonic agility, that's all it ever needs. Also VLO obviously. Rest is really not all that important.

 

[ougoah]

Frankly speaking, it's not impossible that the J-20 is just a bad design necessitated by poor engines. Note that the discourse here has been heavy on the excuses: i.e, the J-20 hasn't shown its "real power" for security reasons and so on. Yet we're already willing to speculate that the J-20 made a stealth fly-by of the Korean peninsula undetected by American counter-stealth radars, which is implausible.

Let's put it this way. Tons of material about the F-22 is highly classified. Yet American pilots are not afraid to brag about 28 deg/sec STR, and there are many videos of an ultra-maneuverable F-22, even if we can safely assume the aircraft is not being pushed to its limits. Have we seen the same with the J-20? We definitely have videos of the J-20 making acrobatic maneuvers; we know the roll rate is excellent even without TVC, but none of the maneuverability videos have impressed; even at low altitude, which implies better maneuverability, we've rarely seen the J-20 exceed 18 deg / sec.

Of course, the jury remains out for want of better evidence. But with the evidence we have available, we can assume that the J-20 has been lackluster, relative to ultra-maneuverable Eurocanards, F-22s, and Russian aircraft, in the subsonic regime. It is possible that the J-20 will end up doing airshow tricks in the future, but this is what we know based on available evidence.

I don't remember any serious member entertaining the thought that J-20 went to Korea undetected. It seems like you're making these things up to add value to your arguments. When did anyone propose this actually happened? All I remember reading are others agreeing on how ridiculous this conspiracy was. American pilots have supported all their equipment be it f-16 or f-22 and everything in between. PLAAF pilots have never revealed info on anything even su-35 or their J-11 flankers despite us all knowing very well they can outturn much of the USAF legacy fleet. So no brags there for superior performance? Get the pattern? Or need I go picking your arguments apart?

 

[ougoah]

If you think J-20 is a poor design due to underwhelming engines, it would help your cause if you could provide actual real evidence. In absence of this, we can all speculate and we're all just expressing opinion. It's pretty worthless and you should know there are chauvinists around who will look at your suggestion with much anger. Lol why go looking for trouble from these members? So I can't imagine why someone would be inclined to express such a controversial idea so openly without any supporting evidence. A few video clips is not evidence. I can find Su-30mki clips where it's turning super slow despite having afterburner on. It shows nothing.

Also when I suggested doubt on J-20 not achieving the claimed weight reductions, I was careful to mention that is my worthless 2 cents and I could be wrong. "Underpowered" engines is pretty much agreed on by most people.

 

[latenlazy]

I'm attacking your statement, which is false, and note that I have not claimed to attempt to use perspective distortion to determine the distance from the aircraft. Likewise, if we're talking about lens distortion, most modern DSLRs correct for distortion through software; in fact, it's become a minor scandal as people complain about DSLRs artificially enhancing their performance.

Only being able to get distance and speed measurements of objects moving in a three space using proper scaling and at least two angles is a false statement? Only being able to measure distance through perspective effects if you know very specific and detailed properties of the lenses optics is false? Sorry, what was your answer to either of those points? Oh right, that I’m a fanboy who is only arguing to defend my own wishful fantasies that the J-20 is the greatest ever. Remember when you were going on and on about how the J-20 must have a more powerful radar than the F-22 and I said that it might not because we don’t know enough about either the actual radar diameter, how many modules it has, or how powerful those modules are? Yeah that’s just me being a fanboy defending my favorite super ultra bestest fighter ever. A great fanboy I make huh?

The work I have done is to try to calculate based on the J-20's length, ignoring perspective distortion, the turn radius shown in videos. Basically, if I were to claim that the J-20 can do 30 degrees sustained turn rate via visual analysis, you wouldn't care a fig because you're a PLAAF fanboy. On the other hand, since I'm showing that the J-20 is not maneuvering well in videos, you're taking issue with it because you need to believe that the J-20 is competent, when we know it's made design compromises because of its inferior engines.

The plane in the video isn’t turning in a 2-space. It’s turning in a 3-space, and we’re only getting one frame of reference when we need 2. I don’t care what you claim to the J-20’s turn radius in that video. I’m taking issue with the quality of your analysis and arguments. You’re taking issue with an imaginary me that gives you convenient straw men to attack. I’m not the one who seems to have a desperate need to believe something immaterial here.

The most you can say in defense of the J-20 is "we can't know that", but the evidence is sufficient for us to assume these factors. You guys seriously went off on a tangent about how "不错" means excellent through understatement when in Chinese, to say an object has an adjectival property, you use the adverb "很", or very, to imply a neutral statement.

With how rigorously you scrutinize “evidence” I’m surprised you’re not a flat earther. Some people used to argue that evidence was sufficient to assume the Earth was at the center of the universe. That you think we have sufficient evidence to assume something is not a great defense of anything.

We weren’t going off tangent over “不错”. We were explaining what is pretty typical of the language. If you want to run around translating “不错” to mean mediocre making a fool of yourself in front of native Chinese language speakers that’s your business. Don’t say no one tried to help you though.

