Su-57 Stealth Fighter: News #6

magnumcromagnon wrote: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.

No need IMHO to be so hard,
A pro-american poster could be an amusing addition to this forum, as long as it could produce arguments that make some sense, so we would exercitate ourselves to evaluate their argumentations and debunk them when they hold no ground (i.e, almost always).
Without some of them this would became something similar to F-16 forum, a place of self -complacency and chest beating.
Just similar I say, because I earnestly think that  both Russian than European (and New Zelander also) still keep in their own mindset an healthy dose of self-criticism and distrust of their own state officials to be able to recognise an exaggerate, biased or baseless propaganda claim even when made by their own side.

GarryB wrote: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...

They are saying non-stop the second stage is for supercruising, we know the engine has higher specific thrust than the F119 and the plane (internally called "the needle") has an aero design intended for specially high supersonic performance, with features like adjustable intakes for 2 < M < 3 that do not make sense unless very high speed is a top requirement. It is not a plane for "supercruising" at 1.1 M

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.

We talk about real supercruising with speeds closer to 2 M than to 1 M here, not about cheap PR for planes that want to tick that box in their sales material. This is intended to make real military difference.

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...

We discussed this already, by the time they engage AB some supercruising enemy will have already shot theirs and be disengaging. Maneuvers in air combat are measured in seconds.

thegopnik wrote:OTH radars(The ones I saw claiming to detect and track 5000 aerial targets like cruise missiles)might have a better chance picking up a flying refueling aircraft over an F-22 which might give away the location of the aircraft being near it, send a military aircraft to target the re-fuelers and the price tags I see for them is pretty expensive.

Forget it, they have already said that they saw the F-35 ready to attack Iran from Russia. No need for refuelling planes, they see the VLO fighters directly. Logical, since their stealth does not work on the wavelengths of those radars and much less with the illumination angle they employ.

I think fuel efficiency is what they are striving more for their 2nd stage as a preference than thrust since the Su-57 is not only for air to air roles like the F-22 but also air to ground roles.

We have hard data: the chief designer has said the engine has highest specific thrust all around and has preserved the fuel consumption of the AL-31F.

It is not a plane for "supercruising" at 1.1 M

A plane that can fly at mach 1.1 is going to be uninterceptable by the F-35, and is going to be a real problem for most other aircraft to deal with... the difference between flying Mach 1.1 and Mach 1.8 is not hugely significant... and when it is they can always put on the ABs and fly faster than mach 2 which means faster than F-16s and F-18s and F-35s.

The MiG-31 is already doing this except it is using ABs...

We talk about real supercruising with speeds closer to 2 M than to 1 M here, not about cheap PR for planes that want to tick that box in their sales material. This is intended to make real military difference.

Like it does for the MiG-31 and soon with the MiG-41... ie has the speed to make a difference... despite using more fuel to do so.

We discussed this already, by the time they engage AB some supercruising enemy will have already shot theirs and be disengaging. Maneuvers in air combat are measured in seconds.

The targets they will be launching long range missile attacks will be big and slow like AWACS and inflight refuelling types who wont be able to retire from the battle zone in seconds...

Forget it, they have already said that they saw the F-35 ready to attack Iran from Russia. No need for refuelling planes, they see the VLO fighters directly. Logical, since their stealth does not work on the wavelengths of those radars and much less with the illumination angle they employ.

They already have 100km range Hermes missiles with IIR guidance and two way datalinks... they also have plans to replace the old coasting second stage of that weapon with a ramjet powered missile that can perform high speed terminal manouvers to evade interception on its way to its target... how long before they develop a scramjet powered version for air to air use based on target data from these radars.

The normal problem is that so what... your radar can detect F-35s from another country away... but what are you going to do about it... if you fly a conventional plane up and try to get them with R-73s or R-77s they can try and shoot you down with something similar, but with an IIR guided missile it is passive and can spot stealth fighters... the new model Hermes with a ramjet motor has a 57kg warhead for destroying ground targets... they could easily make that a 10kg warhead designed for bringing down fragile things like aircraft and put another 47kgs of ramjet fuel in there to extend range dramatically...

