Su-57 News and Discussion -version_we_lost_count!-

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Profile picture for user haavarla

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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

Profile picture for user haavarla

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Not just exaust temp, but HTP temperatur as well

... 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.

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.

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).

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)!

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

EJ200 <-> RB.199 is probably a rough guide.

Profile picture for user LMFS

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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.

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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.

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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.

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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.

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@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.

https://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Ozone_altitude_UV_graph.svg/2000px-Ozone_altitude_UV_graph.svg.png

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?

Profile picture for user haavarla

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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.

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3 years 4 months

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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.

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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/russian-composites-industry-on-the-verge-of-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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Also, i do not understand why all so obsessed with izd.30. AL-41F1 is quite capable engine.

It mostly has to do with the capability for all aspect VLO. You can see the blades of the low pressure turbine when looking at an engine from the rear. That isn't good for your RCS if they are made of metal (see pic in link).

https://www.nextbigfuture.com/2017/09/china-catching-up-on-fighter-and-commercial-jet-engines.html

They should be composite in the product 30. The Russians have been tight lipped about exactly what composites are in the product 30, but you can learn a lot by following unclassified programs. They outright state that the PD-35 will have ceramic matrix composites...and it has a remarkably short development cycle planned for something using new materials. This suggests they aren't that new.

https://www.flightglobal.com/news/articles/contract-docs-reveal-plans-for-russias-new-widebody-445047/

There are other reasons but they are more minor. The new engine really does make or break the program.

Profile picture for user LMFS

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@XB-70
Yes, besides the dry thrust will be increased notably. This is no small issue at all since the whole supercruise performance depends on it

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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.

You need read again what i wrote..

"And if problems affect to the basis concept of the airframe,....(...)"

I used "if"= conditional.

And i talked about stealth problems which could affect to the concept of the airframe. Then it can not fix on the current airframe. They will need a new design. But i talked with conditional "IF".

Current fighters need new weapons already. R-77 and R-73 are obsolete compare with new evolutions of western airtoair weapons.

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Current fighters need new weapons already. R-77 and R-73 are obsolete compare with new evolutions of western airtoair weapons

There is R-77-1 and R-73M family already. Which, adequate and well compared to the generations of Western weapons.

and evolutions are kinda incremental at best. Mostly software related. We will still see AMRAAM or Meteor with conventional planar array seeker for decades ahead. Phased array seekers are at best in development. Airframes are practically unchanged, no real "lifting body" AAM yet, Have Dash is not produced.

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.

How is that different to almost literally any new radar system at the time? 200+h was only the goal, BTW - I would be surprised if the N001 ever actually achieved that kind of reliability. It does account for the fact that the radar was not officially accepted into service until 1990ish (by which time hundreds were already in operation) though. More likely than not, the military simply lowered its standards to a more realistic level at that point.

For reference, the analogue APQ-120 had a MTBF in the single digits, and the first attempt at reliability testing the APG-66 (all-digital, air-cooled) failed, achieving 10 - 15 hours (60 envisaged). Meanwhile APG-63 MTBF goals were reduced from 150 originally to 60 hours (a level it didn't achieve out of the box either, and pre-APG-70 variants never made it past 80h). Last but not least, the infamous Blue Circle saga bears mentioning ;)

For late-production N001s to hit >100 hours is a creditable showing, considering its architecture.

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@ XB-70

Let's add another important point:

4) There is not any rush to put it in service as a substitute for obsolescent fighters.
Su-57 would have been the substitute for Su-27, together with the Su-35S.
ATM only an handful of Cold War era Su-27 (P &S model) are still in service and still have flight hours available, Su-27 SM are from 2004 onward and are being updated to SM3 standard.
So the first ones would probably be replaced with an additional batch of Su-35, for the other they could surely wait for the izdelje-30 version as they were envisaged to from the very beginning.

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There is R-77-1 and R-73M family already. Which, adequate and well compared to the generations of Western weapons.

and evolutions are kinda incremental at best. Mostly software related. We will still see AMRAAM or Meteor with conventional planar array seeker for decades ahead. Phased array seekers are at best in development. Airframes are practically unchanged, no real "lifting body" AAM yet, Have Dash is not produced.

I am not agree.

R-77-1 with around 100 kms data range its miles away from Amraam Aim 120 d (180 km)or C6, and worst situatuon against Meteor with a nez around 90 kms per 20-30 kms R-77-1. R-77 only received 1 update from 30 years ago. R73M can not compete too with Aim 9x or iris-T, do not have ir-imaging and only its 60º off-boresight. All western short misiles are ir-imaging and over 90º off-boresigh.

So no, its outdated weaponry. Of course can be lethal, but its miles away from western missiles in that moment.

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Are you real Sure Amraam 120D max range is 180km?

And if R-77-1 recieved an update very recent.. how is that bad exactly?

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Are you real Sure Amraam 120D max range is 180km?
?

Classified. Probably comes from the statement of “50% greater range than the C7”.

And the range of the C7 is classified, so most likely based on vague statements and estimates.. Those types of ranges are for head-on. The intercept is nowhere near that far (true of all stated AAM ranges).