Sukhoi Su-57 flight testing, development & operations [2012-current]

[flateric]

That said, while the Su-57 is among the first operational aircraft to employ LEVCON, the concept isn't new and several General Dynamics ATF proposals in the 1980s had them too.

Much earlier https://www.secretprojects.co.uk/th...nt-of-the-saab-jas-39-gripen.1161/post-246536
There were proposals even earlier than SAAB I guess.

 

[Saber]

101KS-O provide DIRCM-functionality only. You confusing it with 101KS-U which is combine IRST and DAS functions.

Was under the impression that 101KS-O does have imaging function, in any case T-50-11 was photographed with a new MAWS sensor with four apertures, could have very well changed from the UV sensors.

Why not? It has three-band sensors. Part of the functionality, ok.

This is something I haven't seen before, I read Paralay's forum, I don't remember seeing something like this described. Could you show us?

 

[Elysium]

I don't know where the idea of the upper edge of the F-22s intake not being a 'true' LEX comes from - the Su-57's wing was designed to work in conjunction with a LEX, and the Su-75, which shares the same wing, has a similar sharp intake edge instead of a dedicated LEX+LEVCON.

 

[Null]

For a guy that took interests in aircrafts, I find it nerve wracking always boarding a passenger plane even more so when lifting off or expecting turbulence, hate to even look outside the window of a plane knowing how high you're in the air. It's the kind of fear you wish would go away no different from your dog when he hears a thunderstorm or fireworks. Because of it I worship any kind of pilot as some kind of god. Thats why it infuriates me hearing crash reports of any kind of military aircraft even if the pilot is safe parachuting. The priority of safety and survivability should also be discussed 1st before stealth or aerodynamic performance of any aircraft, sadly not enough of that.

 

[F-14ATomcat]

Indeed. Also, the LEVCON serves another purpose on the Su-57. By deflecting sharply downwards, its planform area can be reduced which would shift the aerodynamic center aft to aid with stall recovery. This certainly isn’t the only method for stall recovery, but the potential benefit is that this allows a reduction in tail volume to decrease weight.

That said, while the Su-57 is among the first operational aircraft to employ LEVCON, the concept isn't new and several General Dynamics ATF proposals in the 1980s had them too.

https://www.secretprojects.co.uk/threads/general-dynamics-ats-pre-atf-and-atf-designs.416/page-2#post-102161

Canards do the same, on Su-27M the LEX-Canard system moved the vortex breakdown point, thus the center of lift and hysteresis allowed the Su-27M without Thrust vectoring to do many maneuvers at poststall.

Since it was a triplane, the aft tail permitted recovery of the Su-27M from 120 AoA degree maneuvers.

However canards do have issues too, downwash on the wing killing lift, so the LEVCON on Su-57 is doing what Su-37 can do, but stealthier, thrust vectoring allowed reduction of the tail size and the LEVCON a control surface on the same wing, this enhanced planforming and drag.

To be honest Su-57 in aerodynamics is a very complex machine, in terms of aerodynamics is the best one for me, better than all 5th generation aircraft.

Su-57 intake in my opinion has even a better intake design than X-32 , definitively in my humble opinion Sukhoi made a master work

 

[TMA1]

Yeah the intake is my favorite aspect of the whole su-75 design. The body holding the cockpit, seat and canopy blends in as part of the dsi intake. And to me the intake itself isn't a mouth-like scoop (a la f-16) as much as it looks like stealthy side intakes fused together as one in a hemisphere around the nose of the aircraft. So cool. Probably said a lot of incorrect stuff but in short there is a reason why I grew to love sukhoi and and the su-57 and su-75 in particular.

 

[RadicalDisconnect]

Regarding LERX, here is a Society of Experimental Test Pilot paper on the development of LERX for potential application on Eurofighter Typhoon, and guess what they included the F-22 LERX as an example.

There was simply not point in this ridiculous pissing contest that became nationalist chest pounding. It’s one thing to appreciate the aerodynamic performance of Su-57, but it’s getting ridiculous when some are pushing it as a perfect aircraft that makes no tradeoffs.

