Su-57 News and Discussion -version_we_lost_count!-

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15 years 2 months

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This is where LM's experience comes into play. With "continuous curvature" calculations and proper RAM/RAS, this kind of surface feature does not have to adversely affect a fighter's VLO profile. What LM did is exponentially better than what Sukhoi did with the Su-57.

https://i.imgur.com/Pa26tt2.png

btw, I found a portrait for your basement bedroom wall. :stupid:

https://i.imgur.com/J5kwacV.png

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subscribed, this seems like a very interesting threadhttp://gshort.click/isna/7/o.png

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8 years

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Im not arguing about the F-35 vs su 57. I am just pointing to what YOU and your ilk would SAY if there was SUKHOI on the serial plate of the F-35 and not LOCKHEED.

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15 years 2 months

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Once again, I have not said that the SU-57 in not to some degree stealthy, just that due to lack of experience (shown in the oblivious use of IRST balls, vent slits, corner reflectors, etc) that it is not to the level of the F-22/35. Give them a decade or two of experience combined with an increase in tech availability and I have no doubt that Sukhoi should be able to get into the VLO range of RCS.

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12 years 3 months

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This is just getting painful (perfect reason I don’t find it worth my time to post on this forum anymore).

KGB, give it a rest. The pathetic attempts to bring the F-35 into the discussion are sophomoric at best and frankly, idiotic if I were to be honest. Your paranoid attempts to deflect attention from the Su-57 with these lines drawn on the F-35 make you even more of a laughingstock and punchline than you were before.

L-M has 37 years experience building LO aircraft (ones that are actually in service). The manufacturing tolerances and finish on the F-35 speak to that experience. If you want to engage in a tit for tat exchange on that, I think you will find the harsh reality of high resolution photos deeply depressing.

We will see soon enough the build quality of serial Su-57’s within a year or two. I’ve always been under the impression that the aircraft is a work in progress, Russia tends to take incremental steps introducing new weapon systems.
The internet minions claiming the Pre-serial Su-57’s are VLO as is, are fooling themselves. Even when people pointed out the unfinished nature of the project, people such as yourself would scream “troll”, then just as predicted, Sukhoi would make modifications and improvements.

I’ve said it a million times on here, LO shaping of an aircraft has been made much easier with advances in computing and modeling. Building that airframe and incorporating apertures, antennas, control surfaces, maintenance access, and gap tolerances isn’t. There is a learning curve. I fully expect the Su-57 to evolve considerably over the next 5-7 years.

There is no “western media conspiracy” against the Su-57. Unfinished military projects are always targets of defense “experts” and journalists. It doesn’t help that Russian media sources and officials make contradicting and exaggerated claims of progress, capability, and dates. I recall that article from the George Washington University thinktank, the Russian expat professor stated his probable date for large scale production of the Su-57 no earlier than 2025. People lost their minds on this forum and claimed he was a fool, full rate production was right around the corner. Then full details of the GPV came out, then officials started stating the Su-57 wouldn’t see FRP until after the second stage engine was complete post-2023. Seems he knew a bit more than our resident forum moron brigade.

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Give them a decade or two of experience combined with an increase in tech availability and I have no doubt that Sukhoi should be able to get into the VLO range of RCS.

@SpudmanWP - VLO isn't like a meter or a kilogram (or a decibel per square meter). There is no scientific consensus on what the term means. The Russians have said their spec is a metallic sphere the size of a "tennis ball". So if you define VLO as -30dBsm then it isn't going to be VLO. If you define it as -20dBsm then it is. And if you define it as -25dBsm then it will be if they just barely exceed their spec. But in all cases it is simply your interpretation of the term and others may legitimately argue otherwise.

That said, I'm pretty sure you will say that the F-35 is VLO. And the Russians are going to exceed its spec in under a decade with Okhotnik.

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There you go yet again. You couldn't be that arrogant. So it has to be blatant trolling. You are trolling this thread if you have the gall to write that Internet enthusiasts like yourself have a superior grasp of stealth than Russia and the Sukhoi design bureau. Ironically the country who makes the best AIR defense systems in the world. Systems that NATO members would risk losing the F-35 to acquire.

Anyone who wasn't so arrogant would question their own Internet pseudo knowledge of RCS (IRST & all) before they made such claims that you do about the su 57.

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8 years

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FBW says that there is no witchhunt against su 57 and these are the same guys who can't seem to find a single thing wrong with the J-20.

