Su-57 Stealth Fighter: News #6

Arrow wrote:

LMFS you can write what you mean exactly what military programs are about, apart from the Su-57.
All 78 Su-57s by 2027 are not a big number. The US will probably have over 1,000 F-35s plus other NATO nations by then

AGAIN with this nonsense!!!!!    
They are not 76 (because also the first two serials are part of definitive contract for the first batch, as everyone could clearly read in the previous page) to be produced until 2027 but AS FUCKING EVERY TIME in the framework of the 2027 long term acquisition program meaning that the order would be fulfilled in a date BETWEEN 2024 and 2027 itself, and AS FUCKING EVERYTIME immediately before it would be completed  another contract for another batch would be signed .
Needless to say 76 is an ENORMOUS number for a single production batch in russian standard, let's compare it with the two of the Su-35, a 48 and a 50 ones, signed BOTH in the framework of the 2020 long term acquisition programme.

And the F-35 (all versions) has still to pass final certification before entering in full rate production.

marcellogo wrote:AGAIN with this nonsense!!!!!    
They are not 76 (because also the first two serials are part of definitive contract for the first batch, as everyone could clearly read in the previous page) to be produced until 2027 but AS FUCKING EVERY TIME in the framework of the 2027 long term acquisition program meaning that the order would be fulfilled in a date BETWEEN 2024 and 2027 itself, and AS FUCKING EVERYTIME immediately before it would be completed  another contract for another batch would be signed .
Needless to say 76 is an ENORMOUS number for a single production batch in russian standard, let's compare it with the two of the Su-35, a 48 and a 50 ones, signed BOTH in the framework of the 2020 long term acquisition programme.

And the F-35 (all versions) has still to pass final certification before entering in full rate production.

My friend, even if it was 76 until 2028 it would be a significant amount, as high a delivery rate per year as VKS has had of any plane lately. This is what we know after the KnAAZ MoD visit:

Year 20 21 22 23 24 25 26 27 28

Units 1 4 4 7 12 12 12 12 12

They just said they can scale the production up to 15 units per year, so they could eventually fulfil the contract in advance, we will see. I of course pity anyone thinking Russia took all the pains of the PAK-FA just to produce 76 planes in total...

Arrow wrote:
LMFS you can write what you mean exactly what military programs are about, apart from the Su-57.
All 78 Su-57s by 2027 are not a big number. The US will probably have over 1,000 F-35s plus other NATO nations by then

All Arrow, across the board Russian armed forces are modernizing every unit, every vehicle, ramping up drills, implementing modern battle management and communications systems, accelerating procurements to the aerospace industry (it has been illustrated with concrete news in this forum), deploying hypersonic weapons and the corresponding hypersonic-countering AD systems. They are reaching unprecedented levels of readiness and behaving more resolutely than ever before, you just have to check the number of contracts and the amounts of units to see this.

As to the number of F-35, it has very little importance when they are away or unable to operate. How many of them are deployed in the European theater? How many can operate from destroyed air bases? What does it matter how stealthy they are supposed to be, when they can be seen 3000 km away heading down the runway, will have to operate without AWACS, under extreme EW and will have to face the best IADS in existence? This constant whining about supposed NATO numbers is nothing but empty rhetoric if the real environment and constraints are ignored.

There was no alternative to F-35, but soon there will be.... the 150 million dollar F-15 remake... and I rather suspect that when they get more new upgraded F-15s they are going to realise the F-35 isn't actually all that good because the F-15 will be faster and longer ranged with much better payload and much wider range of weapons and much larger radar.... the only thing is it wont be stealthy... but really how stealthy is the F-35?

I think you will see the numbers of F-35s ordered drop dramatically and the resulting increase in price will make the numbers ordered drop even more and they will really start looking hard at alternative options...

Honestly I think the more F-35s that HATO buys the better it is for Russia... those gold plated white elephants will mean no HATO country that operates them will have any problem meeting their commitment to spend 2% of GDP on weapons for HATO... it will be keeping it under 10% that will be the problem...

GarryB wrote:There was no alternative to F-35, but soon there will be.... the 150 million dollar F-15 remake... and I rather suspect that when they get more new upgraded F-15s they are going to realise the F-35 isn't actually all that good because the F-15 will be faster and longer ranged with much better payload and much wider range of weapons and much larger radar.... the only thing is it wont be stealthy... but really how stealthy is the F-35?

I think you will see the numbers of F-35s ordered drop dramatically and the resulting increase in price will make the numbers ordered drop even more and they will really start looking hard at alternative options...

Honestly I think the more F-35s that HATO buys the better it is for Russia... those gold plated white elephants will mean no HATO country that operates them will have any problem meeting their commitment to spend 2% of GDP on weapons for HATO... it will be keeping it under 10% that will be the problem...

Bah...the F-15 was a fantastic fighter in the seventies when was introduced and also in the mid eighties when the production was shifted to the E version.

Now, this new version is basically the same that this latter one,(the E, I mean) with updated avionics but carrying AA missiles on its CFT racks, instead of bombs, no advanced anti-stealth, no canard, no TVC.

Naturally, carrying a double payload of missiles wouldn't add nothing and would instead just hamper the plane's performances.

The idea of using them as a sort of flying arsenal ship i.e. practically shooting them under F-35 guidance just didn't ake sense to me, as they would be carrying the same missiles anyway, so that they would be well into opponents' reach.

