Su-57 Stealth Fighter: News #6

@GarryB:

Nobody is saying Russia is going to disappear from the map if they operate a squadron Su-57 for a few years without the second stage capabilities, for the same reason they don't rely 100% on Konteyner and such assets and so can do without supercruise or air force altogether: they never put all their eggs in the same basket and make sure every single element of the force is as capable and self reliant as possible. So, of course the plane is intended for supercruise and arguing how you don't actually need it is a moot point, since all air forces aim for it and VKS in particular has been explicit about it.

thegopnik wrote:

Since I do not take frontal RCS value as the entire value of an aircraft I am starting to think that 5th gens will get reduced to 4th gen aircrafts in terms of tracking to point it is useless that you might as well switch back to 4th gens if they will get tracked the same way and newer air defenses like the S-500 .

Especially once quant radars start getting developed. China claims to have an experimental one going. With a quant radar, whichever plane has the lowest profile will be the hardest to track. And on that score, the su 57 is ahead of both the F-22 and J-20. Because of its true blend wing/podded engines design, its the flattest.

The biggest legacy of 5th gen aircraft might end up being the internal weapons. Because this gives it performance when loaded that a 4th gen cannot match.

LMFS wrote:@Backman:

in general the argumentation seems well built, my main comment is that there are some assertions for which I have not seen evidence.

Backman wrote:In contrast to Su-35S, PAK FA has more powerful engines, better T/W ratio, greater wing surface/lower wing loading, better acceleration/climb rate, better turning characteristics, in essence significantly better than Su-35S according to test pilot Сергей Богдан.

This is the key point, where did he say that, I have personally not seen it. Engines are more powerful, Bogdan even said one needs to be careful with the plane because you can go supersonic before you notice... but I don't know how it is with the Su-35, in any case it sounded as if he was surprised by it and so a substantial improvement vs. Su-35S, but that is only an opinion.

Again, weight unknown, so is T/W so wing loading, acceleration. I have not seen Bogdan saying the Su-57 is more manoeuvrable than the Su-35, do you have links?

And all that using interim engines. Final version of the engine will have 15 to 25% higher thrust, lower specific fuel consumption and about 30% lower specific weight according to manufacturer.

Manufacturer has said that? Would love to see it.

15-25% higher thrust could be meant in mil settings, since it is supposed to be a supercruising engine, but maybe not in AB, since that would mean between 17 and 19 tf (!) for an engine the size of AL-31F. Marchukov said SFC was that of AL-31F. I have not seen that reference of 30% lower specific weight and I find it difficult to believe, izd. 117 is already below 0.1 (TWR for the engine would be above 14!)

PAK FA is F-22 class fighter that is designed to fly very high and fast (did I mentioned that variable intakes help a lot). It is also designed to supercruise at speeds that are probably higher than F-35 top speed, it is designed to "live" there for a long period of time. There is great SEP reserve compared to F-35 in supersonic region when PAK FA is using burners. When F-35 has no more SEP at 1,6 Mach, PAK FA continues accelerating to +2 Mach. This is clear indication of superior transonic/supersonic acceleration.

This is hard to dispute. The AIAA paper studying the EM characteristics of the F-35 shows very poor supersonic performance, which is something almost everybody suspected regardless. The designer and services have admitted supersonic flight regime is not the main goal of the F-35, whereas in the Su-57 this is one of the main priorities. I can only expect it to be head, shoulders and waist above the F-35 in that regard, more when the izd. 30 appears. BTW, the F-35 has still excess power at 1.6 M, but apparently not much.

In other words F-16 block 50 would be very dangerous for F-35 in guns only scenario. Start putting some missiles and F-35 takes the advantage. And I do agree. That is absolutely more realistic scenario! The problem here is we are not comparing F-35 to F-16, we are comparing F-35 to PAK FA.

Here the only advantage of the F-35 is having a monster engine. The F-16 with such an engine would utterly crush the  F-35...

As we already know PAK FA is superior to Su-27 and we can see that Su-27 is superior to F-16 block 50.

The comparison with the Flanker is very well built, but the translation to the PAK-FA is a bit of a leap of faith, since we don't know how much better (or not) the plane is in all flight regimes compared to Su-35. Not that I remotely think the F-35 would fare very well, but a quantitative comparison is still not possible.

