Sukhoi T-50 PAK FA manouverability versus F-22

[chuck4]

But only in gibberish.

 

[Trident]

This may be OT, but the debate prompted me to rummage round for a video of that elusive Su-30 display, and sure enough, I got what I wanted! Here it is, in all its glory (starts at 22:46):
http://www.youtube.com/watch?v=WK2m4bbjvjs
It does not one but TWO tail slides with a highly asymmetrical load totalling north of 5000kg, possibly closer to 5500kg From photos taken at Farnborough 1994, it seems the load comprised of 6xFAB-250M54, 4xR-73M, 1xR-77, 1xR-27ER, 1xKh-31P, 1xKh-59M, 1xKAB-500KR & 1xAPK-9 data-link pod, though I'm not positive on the KAB-500 (it's the forward centre line load - any better ideas?). Sure, the Rafale looked a lot less sluggish, but the Su-30 was carrying half a Rafale around in ballast for god's sake!
For completeness' sake, here's the video showing the aforementioned Su-35 display, actually at the same airshow it turns out (starts at 2:17):
http://www.youtube.com/watch?v=03dkxAk5Qpc


Payload is 3xR-27ER, 4xR-77 and 4xR-73M for a total of some 2200kg - still a very big load by airshow standards and more than most Western aircraft have ever flown with on such occasions.

 

[Trident]

But only in gibberish.

True that, a big part of the reason why the Flanker does not have a similar record is likely to be plain lack of opportunity. Also, some 95% of those 104 kills are opponents which you'd EXPECT the F-15 to outperform - the only victories that were even a contest on paper are a handful of MiG-29s. And even then, half of them (the Serbian airframes) were hardly airworthy at the time, let alone fit for combat against a force that was crushingly superior in numbers, situational awareness and training.
Sure, the Su-27's kill record is in the single digits, but it has almost as many MiG-29s to its credit and managed to accumulate its victories in FAR more trying conditions than the F-15 - no numerical superiority, no AWACS support and enemy pilots of similar skill.

 

[lantinian]

It does not one but TWO tail slides with a highly asymmetrical load totalling north of 5000kg, possibly closer to 5500kg

Impressive displays, however only the bluish SU-35 with the red air to air only armament performed a Cobra maneuver once in a level flight. The second display where the aircraft had the asymmetric weapons load showed no such maneuvers.

I also wonder if air show aircraft are allowed to cary real weapons and if those were mounted on the planes were just mockups or aerodynamic dummies.

 

[Trident]

Impressive displays, however only the bluish SU-35 with the red air to air only armament performed a Cobra maneuver once in a level flight. The second display where the aircraft had the asymmetric weapons load showed no such maneuvers.

I didn't claim the Su-30MK performed a Cobra - I just thought it was worth posting as the point that Russian aircraft are normally flown without weapons at airshows (nevermind the fact that the same is true for Western aircraft) keeps getting repeated over and over again. As Churchill put it: "When you have an important point to make, don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time - a tremendous whack."
And a Tail Slide with 5000+kg of weapons in an asymmetrical configuration (potentially very problematic at high AoA) is certainly nothing to sneeze at!

I also wonder if air show aircraft are allowed to cary real weapons and if those were mounted on the planes were just mockups or aerodynamic dummies.

You can be 100% certain they were dummies. Does it matter though? Their mass, centre of gravity and drag characteristics are designed to match those of the real weapons accurately, so the impact on the aircraft's performance is the same (that's what their real function during actual test flying outside the airshow setting is, after all).

 

[kcran567]

Wouldn't the triangular missile bay under the so called "leading edge extension" on the T-50 act as a sort of tip winglet and inhibit to some degree the formation of tip vortices ? So instead of being true Leading edge extensions optimized to give strong vortices, they would only secondarily generate vortices, sort of like the hard chine on F-22?

Also, I am not entirely sure exactly what LEVCON could do. Has anyone see them deflect upwards? I've only seen them deflect downwards. If they only deflect downwards, then they look to me like an extension of the leading edge flaps on the main wing. If this is true, then when the LEVCON deflect downwards, they permit higher angle of attack without airflow separation over the parts of fuselage above the air intakes. This permit the plane to achieve higher AOA without entering the post stall regime.

