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Thread: Su-57 News and Discussion -version_we_lost_count!-

  1. #211
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    FalconDude said: So have we got any news? Is the PAKFA project on its last legs or not?
    It is way to early to tell. Truth be told, what happens with the "product 30" engines is a better indicator of the health of the program than any commentary on the aircraft itself. ALL of the distinguishing features of the Su-57 are dependent on the engines:

    The specified RCS equivalent to "a tennis ball"
    All aspect VLO
    The ability for Mach 1.6 without reheat
    A 900+ mile supersonic endurance

    And the new engines likely improve IR reduction and electrical power generation (very important going forward into the future) as well. If the new engine design fails its last tests or if that program is cancelled than the Su-57 program will die. If it succeeds then they will start building them in earnest. But flight tests typically lasts for 2.5-3 years and the Product 30 didn't fly until last December. It's likely to be in testing up till the end of 2020 and so there won't be any substantial orders till the tail end of that year or even 2021.

    So pay attention to flight tests with the new engine. If they fly a bird with twin Product 30s (they won't do this unless it has proved itself to be reliable) next year then it is performing well and the Su-57 program is healthy. If they don't then...

  2. #212
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    That really is the billion dollar question. “What is the Russian certification process for turbofans”. If it were a U.S. product, it would have already been bench tested to max hours (not lifecycle testing, that was just completed last year, for the F135 as an example), max power, had various poultry fired at it in a wind tunnel, and been blown apart running it at excess rpm and temp. Then flight testing. So they would have a pretty good idea of any potential issues (though as the F135 fire showed, mating it to the airframe/inlet may expose others).

    I don’t think we have a Russian aerospace engineer on here to give insight into their process.
    Last edited by FBW; 19th July 2018 at 18:26.

  3. #213
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    @FBW - It passed its bench testing phase already. Everyone does the bench phase before the flight phase. But passing that isn't a 100% guarantee. Engines occasionally do require rework, and with tight budgets it is not certain that the Russian government would keep the program that is necessary.

  4. #214
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    Think we are talking about 2020, perhaps 2021. New engines are difficult. Would say a military small diameter turbofan is way harder vs PD-14 civil engine development.

  5. #215
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    Yeah I figured that because I recall the press release when they started bench testing. But that’s not the point, what does their bench testing entail? If you some insight I’d like to hear it. I was very surprised when talking with some P&W engineers on F135 testing process. They purposely destroyed and dissected; entire engines, LPC, HPC. Damaged individual blisks and ran engines. You get the point.

  6. #216
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    ^^Imo all the requirements from VKS.
    Wonder how the nozzle is shaping up. It too would have a llife cycle run before certification.

  7. #217
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    Quote Originally Posted by FBW View Post
    Yeah I figured that because I recall the press release when they started bench testing. But that’s not the point, what does their bench testing entail? If you some insight I’d like to hear it. I was very surprised when talking with some P&W engineers on F135 testing process. They purposely destroyed and dissected; entire engines, LPC, HPC. Damaged individual blisks and ran engines. You get the point.
    We know they did a destruction test.. or several on the PD-14. But the usual for civil engines is simulated bird strike. Not sure how they do it exactly. There is also the water or hydro testing, how much water it takes before flame out. Other test involve prolonged 125% rpm runs. And then they take it apart again for exam.

    So when looking for a millitary engine, with higher requirements. Its the same and then some.

  8. #218
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    What are the major differences between the current engine and the idz.30 ?

  9. #219
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    Well civilian turbofans have a pretty stringent testing and certification process one that has to meet. EASA/FAA recognize each other’s certification, any civilian turbofan would have to meet those testing requirements. PD-14 will undergo EASA validation, 2019?
    A Russian military turbofan wouldn’t, as an aside.

    Back to the point, the Izd. 30 engine is in flight testing. I doubt they encountered any serious deficiencies in bench tests/ wind tunnel, which was my original point.

    I recall a post from secret projects a long time ago from a credible memeber stating that the original AL-41F was problematic even during bench tests, a bit of a technological overreach for the time (interesting parallel with US concerns about the technological readiness of the YF120).

    The type 30 began bench tests in 2016, so they must have gone pretty smoothly for flight testing to have begun a little over a year later. That is a pretty compressed testing period though.

  10. #220
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    @ XB-70

    fact is that in Russian/Soviet acquisition process there is nothing like IOC (and consequently LRIP) , full scale serial production begin when the item is fully ready, period.
    So, just the bench tests is just not enough to begin it.

