Russian Su-57 Aircraft Thread (PAK-FA and IAF FGFA)

[Engineer]

1.Max velocity has a direct relationship with dynamic altitude.
Supercruise capability doesn't replace dash capability for an interceptor. Window of intercept is tight, especially when target can reheat many times longer than your supercruise.
Btw, it shsll be understood what supercruise radius of f-22is still pitiful. Good old MiG-31 on afterburning supercruise flies significantly further. And faster.

That makes no difference in context of this discussion, as it still doesn't disprove that DSI is superior though, especially when F-22 is using a fixed inlet.

2.modification to increase serviceability(=readiness levels) at cost of rarely used performance envelope corner is an improvement. If you aren't in for a **** measurement contest. And PLAAF has faster and more suitable aircraft anyways.
Technically yes, it is possible, but at cost of far more useful part of 4th gen fighter envelope. Are you sure it's clever?

The tradeoff you talked about simply doesn't exist. With DSI, increased serviceability doesn't come at a cost of performance envelope.

3.ah, OK. A pity your truth contradicts to simply verifiable facts.
Just need to spew more, yes~

Funny you should mention it then, because my truth actually corresponds to simply verifiable facts. Simply verifiable facts such as US and China are both using DSI on their latest, top-of-the-line fighters. Simply verifiable facts like how the very first DSI already allowed the aircraft to achieve Mach 2.0.

4. I have nothing against them being pleased. More than that, I sm quite sure it's really capable. Just there are limits to this capable, dsi and current Russian engines, which are far too weak for a 5th gen fighter among them.

Russian engines are a problem, but this is offset by advantages from DSI, specifically the reduction in weight. Weight reduction has the same effect as thrust increase.

5.Su-57 with intermediate engines. Let izd.30 appear first.
Btw, intermediate engines of Russian fighter are well above al-31fm...

Yes, the Russian are more reckless than China and more willing to send immature system to the air. That intermediate engine that you talked about caught fire and burnt up one prototype. I wouldn't be surprise if WS-15 were to mature faster than Izd-30 despite being unveiled later, much like how J-20 overtook Su-57 in progress despite a later first flight.

 

[FORBIN]

 

[Gloire_bb]

That makes no difference in context of this discussion, as it still doesn't disprove that DSI is superior though, especially when F-22 is using a fixed inlet.

Inability of DSI reach certain parameters doesn't disapprove?
It's sofistery, sorry.

1.If speed envelope is limited(which is true for most modern fighters) by m=2 or less ,- yes, DSI is better, if no then it just won't give you necessary performance.

2.Well, there is only one truly fresh mach 2+ design(at least initially mach 2,5 was required, later switched iirc to good old 2,35) out there, and, surprise, it's su-57.
It's equipped with standard plates.
Others are somewhat below mach 2.
Maybe Chinese physics are different from American one, but it's unlikely.

3.US only does so on fighter-bomber design, to which air superiority role was pressed only later on.
and Russia isn't.
Maybe truth is much simpler, and Chinese aerial combat science doesn't place m=2+ performance in as high esteem as did americans in late 1980s , and as Russians still do?
You don't have to find national pride in technical solutions, which are by default sets of compromises.

4.Err, and so? Test aircraft are meant to catch flaws.
Chinese test aircraft also suffer crashes, American suffer fires, and so on.
"Zero risk tolerance" is nothing to be proud of in cutting edge technical development.

Also, let us see. But for now I am sceptical about catch up in engine technology even to Russia, much less united States.

 

[Engineer]

Inability of DSI reach certain parameters doesn't disapprove?
It's sofistery, sorry.

What "certain parameters" are DSI incapable of reaching? I see none except your wild hand-waving. Yeah, you went on-and-on about F-22's supposedly top-speed which has done nothing to disproved DSI's superority.

1.If speed envelope is limited(which is true for most modern fighters) by m=2 or less ,- yes, DSI is better, if no then it just won't give you necessary performance.

Well, there you have it — DSI is better in application. As you said, modern fighters have speed limit near Mach 2.0 and as you pointed out in post 2330, much of that flight envelop is rarely used. I'm glad you still got some sense.

2.Well, there is only one truly fresh mach 2+ design(at least initially mach 2,5 was required, later switched iirc to good old 2,35) out there, and, surprise, it's su-57.
It's equipped with standard plates.
Others are somewhat below mach 2.

You are contradicting yourself. On one hand, you claim F-22 can fly up to Mach 2.5+, mind you that F-22 uses fixed inlet. On the other hand, you claim that variable geometry inlet like that on Su-57 is the only inlet type that allows a plane to travel beyond Mach 2.0.

Maybe Chinese physics are different from American one, but it's unlikely.