If i may, from what i recall from the time Stealth aircraft started appearing, the idea in those day of the F-117 was to infiltrate and Take down or Cripple as much of the enemy's radar and air-force infrastructure as possible in order for the Main Force to deliver the killing blows.

This was also the idea for when the F-22 came about, there were always plans to replace all aircraft with F-22s and later F-35s, but it looks like those ideals are being dropped.
And the U.S is going back to the old plan of a smaller infiltration force (most likely assisted by cheaper Stealth UCAVs) making way for the Main Force.

That or the U.S is going to drop it's emphasis on Stealth almost completely (with the exception of Drones), and pursue a more Russian strategy of using Cruise missiles instead all this expensive Stealth.

AlfaT8 wrote:If i may, from what i recall from the time Stealth aircraft started appearing, the idea in those day of the F-117 was to infiltrate and Take down or Cripple as much of the enemy's radar and air-force infrastructure as possible in order for the Main Force to deliver the killing blows.

This was also the idea for when the F-22 came about, there were always plans to replace all aircraft with F-22s and later F-35s, but it looks like those ideals are being dropped.
And the U.S is going back to the old plan of a smaller infiltration force (most likely assisted by cheaper Stealth UCAVs) making way for the Main Force.

That or the U.S is going to drop it's emphasis on Stealth almost completely (with the exception of Drones), and pursue a more Russian strategy of using Cruise missiles instead all this expensive Stealth.

Mega-expensive US weapons' procurement programs have an unbelievable amount of momentum behind them, so much so that its virtually impossible to hit the brakes. If one was to try, there would be the inevitable push-back by politically-connected MIC heavyweights and corrupt politicians who care for nothing except keeping the MIC industries operating at full-tilt within their electoral jurisdiction.

Expect the USAF to re-evaluate the benefits of stealth when the USN decides to down-size its CVN fleet....

Bah...the F-15 was a fantastic fighter in the seventies when was introduced and also in the mid eighties when the production was shifted to the E version.

If they had dropped the requirement for the F-35 to replace the Harrier for the US Marines it could have been a stealthy F-16 and it could have been very good.

The requirement for a huge engine driven fan has screwed its shape and design... it has turned what could have been a stealthy F-16 into a stealthy Buccaneer.

Now don't get me wrong... the Bucc is my favourite British aircraft... I even prefer it to the Spitfire... the F-16 should not have replaced it in the light strike role because the Bucc was faster at low level with a nuclear bomb under each wing and had better range... and it could operate from aircraft carriers.

If the British still had a real carrier when the Falklands war kicked off if they had taken a half load of Buccs and a half load of F-4 Phantoms the Argentines would not have had a leg to stand on and the silly risky dangerous Vulcan raid could have been performed by the Buccs from the carriers as they arrived on site...

The problem is that the Bucc is no fighter plane, so while it is a better strike plane than an F-16 the F-16 was better because it could do both fighter and light strike/attack.

The F-35 is not a good fighter its aerodynamics are poor and skewed away from light fighter to medium strike.

The F-15 on the other hand with new engines and new electronic and new radar in the F-15E form rather than the F-15C air to air only form will be a much much better aircraft... it will literally be an Su-35 with the Su-34s attack capacity mixed in...

You can call F-35 next gen all you want but the 4th and 5th gen fighters have a huge overlap and the lowest 5th gen fighter (F-35) is not ahead of many of the best 4th gen fighters like the MiG-35 and the Su-35 and even the Rafale... and soon F-15EX.

Use by Israel in Syria shows the F-35s hide in mountain ranges and fire stand off munitions to attack air defence targets from afar... a 4th gen fighter can already do that much much cheaper... it can also carry more payload further and faster and still much much much cheaper.

Now, this new version is basically the same that this latter one,(the E, I mean) with updated avionics but carrying AA missiles on its CFT racks, instead of bombs, no advanced anti-stealth, no canard, no TVC.

Which means it is not as good as Su-35 or MiG-35 in terms of some areas of performance, but it is still much better than the F-35 in many important areas... maintenance should be much much cheaper and flight hours also cheaper too.

Naturally, carrying a double payload of missiles wouldn't add nothing and would instead just hamper the plane's performances.

AFAIK the F-15E is a full 9g fighter with payload... one of the few types out there that can manage that... but having extra weapons options is not normally a bad thing... and certainly carrying the weapons you would need 10 F-35s to deliver on maybe 4 F-15EX aircraft is actually a good thing too.

The idea of using them as a sort of flying arsenal ship i.e. practically shooting them under F-35 guidance just didn't ake sense to me, as they would be carrying the same missiles anyway, so that they would be well into opponents' reach.

I have seen mention of a flying arsenal aircraft but it was not an F-15... it was a converted C-130 that carried all sorts of heavy ordinance like long range heavy missiles... it also retained inflight refuelling capacity so the F-35s essentially carried light self defence weapons and flew ahead to use its sensors to find targets the C-130 could launch standoff attacks against... the F-35 able to head back and refuel via the C-130 to improve endurance on station.

Obviously such aircraft would be primary targets and rather easy meat for R-37M and newer replacement missiles on the way... and they would neither be fast nor stealthy... but obviously much more affordable than stealthy C-17s which were already gold plated lode stones.

If i may, from what i recall from the time Stealth aircraft started appearing, the idea in those day of the F-117 was to infiltrate and Take down or Cripple as much of the enemy's radar and air-force infrastructure as possible in order for the Main Force to deliver the killing blows.