These Levcons are deflecting upwards. I've seen pictures where they are deflecting upwards 5 degrees or less on takeoff as well. You can see them deflecting upwards in a lot of the takeoff pictures. And of course, the things practically drag on the ground when the T-50 is powered down. So they can deflect down quite a bit, and up not so much.

 

[kcran567]

I asked a few questions over at f-16.net, and some of the posters brought up that the T-50 may have a higher bleed rate than the F-22 in tight turns because apparently, greater wing sweep typically means more AOA needed for a given amount of lift and thus more drag.

Also, T-50 has advanced features like LEVCONs and leading edge root extensions to improve lift, while the F-22 has nothing of the sort. I don't see how F-22 can match the T-50 in maneuvering performance.

The Pakfa is going to bleed energy off more than an F-16 would due to the f-16 having a smaller trapezoidal wing. When the F-16 was being designed its wing was optimized for transonic maneuver better than the mig-21. The mig-21 having a high bleed rate due to its delta wing. Supposedly the Levcon helps reduce energy bleed in a delta and that was one reason it was put on the Pakfa.

 

[kcran567]

Although airshow performances does not entirely reflect the plane's aerodynamics in actual combat, the Su-35's demonstrations are a lot more aggressive and shows tighter turns and maneuvers than F-22 demo.

Go and look at some more f-22 demos for pete's sake. The thing is doing J-turns, back flips, tail slides, and all sharp, crisp, high energy maneuvers. when the engines are going the plane practically looks weightless during hard maneuvers, and you can see the vortices ripping off the wing edges at a much higher energy than what I've seen of any Pakfa of Flanker demos I've looked at. And I'm being fair, I like the Pakfa and the Flanker.

 

[TaiidanTomcat]

Its come to this? Airshow demonstrations?

 

[EricChase88]

Although airshow performances does not entirely reflect the plane's aerodynamics in actual combat, the Su-35's demonstrations are a lot more aggressive and shows tighter turns and maneuvers than F-22 demo.

Go and look at some more f-22 demos for pete's sake. The thing is doing J-turns, back flips, tail slides, and all sharp, crisp, high energy maneuvers. when the engines are going the plane practically looks weightless during hard maneuvers, and you can see the vortices ripping off the wing edges at a much higher energy than what I've seen of any Pakfa of Flanker demos I've looked at. And I'm being fair, I like the Pakfa and the Flanker.

And how much fuel does F-22 carry when doing demos? Likely the minimum amount.

Lets not talk about air shows anymore, it's irrelevant and don't represent combat performance.

 

[BioLuminescentLamprey]

The F22 performs airshows at representative combat weights. Full fuel, I believe.


....and this discussion is ridiculous. The F22 is really an impressive plane at high speed/high altitude, where I'm not sure any of us will ever see it. Airshows can really only demonstrate low speed and post-stall maneuverability, as I understand it. Some aspects of performance could be gauged by that, but that's not really what you would need to see to get the important intel on the fighter.

 

[chuck4]

I would wonder why anyone would want the F-22 to perform at airshows with full fuel load unless they plan to make the show so tendiously long as to consume all the fuel. All flying with full fuel would do in an airshow is to waste fuel unnecessarily in throwing around a heavier plane burdened with surplus fuel, stress the airframe more for no reason, and make a bigger fireball if there is an accident.

As to Su-35 carrying a full complement of 10 missiles in air shows, that certain makes it look impressive since all those missiles are necessarily carried non-stealthily for all to see, similar to how Soviet warships were thought to look more impressive than American ones because they had most of their bigger missiles on the outside.

But as others said, those missiles Su-35 are almost certainly not real for safety reasons. Also, regarding the notion that those missiles are inert rounds with same weight as real missiles, I see no reason for it. Why would they use such a thing in a air show? In air show you are not testing the aircraqft's flight, carriage and release characteristics. It is cheap enough to replicate external shape of a missile in a light package that can be cleared for carriage. Using light weight dummy saves on fuel, wear and tear, and still look just as good to put on the plane as any real, weight matched, inert rounds, and those are things you want in an airshow.