Come on guys I want him to feel at home here,

He has introduced himself and is following the rules... I would encourage different views on this forum and as you might have worked out I don't really like to ban members... you really have to cross a serious line to get a permaban.

I would say it is easier for new members to get a ban, but you still have to really not listen to the mod or wantonly break the rules.

GarryB wrote:A plane that can fly at mach 1.1 is going to be uninterceptable by the F-35

F-35 is claimed to supercruise faster than that... Eurofighter 1.4 M, Rafale apparently 1.3 M

the difference between flying Mach 1.1 and Mach 1.8 is not hugely significant...

Of course a difference >60% is very relevant. For altitude of flight and for range of launched missiles / range reduction of enemy launched ones.

The targets they will be launching long range missile attacks will be big and slow like AWACS and inflight refuelling types who wont be able to retire from the battle zone in seconds...

There are not only targets in the sky but also opposing fighters, some of which do supercruise.

how long before they develop a scramjet powered version for air to air use based on target data from these radars.

Of course.

The normal problem is that so what... your radar can detect F-35s from another country away... but what are you going to do about it... if you fly a conventional plane up and try to get them with R-73s or R-77s they can try and shoot you down with something similar, but with an IIR guided missile it is passive and can spot stealth fighters...

A radar guided missile is also passive for most of the flight until it reaches within a few km of the target, by then it is too late for evasive maneuvers. A Su-57 guided by Konteyner can position itself and attack a F-35/22 from say 100 km away while unseen and get them with their pants down, depending on things like how powerful their DAS system is, and disengage. The NATO side would need (considering  European theater) to rely on AWACS with low life expectancy. The obvious solution is for NATO to create similarly advanced OTH radars, otherwise I simply don't see how they can compete.

The claim that F-35 was just another of the numerous card shifting claims american producers pu oon to make people support their products.
They say that the F-35 could fly in supercruise at 1.3mach for about 250 km (or miles,i didn't recall) but this was obtained by accelerating to maximum velocity with AF and after slowing down, an EF can instead keep their speed constant.
Same with the claim that if your plane cannot reach supersonic velocity without using afterburner they cannot be classified as "real" supercruise, tht's just something that make no sense: AF are used to pass the sound barrier i.e. transitioning in the transonic speed range with its sudden hike in drag, a modern plane in AF pass this range in less than a minute and after it reach 1.05m drag return normal so they can switch it off, same as it happen with "hot" take offs, so it something really not relevant at all.

F-22 reach such high supercruise numbers because their F119 engines are basically "leaky" turbojets i.e. they sport a very powerful hot section and a very small (and squared) cold one.
In supercruise mode they act as pure turbojets with no added push given by the air flowing through the LP turbine and are able to get to 1.83 (at 20.000mts, obviously) but activating AF the added thrust given by the cold section is relatively small so that the maximum speed is set to 2.25M, inferior to the one of both F-15 and Su-27.
F135 engine retain (about)the same core of F119 but with a larger Fan section and a Bypass Ratio of 0.57 but despite being even more powerful cannot give supercruise to F-35.
Needless to say, in order to get at this F119 engine is something with an horrible fuel efficiency in about all flight regimes...

marcellogo wrote:Same with the claim that if your plane cannot reach supersonic velocity without using afterburner they cannot be classified as "real" supercruise,

That is something the Su-57 can apparently do already with first stage engines. In any case, supercruise in the proper meaning of the term is speed higher than 1.5 M. Anything else lends itself to the kind PR bullshittery you mention since it includes planes in that classification that are worlds apart from F-22.

after it reach 1.05m drag return normal

It is more complex than that and how far the supersonic "bump" extends depends on the specific design of the plane, but I know what you mean.

F-22 reach such high supercruise numbers because their F119 engines are basically "leaky" turbojets i.e. they sport a very powerful hot section and a very small (and squared) cold one.

