Sukhoi Su-57 / T-50 / PAK FA first flight - pictures, videos and analysis [2010]

[F-14D]

IMHO, they're both going to use their radars. Fighter combat isn't like strike in that you're trying to avoid all contact and release your payload. They are going to want to engage. Now, we know the F-22 has a Low Probability of Intercept radar, and we can assume that Russia is going to try and do something similar, so they will use them. IRST (advantage T-50) can provide passive tracking capability, especially against a supercruising aircraft, but there's still the problem of determining range. In the case of pooping off an AIM-120 or the like, you've got to have fairly precise positional data on the target in order to tell the missile the area to fly to and .when to turn on its radar.

Therein lies the interesting circumstance: The more stealth the better, up to a point. But, the missile's radar is much less capable than that in the fighter itself. So, you don't have necessarily have to be so stealthy in a super fighter that the other super fighter can't track you, all you have to be is stealthy enough that the other super fighter's missiles can't track you.

 

[lancer21]

Lets not forget that machines like F-22 and Su-50 are/will bristle with MAWS, latest generation jammers and decoys ...and also in the case of missiles like AMRAAM and RVV-SD, as soon as they get or try to get lock , they are going to be detected by the passive ALR-94(ski) aswell!

Air combat has ALOT of variables , but if both sides play their cards well one would expect a low( very?) missile PK...

( but lets hope that will never happen...let us ramble about whos better here , and let them "dogfight" at airshows , that i'd like! )

 

[stealthflanker]

hmm talking about "Passive sensors" like ALR-94 or its Russian equivalents (maybe the khibniy-M) reminds me of something..

well i think everyone here is already aware of the existence of Low Probability of Interception recently i heard that such technology already make its use in RADAR Guided Missile seeker with Sweden's RBS-15 as living example that missile emits FMCW transmissions with very low power (in order of Miliwatts) make live difficult for ESM System to pick her transmission . now i'm pretty sure that, soon or later that technology would manage its way on the AAM as well .

and i expect PAKFA's AESA RADAR would also have similar complex waveform modulation , probably based on similar "Pseudorandom Noise Coding" in F-22's and Ultra Low Sidelobe in the order of -30Dbi as their means of LPI.

now i'm wondering whether the ALR-94 or its Russian equivalents have been designed against such threat , if no... then in my opinion the one who gets the first look is likely to be the winner.

i have been hearing so much analysis and opinion on RADAR's but somehow it's kinda rare and difficult to find info on RADAR Warning Receiver and ESM in general

just my 2 cents anyway

 

[saintkatanalegacy]

just wondered if the ALR-94 is capable of detecting pseudorandom radar pulses ???

 

[Dragon029]

In my opinion, I wouldn't be surprised (if an F-22 and Su-50 engage) if they use up all their missiles trying to get a hit, fail due to jammers & other defences and are therefore forced to RTB.

 

[overscan (PaulMM)]

This is entering the realm of pointless speculation... Please stick to informed speculation based on facts

 

[flateric]

Nemetc now admits that he was probably wrong about second flight on Feb. 6 - he just saw T-50 taxying and was said that it was a flight this day http://kyrazh.ru/index.php?action=vthread&forum=6&topic=1076&page=36#msg38474
so, the second flight was on Feb., 12

 

[doolyii]

I did not know that forward LERX is indeed moving surface, almost like F-15 nodding inlet type ? or more canard like ? or F-111/Tornado/F-14 type chine ?

Any information on why the vertical pin is rather small especially when engines are spacing this far ?

 

[mrdetonator]

Nemetc now admits that he was probably wrong about second flight on Feb. 6 - he just saw T-50 taxying and was said that it was a flight this day http://kyrazh.ru/index.php?action=vthread&forum=6&topic=1076&page=36#msg38474
so, the second flight was on Feb., 12

Hmm,...hopefully the new camo looks different as the Su-35 "902", do not like the splinter camo much. As I understood him, they painted with light grey colors except white radome.

 

[flateric]

radar radome is white
splinter camo a-la 902
main color is 25-35% gray
darker color is 35-45% grey

 

[flateric]

almost like F-15 nodding inlet type ? or more canard like ?

or both...

