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Thread: Su-57 (PAK FA) News, Discussion and Pics

  1. #271
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    This is going to be more of a technical question but I hope at this point it wont lead to people bashing each other as shown here awhile ago.

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    Is having a radar 360 coverage better than having 6 passive sensors like the F-35 or J-20 aircraft called EODAS? I am under the impression that it is because of the F-18 using infrared detection for the su-22 missed it at 1st and than had to switch to radar to intercept the Syrian aircraft. Any thoughts here would be fine.

  2. #272
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    Quote Originally Posted by panzerfeist1
    This is going to be more of a technical question but I hope at this point it wont lead to people bashing each other as shown here awhile ago.
    Is having a radar 360 coverage better than having 6 passive sensors like the F-35 or J-20 aircraft called EODAS?
    L-band array is IFF and ECM
    N012 tail boom radar was tested on prototype of Su-35/37 but it didn't go into production. The tail slinger of Su-57 will also hold ECM system.
    There is no K band radar on Su-57 either.
    About your question: radar coverage give you better information (such as range-velocity) for fire-control purpose while passive sensor is more "silent" and harder to detect. Su-57 has passive sensor coverage also.

  3. #273
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    Im interested in cooling capacity the airframe can provide, those arrays are bound to need cooling. Air cooling could be feasible for the side arrays, wing leading edge and tail, but getting them liquid cooled will provide alot of room for power aperture growth.

  4. #274
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    I know it is perhaps not very relevant, but the head of Iran air force is reportedly axed as he failed to make known that Israeli F-35s overflew Tehran without any air defense system picking them up, (not even S-300) . Apparently there are public photos of the F-35 over Tehran ... so ... stealth huh ? what a thing...

    Edit: failed to google fu the photos, but the story is apparently true
    True? Sez who?

    And I can't find anything about it on aljarida.com.

    Evidence, please.
    Juris praecepta sunt haec: honeste vivere, alterum non laedere, suum cuique tribuere.
    Justinian

  5. #275
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    Evidence? You are asking too much (as you know). But the story have been around ( and here) since March (as you know)
    Last edited by TomcatViP; 12th June 2018 at 21:10.

  6. #276
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    @mig31bm but I heard that ECM arrays in the back can swap roles with the radar? L-band is also for friend or foe identification right(is that what you meant by IFF)? I just want to be sure.
    Last edited by panzerfeist1; 12th June 2018 at 22:36.

  7. #277
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    Quote Originally Posted by swerve
    True? Sez who?

    And I can't find anything about it on aljarida.com.

    Evidence, please.
    http://www.aljarida.com/articles/1528470807636820200/


    Quote Originally Posted by tomcatvip
    Evidence? You are asking too much (as you know). But the story have been around ( and here) since March (as you know)
    The site says as much (about March) supposedly this website brought the matter to the surface in March.

  8. #278
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    Quote Originally Posted by Marcellogo
    AGAIN! in one case they (the russian) talk about average value in all the frontal arc i.e. +/- 90° starting from 0° and posterior one i.e. the same interval starting from 180°.

    The various 0,0000 etcetera values firm's propaganda boast about are just a reference value showing the maximum possible reduction

    (...)
    You need be more relaxed. Its a forum, and people talk about airplanes, and it is normal not all people think same about all things.


    What we know about this is what officials from US military told time ago.

    https://www.strategypage.com/htmw/ht.../20051125.aspx

    "The U.S. Air Force, in it's effort to get money to build more F-22s, has revealed just how "stealthy" the F-22 is. It's RCS (Radar Cross Section) is the equivalent, for a radar, to a metal marble. The less stealthy (and much cheaper) F-35, is equal to a metal golf ball. The F-35 stealthiness is a bit better than the B-2 bomber, which, in turn, was twice as good as that on the even older F-117. Much older aircraft, like the B-52, have a huge RCS, which makes them very easy to spot on radar. But with a smaller RCS, it's more likely that the aircraft won't be detected at all."

