Su-57 Stealth Fighter: News #6

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.

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

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

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

thegopnik wrote:

Since I do not take frontal RCS value as the entire value of an aircraft I am starting to think that 5th gens will get reduced to 4th gen aircrafts in terms of tracking to point it is useless that you might as well switch back to 4th gens if they will get tracked the same way and newer air defenses like the S-500 .

LMFS wrote:@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.

thegopnik wrote:Since I do not take frontal RCS value as the entire value of an aircraft I am starting to think that 5th gens will get reduced to 4th gen aircrafts in terms of tracking to point it is useless that you might as well switch back to 4th gens if they will get tracked the same way and newer air defenses like the S-500 will over the horizon strike capabilities engaging aerial targets. I believe it is a better strategic advantage that there air force would cooperate with their air defenses if adversaries dive deep into territory and the Su-57 with the Okhotnik when doing strategic missions can go deep into any territory outside of Russia without the need of refueling aircrafts identifying their locations as well.

Backman wrote:Mystery solved This is just a scale model though

thegopnik wrote:To my own amusement I feel like Russia is competing more in terms of next gen radars and next gen stealth against Italy rather than the U.S. Italy made some big headlines with the PHODIR project or their photonic radar but could not get it to exceed performance specs of a conventional radar but it seems Russia did based on 3 of their companies. Than of course comes this stealth transparency metamaterial which both russia and italy took a part in so I wonder which countries will bribe them for it as a possibility. Photonic radar on su-57 is questionable, but the metamaterial for outside structure is a little more doubtful because it seems to be a physical material and they cannot make any physical appearance altercations with the 2nd Su-57 variant but they said they can put this material around their antennas or other electronics (so there is some hope) to not only stealth it but improve its performance if I read that article right. It would be amazing if the metamaterial and photonic integrated circuits are on the 2nd su-57 variant but if they are not I hope they will push it towards a 6th gen, which based on speed estimates and height claims make lower altitude aircrafts impossible to reach with air to air missiles and maintaining a radar fix on because they have shown projects that they are serious in this field as well..... more or less I think the purpose of the f-35 is just to raid 3rd world countries and not something to put a huge investment on for the future for many reasons shown on this board time and time again.

Stealthflanker wrote:

Well the patent for Su-57 Sidebays is already around for several years.

https://findpatent.ru/patent/261/2614871.html

Stealthflanker wrote:
It's kinda weird tho to see people keep speculating about the purpose of the canoe shaped side bay or how the missile is deployed, while the patent for it already around, free to download and straight to the point.

LMFS wrote:@GarryB:

Nobody is saying Russia is going to disappear from the map if they operate a squadron Su-57 for a few years without the second stage capabilities, for the same reason they don't rely 100% on Konteyner and such assets and so can do without supercruise or air force altogether: they never put all their eggs in the same basket and make sure every single element of the force is as capable and self reliant as possible. So, of course the plane is intended for supercruise and arguing how you don't actually need it is a moot point, since all air forces aim for it and VKS in particular has been explicit about it.

LMFS wrote:

It is not clear what engine he is referring, first or second stage, but on the other side he seems to be either taken out of context or blatantly wrong:

LMFS wrote:
“None of the aircraft has ever been able to ensure that at cruising supersonic speeds (1600 kilometers per hour) it was possible to fly in non-afterburner mode. Nobody in the world has achieved this yet - neither France, nor England, nor Rolls-Royce, nor Pratt & Whitney - nobody, "Tolboyev stressed.

15 years after commissioning of the F-22 I don't think it needs explanation that such claim, without further context, is false. This quotes in the media are frequently misleading so it is good to use them carefully.

LMFS wrote:“None of the aircraft has ever been able to ensure that at cruising supersonic speeds (1600 kilometers per hour) it was possible to fly in non-afterburner mode. Nobody in the world has achieved this yet - neither France, nor England, nor Rolls-Royce, nor Pratt & Whitney - nobody, "Tolboyev stressed.

15 years after commissioning of the F-22 I don't think it needs explanation that such claim, without further context, is false. This quotes in the media are frequently misleading so it is good to use them carefully.

LMFS wrote:
I am reading 30.6.2018, that is half a year after the flight testing of the izd. 30 had started...

Most of my disagreements are in the access panel itself. If it's hinged at the V of the bay, then it needs to have some pretty solid hinges that not only open and close it but are capable of holding the panel from being ripped off the bay with all the airspeed happening at the time. I would think that is a legitimate point, no? So far I haven't seen anything in the patent that shows where the panel opens or is hinged, just that there is a missile in there and that it has a trapeze mechanism that allows the missile to protrude head first at an angle of between 20 to 70 degrees to the plain of the fuselage? I think that's how it's worded. So I'm just trying to find out more info that convinces me, that's all.

Also if an F-22 is supercruising at 1.8M, could it be possible that the airframe is heated enough from air friction for Russian OLS-35 IRST to detect it at over 100km? AFAIK, there is physically no way to reduce heat signature of an airframe at supersonic speeds, even with whatever composite materials americans put on their fighters.

Of course high speed creates more aerodynamic heating, the idea with those kinematically superior planes is that, weapons being equal and even if you can see them, they can shoot you down while staying out of the range of your missiles. To improve performance in IR you would need highly thermally conductive materials to spread the heat all over the airframe and coat with materials of low emissivity, but of course a very hot fuselage is still going to be more visible than a colder one.

Su-57 can supercruise with AL-41 at the speed of 1600km/h, which is about 1.5Mach.

kvs wrote:The F-22 supercruises at 1.5M and not 1.8M.   Where did the 1.8M number come from?