 

[doolyii]

I don't think they are sizing tail for "single engine failure' mode...in fact, I say it's sized for 'full time thrust vectoring for yaw control', otherwise it cannot be this small considering size of F14/15/22..not to mention Su-27 family planes..

 

[lancer21]

radar radome is white
splinter camo a-la 902
main color is 25-35% gray
darker color is 35-45% grey

When can we see a pic? ???

 

[F-14D]

For those who have read the Aviation Week analysis (which to me is highly credible given who wrote it), what are the thoughts on their conclusion? Granted this is at a very early stage, but they seem to say that Sukhoi was not going so much for a "Raptorovitch' (which I find sounds better than their 'Raptorski' which sounds like a hockey player) as a stealthy Ultra Super-Flanker? Or did I draw the wrong inference?

 

[flateric]

When can we see a pic? ???

some say next week or so

 

[lancer21]

When can we see a pic? ???

some say next week or so

Aww , such a long wait ... :'(

 

[flateric]

I thought everyone have worked out a patience till he heard of PAK FA for the first time

 

[Pit]

For those who have read the Aviation Week analysis (which to me is highly credible given who wrote it), what are the thoughts on their conclusion? Granted this is at a very early stage, but they seem to say that Sukhoi was not going so much for a "Raptorovitch' (which I find sounds better than their 'Raptorski' which sounds like a hockey player) as a stealthy Ultra Super-Flanker? Or did I draw the wrong inference?

I think we should wait till next-year MAKS, and then we can start drawing conclusions B)

Per example, as was mentioned, russians have talked a lot on their radar systems, but less on their EW systems, specially on the ESM systems to be used on such aircraft...

Would it be also a version of Khibiny-M used on Su-35S?

 

[mrdetonator]

radar radome is white
splinter camo a-la 902
main color is 25-35% gray
darker color is 35-45% grey

yes, the same as 902 but different, only two shades of grey color....The white,grey,dark grey color combination is not much suitable for a "nevidimka" camouflage , Referring to this camo..

 

[donnage99]

So then hypothetically speaking -lets hope it will never happen btw- but you have these 2 guys in a Su-50 and F-22 respectively ...are they gonna think " gee , i aint gonna put my radar on , coz the other guy is gonna see me and shoot at me"? how are they gonna find eachother then? yes i know AWACS and intel and satelites and so on ...but lets forget about that ftm...if they are alone , are they gonna fly in circles terrified to put their radars on not to be seen ?

No aircraft goes to war alone. They go in pack and well coordinated. So it's more realistic to imagine a scenario of at least 2 aircraft on both side. I'm pretty ignorant in this matter, but I imagine one would scan their radar to search for target (which also takes on the role of the "target" itself), once they acquire the target, pass the information to the second "silent" aircraft to climb to position and fire the missile. This is why link 16 proved to be so decisive in excercise.

As for RWR equipments and radars, even these equipments of both sides are presumably made of the same quality, how well they are intergrated into the whole system to provide a better situational awareness is also important factor in determining who wins.

 

[sanjeev.k]

I have 2 questions for the aerospace gurus on this forum
a) Given that people say the PAK-FA is a lot like the YF-23 (fuselage, all-moving vertical tails) - I am curious why Sukhoi opted for a clipped diamond wing rather than YF-23 like rhomboid wing. The advantages of the rhomboid wing in areas of stealth (so-called '2-electromagnetic lobe' design) and supercruise( good conformance to the area rule) are well known. Even if Sukhoi did not relatively much importance to stealth, I thought they could have used the rhomboid wing for its area-rule adherence qualities.
Are there hidden/not-so-obvious disadvantages of the rhomboid wing? Seems like the YF-23 is the only aircraft (I could be wrong) in modern times that use the rhombus wing layout.

b) Also - unlike the YF-23 - the PAK-FA does not blend the inner side of the intake with the underside of the fuselage. Is it very expensive/complex (from a strictly manufacturing viewpoint) to do so.
regards,
Sanjeev.