I wont contradict you there because there was a belief that in Desert Storm that is what the F-117s did.... but in actual fact the radars... civilian and military that could detect F-117s were taken down first with Apache helicopters.

You would think a long range stealthy anti radiation cruise missile would be much cheaper and also much more effective than the F-117, but long wave radars are hard to hit with ARMs because of the signal width.

Stealthy cruise missiles today with terminal guidance would be much more effective... faster... longer ranged.... and much much cheaper and not needing any sort of escort force.

Interestingly the B-2 was to be a bomber and not a cruise missile carrier like Soviet strategic aircraft like the Bear and Blackjack... before Desert Storm the plan was to sneak into Soviet airspace with B-2s and fly over their ICBM fields and naval ports and attempt to wipe out most of their ICBMs and SSBNs in a sneaky first strike in the hope of demanding surrender terms or wipe them out with the follow up strike of western SSBNs and ICBMs...

With total air control over a relatively small country called Iraq... with the launch areas further reduced by the limited range of the modified Scuds and with practically total air control at least of those areas they thought they could wipe out the Scuds the way the planned to hit the Silos and truck mounted ICBMs the Soviets had... with satellites covering the entire combat area it was going to be easy.

Dozens of launches a day and not a single Scud missile destroyed on a launcher before launch... a total failure... the number of B-2s went from 200 to 20 and that job was dropped from their stage show sales brochures...

That or the U.S is going to drop it's emphasis on Stealth almost completely (with the exception of Drones), and pursue a more Russian strategy of using Cruise missiles instead all this expensive Stealth.

Don't worry... the US MIC doesn't do cheap, so they will find a way of making it expensive...

Mega-expensive US weapons' procurement programs have an unbelievable amount of momentum behind them, so much so that its virtually impossible to hit the brakes. If one was to try, there would be the inevitable push-back by politically-connected MIC heavyweights and corrupt politicians who care for nothing except keeping the MIC industries operating at full-tilt within their electoral jurisdiction.

The C-17 was the first project designed to the idea of putting factories in places where senators on committees that decide funding for the Pentagon have their jurisdictions... It made the aircraft horrendously expensive without making it better, but they didn't even need to ask for them in the end... funding kept getting approved for new planes to keep production going... it broke all the rules of supply and demand but it was a very successful programme.

The F-35 was the same so funding will never be cut and bullshit scams like... the latest models are only 70 million dollars an airframe can be shown to prove cost cutting worked... but when you add the 40 million dollar engine it costs about the same 110 million per aircraft that it did before that they said they could not afford.

They seem to be saving 40 million dollars per aircraft but what they are actually doing is wasting 70 million dollars on an airframe that can't fly until you spend another 40 million dollars to buy the engine.

Really, $40 million for a single jet engine?!?!

AlfaT8 wrote:If i may, from what i recall from the time Stealth aircraft started appearing, the idea in those day of the F-117 was to infiltrate and Take down or Cripple as much of the enemy's radar and air-force infrastructure as possible in order for the Main Force to deliver the killing blows.

This was also the idea for when the F-22 came about, there were always plans to replace all aircraft with F-22s and later F-35s, but it looks like those ideals are being dropped.
And the U.S is going back to the old plan of a smaller infiltration force (most likely assisted by cheaper Stealth UCAVs) making way for the Main Force.

That or the U.S is going to drop it's emphasis on Stealth almost completely (with the exception of Drones), and pursue a more Russian strategy of using Cruise missiles instead all this expensive Stealth.

They have not and will never nominally drop stealth, but in reality:

- They bring the F-15 back
- They create long range hypersonic missiles
- They resort to stand-in jamming and stand-off weapons
- They are making a big push for AI and unmanned
- They are accelerating programs to substitute and modernize their 5G fighters
- They militarize space
- They are leaning very strongly towards in-theater deployment of nukes, promoting low yield tactical weapons and ditching arms control treaties, in order to get advantages they know lost in the conventional armament.

So, their 5G is allegedly far and beyond anything else but they are quietly removing it from the roles they were intended for and those previously very cocky claims that a force composed by such planes could operate unsupported inside IADS are now interestingly absent. Everybody and their dog knows that lower frequency /multiband radars see them and that in a conflict vs Russia in the European theater they would need to operate in a strong disadvantage, because Russia sees them from far away while the enablers that normally allow their fighters to operate with their radars off would have substantial difficulties to survive. Even in all their narcissistic delusion, they perfectly know that flying F-35 and B-2 into Russian IADS is a suicide

Arrow wrote:

Limb.
How do you know what is the temperature at the turbine in izd 30?

I don't, but for some reason US defense employees claim to know it

marcellogo wrote:

You are saying however something completely false: F-100-PW-229 has a lower bypass ratio (0,34:1 to 0,56:1 and 0:49:1 respectively) of both AL-31F and RD-33 while the Al-41 actually increased such value while adopting a larger engine core.

At the contrary the F404 started with 0,34;1 and F414 lowered this already low value to a meagre 0,25:1.
So actually russian engines has both a way greater thrust to weight than a WAY larger bypass ratio of the PW-229 AND the F404/414, thus completely denying your baseless affirmations.
Between the american engines in the legacy fleet only the F110 retained an high bypass ratio, all the rest have gone down the sinkhole.