    (..)


    You can read that they do not talk about front aspect of the RCS or about the maximum reduction of the RCS, so we must think they talk about the average RCS of the F-22. A metal marble is around 0,0001 m2. And the F-22 is a all aspect Stealth, not only in his front aspect, do not forget.

    And what we know about Su-57.

    http://archive.is/ZHbOH


    According to the patent paperwork, taken together, all of the stealthy measures offer significant improvements over legacy fighter designs. The papers claim that the radar cross-section (RCS) of an Su-27 was in the order of 10-15 m 2 , with the intention being to reduce the size of the RCS in the T-50 to an "average figure of 0.1-1 m 2 ".


    And we know the Su-57 is a front aspect stealth in comparison with his side and rear aspect. So, it can be possible this average RCS numbers on the patent of the Su-57.

    You can be agree or not, but it is not so clear as you tell.

  9. #279
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    You are correct, RALL, in affirming that stealth technology provides for substantial RCS reduction from all aspects. But you are incorrect in stating that Sukhoi's published patent describes the average Radar Cross Section of the Su-57. Sukhoi's patent describes the merits of its aerodynamic surface only. There is no description of RAM (and its external RAM coat is now quite extensive) on the aerodynamic surface or RAS built within it - nor is the performance of such material quantified. (There are two exceptions: the air intakes and the IRST as they can not be made stealthy through the aerodynamic surface alone) But RAM and RAS (RAS affects your shaping! They radar receiver sees in radio waves, not visible light!) substantially contribute to stealth. So they are basically saying that their plane would have a RCS of less than 1m^2 when plated with foil. The link below actually provides a translated copy of the document. If anyone here reads Russian, I would be interested in a more thorough translation.

    https://robotpig.net/aerospace-news/...analysis-_2158

    I know of only one source where Russian designers have made a comparison for its RCS and it was to a "tennis ball". This implies an average RCS of .0037m^2 or (-24 to -25dBsm).

    https://www.youtube.com/watch?v=t4uVyDtvBCY

    Taking everyone at face value and assessing for X-band/Ku-band...

    The Su-57 has an average RCS about 37 times that of the F-22 Raptor.
    The Su-57 has an average RCS about 3.7 times that of the F-35.
    A Tomahawk cruise missile (RCS 0.05m^2) has an average RCS 13.5 times that of the Su-57.
    An F-16 with a moderate weapons loadout (RCS 2.5m^2) has an average RCS 675 times that of the Su-57.

    I don't believe the Russians have hit their target just yet. They will need the Item 30 engines and maybe some other improvements. But they have shown that they possess the technology, and they are just going to keep tinkering with it until they get there.

  10. #280
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    Quote Originally Posted by panzerfeist1
    but I heard that ECM arrays in the back can swap roles with the radar?
    It can't
    Quote Originally Posted by panzerfeist1
    L-band is also for friend or foe identification right(is that what you meant by IFF)? I just want to be sure.
    Yes, the L-band is for friend or foe identification

  11. #281
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    The Su-57 has an average RCS about 37 times that of the F-22 Raptor.
    The Su-57 has an average RCS about 3.7 times that of the F-35.
    A Tomahawk cruise missile (RCS 0.05m^2) has an average RCS 13.5 times that of the Su-57.
    An F-16 with a moderate weapons loadout (RCS 2.5m^2) has an average RCS 675 times that of the Su-57.
    You make far-reaching conclusions based on an empty phrase (iron ball), coined for a stronger effect

  12. #282
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    Lol RALL is quoting what the US military chose to tell the Discovery Channel how big the F-22's RCS was. And then using that to compare to the su 57's. Nowhere does he mentioned that under the same parameters in the Sukhoi report, they say that the F-22 has an RCS of about the same value. Which is why they are shooting for that value. Basic military doctrine. The su 57 was designed to counter the stealth of the US fleet. Nothing else.