 

[SOC]

Wouldn't a rhomboid wing have altered the T-50's CG, making the rearmost weapons bay a little problematic?

 

[Husar]

This is my first post here so Hi to everyone

radar radome is white
splinter camo a-la 902
main color is 25-35% gray
darker color is 35-45% grey

Maybe something like this ?

click

 

[Abraham Gubler]

Wouldn't a rhomboid wing have altered the T-50's CG, making the rearmost weapons bay a little problematic?

I think the point is a rhomboid wing would have altered a widened fuselage version of the Su-27's centre of gravity...

 

[Avimimus]

I don't think they are sizing tail for "single engine failure' mode...in fact, I say it's sized for 'full time thrust vectoring for yaw control', otherwise it cannot be this small considering size of F14/15/22..not to mention Su-27 family planes..

The size of the tail is dependent on the flight regime and the flight control system. Conservative flying may be quite possible with smaller control surfaces, while dogfighting might be suicidal. Similarly, more advanced fly by wire systems and airflow sensors may be gradually allowing designs to rely on more actively generated stability (by the FBW system) and compensate for passive instability in the aerodynamics.

Wouldn't a rhomboid wing have altered the T-50's CG, making the rearmost weapons bay a little problematic?

My assumption is that the T-50 aimed for lower wing loading in order to ensure payload/range and short takeoff requirements could be met (not to mention maintaining development potential). There was a report at one point that the maximum speed requirements were relaxed in order to meet payload goals. The wing shape may be aerodynamically required to achieve sufficient wing area (whereas a large rhomboid wing might not be good for performance).

The wing also has a number of very high angle-of-attack features (looking at the change in the distribution of surface area as the aircraft is rotated in pitch relative to the air-stream).

For those who have read the Aviation Week analysis (which to me is highly credible given who wrote it), what are the thoughts on their conclusion? Granted this is at a very early stage, but they seem to say that Sukhoi was not going so much for a "Raptorovitch' (which I find sounds better than their 'Raptorski' which sounds like a hockey player) as a stealthy Ultra Super-Flanker? Or did I draw the wrong inference?

There is one quote floating around stating that the goal wasn't to meet the F-22 in stealth, but to achieve a basic level of stealth while keeping maintenance costs low. Some of those in this forum (with more expertise than I) seem to believe that it is more optimised for stealth in the frontal quarter than other quarters. I think they're aiming for something which is a generation above the Raptor in other respects. Basically, the plane should be analysed on its own before it is compared with other designs and right now we have far too little information to reach any sturdy conclusions.

 

[Sundog]

I have 2 questions for the aerospace gurus on this forum
a) Given that people say the PAK-FA is a lot like the YF-23 (fuselage, all-moving vertical tails) - I am curious why Sukhoi opted for a clipped diamond wing rather than YF-23 like rhomboid wing. The advantages of the rhomboid wing in areas of stealth (so-called '2-electromagnetic lobe' design) and supercruise( good conformance to the area rule) are well known. Even if Sukhoi did not relatively much importance to stealth, I thought they could have used the rhomboid wing for its area-rule adherence qualities.
Are there hidden/not-so-obvious disadvantages of the rhomboid wing? Seems like the YF-23 is the only aircraft (I could be wrong) in modern times that use the rhombus wing layout.

b) Also - unlike the YF-23 - the PAK-FA does not blend the inner side of the intake with the underside of the fuselage. Is it very expensive/complex (from a strictly manufacturing viewpoint) to do so.
regards,
Sanjeev.

I actually see the PAK-FA having as much in common with the YF-23 as the Flanker; not much. The basic layout or "Grouping" of the major areas, fuselage, wing position, engine location, is still that of the Flanker. The wing/horizontal tail arrangement of the PAK-FA is similar to the F-22's, not the YF-23's. The wing planform of the PAK-FA is almost an exact match of the F-22's.

Also, the YF-23 had a butterfly tail, the T-50 does not. The F-22 has all moving horizontal tails. As for the all moving vertical tails on the T-50, I'm willing to bet they confer a higher signature than a conventional vertical tail like the F-22's, but they offer lower drag and they're able to make them that small due to the 3D TV. Which points to more emphasis on advanced aerodynamics than LO.