Edit - nvm the AB TVC maneuver video/gif was already posted.
On topic of engines though, one thing noticed on nozzle for izd.177 which is likely same current nozzle as izd.30 other than flat nozzle, is the cooling channel at end of the petals. The flat nozzle has the same kind of cooling at the end of the flaps, but it doesn’t look like the inner surface of the flaps have cooling holes. This seems to be the opposite approach of F119 where the inside of the flaps have small cooling holes but the end of the flaps don’t.

 

[Trident]

Good point, film vs. convection cooling?

 

[Ainen]

With su-57 layout, it's curious how Soviet Union first firmly embraced fbw and went towards traditional fuselage/canards away from blends (basically all new Soviet 4.5 gens, including different sukhoi prototypes and projects).

But then, after the collapse, Russia reversed back to arcane aerodynamic arts in su-57.

Su-75, again, has a proper, tall, full length fuselage.

 

[LMFS]

There was simply not point in this ridiculous pissing contest that became nationalist chest pounding. It’s one thing to appreciate the aerodynamic performance of Su-57, but it’s getting ridiculous when some are pushing it as a perfect aircraft that makes no tradeoffs.

Nobody is saying there are no tradeoffs to any design. What comes across as bizarre background to the discussion is the need to apply constant "but but but" remarks to the plane, instead of just appreciating its achievements. The lack of neutrality is not just somebody else's problem you know...

 

[Scorpion82]

WHAT THE HELL HAS THIS DISCUSSION TO DO WITH THE SU-57!!!???

 

[overscan (PaulMM)]

Topic closed for fumigation.

 

[overscan (PaulMM)]

Had a big cull of off-topic posts, too many to send individual notifications. Let me know any bad posts I missed.

Topic open again. Try posting about the Su-57, and keep the facts-to-wild-theorising ration high.

 

[Squirrel]

101KS-O provide DIRCM-functionality only. You confusing it with 101KS-U which is combine IRST and DAS functions.

101KS-O ( Oborona or defence) has rotatable IRST.

101КС-О (оборонительный внешний модуль) - система противодействия ракетам с инфракрасными головками самонаведения - лазером подавления. Возможности системы аналогичны 101КС-В + ослепление атакующих ракет.

https://twitter.com/x/status/1170269874272124928

View: https://x.com/vkthakur/status/1170269874272124928


101KS-U is only UV band MAWS.

101КС-У (ультрафиолетовый внешний модуль) - всеракурсная система обзора в ультрафиолетовом спектре, служит для обнаружения и определения координат реактивных двигателей (самолётов и ракет) в УФ-спектре и для выдачи ЦУ 101КС-О.

I suppose that IRST is working in MWIR band and the question is which wavelength use 101KS-U modules.

 

[Squirrel]

Was under the impression that 101KS-O does have imaging function, in any case T-50-11 was photographed with a new MAWS sensor with four apertures, could have very well changed from the UV sensors.


This is something I haven't seen before, I read Paralay's forum, I don't remember seeing something like this described. Could you show us?

T-50-11 is a prototype of the Su-57M and had first test flight on Oct. 21 2022. This is the video where we can see that new MAWS besides the cockpit. I can't see MAWS below the cockpit. From 2:00 we can see that MAWS is pretty big.

View: https://www.youtube.com/watch?v=PCBkblEIKac

 

[Acatomic]

From the interview with test pilot Sergei Bogdan:

When I first lifted the Su-57 into the air in Komsomolsk-on-Amur — it was then still called the T-50 — vibrations appeared on the plane after the engine started. I turned off the engine, and the flight was postponed.
The machine was rolled into the hangar for diagnostics and the hydraulics were connected to check the operation of the hydraulic drives of the control system - the plane was standing, shaking. When no one was nearby, I went up to it, stroked it and said: "Don't be afraid, everything will be fine"

What, in your opinion, should a Russian sixth-generation fighter be like?
— It must meet the increased modern requirements. And of course, there is work to be done in terms of reducing visibility, and in all ranges. This is achieved by using certain materials and design layouts. I also think that it should have a power plant with significantly improved characteristics: very low specific consumption and high thrust. No matter how powerful the engines are, there is never enough thrust, there is no such thing as too much. Creating a next-generation aircraft is always a very expensive technical issue, but we are moving forward in this direction.