Well that is what you need for the task so it is ok, if you don't have VCE. The squared cold section has me intrigued, the only thing square there is the nozzle.

Needless to say, in order to get at this F119 engine is something with an horrible fuel efficiency in about all flight regimes...

It is normally estimated at 0.8, which is a good 20% more than the AL-31F. But of course this depends a lot on the flight regime so a supercruising VCE may not be that much better at high speed.

LMFS wrote:It is normally estimated at 0.8, which is a good 20% more than the AL-31F. But of course this depends a lot on the flight regime so a supercruising VCE may not be that much better at high speed.

But who makes the estimates? Lockheed Martin? Lockheed also claims their F-22A's RCS is like .000001 sq/m or something like that, despite the fact we're seeing with higher frequency photos of F-22A's with their RAM coating resembling broken glass, and flakes like a fresh baked croissant. Despite the fact the the F-22A's RAM requires '40' hours of curing/maintenance for  '1' hour of flight time, which suggests those birds would have significantly different RCS beginning, mid, and ending of a sortie. Also think I remember VKS in Syria saying they tracked the entire flights of F-22A's in Syrian skies.

F-35 is claimed to supercruise faster than that... Eurofighter 1.4 M, Rafale apparently 1.3 M

Lots of claims about F-35s... wouldn't believe any of them from US sources...

Of course a difference >60% is very relevant.

Why?

At mach 1.1 you will be pulling away from subsonic aircraft in military thrust, but it doesn't matter whether you are going mach 1,1 or mach 1.8, a non supercruising aircraft can always catch you by using ABs and accelerating faster than you can supercruise at...

Battlespaces are not infinite... the faster you go the faster you reach the edge and have to turn around or you end up in places you don't want to go.

For the Russians leaving their controlled airspace and their IADS means you become vulnerable.

For altitude of flight and for range of launched missiles / range reduction of enemy launched ones.

Altitude would have more effect on that... and if you intended to launch a weapon you could easily go from 100 dry thrust to full AB to climb and accelerate to boost the weapons performance and then go back to dry thrust and slow down to what ever speed you slow down to.

There are not only targets in the sky but also opposing fighters, some of which do supercruise.

A super cruising target should be an easier IR target than a subsonic one... despite not having a huge AB plume out the back zipping around at medium to high altitude at mach speeds makes you stand out as something needing to be dealt with.

It is normally estimated at 0.8, which is a good 20% more than the AL-31F. But of course this depends a lot on the flight regime so a supercruising VCE may not be that much better at high speed.

Which is enormous because it is a more powerful engine and fuel burn is based on thrust generated so an engine generating twice as much thrust even with the same fuel efficiency burns twice as much fuel... which is further compounded by the fact that most planes with Al-31s carry a lot of fuel...

magnumcromagnon wrote:But who makes the estimates? Lockheed Martin?

People with experience on jet fighter engines. In any way it is not a very optimistic estimation I would say, and I have not seen it being disputed strongly. The engine should have better OPR and TIT than any AL-31F family engine so it should not be inefficient at all, considering the low BPR.

Lockheed also claims their F-22A's RCS is like .000001 sq/m or something like that, despite the fact we're seeing with higher frequency photos of F-22A's with their RAM coating resembling broken glass, and flakes like a fresh baked croissant. Despite the fact the the F-22A's RAM requires '40' hours of curing/maintenance for  '1' hour of flight time, which suggests those birds would have significantly different RCS beginning, mid, and ending of a sortie. Also think I remember VKS in Syria saying they tracked the entire flights of F-22A's in Syrian skies.

I have no problem admitting it is probably very stealthy and a very fine piece of engineering, the same it seems to be a massive pain in the ass to operate. We even had a "cold warrior" here acknowledging the plane is a flying experiment, what more should I say? In US essentially everything is a sales pitch, we must always account for that.

GarryB wrote:At mach 1.1 you will be pulling away from subsonic aircraft in military thrust, but it doesn't matter whether you are going mach 1,1 or mach 1.8, a non supercruising aircraft can always catch you by using ABs and accelerating faster than you can supercruise at..