Also, the reason it isn't as blended around the inlets/engines area, is due to the relaxed LO requirements versus those of the ATF. As I've stated previously, which has been stated by the Russian designers, they weren't going for all aspect stealth in their design and that's quite obvious when one sees it from the side, bottom, and rear quarter views. That isn't to say it's signature is as large as the Flanker's in that regard, it obviously isn't. They moved the engines up higher into the central fuselage, which should lower how much they reflect in the side lobes, but I think it was done more to minimize supersonic wave and trim drag than anything else. But based on how those areas were constructed, with their right angles between the nacelles bottom and the wing/fuselage interface, LO certainly wasn't a priority in those areas.

Regarding the YF-23, it was optimized more for supercruise than the YF-22 was, but the YF-23 couldn't match the F-22's subsonic low speed maneuverability, largely because it doesn't have thrust vectoring. The YF-23 was still quite maneuverable, and honestly I don't think the low speed maneuvering is going to help the F-22 that much. If it ends up bleeding that much energy in combat, well than it probably deserves to be shot down, because it means it gave up all of it's advantages, and that's what we've seen in the training it's performed in and been shot down. At Supersonic speeds, there were certain areas where the F-22 had the advantage in turn rates and areas where the YF-23 had the advantage in turn rates. The YF-23 also had much higher supercruise speeds than the YF-22 and this would have given it's weapons an energy/range advantage. The Production F-22 does match the P&W powered YF-23's supercruise speed, but that's largely through the increased thrust in the production engine, so I can only conclude that a production F-23 would have supercruised that much faster as well. My point being, the Rhomboid wing was optimized more for supercruise speeds and all aspect stealth, where as Lockheed's team was willing to sacrifice stealth in the rear quadrant for some more maneuverability and less supercruise ability. It's really about design trade offs made to optimize different design points.

Ultimately, though, it doesn't come down to why didn't the Russians make the T-50 more like the YF-23 than the F-22. What it comes down to is what the Russian mission requirements were and how could they best meet the requirements. Some of the features appear the same because LO in Russia works the same as LO in the U.S. For instance, the 3D inlets are the same type of design as those found on the F-22, the F/A-18E/F, and the X-36, and many other design studies we've seen. That's because it's an excellent inlet design for LO applications and high alpha requirements. Not to mention, of all the stealthy inlet designs I've seen, it's most likely the easiest to manufacture as well.

I seriously doubt the engineers went into designing the T-50 and said, "Should we make it more like the F-22 or YF-23?" I haven't any doubt they studied both designs in depth and have information on what the advantages and disadvantages of each design were and ran their own tests to determine, based on aerodynamics, LO, costs, manufacturing capability to determine which LO features would best suit their needs. From there, it's obvious that the T-50 is an evolutionary design of the Flanker, in much the same sense one can see the evolution from the McDonnel F-3H to the F-101, to the F-4.

 

[Sundog]

For those who have read the Aviation Week analysis (which to me is highly credible given who wrote it), what are the thoughts on their conclusion? Granted this is at a very early stage, but they seem to say that Sukhoi was not going so much for a "Raptorovitch' (which I find sounds better than their 'Raptorski' which sounds like a hockey player) as a stealthy Ultra Super-Flanker? Or did I draw the wrong inference?

I think you drew the correct inference and I thought it was spot on. Although, in terms of the name referencing the look, I still prefer Flaptor, because I do see it as a "Flanker layout" that has LO features similar to those seen on the F-22 and F-35 and the wing planform very closely matches that of the Raptor. Which really just tells me that it must be a very good wing design, for both Lockheed and Sukhoi to use it.

 

[rousseau]

As for the all moving vertical tails on the T-50, I'm willing to bet they confer a higher signature than a conventional vertical tail like the F-22's, but they offer lower drag and they're able to make them that small due to the 3D TV. Which points to more emphasis on advanced aerodynamics than LO.