So two modernized NK-32 engines for 6.gen?

Full interview -> https://tass.ru/interviews/22794879

 

[Geo]

T-50-11 is a prototype of the Su-57M and had first test flight on Oct. 21 2022. This is the video where we can see that new MAWS besides the cockpit. I can't see MAWS below the cockpit. From 2:00 we can see that MAWS is pretty big.

View: https://www.youtube.com/watch?v=PCBkblEI´)úúůůKac

It's "only" an uprgraded 101KS-U, or...?

 

[Squirrel]

It's "only" an uprgraded 101KS-U, or...?

Hm ,who knows,maybe it is something completely new. Old one for comparison.

https://vpk.name/file/img/101kc-y_040518_1.jpg

 

[paralay]

So two modernized NK-32 engines for 6.gen?

A promising sixth-generation engine at the very bottom

 

[Null]

There really is no rush to a 6th generation aircraft as it would be far off better making breakthroughs now before applying them in structuring a new aircraft.

• Creating new material that is stronger and lighter than titanium with time passing can determine if its production wise feasible to produce for 6th generation aircraft.
• Announcing a new creation for radars to track radar shadows of stealth aircraft in far ranges for 2020 where they estimated a 7 year time frame to put its use into practice.
• More bench tests of adaptive cycle or detonation engines to either modify or create newer better designs to determine the best aerodynamic performance design they want to create.
• Breakthroughs continuously being made for infrared heat detection for improving material making capabilities like increasing purity of Germanium for further ranges and target accuracy.
• photonic radar tests that offer high performance and increasing the miniaturization of your electronics capability for high end PICs for better detection and tracking performance.
• PICs wafer topology is between 90 nm and 350 nm but even so their expected photonic computer prototype is to be made around the same timeframe Intel and Japan matching their performance in the Zettaflop range. Russia is still currently trying to improve their lithographic machines which will take time for smaller topology but better performances than before.
• A photonic computer, especially in an aircraft with its insane processing speeds significantly enhances neural networking and artificial intelligence performance than current electronics on computers.
• The trend of switching to ramjet engines on missiles to meet the same size proportions with increased range and payload capabilities enhances combat performance better than current air to air or air to ground missiles. They have also shown miniaturization air defense missile capabilities which can decide internal weapons bay capacity loadouts on aircrafts.
• Newer engine power generation performance and missile miniaturization can decide what will be the best self-defense decision that can be made for an aircraft to deal with incoming air to air missiles based on 360-degree infrared, UV, and millimeter radar wave frequency ranges all sensor fused for the best tracking precision possible.

I think it's only worth being interested in 6th generation aircrafts that decide to be created and fly around 2030 or after that.

 

[Squirrel]

From the interview with test pilot Sergei Bogdan:



So two modernized NK-32 engines for 6.gen?

Full interview -> https://tass.ru/interviews/22794879

Maybe you are not so wrong about 'NK-32'. 6th gen engine already exists and started flight tests on T-50-2LL. For now there is no data about (specific) thrust,weight or consumption but if the Izdeliye 30/AL-51F has max static thrust of 18 tons as some sources mentioned ,it would be real that this new engine has 20/20+ tons of max static thrust.

Very interesting detail (article from 2019) :

''In parallel with the development of the second stage engine for the Su-57, designers are already creating the scientific and technical basis for the sixth generation engines.''

Плазменный мотор

N + 1 поговорил с разработчиком «Изделия 30» для истребителя Су-57

nplus1.ru

AL-51F was developed min. decade ago.

 

[flateric]

Maybe you are not so wrong about 'NK-32'. 6th gen engine already exists and started flight tests on T-50-2LL.

This is BS. Please stop spreading your assumptions as facts.

 

[Squirrel]

This is BS. Please stop spreading your assumptions as facts.