You seem to refuse to understand it takes a while to reach high speeds in AB, since acceleration is logarithmic, so by the time you cross sound barrier and get to Mach 2 the aggressor is gone.

Altitude would have more effect on that... and if you intended to launch a weapon you could easily go from 100 dry thrust to full AB to climb and accelerate to boost the weapons performance and then go back to dry thrust and slow down to what ever speed you slow down to.

So high level experts in Russia, Europe and US establishing the need for supercruise have no clue, is this what you are saying?

A super cruising target should be an easier IR target than a subsonic one... despite not having a huge AB plume out the back zipping around at medium to high altitude at mach speeds makes you stand out as something needing to be dealt with.

Bad luck for Russia, time to dump the Su-57 and go back to the drawing board

Which is enormous because it is a more powerful engine and fuel burn is based on thrust generated so an engine generating twice as much thrust even with the same fuel efficiency burns twice as much fuel... which is further compounded by the fact that most planes with Al-31s carry a lot of fuel...

And still they insist on supercruising, it tells you all you need to know about its usefulness.

Seen this. Had to post it. Considering all they do at F-16.net is endlessly bash the su 57.

Backman wrote:Seen this. Had to post it. Considering all they do at F-16.net is endlessly bash the su 57.

In all honesty several of those claims cannot be backed with hard data since there are no official figures for the Su-57.

Arrow wrote:Su-57 in most parameters exceeds the F-35. It is also better than the F-22. Currently, Russia is the largest technological power in military aviation.

Su-57 is definitely better than the F-22A because it has plasma ignition, meanwhile F-22A literally sucks the air out the room. USAF pilots are trained not to choke under pressure, but F-22A's make them choke anyway.

Why is some US jet from the 1980s considered timeless in terms of technological and performance characteristics. That
sort of thinking is just inane. The Su-57 was designed and built a good 20 years later than the F-22.

In one of the posts the issue of computers for design came up. Even Cray supercomputers from the 1980s are trash
compared to scalar machines from the early 2000s. The progression of computing technology is perfectly reflected
in stealth aircraft design. The F-117A was a blocky POS because they could not handle curved surface computations
on the Mickey Mouse mainframes of the 1960s and 1970s. They also likely did not even fully understand the Soviet
manual on stealth which was the basis of their whole effort. By the time the F-22 was designed the computing
power and simulation software was more evolved (software is just as important if not more than hardware). The
ignorant pinhead fanboi haters of the Su-57 simply do not understand that the "non-stealth" choices in the F-57 are
reflecting superior stealth design. It is the whole frame that matters and not just some elements that loser fanbois
can hold in their tiny brains.

Sukhoi put the effort in to retain jet fighter performance with stealth without having to choose one over the other
as was the case with the F-117A.

LMFS wrote:

Backman wrote:Seen this. Had to post it. Considering all they do at F-16.net is endlessly bash the su 57.

In all honesty several of those claims cannot be backed with hard data since there are no official figures for the Su-57.

There is some of the data out there. But if you take the su 35's data and then extrapolate that the su 57 is lighter, smaller and more powerful, with better kinimatics, then you can start to make some assumptions about the performance vs the F-35

Backman wrote:There is some of the data out there. But if you take the su 35's data and then extrapolate that the su 57 is lighter, smaller and more powerful, with better kinimatics, then you can start to make some assumptions about the performance vs the F-35

We don't really have the weight of the plane. VLO design is heavy in general. I can personally agree on some assumptions but I would not turn them into dogma because we might be wrong. Who would say that a plane with same size as F-15, the F-22, weights 7 tons more, empty?