New generation ones? F-119 has a bypass ratio of 0,30:1 i.e. between the F404 and the F414 while the F-135 has one of 0,57:1 i.e. practically the same one of Al-31 (0,56) and Al-41 (0,59).
So I guess Saturn get it right from the very beginning.

My analogy of F-100-PW-229  was not suggesting bypass ratios but that AL-41F is not a new engine design but a modification of an existing design.

Regarding bypass ratios, F100-PW-100 was 0.63-0.67 (depending on source). This was a compromise between the 0.4 the numbers said was best for air combat and the 2.0 the Air Force had proposed originally.  

The EJ200 and F119 went for lower bypass ratios suitable for supercruise. Variable bypass was considered too risky and complicated. F135 has a higher bypass ratio partly for design reasons plus F-35 primary mission is strike.

If the Russians are smart, Izdeliyie 30 will be a variable bypass engine, but developing new engine technology is very, very expensive.

Removed some posts to here.

Will bring some relevant points back here related to this topic... though that might take a while.

secretprojects wrote:
Let's go on topic for a bit. I've been interested in Soviet / Russian aviation for 37 years. I've observed the Su-57 program from the start. It seems like a competent design aerodynamically, it's basically just one large lifting surface and is the logical development of the "integral" layout of the Su-27.

The interim engines are a weak point, but the phase 2 engines could change things around. the avionics suite looks interesting if overly complicated. I'm doubtful that Russia has spent enough in R&D to make something completely comparable to the F-22 and F-35, but I don't think that's the intention.

lancelot wrote:If anything I think the Su-57 will have better avionics than the F-22. It is simply a much more recent design.
Even the initial engines have decent performance. I suspect their lifetime is probably not that great though. Probably pushed to the max of materials.
The second stage engines will be ready in a couple of years. That is I think the major reason why we didn't see a big order of the Su-57 any sooner.
I also think comparing the Su-57 with the Su-27 is a bit naive. It is a whole new design. It looks nothing like the Flanker.
It reminds me of people who said the USAF chose the YF-22 over the YF-23 because they wanted an aircraft which looked like a stealthy F-15 and the YF-22 was it.

Just look at the Su-57. It has all moving canted tailplanes. It has more moveable surfaces than the Su-27. The wing looks nothing like the Su-27 wing.
The avionics aren't the same, not even the same as in the Su-35, since this one uses fiber optics to connect the airplane avionics together IIRC.

I mean like nothing is the same as in the Su-27 or the Su-35. Even the engines.
They may also be called Al-41. But there are a lot of engines with Al-41 name and they have next to nothing in common with each other.
One is the engine in MiG Project 1.44. The other is the Su-35 engine. Then there is Su-57 engine. They have nothing in common. Just look at basic specs.

secretprojects wrote:

lancelot wrote:If anything I think the Su-57 will have better avionics than the F-22. It is simply a much more recent design.

The component base will be much more recent, for sure. That doesn't necessarily mean the sensors will be superior operationally. LPI techniques are new to Russia and historically Russian ECCM capabilities have been weaker.

lancelot wrote:Even the initial engines have decent performance. I suspect their lifetime is probably not that great though. Probably pushed to the max of materials.

The second stage engines will be ready in a couple of years. That is I think the major reason why we didn't see a big order of the Su-57 any sooner.

lancelot wrote:
I also think comparing the Su-57 with the Su-27 is a bit naive. It is a whole new design. It looks nothing like the Flanker.
It reminds me of people who said the USAF chose the YF-22 over the YF-23 because they wanted an aircraft which looked like a stealthy F-15 and the YF-22 was it.

Perhaps you need to reread what I said. The Su-27 "integral" layout was conceived as essentially a tailed 'flying wing' based on the T-4MS. Originally the entire airframe, including the entire fuselage and engine nacelles was to be composed of aerofoils, in an attempt to get the greatest possible lift/drag ratio. This was impractical to build as it meant constant curves everywhere so it was vetoed by the structural department, and the final Su-27 design has more conventional design, but the blended body and lifting surface approach is taken even further in the Su-57. Lift generated by the Su-57 configuration must be extremely high, its all lifting surface.

lancelot wrote:The avionics aren't the same, not even the same as in the Su-35, since this one uses fiber optics to connect the airplane avionics together IIRC.

I mean like nothing is the same as in the Su-27 or the Su-35. Even the engines.
They may also be called Al-41. But there are a lot of engines with Al-41 name and they have next to nothing in common with each other.

One is the engine in MiG Project 1.44. The other is the Su-35 engine. Then there is Su-57 engine. They have nothing in common. Just look at basic specs.

Condescending much? How many aviation books have you published? I'd wager fewer than me, even if I've only written one

The AL-41F (1st of that name) was a large, advanced "clean sheet" design for supercruise similar to the XF120 that never made it anywhere near completion. Prototype engines had very short life, and productionising would have needed a lot of money that wasn't available.

The AL-41F (Su-35) is an improved AL-31F akin to the F100-PW-229.

The AL-41F (Su-57) is still just an improved AL-31F, with higher thrust, akin to the F100-PW-232. Its bypass ratio isn't optimal for supercruise, for example.

Izdeliye 30 is indeed a new design.

marcellogo wrote:

The second stage engines will be ready in a couple of years. That is I think the major reason why we didn't see a big order of the Su-57 any sooner.

Have you both forgotten they have signed for a batch of 76 last year?