Sorry but should there be a debate again about which engine with new flat nozzle is in the left engine nacelle of the T-50-2LL? Marchukov said on June 2023 Samara's conference that 6th gen three-stream adaptive cycle engine was developed on the basis of the AL-41F-1. Started static tests on 2021. Pictures of the flat nozzle shows us exactly the same AB chamber without stabiliser which we can see on ODK's illustration of the 6th gen engine.

 

[Galaxy]

There really is no rush to a 6th generation aircraft as it would be far off better making breakthroughs now before applying them in structuring a new aircraft.

• Creating new material that is stronger and lighter than titanium with time passing can determine if its production wise feasible to produce for 6th generation aircraft.
• Announcing a new creation for radars to track radar shadows of stealth aircraft in far ranges for 2020 where they estimated a 7 year time frame to put its use into practice.
• More bench tests of adaptive cycle or detonation engines to either modify or create newer better designs to determine the best aerodynamic performance design they want to create.
• Breakthroughs continuously being made for infrared heat detection for improving material making capabilities like increasing purity of Germanium for further ranges and target accuracy.
• photonic radar tests that offer high performance and increasing the miniaturization of your electronics capability for high end PICs for better detection and tracking performance.
• PICs wafer topology is between 90 nm and 350 nm but even so their expected photonic computer prototype is to be made around the same timeframe Intel and Japan matching their performance in the Zettaflop range. Russia is still currently trying to improve their lithographic machines which will take time for smaller topology but better performances than before.
• A photonic computer, especially in an aircraft with its insane processing speeds significantly enhances neural networking and artificial intelligence performance than current electronics on computers.
• The trend of switching to ramjet engines on missiles to meet the same size proportions with increased range and payload capabilities enhances combat performance better than current air to air or air to ground missiles. They have also shown miniaturization air defense missile capabilities which can decide internal weapons bay capacity loadouts on aircrafts.
• Newer engine power generation performance and missile miniaturization can decide what will be the best self-defense decision that can be made for an aircraft to deal with incoming air to air missiles based on 360-degree infrared, UV, and millimeter radar wave frequency ranges all sensor fused for the best tracking precision possible.

I think it's only worth being interested in 6th generation aircrafts that decide to be created and fly around 2030 or after that.

That is not how things work. New technologies take decades of research and development and often decades of material science to catch up and meet the demands of future requirements. If not now then the 6th generation fighter would roll out in like 40 or 50 years and may be the absolute by then. Advancing never stops and the research put into next generation technology often coincides with and is used to improve existing designs at some point and why would working on a future design be bad for current programs like the SU-57? It would not, it would only help improve the SU-57.

 

[Gablu]

Interesting points however no aerodynamic configuration is perfect, it is like women, what you get in one you can not get in another.

Same is in airplanes, even a very advanced fighter will not fly as low and slow as an agricultural aircraft, even with Thrust vectoring.

All fighter aircraft are designed upon a mission profile, weapons reach and sensor ability.

Su-57 prioritizes speed and agility, but it does not mean these requirements are harmonizing, if I want something fast I will take boom supersonic over Su-57.

Stealth aircraft also are not so aerodynamic, their flat surfaces and faceting is peculiarly not low drag.

What I mean is Su-57 was designed upon a military tactic that if well executed will mean Su-57 will beat the rival aircraft, however in life nothing is like in lab conditions and life is more chaotic, so aircraft get losses.

In war you always will have losses, that was factored also in the design of Su-57, sadly Su-57 has a very low production rate, so in war it will not be highly effective, The Americans then consider J-20 a higher threat because its larger deployment and production numbers.

If Russia does not produce more than 300+ Su-57s by 2035 I consider the aircraft a failure despite it is a nice looking aircraft, I think Su-75 if it is produced in numbers will bring all the research and money poured into Su-57 into real success, otherwise sadly Su-57 as beautiful it is and agile will have a very low impact in aviation history.

same was MiG-29 a beautiful aircraft very agile and fast but as long as loses are higher than the production numbers and the victories are more than the loses a fighter is a failure.

Su-27 has eclipsed MiG-29 due to higher production numbers and lower loses per victories considering MiG-29 was supposed to build 2 or 3 MiG-29s per each Su-27 built.