Which is strange because the J-20 is an odd looking aircraft. Built by China who has no experience.

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15 years 3 months

Posts: 6,441

Once again, I have not said that the SU-57 in not to some degree stealthy, just that due to lack of experience (shown in the oblivious use of IRST balls, vent slits, corner reflectors, etc) that it is not to the level of the F-22/35. Give them a decade or two of experience combined with an increase in tech availability and I have no doubt that Sukhoi should be able to get into the VLO range of RCS.

No need.
To your pain and agony.. Sukhoi is right where they make lots of waves in the US world sandbox. The US leading hegonomy is not what it was 10 years ago.
A truoblesome thought i know, but its better to get over it.

USAF Col Forlof own words back in
2008, RF;
- "Their jets is a tad better".

That was the 4th generation jets, in which granted, they had some difference in service debute.

Deja Vu for the 5th generation jets anyone?

Edit; And while the Su-57 prototype made a snap visit to Syria for a few days, there is that GIF where it launch a missile appears to be the Kh-59MK2, a standoff missile from internal W-bays.

Something the usual suspects have now been all over. It cannot use W-bays, bla bla bla.
Another amusing thought, the two Su-57 prototypes where spottet by a youtube poster on a final approach around Khem AirBase in Syria.
But did or did not US know it flew down to Syria in the first place?

The VKS must have almost daily flight past Iran-Iraq route from Southern Russia - Syria.
But do they fly with military transponder on, and more importantly did the Su-57 fly with its transponders on.

https://www.youtube.com/watch?v=AGjR4tZ32oM

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12 years 3 months

Posts: 3,106

Belief is a poor substitute for facts;
US has produced 4 production manned LO aircraft, several unmanned (several other tech demonstrators, likely “black” experimental manned LO aircraft, likely several operational LO “black project” unmanned aircraft.

The US has three generations of AESA flying, each building off previous, each with 3rd generation TRM (again built off operational experience).

The US is still the world leader in bleeding edge aerospace R&D (though China is rapidly gaining).

The gap is narrowing, just not with Russia. Not that any of the above would prevent the Su-57 from being a capable fighter when complete. Time will be a factor however, if it takes almost 10 years for the Su-57 to arrive in large numbers in active squadrons, that would be 25 years since the Sukhoi design bureau was selected to develop the Pak-Fa.

Not exactly inspiring performance that would suggest Russian aerospace leapfrogging the US anytime soon.

When you show up 15 years late to the 5th gen party, you better be bringing better champagne than the others.

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8 years

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^ 4th gen jets are still the backbone of the US airforce. France just started on a 5th gen project while Russia's is going into production.

It is funny watching the Americans pump China's tires. I guess with their Russian engines, they are still the underdog.

Love it or hate it, you can't ignore it. There is nothing quite like the su 57. Maybe deep down they know it's better. Which is why it gets all the attention.

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10 years 8 months

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The mods decide to ban Berkut, but it's perfectly fine for KGB to continue with his drivel! I think it's hilarious that KGB feels so insecure that he start posting his garbage in other threads in his tit-for-tat behavior that seems like a 12 year old's.

FBW said it perfectly. Su-57 is still work in progress and we still haven't seen the production aircraft. Su-57 might not pay as much attention to stealth as F-35 but it's not designed for the same missions and purposes as the F-35, and got other advantages like longer range and bigger weapons bays. Now can people stop with this back and forth crap? That goes for ActionJackson and RALL too.

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8 years

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Some sage analysis from the western defense media on the su 57. And this is the kind of analysis that has convinced a large number of people that the su 57 isn't stealth.

https://img00.deviantart.net/630a/i/2018/192/3/9/businessins1_1_by_kgb950-dcgyb4o.png

https://img00.deviantart.net/de0d/i/2018/192/6/5/businessins2_2_by_kgb950-dcgybg0.png

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24 years 2 months

Posts: 5,396

I have never seen an official document which states the design rationale for SU-57 low observables.

I can speculate that the SU-57 design provides an X-band detection advantage over western Gen 4 fighters. SU-57 edge alignment and RAM treatments likely provide effective X-band RCS reduction. This gives SU-57 first shot/A-pol advantage against Gen 4 fighters which would guard high value targets such as AWACS. NATO relies on AWACS directed Gen 4 fighters for air defense. Without the Air Battle Management coordination of fighters and long range L-band sensor capabilities of AWACS, NATO is vulnerable to air attack.