I think the main driver for the difference between F-22 and Su-35 routines is F-22 is not being sold at all, much less to anyone so unsophisticated as to be influenced by airshows. Su-35, on the other hand, is being vigorously, some would say desparately, advertised to all and sundry. If anyone is impressionable enough to be influenced by the airshow, so much the better. The big Su-27 family has not been in want of unsophisticated buyers. Countries not long out of the iron age can be found to have a squadron or two of Su-27s, sometimes only operable thanks to mercenary Russian or Ukrainian pilots. Those countries are unlikely to be able to conduct sophisticated comparative analysis and competitive fly offs in making their choices. But money is money even if it is from the horn of Africa.

 

[Machdiamond]

I don't know about the F-22 but when I worked on the F-16 in a previous life, airshow performances always started with full fuel because all it took to burn it all was 7 minutes. Gives you an idea of sea level afterburner fuel flows.
Other than that, I agree with BioLum - this discussion is ridiculous.

 

[bobbymike]

Completely off topic but two F-22 questions:

It is said the F-22 can dramatically increase the range of munitions when at, say, 60,000 ft and Mach 1.6 super cruise. Has anyone seen figures for an AMRAAM and/or a winged SDB II range launched under this scenario?

Thanks and much abliged.

 

[chuck4]

I don't know about the F-22 but when I worked on the F-16 in a previous life, airshow performances always started with full fuel because all it took to burn it all was 7 minutes. Gives you an idea of sea level afterburner fuel flows.
Other than that, I agree with BioLum - this discussion is ridiculous.

Really? I don't remember F-16 going into afterburner for more than 10-15 seconds last air show I saw.

 

[Machdiamond]

That explains why it was the last one I guess.

 

[Machdiamond]

Anyway, if people can't spell the word correctly they probably should not embarrass themselves discussing about boebs like teenagers in public either.
E-M diagrams would be a good starting point, albeit short sighted. Otherwise there are other forums available.

 

[chuck4]

And you find em diagrams for f22 and t50 where?

 

[Machdiamond]

My point exactly.

 

[EricChase88]

According to this document, the F-22 demo is done with 18000 pounds of fuel. That is full or close to full, as I see max fuel numbers of 18000 pounds and 20000 pounds. But why does F-22 demonstrate with so much fuel?

http://www.acc.af.mil/shared/media/document/AFD-130205-068.pdf

 

[EricChase88]

Not much.

In addition, just how much would probably depends on how large the leading edge flaps are compared to the chord of the airfoil. If the LEVCONS act as leading edge flaps for the fuselage, they would seem to be fairly small compare to the chord of the fuselage, furthermore, LEVCON only works on a portion of the fuselage, and that portion is nowhere near an ideal lifting shape, with engine nacelles hanging under it.

The LEVCONs are much longer than the LEFs on the wings, so they should still be very effective. The wing sweep for T-50 is only a little higher than F-22, so the LEVCONs should allow T-50 to have lower AOA and thus drag for a given amount of lift.

 

[Radical]

I honestly don't see how either of the two planes will have distinct advantages over the another. Assuming that both have comparable engines, I think the PAK-FA and the F-22 will be very evenly matched, since they have similar layouts and are probably of similar size and mass.

By the way, since we know the frontal profile of the T-50 is known thanks to those patent documents, does anyone want to take a stab at estimating the frontal area of the T-50 compared to the F-22?

As a side note, I'm actually surprised that these documents are made publicly available. Why would Sukhoi make the T-50's airframe outline diagrams available to the public?

 

[chuck4]

As a side note, I'm actually surprised that these documents are made publicly available. Why would Sukhoi make the T-50's airframe outline diagrams available to the public?

You can see the outlines from the photos, there are plenty of them around. You can get very close with some careful photometry by noting surface markings and using multiple photos from different angles covering the same area.

 

[Radical]

Given that it's publicly available, it does make me wonder if that schematic is accurate. Would Sukhoi release an inaccurate diagram to throw people off? And are such outlines of the F-22 publicly available?

 

[Radical]

I made rough silhouettes using the PAK-FA patent image and F-22 diagram from Lockheed Martin's site. I assumed that both planes have the same wing span. Frontal area seems almost the same, and I think surface area would be comparable too. Question now is which one is better area ruled. My hunch is on the PAK-FA due to its extensive blending and volume positioning.

EDIT: Changed image to more accurate T-50 wingspan of 13.95 m.

 

[flanker]

Why did you assume PAK FA and F-22 has same wingspan when we know the correct wingspan of both aircafts?