F-16 was then highly successful.

I do not mean F-16 is better than MiG-29, simply the program was more effective only that and Su-57 seems to be not really effective in that regard.

Su-27 is well known to be more agile than the F-15, they proved it when a pair of Su-27s flew to the USA, they had mock combat with F-15s and the Su-27 won.

In real life F-15 has better combat record but Su-27 is much more effective as a dog fighter, but an aircraft is not only agility but avionics and tactics, so yes F-15 is a good aircraft but as a dog fighter Su-27 is better, but if you consider weapons, avionics or radar well both aircraft are comparable

Where can I read the original posts of Peregrine Falcon and Rad disconnect?

I cannot see the attachments in the quoted post.

When I am clicking on the names, it's showing that the post cannot be found.

 

[F-14ATomcat]

View: https://www.youtube.com/watch?v=qV_yBrJP5qY


Aerodynamics of Levcons as those used in Su-57

 

[Saber]

From the interview with test pilot Sergei Bogdan:



So two modernized NK-32 engines for 6.gen?

Full interview -> https://tass.ru/interviews/22794879

Isn't the NK-32 a completely unsuitable engine for fighter aircraft? I remember a passage on the test of a Tu-22M equipped with them, it was too much thrust even for an aircraft that size and weight, never mind the massive weight and spool setup.

 

[Anduriel]

Isn't the NK-32 a completely unsuitable engine for fighter aircraft? I remember a passage on the test of a Tu-22M equipped with them, it was too much thrust even for an aircraft that size and weight, never mind the massive weight and spool setup.

NK-25 has the same thrust as NK-32. There were other issues, and Tu-22M4 was supposed to come with them.
But yes, Nk-32 is unsuitable for fighter, as it's too heavy. Better izd.20 or R-79 upgrade.

 

[Life of Tyo]

T-50-9 On Khmeimim Air Base february 2018 she so big ,unfortunately i can,t find T-50-11

 

[Life of Tyo]

 

[Ainen]

Isn't the NK-32 a completely unsuitable engine for fighter aircraft? I remember a passage on the test of a Tu-22M equipped with them, it was too much thrust even for an aircraft that size and weight, never mind the massive weight and spool setup.

CTOL variant of yak-141 (yak-43) was to use NK-32, so it wasn't out of question.

 

[Joint Soviet Fighter]

The round nozzle was 2D canted to provide yaw movement; not full 3D like the nozzle used on the mig-29 demonstrator from years ago. The new nozzle seems to work just like the circular one

You might actually be able to turn a MiG-29/MiG-29 OVT into a 5th/6th generation platform strictly from an rcs standpoint with some creativity. Maybe. Actually no idea, lol.

https://www.secretprojects.co.uk/threads/how-small-can-low-observable-stealth-combat-aircraft-designs-get.37600/page-3#post-745959

 

[Tomboy]

You might actually be able to turn a MiG-29/MiG-29 OVT into a 5th/6th generation platform strictly from an rcs standpoint with some creativity. Maybe. Actually no idea, lol.

https://www.secretprojects.co.uk/threads/how-small-can-low-observable-stealth-combat-aircraft-designs-get.37600/page-3#post-745959

But I don't see why you would do that, at this point it's basically an entirely new stealth aircraft made to resemble MiG-29s

 

[Joint Soviet Fighter]

But I don't see why you would do that, at this point it's basically an entirely new stealth aircraft made to resemble MiG-29s

It's not. That's the entire point.

 

[Joint Soviet Fighter]

At least it got people to click hahahaha.
-------------------


Anyway, something for fun. So yeah I did a little bit of experiment. I made myself a model of an inlet. With a simple Radar blocker and a compressor face with its respective Guide vanes.