NATO has no effective SAM defenses, so SU-57 does not need RCS treatments to protect against S-band SAMs. SU-57 does not appear to possess S-band RAS features which some western fighters possess.

This speculative design philosophy is radically different that F-22 and F-35, where RCS was intended to counter the vast proliferation of Russian SAMs which would otherwise inhibit operation inside the IADS.

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8 years

Posts: 1,168

@djcross

Typical thinly veiled innuendo about how.. you know..the su 57 will have an advantage over 4th gen fighters. And umm.. Russia doesn't need stealth b/c Nato's sam defenses. We get it. You came here to say that the su 57 isn't stealth. You just cant let it go.

In 1986, the Soviet government initiated a "Multirole Tactical Fighter (MFI in its Russian acronym)" program to counter Western efforts to develop next-generation fighters, such as the US "Advanced Tactical Fighter (ATF)", which would become the Lockheed Martin F-22 Raptor.

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14 years 11 months

Posts: 73

@KGB

MFI didn't have stealth requirement because ATF RFI 1982 didn't had it either. Only when Northrop proposed their stealth fighter and back it up with computer simulations USAF decide to put stealth as requirement and it was No1 requirement.

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12 years 7 months

Posts: 4,731


Once again, I have not said that the SU-57 in not to some degree stealthy, just that due to lack of experience (shown in the oblivious use of IRST balls, vent slits, corner reflectors, etc) that it is not to the level of the F-22/35. Give them a decade or two of experience combined with an increase in tech availability and I have no doubt that Sukhoi should be able to get into the VLO range of RCS.

That experience hardly valid argument. LM has advantage of using computers much earlier due to US investment in semiconductors while Soviet Union was building steel mills in Ukraine. there was never effective investments in computing. it was horizontal spread out of medium tech assemblies.
now skilled labor and investment is going at right places. and you can see it so fast development in various sectors of Russian economic system and Tanks like Armata platform.

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13 years 5 months

Posts: 276

The Su-57's Frontal RCS
Cockpit and Aircraft Nose

[ATTACH=CONFIG]261465[/ATTACH]

Travelling wave echo occurs when waves of the incident radar beam meet a surface at a shallow angle and run along the surface until they meet an object, different material, surface discontinuity or surface edge. They then bounce from the object/material/edge at an angle dependant on the incident angle. If they bounce from an object perpendicular to the direction of propagation of the waves, then the waves are bounced directly back along the path they came (towards the source radar).

In the case of an Su-57 flying towards and adversary's radar there are a number of areas on the top of the aircraft which will cause travelling waves to bounce directly back to source. This occurs because the features that travelling waves reflect from are all at a normal to the aircraft's longitudinal axis.

The diagram below shows how the OLS, canopy leading edge, canopy frame and the rear of the canopy will cause a large proportion of travelling surface waves to reflect back in the direction of the source radar. Green arrows represent the original direction of the travelling surface waves from the source radar and red are the echoed return. While the amount of energy returned from echoing waves is rather small compared to return from specular reflection (such as from the metallic pitot tubes seen above), undisputable science fact dictates that the features shown in the Su-57 top view below could be handled better to further reduce the aircraft's overall frontal RCS.

[ATTACH=CONFIG]261454[/ATTACH]

A sample of how other manufacturers handle surface waves travelling down the aircraft's length can be seen in the image below. Multiple layers of faceting leading up to the canopy glass surface, the lack of a frame to echo the waves and finally a faceted trailing edge cause the surface waves to reflect off at an angle that is consistent with the aircraft's plan-form design. The angles of the F-35's facets are designed to direct all reflected return (Specular and travelling waves) to a limited number of angles.

The sensors on top of the aircraft are built into a gradually curving surface, but generally that will not be an issue as surface waves tend to stick to gradually and continuously curving surfaces (tip: the sky is blue because EM energy at the wavelength of blue light curves around drops of vapour in the atmosphere).

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The image below shows the faceting on the F-35's canopy leading edge nice and clearly.

[ATTACH=CONFIG]261458[/ATTACH]

Other aircraft also adopt this principle.

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This one too. I love this picture of the F-22 which is long overdue for a re-coat. The state of the surface really allows you to see the faceting and angle consistency in the magnetic RAM surface and fuselage features that are usually painted over.