3.US only does so on fighter-bomber design, to which air superiority role was pressed only later on.
and Russia isn't.
Maybe truth is much simpler, and Chinese aerial combat science doesn't place m=2+ performance in as high esteem as did americans in late 1980s , and as Russians still do?
You don't have to find national pride in technical solutions, which are by default sets of compromises.

Oh, I agree that there are different technical solutions and compromises, but let's be real — the Russian explanation about why their 5-th generation aircraft being different is more of an excuse than anything else. The F-22 is fast too, yet it doesn't look anything like the Su-57. Yeah, physics work the same everywhere, but when it involves Russia then some people try to convince you that some physics is more important than others.

4.Err, and so? Test aircraft are meant to catch flaws.
Chinese test aircraft also suffer crashes, American suffer fires, and so on.
"Zero risk tolerance" is nothing to be proud of in cutting edge technical development.

There are acceptable risks and there are unacceptable risks. In Western countries, when a serious incident occurs, the whole fleet is grounded until the problem is found and rectified. As an example, this was done when F-35 had an engine fire. China does the same as it values Western engineering standard and procedure very highly. Russian on the other hand, in response to their PAKFA prototype being burnt, basically said that test program will continue at the same pace as usual.

Also, let us see. But for now I am sceptical about catch up in engine technology even to Russia, much less united States.

Russia isn't that advance in engine technology. Almost all of the engine technology in Russia is inherited from Soviet Union. Russia has done very little since Soviet Union collapsed, whereas China pretty much has reinvented everything there is in fighter engine in that same time period. Russia still had to source gas turbines from Ukraine, and when Russia got embargoed, there is no more Russian destroyer programs.

 

[Tirdent]

LOL! Engine fire located "good distance forward of the engines", I don't think you even know what you are talking about anymore.

Nope, the issue is that you have it bass ackwards - the damage is located where it is because the fire more likely than not wasn't an *engine* fire at all. You first jumped to the conclusion that it had to be one, and are now trying to retro-actively distort the facts to fit that twisted perception.

You're just digging yourself deeper into a hole.

The Su-57 is a heavily modified Flanker variant. This is concurred by many people. Only the blind and the unwillings can't see this.

As for that picture, it's chock full of the most ridiculous errors.

I mean, the Su-57 has the same nozzles as the Su-35? No sh*t Sherlock, it has closely related variants of the same engine. Does that make the F-15SG a variant of the F-14B? Or the J-20 a Flanker copy? The Su-57 main landing gear is not actually the same at all, it lacks the locking sockets on the side of the air intake ducts and has other confirmed mechanical differences (larger wheel diameter etc.). #4 on the Su-35 and Su-57 aren't even superficially similar (blade antenna on the Flanker, dummy DIRCM turret on the Su-57) - must be that eye-sight of yours again. IRST location? How is that even relevant to the question at all? I guess that means the Su-34 isn't based on the Su-27 airframe.

Quite apart from all the rather fundamental differences in configuration between the Su-57 and Su-35 which are readily apparent to anybody with even a modicum of sense.

Losing a prototype isn't uncommon, and frankly it would have make no difference to me except you are the one who was trying to convince me that no prototype is lost. I merely corrected you with facts.

What? Where on earth am I supposed to have claimed that it was not lost? I merely pointed out that the cause was probably not an *engine* fire (lost, but not to an engine failure). Reading comprehension dude - apparently the notion that somehow it was engine-related is so deeply rooted in your mind that you even projected that baseless conviction on my comment. If you are going to launch on a tirade like that, you'd better make sure you've even comprehended what the object of your wrath was talking about.

Way to look a fool!

Don't blame me for your own despicability. I merely pointed out Russia is reckless, then you started red herring and proceeded to throw mud hoping for something to stick. I responded professionally, sticking with discussion about Russia's faulty engineering and provided further proof of Russia's reckless track record going all the way back to Soviet's time — something which you can't even deny. I literally laughed out loud when I read your threat about bringing Great Leap Forward into an engineering discussion. It is the exact type of low-grade response I expect from you.

Ok, that does it - you're on my ignore list as soon as I'm done debunking this round of your nonsense.

No, variable geometry inlet is the technical term. Your knowledge is patchy, and it shows.

Meanwhile, we're still waiting for you demonstrate your understanding of the theory behind DSI. What a blatant piece of evasion!

Nice try with strawman fallacy, and it is a strawman because I never made such point. I simply exposed your falsehood by pointing out that DSI is lighter, more stealthy, and has comparable performance with traditional inlet. You objected, so I cited how US and China use DSI on their top-of-the-line fighters. The fact remains that Russia does not have anything to show for with DSI, indicating the country is lagging behind.

While we're on the subject of fallacies, how about ignoring that "traditional inlet" comprises such a huge variety of solutions with so wide a range of characteristics that a blanket statement of this sort is doomed to be so inaccurate as to be useless?