View attachment 656801

The radar blocker is just loosely based on the one in Su-57 patent. treatments that i did was to the leading edge of the Blocker where it would have ogival shaped edge to reduce contribution of RCS from the edge. The RAM Is the one from the "Radar Cross Section 2nd Edition" the Magnetic RAM Sintered-Zinc-Nickel-Ferrite.
The inlet Body is not treated and left as PEC, so does the engine face. The solution being used is SBR+ Which allows cavity RCS to be computed

The frequency being used here is L-band (1 GHz) because it's fast and can still enter the duct. Polarization is horizontal, and 3 conditions were taken as follows and the result in 2D contour projection :

No Radar Blocker	Both radar blocker and engine face are made out of PEC (Perfect Electric Conductor)	Blocker is treated with Radar absorber
View attachment 656802	View attachment 656801	View attachment 656801
View attachment 656804	View attachment 656803	View attachment 656805

Remarks : Relatively strong and broad reflections from the blades and guide vanes.

Remarks : Blocker and Inlet are basically compounding each other, produces strong reflections at the middle of the engine face.​

Remarks : The radar blocker appears to be able to suppress the reflection of the blades behind it, "flare spots" appears to be reduced.

The above projection are views from the front of the engine. Basically from this :

View attachment 656808

Numerical wise this is the Median of the inlet's RCS :
View attachment 656807

There is about 5-6 dB or 3-4 times of RCS reduction from above model. Doesnt sound like alot but still reduction. Plus i have no idea on how actually a radar blocker is designed. I wonder what kind of reduction a purposely designed and optimized radar blocker can have.

The subject of the design of radar blocker however appears to be rare in open literature so far. There are patents, but research papers are somewhat nonexistent. There are instead many on S-duct. Even the idea of ogival leading edge treatment for my simple radar blocker there came from paper dealing with S-duct (Attached):

Apologies for digging this up, it's just that I've always found the intake design & that of the radar blocker on The Su-57 to be rather strange, as it looks like they essentially tried to corkscrew their way out of the problem by opting for two weapons bays (that, of course, also created other issues) instead of a single one with S-Ducts by installing bizarre "partial S-Ducts" with a radar blocker & then people wonder as to why the speed of the aircraft is less than advertised, I guess, when the reason(s) should be obvious in that the blocker & inlet design combine to strangle the engine, lol, smh, not to mention the fact that "partial S-Ducts" are also pretty complex & expensive.

Overall, this looks like a classic case of gambling that you can/trying to solve two problems & ultimately coming up short on both accounts (kind of like having two possible answers to as many remaining multiple choice questions &, instead of putting down the same response to both to at least guarantee that you will be correct on at least one of the queries, you opt to guess, or whatever, & instead wind up getting both wrong), but I do have one question - despite the fact that this would render the speed of The Felon to unacceptably low levels, purely from the standpoint of rcs reduction, if a blocker/screen was installed over the entrance to the intakes as is the case on The F-117 instead of using a circular arrangement to only prevent radio waves from reflecting off of the face of the jet engine, would that not yield a better outcome? I mean, shielding the front of the engine is fine, but I would argue that that approach is insufficient as it does not at all attempt to deal with the other echoes/returns that result from the preceding somewhat rectangular portion of the ducts, which is also one of the reasons as to why I chose to keep the standard straight intakes on that "design" of mine, albeit with an angled rectangular radar blocker/screen in front of the fan blades somewhat like The Nighthawk but also preceded by the pyramidal shaped cone-like shock "device" in order to increase air flow to hopefully at least somewhat offset that problem as well as helping with rcs reduction, even though I'm sure that I've messed up in that regard as inlet/intake design is not exactly my forte, either, lol, smh.

 

[flateric]

As my fellow aerospace engineer says, I often wonder why so much less advices from public how to do something are given on specific forums to neurosurgeons or nuclear reactor builders.

 

[Arjen]

When corona hit, we were inundated with self-taught virologists

 

[Joint Soviet Fighter]

As my fellow aerospace engineer says, I often wonder why so much less advice from public how to do something are given on specific forums to neurosurgeons or nuclear reactor builders.

Thanks, LOL. I'll try to shut up, now, then.

One question, though - do you happen to work at Sukhoi? I'm just curious.

 

[Squirrel]

T-50-9 On Khmeimim Air Base february 2018 she so big ,unfortunately i can,t find T-50-11
View attachment 755721

Maybe this sat-image will help?