The math can be done for wing loading and stuff just by knowing the surface area of the aircraft which is known. I think thats what he means.

As for engines, I thought the 15-20% was always the rumor number. 25% seems too high though. That's overkill territory.

He provided a few links but they are all expired. Error 404 when i clicked on them.

Mystery solved This is just a scale model though

thegopnik wrote:Since I do not take frontal RCS value as the entire value of an aircraft I am starting to think that 5th gens will get reduced to 4th gen aircrafts in terms of tracking to point it is useless that you might as well switch back to 4th gens if they will get tracked the same way and newer air defenses like the S-500 will over the horizon strike capabilities engaging aerial targets. I believe it is a better strategic advantage that there air force would cooperate with their air defenses if adversaries dive deep into territory and the Su-57 with the Okhotnik when doing strategic missions can go deep into any territory outside of Russia without the need of refueling aircrafts identifying their locations as well.

Stealth shaping's best usage is within air-to-air engagement envelopes between 2 fighter aircraft by themselves. If it's a dogfight only between 2 fighters than the low-observable aircraft will have the 'surprise advantage' while the 4th-gen fighter will have the ammunition surplus advantage.

Backman wrote:Mystery solved This is just a scale model though

Well the patent for Su-57 Sidebays is already around for several years.

https://findpatent.ru/patent/261/2614871.html

It's kinda weird tho to see people keep speculating about the purpose of the canoe shaped side bay or how the missile is deployed, while the patent for it already around, free to download and straight to the point.

thegopnik wrote:To my own amusement I feel like Russia is competing more in terms of next gen radars and next gen stealth against Italy rather than the U.S. Italy made some big headlines with the PHODIR project or their photonic radar but could not get it to exceed performance specs of a conventional radar but it seems Russia did based on 3 of their companies. Than of course comes this stealth transparency metamaterial which both russia and italy took a part in so I wonder which countries will bribe them for it as a possibility. Photonic radar on su-57 is questionable, but the metamaterial for outside structure is a little more doubtful because it seems to be a physical material and they cannot make any physical appearance altercations with the 2nd Su-57 variant but they said they can put this material around their antennas or other electronics (so there is some hope) to not only stealth it but improve its performance if I read that article right. It would be amazing if the metamaterial and photonic integrated circuits are on the 2nd su-57 variant but if they are not I hope they will push it towards a 6th gen, which based on speed estimates and height claims make lower altitude aircrafts impossible to reach with air to air missiles and maintaining a radar fix on because they have shown projects that they are serious in this field as well..... more or less I think the purpose of the f-35 is just to raid 3rd world countries and not something to put a huge investment on for the future for many reasons shown on this board time and time again.

What so surprised? Man, we invented it!

https://en.wikipedia.org/wiki/Guglielmo_Marconi
And after WWII we were always in the forefront for competition into Radar and radio communication.

Stealthflanker wrote:

Well the patent for Su-57 Sidebays is already around for several years.

https://findpatent.ru/patent/261/2614871.html

What is a "patent" anyway?  I've never even heard of that until LMFS brought it up a few pages ago and my knowledge of what a patent means relates to copywriting lol.  So who writes these patents, is it Sukhoi themselves?  Or another defense agency out of Russia?  Just trying to understand a little better.

And here's the other thing is that just because we (or I should say "I") question it or disagree with the assessment of whatever the case may be, and I live in the US doesn't mean that I'm the enemy's fan boy by any stretch of the imagination.  It's quite the opposite as my country of origin is actually Egypt and we're VERY fond of Russian military equipment and I specifically have a personal vested interest in this beauty of an aircraft since my hope is that after purchasing 46 MiG-29M/35s and 30 Su-35SEs that they end up acquiring the Su-57 as their 5th generation fighter.  So laying down the disclaimer from the start here just to make it clear that simply because we question certain specific elements doesn't mean we are the enemy or think it's a lie or think it's a hoax etc.  I'm just trying to understand how it works since a lot of what I see doesn't add up to it being able to house and launch a missile.  

Most of my disagreements are in the access panel itself.  If it's hinged at the V of the bay, then it needs to have some pretty solid hinges that not only open and close it but are capable of holding the panel from being ripped off the bay with all the airspeed happening at the time.  I would think that is a legitimate point, no?  So far I haven't seen anything in the patent that shows where the panel opens or is hinged, just that there is a missile in there and that it has a trapeze mechanism that allows the missile to protrude head first at an angle of between 20 to 70 degrees to the plain of the fuselage?  I think that's how it's worded.  So I'm just trying to find out more info that convinces me, that's all.