The All-Moving Vertical Tails(AMVT) offer either lower drag as you realized or lower observation you didn't realized, because you forgot the smaller the span & area of fin or wing be, the smaller RCS it result. In order to same effort, the AMVT brings slighter deflected angle than that flag-like fin on F-22, which also makes LO more than F-22.
Since we accepted the LO of YF-23 were better than F-22 under such condition the swept angle of YF-23's wing is smaller than F-22, we ought to remember what's the condition bring this advantage.

Also, the reason it isn't as blended around the inlets/engines area, is due to the relaxed LO requirements versus those of the ATF. As I've stated previously, which has been stated by the Russian designers, they weren't going for all aspect stealth in their design and that's quite obvious when one sees it from the side, bottom, and rear quarter views. That isn't to say it's signature is as large as the Flanker's in that regard, it obviously isn't. They moved the engines up higher into the central fuselage, which should lower how much they reflect in the side lobes, but I think it was done more to minimize supersonic wave and trim drag than anything else. But based on how those areas were constructed, with their right angles between the nacelles bottom and the wing/fuselage interface, LO certainly wasn't a priority in those areas.

Oh, yeah? Does F-22 care all aspect stealth?
First of all, I come to remind you the rectangle nozzle on F-22 is much larger and heavier than you imaged. Don't forget the engine of the F-22 still is circle section, the circle is totally INSCRIBED by a rectangle. So you press at height, the fat at wide it must be. That's why US adds triangle blade at top and bottom of nozzle's edge. This was a reluctant way they have to use, but other do it reluctantly, you do it again will become stupid.

Secondly, if nacelle moved up higher into central fuselage, we could accuse it bad for stealth in side view because it makes its airframe seemingly more thick. If the nacelle was paralleled with central line, we could accuse it harmed stealth. So, how the nacelle shall set? Throw it away? Why Russian do something always wrong, and what done by American is right forever?
Someone should be taught there are variant way to decrease the sonic drag due to different area of sonic.
The waspish fuselage is for transonic good, and, for supersonic good, you should make fuselage close to arrow-like, Eurofighter for example.
The swell nacelle YF-23 used, gave it a narrow section from side view where the wing span is maximum from up-look, which for transonic.
The V-tail or one say butterfly-tail decreased bottom drag out of tail very much,m which brings a huge advantage for supersonic. Notice that main drag in fly is from tail no matter trim or shockwave.
The nacelle of PAKFA we saw is not swell so much as YF-23, but the very large swept angle of wing delay the sonic wave just like Eurofighter used even more.

Thirdly, how the inlet designed would influenced RCS for sure, but this depends on what object you compare to.
As someone mentioned it very good

one can see the evolution from the McDonnel F-3H to the F-101, to the F-4.

I draw anyone read here pay attention to so many aircraft in history. Uncountable aircraft was designed "S" piper inlet, such as F-101, F-105, even MiG-21 and MiG-23, but nobody has been saying those ARE stealth aircraft. The truth was and always been there, the air-intakes was forced to design as "S" shape, which become to straight on F-14 with particular purpose. Those F-22 fans are so uneducated that seeking the reason reversed in results. After RAPTOR fans stood in front of MiG-19's nose, I could give a reasonable ask, "could you see engine blade"?
You guys can bring this occasion to anywhere and waiting for see how smart they are as how stealth farmer is.

 

[flateric]

Vympel UVKU launcher for internal weapon bay of guess what...

 

[flateric]

On Saturday, Feruary, 13, T-50 has performed her third flight
http://www.vz.ru/news/2010/2/15/375944.html

 

[Husar]

On Saturday, Feruary, 13, T-50 has performed her thirdflight
http://www.vz.ru/news/2010/2/15/375944.html

No pics yet

Guess we'll have to be patient.

........

Came across the following regarding the T-50's rear RCS/IR signature from an old Bill Sweetman article, which seems like a novel idea (to me at least)

The ITAE and its partners use plasma technology for applying ceramic coatings to the exhaust and afterburner.