I am not seriously disagreeing with your notion that outsiders are typically too negative on Chinese PLAAF capabilities, but neither do I agree with your inflated estimate of the PLAAF equipment.

Where have I ever given an inflated estimate of anything? Quote me.

 

[Inst]

Only being able to get distance and speed measurements of objects moving in a three space using proper scaling and at least two angles is a false statement? Only being able to measure distance through perspective effects if you know very specific and detailed properties of the lenses optics is false? Sorry, what was your answer to either of those points? Oh right, that I’m a fanboy who is only arguing to defend my own wishful fantasies that the J-20 is the greatest ever. Remember when you were going on and on about how the J-20 must have a more powerful radar and I said that it might not because we don’t than the F-22 know enough about either the actual radar diameter, how many modules it has, or how powerful those modules are? Yeah that’s just me being a fanboy defending my favorite super ultra bestest fighter ever. A great fanboy I make huh?

Yes, you are a fanboy, and your arguments are garbage, and there's little point to engage with your delusions.

As far as radars, my point was that the J-20 had a larger radar aperture. We do measurement, it comes out to 1.2-1.3 meters from the external radome itself and get a radar aperture of between 950mm and 1000mm compared to 925mm on the F-22. With the same technology level, the J-20 has greater radar power than the F-22. Moreover, note that PLA commentators have mentioned that the J-20 is supposed to have the larger radar aperture.

Basically, that's just you; when the evidence doesn't go your way, bash it as "insubstantial".

@ougoah:

Note we have a statement of PLAAF test pilots claiming that the J-20, in their simulator, has good maneuverability in subsonic but excellent in supersonic. So your claim that the PLA never says anything about their pilots is false.

 

[latenlazy]

Yes, you are a fanboy, and your arguments are garbage, and there's little point to engage with your delusions.

Ah. So rich coming from a guy who’s been called out for making stuff up about how radars work by actual RF engineers, and then *persists* with those arguments.

As far as radars, my point was that the J-20 had a larger radar aperture. We do measurement, it comes out to 1.2-1.3 meters from the external radome itself and get a radar aperture of between 950mm and 1000mm compared to 925mm on the F-22. With the same technology level, the J-20 has greater radar power than the F-22. Moreover, note that PLA commentators have mentioned that the J-20 is supposed to have the larger radar aperture.

And my point is if I was such a fanboy I might have eaten up your shoddy arguments about the J-20’s radar instead of questioning it. I see that your analytical deficiencies also seem to apply to judgments about people.

Basically, that's just you; when the evidence doesn't go your way, bash it as "insubstantial".

“Insubstantial” isn’t bashing. It’s pointing out the reach of claims do not fit the quality of evidence. Some people declare that massive snowstorms are sufficient evidence to prove that climate change a hoax. That’s what you’re doing with your armchair video analysis. That’s not the evidence not going my way. It’s just objectively weak evidence.

Do you really dislike being wrong (or the idea that you don’t know enough to qualify anything you believe) so much that your only response is to smear other people and make up things about them?

 

[Inst]

latenlazy: you're assuming that veroth is being honest when he's making the claims about aircraft; based on his credibility as an "ee graduate from a top 5 school" he's made claims that half-wave resonance doesn't exist, that the J-10B can run AESA when big shrimps tell us it's PESA, and he goes around chasing me like a buffoon.

As to J-20 arguments being shoddy, show HOW it's shoddy. I actually noted that Chinese AESA technology is probably not up to the US's level back at the time, and I noted that for a Chinese to be able to exploit their aperture advantage they'd need the same technology level, but all other factors being equal, the larger AESA is more powerful, and that the J-20 has a slightly larger radar than the F-22 based on exterior measurements and projections.

 

[latenlazy]

latenlazy: you're assuming that veroth is being honest when he's making the claims about aircraft; based on his credibility as an "ee graduate from a top 5 school" he's made claims that half-wave resonance doesn't exist, that the J-10B can run AESA when big shrimps tell us it's PESA, and he goes around chasing me like a buffoon.

1) As I recall he never claimed that half wave resonance doesn’t exist but that you were misapplying a concept digested for laymen. 2) And you’re qualified to assess his claims because what? You’re an RF engineer? Because you think reading Wikipedia pages and internet articles you barely seem to comprehend makes you a genius?

As to J-20 arguments being shoddy, show HOW it's shoddy. I actually noted that Chinese AESA technology is probably not up to the US's level back at the time, and I noted that for a Chinese to be able to exploit their aperture advantage they'd need the same technology level, but all other factors being equal, the larger AESA is more powerful, and that the J-20 has a slightly larger radar than the F-22 based on exterior measurements and projections.

I do show why your arguments are shoddy, consistently. For example, every time you try to claim the J-20 must have a larger radar apeture I have to point out we don’t know how much space the radar takes inside or where along the nose the radar is situated. Your answer seems consistently to be “latenlazy is a fanboy so I don’t need to engage with his points”.