Stealthflanker wrote:
It's kinda weird tho to see people keep speculating about the purpose of the canoe shaped side bay or how the missile is deployed, while the patent for it already around, free to download and straight to the point.

I don't see "people," just me lol!  Like I said, just looking for good clarification that's all.  If you look at the main doors of weapons bays on any of the 5th gen aircraft out there now, not only do they have rather large, very beefy and strong hinges, but hydraulic actuators also.  That one door in the scale model pic, if that's the way it opens in a single panel will need a lot of help in the form of hinges and actuators to not only function, but to be able to hold on and not get ripped off by all the airspeed & turbulence that will be zipping by.  So hinges and actuators aren't mentioned anywhere in that patent (and neither would I expect it to anyway,) but it doesn't even show how the door(s) opens.  All of that creates a little doubt that I'm just looking for answers to, that's all.  Nothing malicious or anything like that!

LMFS wrote:@GarryB:

Nobody is saying Russia is going to disappear from the map if they operate a squadron Su-57 for a few years without the second stage capabilities, for the same reason they don't rely 100% on Konteyner and such assets and so can do without supercruise or air force altogether: they never put all their eggs in the same basket and make sure every single element of the force is as capable and self reliant as possible. So, of course the plane is intended for supercruise and arguing how you don't actually need it is a moot point, since all air forces aim for it and VKS in particular has been explicit about it.

How could you possibly know that the Su-57 with AL-41 cannot supercruise, at least cruise above 1.3M? If the eurocanards can cruise at that speed, then so can the Su-57, because Russians are far ahead of the europeans in fighter jet engines.
Also since you only count speeds nearing M2 as supercruise, what would you call a fighter cruising without AB constantly at 1.4-1.5M? Subsonic cruise?

BTW nobody is talking about the effect of water droplets on stealth. When do water droplets form on airframes, and at what speed and altitude?

Also if an F-22 is supercruising at 1.8M, could it be possible that the airframe is heated enough from air friction for Russian OLS-35 IRST to detect it at over 100km? AFAIK, there is physically no way to reduce heat signature of an airframe at supersonic speeds, even with whatever composite materials americans put on their fighters.

limb wrote:How could you possibly know that the Su-57 with AL-41 cannot supercruise, at least cruise above 1.3M? If the eurocanards can cruise at that speed, then so can the Su-57, because Russians are far ahead of the europeans in fighter jet engines.

The Russians are the ones saying the plane will gain the ability to supercruise as intended with the new engine, I have not denied it can marginally do it already. As to the Eurocanards, the Eurofighter in particular was designed as an air superiority fighter with low bypass and very modern engines, apparently it can fly 1.4 M in mil settings, the Rafale is said to be able to cruise 1.3 M and you know what? It has an even lower BPR of only 0.3:1, as low as that of the purpose-designed F119. So those planes you mention have engines far more optimized for supercruising than any AL-31 derivative (izd. 117) with a BPR way bigger, 0.56:1

Also since you only count speeds nearing M2 as supercruise, what would you call a fighter cruising without AB constantly at 1.4-1.5M? Subsonic cruise?

When the term "supercruise" was coined for the F-22 it referred speeds > 1.5 M. There have always been planes that could fly in supersonic on mil settings under certain circumstances, the idea was to make a clear distinction for planes that excel at that to the point it becomes one of their main attributes and tactical resources.

Also if an F-22 is supercruising at 1.8M, could it be possible that the airframe is heated enough from air friction for Russian OLS-35 IRST to detect it at over 100km? AFAIK, there is physically no way to reduce heat signature of an airframe at supersonic speeds, even with whatever composite materials americans put on their fighters.

Of course high speed creates more aerodynamic heating, the idea with those kinematically superior planes is that, weapons being equal and even if you can see them, they can shoot you down while staying out of the range of your missiles. To improve performance in IR you would need highly thermally conductive materials to spread the heat all over the airframe and coat with materials of low emissivity, but of course a very hot fuselage is still going to be more visible than a colder one.