  11. #221
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    Quote Originally Posted by Marcellogo View Post
    @ XB-70

    fact is that in Russian/Soviet acquisition process there is nothing like IOC (and consequently LRIP) , full scale serial production begin when the item is fully ready, period.
    Right on the first part, the second part, fully ready? That isn’t at all the Russian/Soviet acquisition model.

    The Soviets basically invented concurrency (hyperbole). The Su-27 went into mass production with unsatisfactory radar performance that took several years to meet requirements. The Soviets would begin mass production before the weapon system was fully operationally suitable. Very apparent in their ship/sub classes. The first few in a production series would basically be mules, each slightly different. Their tank series was the same. Russia seems to be following a similar model, the first three 955 SSBN, the first 885 SSN, first four 22350.

    Basically, get it into production and make incremental improvements.
    Last edited by FBW; 19th July 2018 at 21:08.

  12. #222
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    fact is that in Russian/Soviet acquisition process there is nothing like IOC...
    I'm sure the Russians have something similar, just under a different name. Certainly there is such a thing as certification tests and certification for final acceptance into service for all military equipment in the Russian military.

    full scale serial production begin when the item is fully ready, period.
    I wouldn't call 12 Su-57 by 2021 'full scale serial production', period.
    Last edited by Levsha; 19th July 2018 at 21:46.

  13. #223
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    FBW. Civil jet engines certification with FAA, mostly evolve around noise and climat emission. Mostly.
    A military jet as stated has many of the same requirements even if military engines does not need FAA certificate. TBO, fuel consumption. Thrust. Spool-up time. Weight. Temperature. But military comes with Afterburner, and very spesiffic exaust temp.
    A 5th gen engine anyway..
    As i saif much more requirements

  14. #224
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    Not just exaust temp, but HTP temperatur as well

  15. #225
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    Quote Originally Posted by FalconDude View Post
    ... but faces problems with :
    ...
    software
    I'm sure it does - don't they all? Bit of a cheap shot, really

    Software = problems, even without adding an aircraft into the equation.

    How serious are the issues? There has been no information published, so it's all speculation either way.

    Quote Originally Posted by FalconDude View Post
    engines

    with the engines being the most important one (which probably condemns the project)
    I'd be interested to know where they're getting that from - some unofficial leaks aside, there isn't a whole lot of info on the Izd. 30 in the public domain. Once you collate all the leaks and crumbs of official statements, you can form a pretty decent picture, but nothing about it suggests undue difficulties. As far as the development schedule goes, pretty much the only statements I'm aware of are a) total duration from contract award (which would presumably have happened a couple of years before 2010) 10 - 12 years b) flight tests to start in 2017 (stated in 2014 by an UEC official).

    That suggests it was originally supposed to wrap up by 2020ish (getting close, but that plan is almost 10 years old) and is - if only just - keeping roughly to the milestones as specified 3 years ago. A mere 17 minute flight three weeks before 2017 is out and no further flying until February 2018 indicates eleventh-hour box-ticking, but let's say they're within 6 months of the 2014 schedule - could be MUCH worse without making it a disaster by recent aerospace industry standards.

    Quote Originally Posted by FBW View Post
    I recall a post from secret projects a long time ago from a credible memeber stating that the original AL-41F was problematic even during bench tests, a bit of a technological overreach for the time (interesting parallel with US concerns about the technological readiness of the YF120).
    Yup. The aim was for a turbine inlet temperature of 1900K, or 50K - 100K higher than its Western counterparts. Even accounting for Soviet practice allowing for shorter TBO intervalls, that was going to be a tall order, given how steep the TBO/temperature gradient is. For reference, the AL-31F family has temperatures on par with the F100/F110 families, with TBO shorter by a factor of approximately 2 (early versions being worse and recent models, despite running hotter, getting closer).

    Quote Originally Posted by FBW View Post
    The Soviets basically invented concurrency (hyperbole). The Su-27 went into mass production with unsatisfactory radar performance that took several years to meet requirements.
    That particular example is another instance of overambition though. MTBF was required to be 200+h, which just wasn't going to happen with a hybrid analogue/digital architecture built out of 1980s Soviet electronics. Heck, contemporary fully-digital Western radars (e.g. EL/M-2032) were happy to hit 150h (modern incarnations of these designs are a lot better, but we're talking about their performance when first entering production in the late-1980/early-1990s)!

    Quote Originally Posted by FalconDude View Post
    What are the major differences between the current engine and the idz.30 ?
    EJ200 <-> RB.199 is probably a rough guide.
    Last edited by Trident; 20th July 2018 at 00:21.