Is a DSI lighter than a F-16-style pitot intake? Not unless both are designed for the same low RCS. Does a DSI have better pressure recovery than a variable intake? No. Period. Is it the stealthiest *supersonic* inlet design currently available? Yes, although for a weight penalty you can build a caret intake with comparable RCS.

Furthermore, DSI first flew at end of 1996 whereas first F-22 rolled out in Spring of 1997. In short, DSI wasn't even available when F-22 was being designed. Your attempts at trying to present F-22 as some big revelation is nothing but a grasp at straws.

Wrong. The final F-23 design submitted at the same time as the F-22 configuration which was rolled out in 1997 would have had DSI if built. Anybody else note the irony of a design with DSI being beaten by one *without* in the competition for America's top of the line fighter, BTW?

US and China both use DSI on their top-of-the-line fighter. The airforce of two major powers put their money where their mouth is. That is a proof of DSI superiority. Your argument has nothing to stand on.

Not at all - it merely proves the US and China have similar design priorities. And no matter how much you're going to dance around the issue, the document I provided implies with that you are dead wrong about DSI pressure recovery. Get over it (I suppose an apology would be too much to ask)!

An entire engineering branch, people with concrete data and much more knowledge than I, decided to replace J-10's variable inlet with DSI, so DSI having better performance is a fact and not an assumption. This real world example torpedoed your entire thesis on how variable geometry is better.

Rubbish - that logic would work only if DSI had no advantages in other areas which might have compelled the switch instead. As I said, your entire reasoning is founded on a premise which is demonstrably false.

The development of LERX replaces the need for an adaptable wing geometry. DSI replacing archaic variable geometry inlet is similar. In both cases, fixed structure replaces complex movable mechanisms.

LERX doesn't help you combine a Mach 2+ top speed with long subsonic loiter - providing a means to adapt wing aspect ratio to flight speed (variable sweep) does. Priorities have shifted, but the advantages and disadvantages of VG wings remain unaffected by that.

 

[Gloire_bb]

Oh, I agree that there are different technical solutions and compromises, but let's be real — the Russian explanation about why their 5-th generation aircraft being different is more of an excuse than anything else.

In many ways, Russian is closer to American naval one, because necessary priorities match in many ways.
For example, less empasis on offensive anti air(especially some kind of knightly air dominance operations) , more on integral long range loitering intercept(including sniping out high value enemy enablers in air), long range strike/interdictor aircraft qualities, and so on.
Qualities which both F-22 and F-35 lack.

The fact what navair 5th gen is dead(largely their own fail) doesn't mean what it had never existed.
Just died. Which is probably a good thing to China, since superbug lacks them too.

Interesting part here is j-20(especially since it's backed by large and fresh 4th gen fleet) , but it isn't matter of this topic.

 

[Engineer]

Nope, the issue is that you have it bass ackwards - the damage is located where it is because the fire more likely than not wasn't an *engine* fire at all. You first jumped to the conclusion that it had to be one, and are now trying to retro-actively distort the facts to fit that twisted perception.

You're just digging yourself deeper into a hole.

LOL! According to you, it wasn't an engine fire but the plane simply spontaneous combusted for no reason, and that is somehow better. Clearly you have never seen an engine fire. The engine casing made entirely of metal is a pretty good container for fire, but the inlet itself isn't. Flame spills out of the engine's ends and starts burning the front or back first. Here is an example.

As for that picture, it's chock full of the most ridiculous errors.

I mean, the Su-57 has the same nozzles as the Su-35? No sh*t Sherlock, it has closely related variants of the same engine. Does that make the F-15SG a variant of the F-14B? Or the J-20 a Flanker copy? The Su-57 main landing gear is not actually the same at all, it lacks the locking sockets on the side of the air intake ducts and has other confirmed mechanical differences (larger wheel diameter etc.). #4 on the Su-35 and Su-57 aren't even superficially similar (blade antenna on the Flanker, dummy DIRCM turret on the Su-57) - must be that eye-sight of yours again. IRST location? How is that even relevant to the question at all? I guess that means the Su-34 isn't based on the Su-27 airframe.

Quite apart from all the rather fundamental differences in configuration between the Su-57 and Su-35 which are readily apparent to anybody with even a modicum of sense.

Talk about looking for a tree and missed the forest! The picture illustrates the similarities between a regular Flanker and the Su-57. No one claims the two planes use the exact components, so quit your strawman fallacy. By the way, I wasn't the author of the diagram, showing I am not the only one who sees the Su-57 as a modification of Flanker. Yeah, someone needs his eyes checked — the one who is insisting no similarities when they are glaring obvious.

What? Where on earth am I supposed to have claimed that it was not lost? I merely pointed out that the cause was probably not an *engine* fire (lost, but not to an engine failure). Reading comprehension dude - apparently the notion that somehow it was engine-related is so deeply rooted in your mind that you even projected that baseless conviction on my comment. If you are going to launch on a tirade like that, you'd better make sure you've even comprehended what the object of your wrath was talking about.