    Everyone has really drunk the kool aid of the F-22. It really is just an F-15 with LO features. Yet it has the reputation as if the US built the YF-23. Which actually was a visionary design. The F-22 was not.

    He is trolling

    This is the kind of stuff that gets this thread deleted.





    And since the F-15 is a copy of the Mig 25, the F-22 is really just an evolved design of the Mig 25 with LO features. In military circles though, the US see's the F-22 as its trophy for winning the cold war. And no matter what, Russia cant have a stealth fighter. China can, but Russia cant. Because it was the successor state of the USSR. And this is what gives ppl like Rall, the gall to come on this thread and declare that the F-22 has 37 times smaller RCS than the su 57 with the expectation of getting away with it. And most Russia fans barely fight it. B/c they've been fed the propaganda that the F-22 is some revolutionary design.
    Last edited by KGB; 13th June 2018 at 17:59.

  13. #283
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    In spite of the lack of experience, Sukhoi’s PAK FA incorporates every major stealth enhancing measures seen on the F-22. Internal structure is mainly constructed of composite alloys and carbon fiber yielding more strength, reduced weight and result in thinner wings, tail planes and fins. The external structure has minimized number of horizontal, vertical, lateral and longitudinal angles. The nose radome and canopy prevent radar waves from penetrating and bouncing off of metal components.

    The outer skin is made of composite materials. Stealth composite absorbents are made by loading matrices with electromagnetic materials ranging from metallic particles to carbon nanotubes. Thus, for example, carbon impregnated polyurethane foam, carbon-loaded silicone and neoprene, and iron-loaded urethane are among material combinations known to soak up microwave energy. Chinese researchers have laminated RAM with face sheets of glass and carbon fibre/epoxy composite sandwiching polyurethane foam doped with carbon nanotubes.
    The F-22 is plagued by problems caused by it’s radar absorbent material (RAM) it has durability issues in adverse whether conditions, it’s very heat conductive and reaches high temperatures in supersonic fight and has to be serviced after each mission. Rainy weather conditions reportedly posed technical difficulties to F-22A’s operating out of Guam in 2009. The jets’ cooling systems drew in moisture from the air, which caused shorts and failures in sophisticated electrical components (avionics). There were also reports of rain damaging the RAM coating in flight.

    Because of the delicate nature of the aircraft, it has poor availability rate. The cost per flight hour was $68,362, over three times as much as the F-16. In 2014, the F-22 fleet required 43 maintenance man-hours per flight hour. Each aircraft requires a month-long packaged maintenance plan (PMP) every 300 flight hours.
    The radar absorbing coating is kept in place using an adhesive that emits lethal toxic gas while the aircraft is traveling at high speeds. Toxins were found in the blood of pilots and this issue has already has claimed the life of one pilot.

    Diisocyanates, which are found within the polyurethane glues that comprise the stealth coatings, can reportedly cause cancer and severe lung and neurological problems.
    The PAK FA’s carbon nanotube based RAM is much more reliable and cheaper to maintain and from a scientific perspective is as effective as the F-22’s RAM based on graphite particles.

  14. #284
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    The average value of this indicator in T-50 is 0.3-0.4 m˛. It must be borne in mind that these data are estimated, there is no official information on the RCS of the aircraft.

    The only official message is the phrase of the general designer of the aircraft Alexander Davidenko, where he compares the PAK FA and the F-22: "At the F-22 - 0,3-0,4 m˛. We have similar requirements. "


    ^ Of course. That's the only point of the su 57. The most distinct feature is the stealth.