  16. #226
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    Quote Originally Posted by FalconDude
    What are the major differences between the current engine and the idz.30 ?
    It will have less stages in LPC, HPC and turbine IIRC but apparently can be replaced 1 to 1 with the old one (not really sure the front compressor has exactly the same diameter or not)
    Composite materials for better RCS in front compressor.
    Also different nozzle for RCS too and other unspecified measures for IR signature reduction
    Higher efficiency and thrust, expected ca. 110 kN dry, 170 kN or higher in A/B. Should allow supercruise in similar conditions to F-22
    Claimed a 5+ generation engine by Russian sources, should be a rough equivalent to F-119 with maybe little higher thrust.

  17. #227
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    @Levsha

    No, Russian sequence is acceptance trials, state test completion, first serial, serial production and officially entering in service.
    All those term indicates something with a completely different meaning from the wastern ones.
    Acceptance trials are made at a very initial stage of development, just for to compliance between the offered product and the performance requested, state trials encompasses the most part of the development , first serial production has nothing to do with IOC but it's just the way to hone assembly line procedures, serial production phase happen after the state trials are completed while official entering in service marks the moment the planes are handled exclusively by the Air force with not any intervention by the production's association support team (and with no further post production fixing).

    I wouldn't call 12 Su-57 by 2021 'full scale serial production', period.
    Infact they call it just "first contracted batch" but in the case they would be produced on a fully developed assembly line and with the same work schedule they would use in other full scale serial production (i.e. instead of working them one after one on a single bench) they would qualify as such anyway, just limited to a ludicrous number of planes.
    And no, 12 Su-57 by 2021 doesn't mean absolutely that there would not be produced more of them before of that date, just that eventual new contracts would eventually fall into the 2018-2027 state acquisition programme, that's already started.

    So it could be either that in the end only 12 Su-57 would be ordered in total or that after this first contract, awarded for the 2011-2020 state acquisition programme, another one would immediately follow, just being inserted into the 2018-2027 one.
    Most probable thing is however IMHO would be that after the first batch with -117 engines they would wait for the development of izdelye 30 to be completed and produce the whole of Su-57S in 2021-2030 state acquisition programme timeframe, covering the substitution of the remaining su-27 P and S models with Su-35 instead.
    Last edited by Marcellogo; 20th July 2018 at 01:29.

  18. #228
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    Quote Originally Posted by Trident View Post
    That particular example is another instance of overambition though. MTBF was required to be 200+h, which just wasn't going to happen with a hybrid analogue/digital architecture built out of 1980s Soviet electronics. Heck, contemporary fully-digital Western radars (e.g. EL/M-2032) were happy to hit 150h (modern incarnations of these designs are a lot better, but we're talking about their performance when first entering production in the late-1980/early.
    200+ hours? From the literature at the time, the MTBF was around 5 hours for the early versions at state trials in 1985! That isn’t overreach, that’s a GD disaster.

    It wasn’t just that, it was multiple target tracking and range. Anyway, it puts Marcellogo’s statement about Russian/Soviet acquisition practice into context. The Su-27 proved to be a capable platform, one that evolved into a world class platform. One reason why I think current comments on the Su-57 (positive and negative) are overreach. The one thing I agree with is the Russians do things differently. They tinker and improve over time.

  19. #229
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    Quote Originally Posted by FBW
    200+ hours? From the literature at the time, the MTBF was around 5 hours for the early versions at state trials in 1985! That isn’t overreach, that’s a GD disaster.

    It wasn’t just that, it was multiple target tracking and range. Anyway, it puts Marcellogo’s statement about Russian/Soviet acquisition practice into context. The Su-27 proved to be a capable platform, one that evolved into a world class platform. One reason why I think current comments on the Su-57 (positive and negative) are overreach. The one thing I agree with is the Russians do things differently. They tinker and improve over time.
    Su-27 had some big problem, USSR dissapeared. So improvement was very slow, because no money. That is not the same case. If the problem of the Su-57 are the engines, and need wait for the new engines, ok they can wait to 2025. But what official seem tell, problems are deeper. It affects to other areas. And if problems affect to the basis concept of the airframe, proyect will be frozen for ever. Anyway, we are talking 2025 and forward, now is 2018. This proyect have entered inside the refrigerator.

    RT and Sputnik created overrated hype about this airplane, and many people did not want to believe what rumours told about problems aircraft had. But really, normal problems when a country aproach for its first time a 5th generation airplane. The hype created was the real problem, i think. We will se with franco-german fighter.
    Last edited by RALL; 20th July 2018 at 14:40.