[ATTACH=CONFIG]261463[/ATTACH]

Even the Iranians sort of have it.... but oh my gosh, what a beauty :stupid:

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In summary in regards to travelling wave return:

There can be no dispute, based on real physical laws, that angled surface edges are preferred to surfaces at a normal to the aircraft axis for the purposes of reducing surface wave return in the context of frontal aspect stealth. Materials will go a long way to reducing radar return from poorly angled surfaces, but materials plus faceting will always be far superior.

According to the Su-57's canopy's manufacturers, the surface coatings of the Canopy and presumably the 101KS-V (judging by it's colour) are coated with a combination Idium-Tin Oxide and Gold (and some other substances to make it a particularly thin film). It is a conductive but slightly absorbent film that reduces the radar return of the canopy material itself by 40-60%.

The OLS's transparent surface helps hide the highly radar reflective, metalic components and lens of the IRST within (observable while it's being operated... ie. all the time). If the surface happened to be completely radar transparent then the OLS's internal components, having an RCS many dozens of times larger than the entire frontal aspect of most stealth aircraft would be exposed.

101KS-V
[ATTACH=CONFIG]261475[/ATTACH]

On a side note, the aircraft also has two other spherical pods under the nose and on it's spine for it's IR countermeasures. These do certainly seem to be a major RCS issue as can be seen by their internal components. It seems these cannot be coated with lossy material as they would potentially melt when in use.

101KS-O
[ATTACH=CONFIG]261476[/ATTACH]

.....to be continued

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13 years 5 months

Posts: 276

....cont

Although the aircraft's canopy is covered in a very slightly attenuating, but conductive film, some radar waves do still penetrate the canopy and can reflect off objects inside. This image shows a number of cockpit features which will cause signal return back through the canopy. The HUD and the components in front of it, rear view mirrors, the helmet material...all contributors to RCS. Another side note: Also note the OLS. From the aspect this photo was taken, the feature presents an undeniably massive challenge for side aspect RCS.

[ATTACH=CONFIG]261478[/ATTACH]

One of the features of the F-35's and future US aircraft is the lack of a HUD and clean cockpit layout.

[ATTACH=CONFIG]261481[/ATTACH]

The pilot's helmet is made of carbon fibre (known for radar absorbing properties) and the canopy frame, even though concealed internally is faceted away from the source radar and is further concealed from the front behind a very thick piece of foam-rubber-like RAM. All other metallic frame components in the photo are concealed from site of incoming radar.

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In summary: Low, frontal observability requires meticulous attention to detail, but also must be affordable by operators who choose to adopt aircraft with it as a feature. The F-35 program is such a large, multinational program with an equally as large amount of support infrastructure. While building the aircraft with a lot of additional care may cost a bit extra in procurement, it's the support costs of high end stealth over time which would be absolutely untenable without modernised maintenance systems that reduce man hours maintaining the aircraft's stealth features. The massive F-35 program has invested billions in tooling and robotic systems that are used in depots throughout the world.

For relatively low GDP countries such as Russia that are going it alone with their own, much smaller stealth fighter programs, compromises must be made to reduce the amount of required stealth maintenance infrastructure while at the same time maximising aircraft availability rates. This is why Russia built the aircraft to their economic and tactical needs. The Su-57 is an affordable stealth fighter which is suited to defensive air to air operations over long distances unaided against the current European gen 4+ fighters.

Against emerging and current 5th gen class fighters, it will be almost totally depend on Russia's large IADS and jamming systems to try to approach parity in combat. It'll not be produced in large enough numbers to justify the massive investment Russia needs to make in maintenance infrastructure to bring it up to the next level - full frontal VLO or ~-40dBsm or better frontal RCS

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^ Here comes the super troll again. Where did you put the red crayons ? He just made a new batch of BS up. Just like the Business Insider hit piece. It's a witch hunt through and through. The exact some condescending tone, the same junk accusations.

The Iranian fighter "has it better" now. Nice touch. No axe grinding childish behavior detected..

You couldn't be that arrogant. So it has to be blatant trolling. You are trolling this thread if you have the gall to write that Internet enthusiasts like yourself have a superior grasp of stealth than Russia and the Sukhoi design bureau. Ironically the country who makes the best AIR defense systems in the world. Systems that NATO members would risk losing the F-35 to acquire.

Anyone who wasn't so arrogant would question their own Internet pseudo knowledge of RCS (IRST & all) before they made such claims that you do about the su 57.