Way to look a fool!

Of course someone who denies Russian recklessness in putting an experimental engine in an experimental airframe would also have to deny consequence of such recklessness, even though the evidences are staring at him squarely in the face. Frankly, I am not surprise at your response at all.

Ok, that does it - you're on my ignore list as soon as I'm done debunking this round of your nonsense.

You do not have any moral high ground, so you can step down from your pedestal and quit your pretentiousness; nor are you in a position to debunk anything, because I am debunking you.

Meanwhile, we're still waiting for you demonstrate your understanding of the theory behind DSI. What a blatant piece of evasion!

No, it's just your psychological projection at work and you being frustrated that I am not playing your silly games. You are the one evading the fact that DSI is being used by air force of two major powers in their top-of-the-line fighters. Red herring by demanding me to proof my knowledge of DSI principles isn't going to change the fact that DSI was chosen due to its superior performance.

While we're on the subject of fallacies, how about ignoring that "traditional inlet" comprises such a huge variety of solutions with so wide a range of characteristics that a blanket statement of this sort is doomed to be so inaccurate as to be useless?

The fact that you would even say this further reaffirms my view that your knowledge of inlet design is patchy. This is pretty much the same situation as you making up a term "moving ramp inlet" to describe the variable geometry inlet.

Is a DSI lighter than a F-16-style pitot intake? Not unless both are designed for the same low RCS.

DSI is both lighter and stealthier, no if or but.

Does a DSI have better pressure recovery than a variable intake? No. Period. Is it the stealthiest *supersonic* inlet design currently available? Yes, although for a weight penalty you can build a caret intake with comparable RCS.

DSI being better doesn't need better pressure recovery, it only needs to do the same job without penalties of variable geometry inlet. As I pointed out already, DSI offers comparable pressure recovery, but with less weight and RCS. That is why DSI is better.

Wrong. The final F-23 design submitted at the same time as the F-22 configuration which was rolled out in 1997 would have had DSI if built. Anybody else note the irony of a design with DSI being beaten by one *without* in the competition for America's top of the line fighter, BTW?

F-23 was beaten because it posed higher development risks. By the time the first F-22 is rolled out, DSI was still being tested. DSI was simply not available, and any decision to use DSI then would be using untested technology. Once DSI's superior performance became verified, it was quickly adopted, as is the case on F-35.

Not at all - it merely proves the US and China have similar design priorities. And no matter how much you're going to dance around the issue, the document I provided implies with that you are dead wrong about DSI pressure recovery. Get over it (I suppose an apology would be too much to ask)!

DSI being chosen, as opposed to other alternatives, mean DSI is better suited to those priorities, hence better. You can keep dancing around that fact, making up falsehood about DSI's pressure recovery, but they aren't going to help you.

Rubbish - that logic would work only if DSI had no advantages in other areas which might have compelled the switch instead. As I said, your entire reasoning is founded on a premise which is demonstrably false.

My premise is that both by US and China chose DSI for their top-of-the-line fighters. There is nothing false about this. That premise supports the conclusion that DSI is better in application. Your argument doesn't work, because you are trying to challenge established engineering decisions.

LERX doesn't help you combine a Mach 2+ top speed with long subsonic loiter - providing a means to adapt wing aspect ratio to flight speed (variable sweep) does. Priorities have shifted, but the advantages and disadvantages of VG wings remain unaffected by that.

LERX does. That's why modern fighters all incorporate LERX and not variable swept wing.

 

[Gloire_bb]

LERX does. That's why modern fighters all incorporate LERX and not variable swept wing.

Tomcat isn't exactly modern, but it's 4th gen nevertheless.

 

[Jeff Head]

What's the latest Russian estimate of the numbr of aircraft they are going to build and when.

INitially it was 150 fighters by the early to mid-2020s.

Then it dropped I believe to 55 fighters by 2020-2022.

The latest I remember hearing was that the intial order now would be 12 fighters to be available in 2019-2020.

WHat is the latest procurement plan? does anyone know at this point.

And what has become of India's involvement. Intially they were going to order 166 single seat and 44 two seat, or 210...but that then dropped to 130 single seat and no two seat version in 2014...but I believe since that time they have either further reduced the number or waffled n future involvement significantly.

I am just wondering what the most current offical word is on how many Russia and India are actually planning for sure at this point?

 

[Gloire_bb]

The latest I remember hearing was that the intial order now would be 12 fighters to be available in 2019-2020

Current contract is 12 aircraft for s.c. "Ustsnovochnaya parties"(0 series), to be delivered in 2018-2019. All but last two will be in current production standard, last two will be outfitted with new engines.
Afterwards, VKS is waiting for izd.30 equipped aircraft to finish trials, and all numbers are speculative.