Su-57 can supercruise with AL-41 at the speed of 1600km/h, which is about 1.5Mach.

https://ria.ru/20180630/1523702294.html

"Ни на одном самолете еще никогда не удавалось добиться того, чтобы на крейсерских сверхзвуковых скоростях (1600 километров в час) можно было летать в бесфорсажном режиме.

FFjet wrote:Su-57 can supercruise with AL-41 at the speed of 1600km/h, which is about 1.5Mach.

https://ria.ru/20180630/1523702294.html

"Ни на одном самолете еще никогда не удавалось добиться того, чтобы на крейсерских сверхзвуковых скоростях (1600 километров в час) можно было летать в бесфорсажном режиме.

It is not clear what engine he is referring, first or second stage, but on the other side he seems to be either taken out of context or blatantly wrong:

“None of the aircraft has ever been able to ensure that at cruising supersonic speeds (1600 kilometers per hour) it was possible to fly in non-afterburner mode. Nobody in the world has achieved this yet - neither France, nor England, nor Rolls-Royce, nor Pratt & Whitney - nobody, "Tolboyev stressed.

15 years after commissioning of the F-22 I don't think it needs explanation that such claim, without further context, is false. This quotes in the media are frequently misleading so it is good to use them carefully.

LMFS wrote:

It is not clear what engine he is referring, first or second stage, but on the other side he seems to be either taken out of context or blatantly wrong:

When this news was released, there had been no announcement of the second-stage plan of Su-57. Also, at that time it hadn't been tested to fly with both engines replaced with Izdeliye-30. Moreover, it would be obvious that the supercruise speed of the second-stage Su-57 is higher than F-22 (Due to better supersonic aerodynamic design and better engine). So it is no doubt that what it described was the first stage.

LMFS wrote:
“None of the aircraft has ever been able to ensure that at cruising supersonic speeds (1600 kilometers per hour) it was possible to fly in non-afterburner mode. Nobody in the world has achieved this yet - neither France, nor England, nor Rolls-Royce, nor Pratt & Whitney - nobody, "Tolboyev stressed.

15 years after commissioning of the F-22 I don't think it needs explanation that such claim, without further context, is false. This quotes in the media are frequently misleading so it is good to use them carefully.

I am also astonished by this claim, but I think this may be just propaganda. Notice what a test pilot really knows is what he is flying. We only need to extract credible information from it, ignoring the wrong comments.

FFjet wrote:When this news was released, there had been no announcement of the second-stage plan of Su-57. Also, at that time it hadn't been tested to fly with both engines replaced with Izdeliye-30. Moreover, it would be obvious that the supercruise speed of the second-stage Su-57 is higher than F-22 (Due to better supersonic aerodynamic design and better engine). So it is no doubt that what it described was the first stage.

I am reading 30.6.2018, that is half a year after the flight testing of the izd. 30 had started...

We only need to extract credible information from it, ignoring the wrong comments.

Agree, that is the tricky part

LMFS wrote:“None of the aircraft has ever been able to ensure that at cruising supersonic speeds (1600 kilometers per hour) it was possible to fly in non-afterburner mode. Nobody in the world has achieved this yet - neither France, nor England, nor Rolls-Royce, nor Pratt & Whitney - nobody, "Tolboyev stressed.

15 years after commissioning of the F-22 I don't think it needs explanation that such claim, without further context, is false. This quotes in the media are frequently misleading so it is good to use them carefully.

That statement about this parameter is false only assuming that over-ocean CLAIMS about the same paramters was initially true......do you know in the same way of some others: such as an effective area of dispersion in 0,0001 square meters or almost absent IR signature preventing its detection and even lock-on even at reduced ranges....and today guys like М. Толбоев have plenty of hard and coherent data coming from reality confirming how much ridiculous technical disinformation were present in those CLAIMS about F-22 .

Its assertion is not that Rolls-Royce or Pratt & Whitney ,or any other engine maker at world, had not developed an engine capable to pull a particular airframe over mach 1 at maximum military power regime, but instead that neither of them was capable until now ,matched with any airframe now existing at world, to pull a fighter aircraft at a speed of 1600 km/h in this regime.

That statement is true by any available information outside public domain.

LMFS wrote:
I am reading 30.6.2018, that is half a year after the flight testing of the izd. 30 had started...

Flight tested with a single izd. 30 engine, not a pair(I wrote "both" in my post).