  15. #285
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    Come on everyone lets be a little serious here. How can a F-35 be less stealthy than an F-22 if its smaller than an F-22 and carries at least 10% more composites than an F-22? There is even a certain "moron" on quora that states the F-35 is .00001m2 switching his previous story when a US General announced the F-35 is more stealthy than an F-22 making past claims look like BS. Because they are BS I no longer pay any attention to RCS claims. SU-57 and F-22 have the same amount of composite materials, internal weapons, F-22 being slightly smaller in size and now saying that one aircraft is 1,000-10,000 times smaller than the other is sort of stretching the truth.....This is no different than China saying they can see an RCS of 1m2 from 450kms away http://www.asian-defence.net/2013/10...or-j-11b.html/ with 1760 T/R modules while their KLJ-7A latest radar can see either 5m2 or 3m2 at 170km with the newer 1000 modules. This drivel belongs on F-16.net lets not bring it up here. Even I had to give the ROFAR radar claims of su-57 and mig-41 a break from KRET.

    @mig-31bm

    The L402 "Himalayas" electronic countermeasures (ECM) suite made by the KNIRTI institute uses both its own arrays and that of the N036 radar.It makes use of the Russian processors Elbrus. https://fighterjetsworld.com/2018/02...le-in-english/

  16. #286
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    Are we still supposed to avoid responding to KGB? Because his nonsense about the F-15 and F-22 is really quite frustrating to witness.

  17. #287
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    Quote Originally Posted by F/A=XX
    Are we still supposed to avoid responding to KGB? Because his nonsense about the F-15 and F-22 is really quite frustrating to witness.
    Yes, especially the more frustrating they get

  18. #288
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    KGB, get a grip; you are embarrassing yourself. RALL didn't post the comparisons. I did. But I did not say that the Su-57 has a RCS 37 times that of the Raptor. I simply did the math, and math does not lie. However, all governments do lie. So it is possible that some, or even all, of the ones who have made comparisons to "marbles", "golf balls", and "tennis balls" are exaggerating. But each of the three fighters - the F-22, F-35, and the Su-57 - has considerable public pictorial information available and so one can verify notable similarities in construction technique and such which is needed for stealth. Nobody can be 100% certain though.

    Something else...I was not denigrating the Russian fighter. Sukhoi has likely done a fine job. The Su-57 almost certainly cannot compete with the F-22 in RCS but that is not saying that the Russians are incompetent. That is simply because of the way the technology works. A good stealth design draws in RF energy similar to how a sponge soaks in water. It draws it into the structure of the aircraft and then traps it there, where all it can do is circulate in a lossy medium and dissipate into thermal energy. And every time you interrupt that circulation - such as by installing an aperture - you add a weakness where energy can escape. And the F-35 and Su-57 has far, far more apertures for things that are quite useful on the battlespace such as EODAS, cheek arrays, DIRCMs, etc.

    This is why the F-35 isn't as stealthy either. Engineering is all about tradeoffs. Nothing is free. Sukhoi could substantially increase the aircraft's stealth. But they would have to give up some of those goodies. As it is, like with Lockheed and Chengdu, they feel it is worth it. And they have a design which holds the promise to come close to the F-35 in RCS, even with these apertures. That is no small achievement.

    With regard to kinematics, the F-22 is a very good aircraft to compare the Su-57 with. But in most regards the better aircraft to compare it with is the F-35. Both designs have a sensory and avionics package that demolishes that of legacy fighters. Sukhoi just has to clear the last hurdles (such as the Item 30 engines) and then prepare the design for production. They are going to actually beat the Chinese to all aspect VLO.

    Last, you cannot eyeball stealth. You have to know the details of all of the RAM and RAS that isn't visible. Publishing some Russian engineer's eyeball estimate of the F-22 is just as pointless as pointing to Sukhoi's patent on the aerodynamic surface and capabilities to gauge that aircraft. I mean, think about it. If you could eyeball stealth then everyone would be doing it and it wouldn't be so damn expensive. Visible features that are talked about such as planform alignment doesn't actually get you stealth - it is a design technique to enable the engineer's to limit the number of threat aspects so that they can implement the "magic" that really does enable stealth.