  20. #230
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    Quote Originally Posted by panzerfeist1
    @Rall

    "
    Really Uv sensor works well at low height but poorly at medium and high altitudes, because effect of the ozone. So, its good for advice about coming mampads or surface-air missiles, but not against air-air missiles or airplanes. And IR is much better for medium and hight altitudes."

    Do you agree with Wikipedia's statement? on the advantages and disadvantages? https://en.wikipedia.org/wiki/Missil...warning_system

    The funny thing is it seems to show that UV has more advantages than infrared.


    It seems problem is the quantidy of ozone in medium and hight heights, so if you want to have good misil warning aproaching you will need IR sensors, also uv sensors seems have few range detection in comparison. Although It seems for low height UV sensors is better.

    If you can have both sensors, would be the best option, no?

  21. #231
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    Quote Originally Posted by RALL View Post
    Su-27 had some big problem, USSR dissapeared. So improvement was very slow, because no money. That is not the same case. If the problem of the Su-57 are the engines, and need wait for the new engines, ok they can wait to 2025. But what official seem tell, problems are deeper. It affects to other areas. And if problems affect to the basis concept of the airframe, proyect will be frozen for ever. Anyway, we are talking 2025 and forward, now is 2018. This proyect have entered inside the refrigerator.

    RT and Sputnik created overrated hype about this airplane, and many people did not want to believe what rumours told about problems aircraft had. But really, normal problems when a country aproach for its first time a 5th generation airplane. The hype created was the real problem, i think. We will se with franco-german fighter.
    Where are the sources that the Airframe of Su-57 have problems?

    Its most likely the engines. As several has debated already here, the Russians sort of invented secuenstration.
    That means sensor and software surly will see further enhancement as time goes by.
    But if they already have accepted several new weapons for Su-57, the idea of any problems with airframe is silly.
    At worst, some minor changes to engine compartments will happen.
    There was crack issues many years ago, this has long sinse been corrected.
    Sukhoi has done intensive testing on durability and destruction test on static airframes. This is even on youtube.

  22. #232
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    Its most likely the engines.
    Indeed. Most of airframe rework was caused by inability to produce an engine wich was planned for Su-27. Delay with the engine was caused by metallurgical institute which fail to create single crystal turbine blades for it in time.

    Also, i do not understand why all so obsessed with izd.30. AL-41F1 is quite capable engine. It's not an alien tech, but it's on par with F119 in most parameters. At least it's in top 5 of fighters engines in the world right now. No reason to whine here.

    Also, i surprised how many people here don't understand simple fact that Russian MoD and defence industry is completely different to the US. No reason to use US logic in this case. Government controls MoD and it controls over 90% of defense industry. So no reason to order hundreds or thousands of jets with a goal to cut acquiring price. It's literally buying from yourself. It's all about the technology and people employment only. So buying 12 jets clearly means fail in the US, but in Russia it means really noting.

  23. #233
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    RALL said: But what official seem tell, problems are deeper. It affects to other areas.

    The most credible official is money. If the program was in danger of failing to meet its requirements then the paychecks to it would have been cut already. But they are continuing - both for initial production and for R&D on product 30. So, as I mentioned earlier, the flight testing of the product 30 is the best indicator of what will happen with this project - because so many technical requirements depend on it. As for statements about not immediately placing the program in mass production, well, there are a number of reasons for this.


    1) Money - tight budgets.


    2) Material and technological shortages. The Su-57 is heavily composed of composite materials. So are all of the other aircraft they are planning to make (new variant SSJ, MC-21, CR929 wing, etc.), as well as other aerospace projects such as PRS-1M, 'Federation' spacecraft, etc. And then shipbuilding, construction, and the automotive industries are making increased use of it too. It's a high growth market in Russia and production has increased considerably over the last 10 years - but so has demand! And so it is a tight market. It will stay that way for a while, and so the only way they could mass produce the Su-57 in the near future is to cut something else. They need further investment and are slowly phasing it in.

    https://www.insidecomposites.com/rus...f-big-changes/

    3) They have the time to get it right. Sure, back in the early 2010s practically everyone was talking about developing a 5th gen fighter. Other than China - who also needs to complete their development cycle - nobody has made much progress at all. Japan came the closest, but they only flew a demonstration model, not a fighter. (Too small for weapons) All of their fighters exist only on paper. The Russians aren't in any danger of falling behind.


    Also, regarding MAWS, they are just like industrial flame detectors. There are two general methods for going about it: 1) multi (3 band) IR and 2) dual IR/UV band. Either way, you need more than one band so that you can reduce false indications through signal processing.

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