That was something that looked almost incredible when it was first published both in russian specialized defence press than in this forum as no similar order was EVER put in (new) Russia, in which, I wrote AGAIN for the nth time, THEY ORDER A BATCH AT TIME with no predetermined total number of  a certain model fixed in advance of beginning of serial production (but even after)...

Sorry for tantrums but it has been years that I have  repeat same things in both Key aereo than there: Russian procurement system is absolutely peculiar and has no foreign equivalent, so making direct comparisons is absolutely impossible...

No number fixed in advance, no IOC and FOC and ABSOLUTELY NO LRIP but Design Bureaus, Aircraft Production Organizations (APO) State Trial and First Serial.
Above all no single decades long omni-comprensive contracts with a single firm covering anything from preliminary design to the rolling out of the last produced item of a certain model if not until the last day of service in the Air Force of the last of said planes but a series of successive contracts made with different legal entities, each one covering just a phase of development (or a productive batch) and
PAYED SEPARATELY one from the other at its own conclusion.
Actually, until the end of the first serial phase, Russian state is only happy if it has to pay more money to their counterparts, not less (because it means that everything in the development has gone smoothly and so production bonus could be awarded).

secretprojects wrote:

The AL-41F (Su-35) is an improved AL-31F akin to the F100-PW-229.

The AL-41F (Su-57) is still just an improved AL-31F, with higher thrust, akin to the F100-PW-232. Its bypass ratio isn't optimal for supercruise, for example.

No, thanking God the Su-35 engine is nothing akin to the PW-229.
That's because the precedent (F-100-)PW-220 got a Bypass ratio: 0.71:1 while the PW-229 has a  bypass ratio of 0.36:1: it means that to get the required performance increase they have to drastically change the internal structure of the engine itself installing a way larger and heavy jet turbine inside without modify the outer part.
Result was that it is way heavier ((1,737 kg instead of 1,467 kg), so in the end its own trust/weight ratio increased only marginally (7,8:1 from 7,4:1) in front to a anything other than ideal bypass ratio.
AL-41F-1S has a larger outer diameter  compared to original model also, so it has not just a way greater thrust to weight ratio compared to it (actually also the Al-31F has a way better one than PW-229) but also a marginally larger bypass ratio leading to a better specific consumption.

The version on Su-57 has an even larger one, equal to the one of the second stage engine but compared to it is longe as it still got the same 4LP/9HP compressor stages of the one on the Su-35.
The engine core  of izdelje 30 would sport a way lover number of stages but they would be wider hence the necessity of a larger overall diameter.
And thank God, although being perfectly capable of get the Su-57 well into such flying regime it would NOT be optimized for supercruise in the sense the F-119 is: it will still remain a turbofan with an healthy bypass ratio, not a "leaky turbojet" in disguise like the one actually propelling the F-22A and incapable to be installed in anything else or even to operate efficiently in any other flying regime than that...

secretprojects wrote:

marcellogo wrote:

No, thanking God the Su-35 engine is nothing akin to the PW-229.
That's because the precedent (F-100-)PW-220 got a Bypass ratio: 0.71:1 while the PW-229 has a  bypass ratio of 0.36:1: it means that to get the required performance increase they have to drastically change the internal structure of the engine itself installing a way larger and heavy jet turbine inside without modify the outer part.
Result was that it is way heavier ((1,737 kg instead of 1,467 kg), so in the end its own trust/weight ratio increased only marginally (7,8:1 from 7,4:1) in front to a anything other than ideal bypass ratio.
AL-41F-1S has a larger outer diameter  compared to original model also, so it has not just a way greater thrust to weight ratio compared to it (actually also the Al-31F has a way better one than PW-229) but also a marginally larger bypass ratio leading to a better specific consumption.

The version on Su-57 has an even larger one, equal to the one of the second stage engine but compared to it is longe as it still got the same 4LP/9HP compressor stages of the one on the Su-35.
The engine core  of izdelje 30 would sport a way lover number of stages but they would be wider hence the necessity of a larger overall diameter.
And thank God, although being perfectly capable of get the Su-57 well into such flying regime it would NOT be optimized for supercruise in the sense the F-119 is: it will still remain a turbofan with an healthy bypass ratio, not a "leaky turbojet" in disguise like the one actually propelling the F-22A and incapable to be installed in anything else or even to operate efficiently in any other flying regime than that...

You are missing the point. The AL-41F is still just a progressively tweaked AL-31F sharing the same basic cycle, stages, etc. Izdeliye 30 is the first 'new' engine.

A low bypass ratio is essential for highest performance in air-to-air combat, especially supersonic, as well as supercruise. The equations for this are pretty clear and were explored during the FX (F-15) era.  That's one reason AL-31F and RD-33 used lower bypass ratios than the F100, being more comparable to the F404 - this increases thrust to weight ratio at the expense of subsonic efficiency. A higher bypass ratio boosts subsonic cruise range. To go forward you need to look at variable bypass technologies to try to combine the best parts of each, which is where the three stream engine work in the US comes in.

kvs wrote:@secretprojects

From what I can tell use of higher temperature turbines is the way to go.  Hence the effort to develop advance ceramic blades and
other components.   All engines are heat engines and increasing the temperature relative to the ambient is the way to increase their
efficiency (in the absence of staging such as used in gas power plants).    A higher temperature turbine can have a reduced size and
still give the same thrust.  