  19. #289
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    They declare that the su 57 isn't stealth and then they try and butter it up and change the subject to anything but stealth.

    Grow up and learn something about basic military doctrine. Russia did not need a new jet. The su 35 has 5th gen avionics, supercruise and 3D TVC. But there's something that the su 35 doesn't have. And its the most distinctive feature of 5th gen aircraft. Its called stealth. That is the ONLY reason the su 57 exists. So if there is one thing that Sukhoi didn't cheap out on, its the stealth.

    The su 57 is more stealthy than the F-22 or F-35. You can see it just by looking at the pictures. The su 57 is cleaner, lower profile, sleeker and has more composite material.

    Last edited by KGB; 14th June 2018 at 21:02.

  20. #290
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    im waitin for more disclosure of avionics set.

  21. #291
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    @KGB

    A-5 Vigilante first proposal with twin vertical fins:
    https://ic.pics.livejournal.com/thex...5_original.jpg

    As you can see that kind of design (MiG-25/F-15) wasn't something new for Americans even in mid 1950s.

    BTW numbers you put for F-22 aren't right:
    http://www.f-16.net/f-22-news-article3622.html

    It was journalist which didn't done its homework and wanted sensation.
    Last edited by Krivakapa; 14th June 2018 at 16:49.

  22. #292
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    F-35 have more advenced signature that F-22, and three oficials confirmed it.

    oficial claims about RCS here:

    2005:
    It's (F-22) RCS (Radar Cross Section) is the equivalent, for a radar, to a metal marble. The less stealthy (and much cheaper) F-35, is equal to a metal golf ball. The F-35 stealthiness is a bit better than the B-2 bomber, which, in turn, was twice as good as that on the even older F-117.

    https://www.strategypage.com/htmw/ht.../20051125.aspx


    2014:
    After they tested F-35 RCS...

    [1]The F-35′s cross section is much smaller than the F-22′s. “The F-35 doesn’t have the altitude, doesn’t have the speed [of the F-22], but it can beat the F-22 in stealth.”
    http://aviationweek.com/blog/f-35-stealthier-f-22

    [2]"I would say that General Hostage … is accurate in his statement about the simple stealthiness of the F-35 [with regard] to other airplanes," Bogdan said in the interview. The statement was accurate for radar cross section, as measured in decibels, and range of detectability, he said, and he scoffed at the notion that anyone can tell how stealthy an aircraft is just by looking at it.

    http://www.airforcemag.com/MagazineA...-Approach.aspx

    2017:

    On a radar map, a 747 would appear the size of a hot air balloon and an F-16 would look like a beach ball. Drill down to legacy stealth aircraft and Lockheed’s F-117 Nighthawk would show up as a golf ball while an F-22 Raptor might appear as a pea. With the F-35, Lockheed is getting down to pebble size, according to Robert Wallace, senior manager for F-35 flight operations. Wallace, a former chief of low-observability for the US Air Force’s B-2 bomber, says the F-35 has leveraged LO qualities from the bomber – but he could not elaborate on specifics. Pilots will see a more advanced low-observable signature on the F-35 versus the F-22,...

    https://www.flightglobal.com/news/ar...ramp-u-432983/
    or
    http://www.f-16.net/forum/viewtopic....360800#p360800


    and bonus article about RAM

    https://www.reddit.com/r/F35Lightnin...materials_for/

  23. #293
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    Double post
    Last edited by KGB; 14th June 2018 at 21:01.

  24. #294
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    Could we please stop this discussion? It is going nowhere... like the previous million times.

  25. #295
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    A thought:
    Before responding to KGB. Compose your reply on a piece of paper, walk outside until you find a rather large tree. Read your rebuttal to the tree as its bark is considerably more penatrable, and the tree is of comparable cognitive functioning.

  26. #296
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    LOL! Sage advice.