Multi-layer coatings formed from microparticles of dielectric, metal, or semi-conductor material are deposited by an arc-discharge plasma under atmospheric pressure. Challenges include the need to keep the ceramic bonded to the metal structure over a wide temperature range (600°C to 1,200°C), despite the fact that the materials have widely different thermal-expansion characteristics. The coating materials also need to maintain constant electrical characteristics in the face of widely varying temperatures.

Researchers describe this problem as "partially solved," and engines treated with ceramic RAM have already been flight-tested.

I can't find the original link, but the whole piece can be seen here:

http://forum.keypublishing.co.uk/showpost.php?p=801988&postcount=4

 

[Matej]

Someone speaking about the fully detailed color 5 view reconstruction?

 

[flateric]

On Saturday, Feruary, 13, T-50 has performed her third flight

...and then was dismantled for retrofits, according to Nemetc
http://kyrazh.ru/index.php?action=vthread&forum=6&topic=1076&page=36#msg39335
no new flights till April or so...

 

[lantinian]

Someone speaking about the fully detailed color 5 view reconstruction?

I wanna know already

 

[Sundog]

The All-Moving Vertical Tails(AMVT) offer either lower drag as you realized or lower observation you didn't realized, because you forgot the smaller the span & area of fin or wing be, the smaller RCS it result. In order to same effort, the AMVT brings slighter deflected angle than that flag-like fin on F-22, which also makes LO more than F-22.
Since we accepted the LO of YF-23 were better than F-22 under such condition the swept angle of YF-23's wing is smaller than F-22, we ought to remember what's the condition bring this advantage.

The all moving tail will create a higher signature while moving than the standard design of the F-22's, as the leading edge of the F-22's is always fixed. Of course, for most cases, the T-50's tail may remain mostly fixed, and used just for stability, while the 3D TV is used for control at relatively small offset angles (Alpha, Beta, Gamma)

Oh, yeah? Does F-22 care all aspect stealth?
First of all, I come to remind you the rectangle nozzle on F-22 is much larger and heavier than you imaged. Don't forget the engine of the F-22 still is circle section, the circle is totally INSCRIBED by a rectangle. So you press at height, the fat at wide it must be. That's why US adds triangle blade at top and bottom of nozzle's edge. This was a reluctant way they have to use, but other do it reluctantly, you do it again will become stupid.

Compared to most other aircraft, the F-22 has a smaller RCS than any other fighter flying from all angles. 2D rectangular nozzles are known to have a smaller signature than axisymmetric nozzles, even if they are of a reduced L.O. type. I thought it was already well known that the F-22 has lower rear aspect stealth than the F-35? There aren't any indications that the T-50 will have a lower RCS than that of the F-35 in the rear aspects and if the production version matches the prototype in this regard, it's a given.

Secondly, if nacelle moved up higher into central fuselage, we could accuse it bad for stealth in side view because it makes its airframe seemingly more thick. If the nacelle was paralleled with central line, we could accuse it harmed stealth. So, how the nacelle shall set? Throw it away? Why Russian do something always wrong, and what done by American is right forever?

I have no idea what the hell you are trying to say there. I can only conclude you completely misunderstood what I wrote. I was referring to the the ninety degree face plate effect caused by the sides of the nacelle. By moving the engine up into the fuselage, they reduce this effect, although they still have the problem of the ninety degrre angle interface at the fuselage wing juncture. Also, I still contend it was done to minimize trim drag as well.

Someone should be taught there are variant way to decrease the sonic drag due to different area of sonic.
The waspish fuselage is for transonic good, and, for supersonic good, you should make fuselage close to arrow-like, Eurofighter for example.

Indeed, someone should be taught about area ruling. I would assume you meant yourself, sense I have actually performed area ruling on designs before and I'm quite familiar with it.

The swell nacelle YF-23 used, gave it a narrow section from side view where the wing span is maximum from up-look, which for transonic.
The V-tail or one say butterfly-tail decreased bottom drag out of tail very much,m which brings a huge advantage for supersonic. Notice that main drag in fly is from tail no matter trim or shockwave.