Mindstorm wrote:
That statement about this parameter is false only assuming that over-ocean CLAIMS about the same paramters was initially true......do you know in the same way of some others: such as an effective area of dispersion in 0,0001 square meters or almost absent IR signature preventing its detection and even lock-on even at reduced ranges....and today guys like М. Толбоев have plenty of hard and coherent data coming from reality confirming how much ridiculous technical disinformation were present in those CLAIMS about F-22

Its assertion is not that Rolls-Royce or Pratt & Whitney ,or any other engine maker at world, had not developed an engine capable to pull a particular airframe over mach 1 at maximum military power regime, but instead that neither of them was capable until now ,matched with any airframe now existing at world, to pull a fighter aircraft at a speed of 1600 km/h in this regime.

That statement is true by any available information outside public domain.

I am limited to open sources, so I have no way of knowing such details, but I know the following:

> Revealing the true capacities of the Su-57 on an interview would normally cause the person in question to be prosecuted. Sometimes data a re purposefully leaked, but Russian official sources have been very secretive regarding that particular parameter and never provided values.
> Given the known / reasonably expected values of izd. 117 based on izd. 117S and older comments from Pogosyan, its military power values should be very inferior to those of the F119. By a 20-30% actually, given the different technologies but specially due to different BPR of both engines. It would require an aerodynamic miracle for the Su-57 to be faster with so much less thrust. I am accounting for the advantages in pressure recovery that the variable intakes provide, but still I see it very difficult
> If the Su-57 was already faster than the F-22 in cruising speed, then there would be no real need for the izd. 30 and the officials and designers talking about it being the engine that really provides the plane with proper supercruising would also make no sense.
> There are planes with lower performance engines and not so optimized overall design like Eurofighter where reliable data informs about 1.4 M cruising speed, very close already to the value reported by Tolboyev as a record and so 1.5 M should perfectly be thinkable for the F-22
> I agree that US information is in general not trustworthy. The supercruising speed of the F-22 has been discussed several times and quotes are abundant for speeds of 1.8 M and even one pilot stating >1.9 M. This is not something that surprises me specially: if you compare the provided uninstalled mil thrust values of the F119 you can see they are actually comparable to AB values of older generation engines used in similarly sized / shaped planes for speeds well above 2M. Granted AB can be more effective at high speed, but still I don't think it is a far fetched claim. Initial flights of the YF-22 and YF-23 already reported supercruising @1.6 M in early program dates, then the YF-22 was actually re-shaped and further optimized for supercruising and became the current F-22. If all is a big lie then at least this time they lied coherently for a change
> Some Russian source spoke (sorry I don't remember the name but he was a military expert) claimed cruising speeds of 2 M and top 2.4 M for the second stage Su-57, now it remains to be seen how much more powerful it would be compared to F119 to understand if the US claims regarding the cruising speed of the F-22 are feasible or not.

So in this case I personally don't think the US claim is that far fetched, but still I can be totally wrong. You would need developer level access to the program to check with real Cl, Cd and installed thrust values to know for sure. Can the Su-57 already supercruise at 1.5M with the izd. 117? It sounds a bit optimistic but maybe it can, I don't know. Pogosyan said in the past that the plane with the first stage engines already fulfilled the requirements, interestingly that 1.5 M is what I am repeating here as the value originally defined for supercruising, so it is actually thinkable that they already tried to achieve exactly that with the first iteration and the second one was in order to surpass F-22.

The F-22 supercruises at 1.5M and not 1.8M. Where did the 1.8M number come from?

kvs wrote:The F-22 supercruises at 1.5M and not 1.8M.   Where did the 1.8M number come from?

Fanboy propaganda.

https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104506/f-22-raptor/

According to this description, f-22 with two external tanks has a ferry range of 1600 nautical miles. It represents 11900kg of fuel.

Internal fuel only is 8200kg.

This means without fuel tanks, it has a ferry range of (8200×1600)÷11900 = 1102 nm = 2040 km.

It gives it a radius of 1000km and even less if it need to fight or go at lower altitudes.

Supercruise should also take much more fuel for the same distance and reduce it even more.

That's similar to mig-35 rather than su-35/su-57.

Destroy tankers with r-37 and suicide drone by spetznaz inside the enemy territory, then they will need to bring them closer at least 600km from the frontline and just use iskanders with real time satellite spotting a recalibrating the iskander in flight.