My take, based on evidence I consider solid:

> STOL performance: yes, confirmed by designers and plane spec., F-35 does not have that.
> Rate of climb: not known but for some claimed data (384 m/s IIRC) which I don't know if were official
> Service ceiling: unknown but likely higher than F-35
> Acceleration: subsonic is not so clear, F-35 is claimed to accelerate faster in that regime than Su-35 and the numbers look good, its very powerful engine and smallish wing area with little sweep help there. Su-57 has a bit more power than Su-35 but the verdict ultimately depends on weight and drag, which we cannot calculate accurately. Supersonic: I really hope the Su-57 is not as bad as the F-35, which sucks in that regard.
> Turn rates: we have not seen the Su-57 being flown as hard as the Su-35 for instance, for this I think we have at least solid values on ITR from airshows. The Americans came up with their "Dojo's drift" BS maneuver by which they accelerate the plane and then pull the stick as hard as it gets and then some more... and still the turn rate is like half, at best, of what we have seen the Su-35 doing on some isolated occasions. STR is not really known
> Post-stall: the F-35 has this capability too, despite US mocking Russians for developing it in the first place. Obviously with fewer control surfaces and without TVC it cannot compete in that regard.
> Supercruise: current capability is unclear, as there are claims about the F-35 too.
> Range/ endurance: Su-57 should have the range of the Flanker, all being normal. But the plane is a bit smaller in some dimensions, there are different opinions as to whether it has the same fuel. The F-35 is not bad in that regard, ca. 2800 km on internal fuel is quite nice for a plane its size. It almost matches Su-30/33
> 8+ t claimed for the F-35, actually more than a Su-35 or even Su-34. It will probably need more runway than a transport plane to take off in those conditions, but that is what they say. Internal capacity: the Su-57 wins hands-down.

Also, many of those values depend on the engine so the second stage should be way ahead of the current planes.

LMFS wrote:

Backman wrote:There is some of the data out there. But if you take the su 35's data and then extrapolate that the su 57 is lighter, smaller and more powerful, with better kinimatics, then you can start to make some assumptions about the performance vs the F-35

We don't really have the weight of the plane. VLO design is heavy in general. I can personally agree on some assumptions but I would not turn them into dogma because we might be wrong. Who would say that a plane with same size as F-15, the F-22, weights 7 tons more, empty?

My take, based on evidence I consider solid:

> STOL performance: yes, confirmed by designers and plane spec., F-35 does not have that.
> Rate of climb: not known but for some claimed data (384 m/s IIRC) which I don't know if were official
> Service ceiling: unknown but likely higher than F-35
> Acceleration: subsonic is not so clear, F-35 is claimed to accelerate faster in that regime than Su-35 and the numbers look good, its very powerful engine and smallish wing area with little sweep help there. Su-57 has a bit more power than Su-35 but the verdict ultimately depends on weight and drag, which we cannot calculate accurately. Supersonic: I really hope the Su-57 is not as bad as the F-35, which sucks in that regard.
> Turn rates: we have not seen the Su-57 being flown as hard as the Su-35 for instance, for this I think we have at least solid values on ITR from airshows. The Americans came up with their "Dojo's drift" BS maneuver by which they accelerate the plane and then pull the stick as hard as it gets and then some more... and still the turn rate is like half, at best, of what we have seen the Su-35 doing on some isolated occasions. STR is not really known
> Post-stall: the F-35 has this capability too, despite US mocking Russians for developing it in the first place. Obviously with fewer control surfaces and without TVC it cannot compete in that regard.
> Supercruise: current capability is unclear, as there are claims about the F-35 too.
> Range/ endurance: Su-57 should have the range of the Flanker, all being normal. But the plane is a bit smaller in some dimensions, there are different opinions as to whether it has the same fuel. The F-35 is not bad in that regard, ca. 2800 km on internal fuel is quite nice for a plane its size. It almost matches Su-30/33
> 8+ t claimed for the F-35, actually more than a Su-35 or even Su-34. It will probably need more runway than a transport plane to take off in those conditions, but that is what they say. Internal capacity: the Su-57 wins hands-down.

Also, many of those values depend on the engine so the second stage should be way ahead of the current planes.

Good points.

A couple things though. On weight, the su 57 is a clear winner vs the su 35. the su 57 uses more composite material. The vertical stabilizers are mostly composite. They are tiny as well.