So I supposed that the bypass ratio can be increased in the same engine dimensions.    But design work has to done to be able to
shut down the bypass blades when they are not useful.   I have not heard of such designs so maybe they are not practical.

limb wrote:

kvs wrote:From what I can tell use of higher temperature turbines is the way to go.  Hence the effort to develop advance ceramic blades and
other components.   All engines are heat engines and increasing the temperature relative to the ambient is the way to increase their
efficiency (in the absence of staging such as used in gas power plants).    A higher temperature turbine can have a reduced size and
still give the same thrust.  

So I supposed that the bypass ratio can be increased in the same engine dimensions.    But design work has to done to be able to
shut down the bypass blades when they are not useful.   I have not heard of such designs so maybe they are not practical.

There were constant claims on keypublishing that russia was always behind the US in terms of temperature of their jet engines(comparing the temperatures of the F119 and AL-41F), and that the Izd.30 is allegedly 200-300 degrees celsius cooler than the F135. Of course, since the izd.30 and AL-41FN is classified, I dont know how they came to that conclusion.

marcellogo wrote:

secretprojects wrote:
You are missing the point. The AL-41F is still just a progressively tweaked AL-31F sharing the same basic cycle, stages, etc. Izdeliye 30 is the first 'new' engine.

A low bypass ratio is essential for highest performance in air-to-air combat, especially supersonic, as well as supercruise. The equations for this are pretty clear and were explored during the FX (F-15) era.  That's one reason AL-31F and RD-33 used lower bypass ratios than the F100, being more comparable to the F404 - this increases thrust to weight ratio at the expense of subsonic efficiency. A higher bypass ratio boosts subsonic cruise range. To go forward you need to look at variable bypass technologies to try to combine the best parts of each, which is where the three stream engine work in the US comes in.

And you are missing mine.

Izdeliye 30 would be the new gen one and it would be installed on Su-57 from 2022, it would means that only an handful of Su-57 would have the Al-41, still no need to wait to start production until it would be ready as the two are designed to be swapped also at air base level.
So, probably only one OCU squadron or regiment would be equipped with it and they would be replaced with the definitive one a.s.a.p.

You are saying however something completely false: F-100-PW-229 has a lower bypass ratio (0,34:1 to 0,56:1 and 0:49:1 respectively) of both AL-31F and RD-33 while the Al-41 actually increased such value while adopting a larger engine core.
At the contrary the F404 started with 0,34;1 and F414 lowered this already low value to a meagre 0,25:1.
So actually russian engines has both a way greater thrust to weight than a WAY larger bypass ratio of the PW-229 AND the F404/414, thus completely denying your baseless affirmations.
Between the american engines in the legacy fleet only the F110 retained an high bypass ratio, all the rest have gone down the sinkhole.

New generation ones? F-119 has a bypass ratio of 0,30:1 i.e. between the F404 and the F414 while the F-135 has one of 0,57:1 i.e. practically the same one of Al-31 (0,56) and Al-41 (0,59).
So I guess Saturn get it right from the very beginning.

LMFS wrote:

marcellogo wrote:
And thank God, although being perfectly capable of get the Su-57 well into such flying regime it would NOT be optimized for supercruise in the sense the F-119 is: it will still remain a turbofan with an healthy bypass ratio, not a "leaky turbojet" in disguise like the one actually propelling the F-22A and incapable to be installed in anything else or even to operate efficiently in any other flying regime than that...

Well that is the point, what kind of engine izd. 30 is?

According to Marchukov, it will have BOTH the highest specific thrust AND preserve the fuel consumption of the AL-31F. There are three options as far as I can see it to achieve that:

> Relatively high bypass ratio like the AL-31F, in that case how do they surpass F119's specific thrust, which is simply huge?
> Low bypass ratio like the F119, for supersonic cruise. It has been said many times by official and other serious sources that the izd. 30 is created to be a supersonic cruising engine. But then, how to match AL-31F's SFC?

So these two options demand Russia to be quite significantly ahead (of the F119 at least) in key technological parameters (OPR, TIT) which are VERY difficult to improve, I cannot compare to F135 since it is not a supercruising engine but leaving the F119 that far behind technology wise  would get US planers apoplectic. I wish I could read some expert's opinion on this, but it is also IMHO quite unlikely because of the technological jump they would need to accomplish in so little time.

> My favourite option is that izd. 30 is a continuation of izd. 20 and hence a two-stream VCE. Technology was developed quite a few years ago and improving materials, control and aero design would result in a superior motorization for a proper 5G plane, that is, one that can both supercruise really fast and be economical in subsonic flight. The technological parameters would not need to be so extreme and even maybe below F135 actually but still the superior layout would more than compensate for it.

In any case, US is now forced to move, because only with the few details that have been revealed in the public sphere it seems the F-22 has been kinematically surpassed and of course that means the F-35 will be slaughtered in that regard. How soon they can deploy the adaptive engines will determine for how long they need to live with that new and probably unexpected situation.

kvs wrote:
From what I can tell use of higher temperature turbines is the way to go.  Hence the effort to develop advance ceramic blades and
other components.   All engines are heat engines and increasing the temperature relative to the ambient is the way to increase their
efficiency (in the absence of staging such as used in gas power plants).    A higher temperature turbine can have a reduced size and
still give the same thrust.  

So I supposed that the bypass ratio can be increased in the same engine dimensions.    But design work has to done to be able to
shut down the bypass blades when they are not useful.   I have not heard of such designs so maybe they are not practical.