  27. #297
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    Quote Originally Posted by XB-70
    You are correct, RALL, in affirming that stealth technology provides for substantial RCS reduction from all aspects. But you are incorrect in stating that Sukhoi's published patent describes the average Radar Cross Section of the Su-57. Sukhoi's patent describes the merits of its aerodynamic surface only. There is no description of RAM (and its external RAM coat is now quite extensive) on the aerodynamic surface or RAS built within it - nor is the performance of such material quantified. (There are two exceptions: the air intakes and the IRST as they can not be made stealthy through the aerodynamic surface alone) But RAM and RAS (RAS affects your shaping! They radar receiver sees in radio waves, not visible light!) substantially contribute to stealth. So they are basically saying that their plane would have a RCS of less than 1m^2 when plated with foil. The link below actually provides a translated copy of the document. If anyone here reads Russian, I would be interested in a more thorough translation.

    https://robotpig.net/aerospace-news/...analysis-_2158

    I know of only one source where Russian designers have made a comparison for its RCS and it was to a "tennis ball". This implies an average RCS of .0037m^2 or (-24 to -25dBsm).

    https://www.youtube.com/watch?v=t4uVyDtvBCY

    Taking everyone at face value and assessing for X-band/Ku-band...

    The Su-57 has an average RCS about 37 times that of the F-22 Raptor.
    The Su-57 has an average RCS about 3.7 times that of the F-35.
    A Tomahawk cruise missile (RCS 0.05m^2) has an average RCS 13.5 times that of the Su-57.
    An F-16 with a moderate weapons loadout (RCS 2.5m^2) has an average RCS 675 times that of the Su-57.

    I don't believe the Russians have hit their target just yet. They will need the Item 30 engines and maybe some other improvements. But they have shown that they possess the technology, and they are just going to keep tinkering with it until they get there.
    Thanks for your opinion.

    I did not know that patent only talked about RAS and not RAM. Of course RAS is very important and in this case the final number of the RCS will be smaller than it was published.

    Never we will know exact numbers but we can get some idea.

    I think frontal aspect of the Su-57 will have good RCS, not very far from F-22 or F-35, but average RCS of the Su-57 is penalized by its side and rear aspect.

    Air Combat Command chief Gen. Mike Hostage, told F-35 was stealthier than F-22.

    The F-35′s cross section is much smaller than the F-22′s. “The F-35 doesn’t have the altitude, doesn’t have the speed [of the F-22], but it can beat the F-22 in stealth.”


    http://www.defense-aerospace.com/art...n-on-f_35.html

    But i think he was talking about front aspect of the aircrafts and not about average RCS. And really it has sense, the rear and side aspect of the F-35 is less stealth than the F-22, so it can be more stealth in front aspect but average RCS to be litle worst.

    This can be similar with the Su-57, its average RCS will be penalized by its rear and side aspect. This is the first airplane with stealth technology on the russian side, but for Usa is more than 30 years flying stealth airplanes, and F-35 is the last after F-117, B-2 and F-22.

    People need think it is impossible for russian side on his first adventure with stelath airplanes get the same development point than american side. It is simple logic. Same case for the next stealth european fighter.
    Last edited by RALL; 14th June 2018 at 23:16.

  28. #298
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    @RALL

    I think frontal aspect of the Su-57 will have good RCS, not very far from F-22 or F-35
    The frontal RCS is superior to both and the all aspect stealth as well. The rear is certainly lower RCS than the F-35.

    Russia was the first to put the stealth math into practice and they used it on ships.

    Last edited by KGB; 15th June 2018 at 04:39.

  29. #299
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    "The early bird gets the worm but the second mouse gets the cheese."

  30. #300
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    There is chinese study from 2016 where they analyse Su-57 model, it was done by engineers and professors. Their conclusion it is VLO design, so if engine is hidden no reason it can't be consider stealth:
    http://www.scielo.br/pdf/jatm/v8n1/1...m-8-1-0040.pdf
    Last edited by Krivakapa; 15th June 2018 at 13:39.

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