And I also think that the LEVCON's and the all-moving verticals haven't been close to exploited, air performance wise by the pilots. Once the pilots get acquainted with the su 57, there's no reason to think that it wont do everything that the su 35 does except better plus some new tricks up its sleeve.

The list that the picture i posted was made by a F-16 .net poster by the name of Fastestbird. He made the point in the F-35 vs Pak fa thread. Its a good long thread with many good points made in it. Fastestbird made the list 3/4 of the way down this page. Edit aw i cant post links yet On the 7 day probation period. Just add the www and paste it  http://.f-16.net/forum/viewtopic.php?f=55&t=21808&sid=1215022957e56a0976f9d01f896aa832&start=1125

He also posted 2 videos which he uses to try and prove some of the points about the performance of the jets. Its worth a look.

Some of Fastestbirds evidence for his claims

Here you can see PAK FA chief test pilot comparing PAK FA with Su-35S.
Su-35S is drastically upgraded Su-27. Far more maneuverable, with better thrust to weight ratio, TVC engines etc. He said that the acceleration on that plane is great. For example, when we look at the official data, Su-35S has 8% better acceleration time than base Su-27 from 600 to 1100km/h while at the same time having 1050kg of fuel more (Su-35S-5750kg vs Su-27-4700kg).

In contrast to Su-35S, PAK FA has more powerful engines, better T/W ratio, greater wing surface/lower wing loading, better acceleration/climb rate, better turning characteristics, in essence significantly better than Su-35S according to test pilot Сергей Богдан.
And all that using interim engines. Final version of the engine will have 15 to 25% higher thrust, lower specific fuel consumption and about 30% lower specific weight according to manufacturer.

Regarding climb rate and subsonic/transonic/supersonic acceleration.

Is there any chance that plane (F-35) with lower T/W ratio, higher wing loading, worse L/D ratio, fixed intakes, can perform better than the plane (PAK FA) with superior characteristics in that field?
I don`t think so.

PAK FA is F-22 class fighter that is designed to fly very high and fast (did I mentioned that variable intakes help a lot). It is also designed to supercruise at speeds that are probably higher than F-35 top speed, it is designed to "live" there for a long period of time. There is great SEP reserve compared to F-35 in supersonic region when PAK FA is using burners. When F-35 has no more SEP at 1,6 Mach, PAK FA continues accelerating to +2 Mach. This is clear indication of superior transonic/supersonic acceleration.

Regarding maneuverability.

F-35 is often compared to clean F-16 block 50 regarding agility/maneuverability. Pilots like USAF Lt Col Lee Kloos are saying that F-35's acceleration is "very comparable" to a Block 50 F-16 and it probably is, but mostly in subsonic region. The F-16, Kloos says, is a very capable aircraft in a within visual range engagement--especially in the lightly loaded air-to-air configuration used during training sorties at home station. "It's really good at performing in that kind of configuration," Kloos says. "But that's not a configuration that I've ever--I've been in a lot of different deployments--and those are the configurations I've never been in with weapons onboard."
So that’s certainly not the configuration by which the two aircraft should be compared. It is an apples to oranges comparison. Instead, it is a much better comparison with the usual configurations Kloos and other F-16 pilots used in combat. And in that configuration, per Kloos, the F-35 outperforms the F-16.

In other words F-16 block 50 would be very dangerous for F-35 in guns only scenario. Start putting some missiles and F-35 takes the advantage. And I do agree. That is absolutely more realistic scenario! The problem here is we are not comparing F-35 to F-16, we are comparing F-35 to PAK FA.

For the argument sake, let say that F-35 can mach F-16 block 50 in turning game with guns only.
We know that the PAK FA is much more capable plane than basic Su-27 and upgraded Su-35S.
Now let`s compare base Su-27 and F-16 block 50.