Progress is pursued in every possible development vector, 3D aero design, temperature tolerance of materials, reduction of weight and number of the stages etc., since a 1% improvement in overall efficiency is already really hard to get. That is why the layout is being so actively explored now, because it is simply the only way double digit percentage gains can be achieved. It will also have many beneficial side effects like reducing drag, improving thermal management and others even crazier like creation of ramjet-type engines based on them.

secretprojects wrote:
The second stage engines will be ready in a couple of years. That is I think the major reason why we didn't see a big order of the Su-57 any sooner.

Welcome, nice to see you here. Reading people like flateric and other knowledgeable guys it seems the program got started, well, because they needed to get it going no matter under what difficult conditions. So probably if they had decided to commission it by 2015 like originally claimed, it would have indeed been a half cooked plane, but probably the results with Su-35S and good progress with the Su-57 and its systems made them switch from low risk approach of minimums to a more ambitious one where they bridge some years with 4++ models while they mature the second stage design with the new engines but also actuators, avionics and probably some other systems



There is nothing better than time to improve technology, so they being able to commission Su-57 later means good savings from not having to buy a very expensive plane earlier, and needing to retrofit way fewer of them to reach second stage. Also less information is revealed to potential rivals, while the platform itself keeps moving relatively fast because all of the new systems being integrated. I find many reasons to praise the overall program management by Sukhoi under difficult conditions and the very wise layout and design philosophy decisions they took early on. The big question mark about the plane is of course the avionics + systems performance that can make the difference between a good plane or an excellent one, but I think the details about them will remain unknown for many years.

[quote="GarryB"]

The interim engines are a weak point, but the phase 2 engines could change things around.

Why do people keep saying that?

The current engines are just fine... I don't remember any American anywhere saying Iranian F-14s are shit because they are F-14As and have pathetic engines that are OK for strike aircraft (F-111s) but shit for fighter planes.

the avionics suite looks interesting if overly complicated.

The Russians tend to use multiple solutions instead of relying on one magic super feature like for instance the US does... so American tanks are 70 tons but not better protected than Russian tanks that are 20 tons lighter but have ERA and APS and SHTORA and Nakidka and all sorts of other technologies they have developed. Equally US fighters have stealth as their most expensive feature... which would be fine if it was 1985, but now the Russians have modern electronics and new radar technology to render it not so effective which makes its enormous cost a joke.

I'm doubtful that Russia has spent enough in R&D to make something completely comparable to the F-22 and F-35, but I don't think that's the intention.

Russia doesn't seem to want an F-22 or F-35 type aircraft... they are more interested in self defence than western experts ever give them credit for.

Even the initial engines have decent performance. I suspect their lifetime is probably not that great though.

It is a stealth fighter, it is not going to be cheap. Getting world record engine life would be a waste of energy and resources... it would be easier and cheaper to make extra engines... they can be installed in S-70s as they get older too.

That is I think the major reason why we didn't see a big order of the Su-57 any sooner.

It is a brand new type of aircraft... there will be no 3,500 aircraft orders for the Su-57 or MiG-35 or Su-35... they don't need such bullshit to hide airframe cost from the people paying the bills.

It reminds me of people who said the USAF chose the YF-22 over the YF-23 because they wanted an aircraft which looked like a stealthy F-15 and the YF-22 was it.

Which makes the F-22 a stealthy MiG-25 really...

That doesn't necessarily mean the sensors will be superior operationally.

Do they need to be?

Su-57 is part of a nation wide IADS and with R-37M missiles and their future replacements it looks ideally suited to take down the HATO IADS based on AWACS and JSTARS platforms...

Do you really think the F-22 having 30km greater radar detection range will make any difference?

Especially when the Su-57 is using an L band wing mounted detection system together with nose mounted higher frequency sets optimised to detect stealth targets and the F-22 doesn't even have IRST.... and is a high flying sniper expecting to shoot down unaware poorly equipped 4th gen planes at max range.

Condescending much? How many aviation books have you published? I'd wager fewer than me, even if I've only written one

Arrogant much... George W Bush has written a book... a childrens pop up book is still a book.

That is I think the major reason why we didn't see a big order of the Su-57 any sooner.

Surely a writer of books would know an order for 76 aircraft IS a big order for Russian aircraft.

The AL-41F is still just a progressively tweaked AL-31F sharing the same basic cycle, stages, etc. Izdeliye 30 is the first 'new' engine.

And you are missing the point... the Al-41F is still a very good engine and certainly good enough for now.

They seem to have managed a useful fuel fraction for the aircraft so it does not need gimmicks like super cruise to make it seem useful.

So, probably only one OCU squadron or regiment would be equipped with it and they would be replaced with the definitive one a.s.a.p.

The older engines removed from the Su-57s already produced with the older engines could be sent to the S-70 factory and installed on those drones...

Amazing how this new member:

1.) Seems to like advertising other forums on this forum, to the point that their username is advertising another forum (a big no no).

2.) Seems to completely derail this thread with off-topic, even off-forum discussion.