Actually, nacelles on the bottom are usually better than those on the top to reduce trim and wave drag at supersonic speeds, since nacelles on the bottom provide a net gain in lift due to the boost from the pressure increase. The reason Northrop put the nacelles on top was for stealth reasons.

The nacelle of PAKFA we saw is not swell so much as YF-23, but the very large swept angle of wing delay the sonic wave just like Eurofighter used even more.

Comparing the size of the nacelles isn't nearly as important as their shape, with regard to LO. The T-50's nacelles aren't shaped with the angled sidewalls of the YF-23's.

Thirdly, how the inlet designed would influenced RCS for sure, but this depends on what object you compare to.
As someone mentioned it very good

one can see the evolution from the McDonnel F-3H to the F-101, to the F-4.

I draw anyone read here pay attention to so many aircraft in history. Uncountable aircraft was designed "S" piper inlet, such as F-101, F-105, even MiG-21 and MiG-23, but nobody has been saying those ARE stealth aircraft. The truth was and always been there, the air-intakes was forced to design as "S" shape, which become to straight on F-14 with particular purpose. Those F-22 fans are so uneducated that seeking the reason reversed in results. After RAPTOR fans stood in front of MiG-19's nose, I could give a reasonable ask, "could you see engine blade"?
You guys can bring this occasion to anywhere and waiting for see how smart they are as how stealth farmer is.

Once again, you had absolutely no idea what I was talking about.

 

[Spring]

..................................

An inefficient rectangular nozzle with poor expansive area? cooling a high temperature jet? , btw,every design that has tried to decrease it IR signature had separated nozzles, unlike the F22.

Are you sure the F22 did not get these flat nozzles,because was the only design available for STOL in the late 80's

A full control surface could need less incidence for maneouvres (well,actually for trajectory correction) than a conventional rudder, the yf-23 needed it flats to work as rudders as well,it workload demand was pretty high...

And the stealth thing is actually vastly overated, if the F22 had actually been designed mainly for RCS goals, we should not see the large surface oriented downwards, or slats,or flats or the profile with optuse angles.

I hope the T-50 to get a good RCS, comparable with the Raptor from ahead, and a good RCS value from sides (if you think these huge raptor's fins are not good reflectors, you are very wrong )

Still a long way to go, the last thing i'm worried about is the mythical 5th gen RCS value, but the weight and the performance, and what are these rudders/lerx for...for supersonic control? for super-agility?,time will tell

 

[flanker]

Someone speaking about the fully detailed color 5 view reconstruction?

Beautiful so far Matej! Are you open for critique? It is nothing earth shattering, just small (almost litteraly rivet-counting stuff) things here and there.

 

[Matej]

Its still in progress, so there is some time for the corrections - please tell.

 

[Spring]

Another thing, i really doubt there was any real work to decrease the IR signature even for the yf-23,other than to put a screen around.

You won't decrease the IR signature cooling the exhaust at the nozzle, what people don't understand is what is cooled is what the IR sensor watch.

If it is cooled at the exhaust, the photon that comes out from the cooling will go to the sensor,no matter if is cooled at the exhaust or at the end of the plume.

Jet plumes are long as well, they must be long actually, to be efficient (hope some engineers could understand this)

So even the screening over the yf-23 is not really useful, the plume does have a lenght, even if the engine is set at low power

IMO all the screen over the yf-23 are actually radar blockers

The only way to decrease the temperature is increasing it flow,but then ,there are thermodynamic limits, because a high performance propulsion does need high temperature.

 

[Abraham Gubler]

Spring the point of cooling the exhaust is not to cool the plume but to cool the airframe. A hot airframe provides a much more useable IR signature to the various threats from detection to targeting. The V tails of the YF-23 type configuration work to shield that part of the aircraft exposed to the hottest part of the plume from line of sight. As to the plume itself it is rapidly cooled by the atmosphere and while visible does not provide the right kind of information most IR seekers need. As to stealth being vastly over-rated that is a popular and uninformed fiction. Stealth in air battle can be compared to mass in boxing. A small but good boxer will often beat a big but bad boxer. But a big good boxer will always beat a small good boxer.