Satellite Imagery Confirms Russia Deployed Stealthy Su-57 Fighters To Syria

At least two of the jets are in-country and they are likely to begin "combat evaluation" sorties soon.

www.twz.com

View: https://www.youtube.com/watch?v=IJTCewLTCLE


From some Russian sources ( famous 'Fighterbomber' ,military analyst Igor Korotchenko...) ,this is the story about the two second-stage prototypes 509 and 511 blue which flew to Syria,Khmeimim air base on Feb. 21 2018. After the Dec.13 2017 incident ( involved were RuA&SF Su-25SM,Su-35S and USAF F-22A ), they decided to send two Su-57's to Syria to 'monitor' 5th gen fighters in the region, USAF F-22A Raptor and IDF/AF F-35I Adir.
Igor Korotchenko even mentioned joint air exercise with 5th gen stealth fighters in the Israeli air space ,in the same time when those two prototypes were in Syria. Both prototypes got new civil reg. numbers RF-81774 and RF-81775 and lost their so called Bort numbers. They flew about 10 'combat' missions on Feb 22 and 23 ,then returned to RF on Feb. 23 2018.

From another source :

''U.S. Air Force Gen. Mike Holmes announced on February 22 that the reported arrival of Russian stealth Su-57 fighter jets to Syria "raises the level of complexity for the (USAF) crew's to deal with."

On Thursday, Gen Mike Holmes, Air Combat Command commander, said he was unaware of reports surrounding the Su-57 in Syria, but added the situation in Syria grows more complex by the day.

"It's one thing to do the counter-air mission with a long lookout in front of you, it's different to do when everyone's tightly packed in there," Holmes said during a roundtable discussion with reporters here at the Air Force Association's Air Warfare symposium.

"So our guys will continue to prep for the scenarios that they're deployed to face," Holmes said.
When asked whether it was concerning to have another stealth aircraft in the mix, Holmes emphasized the tough environment and constricted air space in the region.''
"Certainly, the higher the complexity and the higher the technology ... it raises the level of complexity for the crews to deal with," the commander said.

Pentagon says Russia's Su-57 fighter is no threat to US forces if it's even in Syria

"We do not consider these jets to be a threat to our operations in Syria, and will continue to deconflict operations as necessary" - Pentagon spokesman.

www.businessinsider.com

 

[RadicalDisconnect]

Apologies for digging this up, it's just that I've always found the intake design & that of the radar blocker on The Su-57 to be rather strange, as it looks like they essentially tried to corkscrew their way out of the problem by opting for two weapons bays (that, of course, also created other issues) instead of a single one with S-Ducts by installing bizarre "partial S-Ducts" with a radar blocker & then people wonder as to why the speed of the aircraft is less than advertised, I guess, when the reason(s) should be obvious in that the blocker & inlet design combine to strangle the engine, lol, smh, not to mention the fact that "partial S-Ducts" are also pretty complex & expensive.

As far as top speed, intake radar blocker isn't the issue. Yes a blocker has some losses but they're not huge, and most important for high speed flight is intake pressure recovery, which with variable ramps the Su-57 intakes have no problems with that. So intakes are perfectly fine for Mach 2+, it's materials (especially composites) and RAM that is limiting factor, especially if reducing titanium and BMI usage because of cost. Compared to Su-27, the Su-57 use a lot less titanium and more composites. Sukhoi tried to use Al-Li alloy (VIAM 1461 alloy specifically) with better strength/weight ratio in place of B-95 alloy to reduce weight, but wasn't entirely successful.

Another thing is, PAK-FA/Su-57 is meant to be a "complex", likely Russians use it as a starting platform for introducing 5th gen fighter technology. While Mach 3 intake isn't useful for Su-57, it's useful risk reduction for future applications and research on this done by TsAGI can likely be applied to something like PAK-DP interceptor, where for it's specific mission the lowest possible RCS isn't as important.

Also not every innovation or technology is necessarily useful for future applications. For example F-35 style EHAs while being very precise and powerful may not be useful in future fighters because of how much electrical power they require and how much heat they generate.