3.) Likes to lecture others about breaking rules, but has broken many rules in under 10 posts, and even refuses to read the members section that requires that new members introduce themselves.

thegopnik wrote:Not trying to stir shit but I am more of a distance and range queen when it comes to military aircrafts, I am more interested in fuel efficiency than I am with speed. Example Su-57 with 10,300kg is estimated at 3,500kms while the F-22 is estimated at 18,000 lb (8,200 kg) internally, or 26,000 lb (12,000 kg) with two 2× 600 US gal tanks. But those two fuel tanks give it a 3000km range according to sources I am seeing, and dividing the 8,200 by 12,000 I get .683 times 3000 which I am assuming without tanks the range of the F-22 is like a 2,049km ferry range. I am pretty interested in the design concept of more thrust and better fuel efficiency for the Su-57 2nd stage. I already like the range of the okhotnik-B and Su-57(can wait for new avionics, missiles and engines) since they seem to be more designed on a deep into territory strike level.

Jut just a warning - external fuel tanks cause drag. Therefore the extra fuel doesn't translate proportionally into extra range.

The F-22 was optimised for supersonic range rather than subsonic, and also its internal fuel capacity was reduced somewhat during development due to weight growth. The USAF can always rely on tankers to extend range.

The Russians don't really need to worry about invading other countries so very long range flights will most likely be transfers from one side of the country to the other for which it has an inflight refuelling probe.

External fuel tanks for a stealth aircraft is like bay windows on a submarine...

You have to be careful about measurements as irrelevant measures are of course irrelevant.

You can add range easily by increasing the fuel fraction of any design but such changes impact in other areas... for instance like the Flanker I would think most of the time the Su-57 will not be operating with full fuel tanks... that would reduce manouver performance and most of the time would be redundant.

@Magnumcromagnon You are correct, but we do tend to give a little slack to new members normally.

GarryB wrote:
And you are missing the point... the Al-41F is still a very good engine and certainly good enough for now.

They seem to have managed a useful fuel fraction for the aircraft so it does not need gimmicks like super cruise to make it seem useful.

Supercruise is one of the key parameters of a 5G fighter, according to Russians. Even if the Al-41F1 is quite modern engine with very respectable thrust and very small weight, it will never be able to produce the necessary amount of thrust in mil settings. So it can be a more than good enough engine, just not for a supercruising fighter like Su-57. That does not mean the plane is useless due to that, honestly the only plane that should surpass it is the F-22 which is so scarce and has so little supercruising range that I am not sure it is a huge threat. Eurofighter's 1.4 M should not be that far ahead of what the Su-57 can already do. But to fulfill the plane's inherent design and operational concept it needs the second stage engines.

The older engines removed from the Su-57s already produced with the older engines could be sent to the S-70 factory and installed on those drones...

Maybe, who knows. Modern Russian engines have 4000 operational hours, that is quite a few years, depending on use intensity, I assume the first stage engine is not worst so after a major overhaul it could make sense to use it somewhere. The issue I see is that Okhotnik's engine is a special version without AB and it seems questionable that they would prepare them from AB equipped engines... but they are also saying the rest of the Flankers will get new engines and no detail has been given on whether it will be directly izd. 117 or 117S, as said before to me it would not make sense to prepare the 117's production for just a squadron's worth of them.

thegopnick wrote: I am pretty interested in the design concept of more thrust and better fuel efficiency for the Su-57 2nd stage.

The current ones are actually among the most fuel efficient, from what is said the breakthrough in the second stage is not that much in fuel consumption but in dry thrust, that is where a supercruising engine needs to stand out by a fair margin.

Supercruise is one of the key parameters of a 5G fighter, according to Russians.

Actual stealth is also a key feature according to everyone, yet they make it clear their goals were useful levels of stealth rather than super expensive levels...

Even if the Al-41F1 is quite modern engine with very respectable thrust and very small weight, it will never be able to produce the necessary amount of thrust in mil settings. So it can be a more than good enough engine, just not for a supercruising fighter like Su-57.

The benefits of supercruising are not all cancelled if you have to use AB to get to supersonic and with a very low drag configuration with no external stores I would think the Su-57 should be able to supercruise so some degree... certainly better than any of the Eurocanards which will likely be their main threat... the F-35 is barely supersonic.

That does not mean the plane is useless due to that, honestly the only plane that should surpass it is the F-22 which is so scarce and has so little supercruising range that I am not sure it is a huge threat.

But then a supercruising F-22 would be a gift to any enemy aircraft with an IRST... which in the case of Russia is most of them...

I would suspect it would be more useful for Russian aircraft to tap on AB and climb and accelerate only to launch long range missile attacks...

Eurofighter's 1.4 M should not be that far ahead of what the Su-57 can already do. But to fulfill the plane's inherent design and operational concept it needs the second stage engines.

Supercruising has never actually been used in real combat.... I could see the advantages for a bomber like a Blackjack evading F-35 interceptors because they are just too slow, but for a Russian fighter it would only really be used to increase airspace coverage of the stealthy fighters and I would say making more of them would be a better solution... but the MiGs and Sukhois they are making numbers should not be a huge issue.

The issue I see is that Okhotnik's engine is a special version without AB and it seems questionable that they would prepare them from AB equipped engines... but they are also saying the rest of the Flankers will get new engines and no detail has been given on whether it will be directly izd. 117 or 117S, as said before to me it would not make sense to prepare the 117's production for just a squadron's worth of them.

Depends how you see them using them I guess... if they are going to be flying around all the time with Su-57s then they will get a lot of engine usage, but if they operate one per squadron in training and peace time and keep the rest for combat then used engines with the AB removed (to save weight)... or just not used, could be fitted to the drones that are kept for war time when the operational flight hours are likely not going to be enormous realistically.

They could select the drones with the fewest engine hours left for the most dangerous missions and the suicide missions....

double post