Flight manual data - Sea level, 50% of fuel:

F-16 block 50 has 24,8°/s ITR and 21,5°/s STR
Su-27 has 30,2°/s ITR and 21,75°/s STR

We can see that Su-27 has the edge and at the same time has greater range (it has better fuel fraction). In order to have the same range as F-16, Su-27 would need about 38% of fuel. In that case Su-27 would have about 32,4°/s ITR and 22,7°/s STR.
Start putting weapons on both planes and F-16 suffers even more because for the same amount of payload smaller plane will have proportionally higher increase in wing loading and drag.

How does F-35 compare to PAK FA with all the things above in mind?
Not good!
As we already know PAK FA is superior to Su-27 and we can see that Su-27 is superior to F-16 block 50.
Again, start putting weapons on F-35 and PAK FA and the gap between the two widens. The smaller plane with worse wing loading suffers even more with the same amount of payload and at height.
When talking about nose pointing/supermaneuverability there is no contest!

Backman wrote:On weight, the su 57 is a clear winner vs the su 35. the su 57 uses more composite material. The vertical stabilizers are mostly composite. They are tiny as well.

I don't have certainty to say that myself. What you say is right, on the other hand the bays are very heavy, because they imply a lot of extra volume, material and mechanisms, plus the need for serious reinforcements to compensate for the empty space created which structural members cannot cross. RAM/RAS is also heavy. The plane has a way bigger lifting area. Estimations by now have it that it should weight practically the same than the Su-35 and I find it reasonable. But depending on how good or bad solutions the Sukhoi guys found, it may be much less or much more. If you notice, almost everyone thinking about 5G is using the compact, conventional and low risk layout used by LM on the F-22, not the more ambitious and risky one on the Su-57. It was challenging to the point it demanded a second version of the structure that appeared in 2016-2016 IIRC. That is what innovation means, not everyone is willing to take the risks it implies. So they may be much better than we think, but I don't it is fair expecting that.

And I also think that the LEVCON's and the all-moving verticals haven't been close to exploited, air performance wise by the pilots. Once the pilots get acquainted with the su 57, there's no reason to think that it wont do everything that the su 35 does except better plus some new tricks up its sleeve.

Yes, I also don't think they have the slightest interest in showing the US (and others) what is the limit of the plane so they can design their answers to it with total certainty, that would be very dumb. I don't see any reason why the plane should be less manoeuvrable than the Su-35, probably the wings are worse generating lift but the LEVCONs, huge lifting body and further aero refinements should more than compensate for that. I have the impression the plane moves like a feather, as if it was weightless. It takes off very easily too, I assume it generates a lot of lift.

Some of Fastestbirds evidence for his claims

Interesting, I will check that later

@Backman:

in general the argumentation seems well built, my main comment is that there are some assertions for which I have not seen evidence.

Backman wrote:In contrast to Su-35S, PAK FA has more powerful engines, better T/W ratio, greater wing surface/lower wing loading, better acceleration/climb rate, better turning characteristics, in essence significantly better than Su-35S according to test pilot Сергей Богдан.

This is the key point, where did he say that, I have personally not seen it. Engines are more powerful, Bogdan even said one needs to be careful with the plane because you can go supersonic before you notice... but I don't know how it is with the Su-35, in any case it sounded as if he was surprised by it and so a substantial improvement vs. Su-35S, but that is only an opinion.

Again, weight unknown, so is T/W so wing loading, acceleration. I have not seen Bogdan saying the Su-57 is more manoeuvrable than the Su-35, do you have links?

And all that using interim engines. Final version of the engine will have 15 to 25% higher thrust, lower specific fuel consumption and about 30% lower specific weight according to manufacturer.

Manufacturer has said that? Would love to see it.

15-25% higher thrust could be meant in mil settings, since it is supposed to be a supercruising engine, but maybe not in AB, since that would mean between 17 and 19 tf (!) for an engine the size of AL-31F. Marchukov said SFC was that of AL-31F. I have not seen that reference of 30% lower specific weight and I find it difficult to believe, izd. 117 is already below 0.1 (TWR for the engine would be above 14!)