 

[chuck4]

Why did you assume PAK FA and F-22 has same wingspan when we know the correct wingspan of both aircafts?

Wouldn't make any difference if the area comparison is based on "it looks like".

 

[Radical]

Why did you assume PAK FA and F-22 has same wingspan when we know the correct wingspan of both aircafts?

Wouldn't make any difference if the area comparison is based on "it looks like".

I thought I saw a figure of 13.95 m for the wingspan in the patent document, which is almost the same as the F-22.

 

[EricChase88]

I saw this link when going through keypublishing. Apparently the test pilot said at around 7:10 of video that the T-50 will be much more maneuverable than Su-35S.

http://www.vesti.ru/only_video.html?vid=438341

 

[EricChase88]

Dr. Carlo Kopp from Australia have a very thorough and extensive analysis of T-50. It is very insightful. It looks like the T-50 can be as stealthy as F-22 if the back is modified in the future.

http://www.ausairpower.net/APA-2010-01.html

 

[flateric]

 

[flateric]

if the back is modified in the future

it will be not

 

[EricChase88]

if the back is modified in the future

it will be not

How do you know? I cant see why not.

 

[TaiidanTomcat]

Dr. Carlo Kopp

have a very thorough and extensive analysis of T-50. It is very insightful. It looks like the T-50 can be as stealthy as F-22 if the back is modified in the future.

the most tactful thing I can say about Airpower Australia, is that they have decided on the result before they do the analysis. That
is the nicest way I can say they are liars, or incompetent, or biased, or just poor analysts. You can take your pick. So yes, the PAKFA was going to be at or near F-22 level before its first flight in APA eyes no matter what, because years ago Kopp hatched a scheme that involved getting F-22s for Australia, so he could then sell upgraded F-111s to the Australian government. it failed, but the show must go on.

 

[flateric]

How do you know? I cant see why not.

I just know. Trust me. (c)

 

[flateric]

the most tactful thing I can say about Airpower Australia, is that they have decided on the result before they do the analysis.

you just start reading, it goes kinda good, good (analysis, analysis) but at the unnoticed moment you feel like that you are reading The Hatter memoirs or front page of Pravda or People's Daily.

 

[EricChase88]

How do you know? I cant see why not.

I just know. Trust me. (c)

So you have inside information? How can you know they won't make big stealth improvements in the future like in Su-35S? Also, Dr. Carlo Kopp is a reputable source and member of well known groups.

http://www.ausairpower.net/editor.html

 

[TaiidanTomcat]

the most tactful thing I can say about Airpower Australia, is that they have decided on the result before they do the analysis.

you just start reading, it goes kinda good, good (analysis, analysis) but at the unnoticed moment you feel like that you are reading The Hatter memoirs or front page of Pravda or People's Daily.

FTFA:

Notes/References/Bibliography

More than 40 Russian publications were employed in the preparation of this Technical Report. Due to this large number, and the reality that most redundantly restate the same content, the authors have opted not to list these comprehensively.

That was nice of him. wish I had thought of that trick in college. References? oh there were just so many that said the same thing, I didn't feel I needed to list them all!!

Aw here we are:

The only aircraft built by the United States which can survive in airspace contested by the PAK-FA is the F-22 Raptor, and given the time frame of interest, it is the only design which can be adapted to defeat the PAK-FA.

In basic grand strategy terms, the arrival of the PAK-FA leaves the United States with only one viable option if it intends to remain viable in the global air power game - build enough F-22 Raptors to replace most of the US legacy fighter fleet, and terminate the F-35 Joint Strike Fighter as soon as possible,

I knew it was in there somewhere, every viable analysis ends the same viable way. In basic grand strategy terms, Airplane Y is vastly superior in to Airplane Z and only the F-22 has a chance against Aircraft Y.

 

[flateric]

So you have inside information? How can you know they won't make big stealth improvements in the future like in Su-35S?

There's enough open sources information to say that there will be no redesign you think of.
"big stealth improvements in Su-35S"? where?

 

[saintkatanalegacy]

Must have referred from my "speculation/whiff" ejector nozzle ages ago ;D

Well, from where things are heading, it's most likely going to be axis-symmetric nozzles for the Type-30 engines with reduced stages(relative to current ones).