PAK FA is F-22 class fighter that is designed to fly very high and fast (did I mentioned that variable intakes help a lot). It is also designed to supercruise at speeds that are probably higher than F-35 top speed, it is designed to "live" there for a long period of time. There is great SEP reserve compared to F-35 in supersonic region when PAK FA is using burners. When F-35 has no more SEP at 1,6 Mach, PAK FA continues accelerating to +2 Mach. This is clear indication of superior transonic/supersonic acceleration.

This is hard to dispute. The AIAA paper studying the EM characteristics of the F-35 shows very poor supersonic performance, which is something almost everybody suspected regardless. The designer and services have admitted supersonic flight regime is not the main goal of the F-35, whereas in the Su-57 this is one of the main priorities. I can only expect it to be head, shoulders and waist above the F-35 in that regard, more when the izd. 30 appears. BTW, the F-35 has still excess power at 1.6 M, but apparently not much.

In other words F-16 block 50 would be very dangerous for F-35 in guns only scenario. Start putting some missiles and F-35 takes the advantage. And I do agree. That is absolutely more realistic scenario! The problem here is we are not comparing F-35 to F-16, we are comparing F-35 to PAK FA.

Here the only advantage of the F-35 is having a monster engine. The F-16 with such an engine would utterly crush the  F-35...

As we already know PAK FA is superior to Su-27 and we can see that Su-27 is superior to F-16 block 50.

The comparison with the Flanker is very well built, but the translation to the PAK-FA is a bit of a leap of faith, since we don't know how much better (or not) the plane is in all flight regimes compared to Su-35. Not that I remotely think the F-35 would fare very well, but a quantitative comparison is still not possible.

kvs wrote:The
ignorant pinhead fanboi haters of the Su-57 simply do not understand that the "non-stealth" choices in the F-57 are
reflecting superior stealth design.

I like that new aircraft the F-57. What's even better is that if you add the F-22 and the F-35, you get the F-57 or should I say, the Su-57?

Hoping the final RAM coating will be a dark and intimidating color like when they experimented with it on 05.

Fastestbird also had some notes on the levcons which are interesting

Now, according to Sukhoi chief test pilot PAK FA has much better turn performance, acceleration, climb rate etc. than clean Su-27 and Su-35S. Sukhoi engineers worked very hard on PAK FA to achieve better aerodynamic efficiency, lower wing loading and higher T/W ratio.

The thing that stands out beside TVC are LEVCON`s.

LEVCON`s are automatically trimmed to give optimal lift-to-drag (L/D) ratios for all Cg positions, Mach number and AOA. They can also increase AoA (generating more lift in front of Cg) during take off and can be used asymmetrically at extremely high AoA`s for directional control. In the case of TVC malfunction they can be used for pitch/yaw control at extremely high AoA.

They can also increase instantaneous turn rate not just by providing optimal lift-to-drag conditions but also by delaying wing stall.
LEVCON can also be observed as moving part in front of the LERX. LERX generates a vortex that attaches to the top of the wing. The vortex action maintains a smooth airflow over the wing surface well past the normal stall point at which the airflow would otherwise break up. At some critical AoA point vortex eventually bursts and stall occurs.
Deflecting LEVCON`s are "feeding" LERX with a smooth airflow well beyond vortex burst point. That way the plane can increase AoA even more without stall and can generate more lift.



That can be observed nicely here at 8:45 sec. of the video where PAK FA is doing high AoA loop. We can see extremely powerful vortex formation at very high angle of attack. In similar conditions Su-27 would stall its wings because of vortex burst.

The "LEVCONS" in Su-57 are simply LE flaps for the body lifting surface, they are scheduled, for what I have seen, absolutely the same way that LE flaps on the wings. So they allow to increase AoA without airflow detaching and that is very important when the lifting surface outside of the wings is so big as in the Su-57. They don't deflect upwards like canards would do to pitch the nose upwards, some people get confused by this.

The effect of the LERX seems less pronounced in Su-57 than in other planes like Flanker itself, vortexes always generate drag so that may be a good thing, if the manage to keep the airflow attached more with the LEVCONS and less with LERX turbulence.