Sukhoi Su-57 / T-50 / PAK FA - flight testing and development Part I [2010-2012]

[sferrin]

Well, I've always assumed that any Sukhoi design uses past Sukhoi (or TsAGI) studies and that Russian air doctrines require widely spaced engines, high maneuverability etc. - Similarities don't surprise me.
After all, the F-22 is just a derived F-15

But let's not start that discussion again!

In your shoes I wouldn't want to either.

 

[saintkatanalegacy]

...

people don't even bother mentioning the drag reduction patents

 

[Ogami musashi]

There're patents for every plane designed....The ATF programs was full of patents!

My very point is that we know too little to judge those planes; I can't understand how some people can believe they have it right when they judge a plane by looking at it and mentionning 3 or 4 tidbits!

The web (and surely the world) is full of that; I recall in france, on some french forums, some people did really believe that because they don't see condensated vortex on Rafale's photos the rafale had laminar aerodynamics all the way!!

...And i see on AFM the same thing with J-20..."The plane is heavy so it is a striker" ..."the wing are too far back of the CG for the plane to be maneuverable.."

Damn, if engineers and researchers where like that fokker would have never tried thick wing profile on the DR.I..."Because it drags too much!"


sigh....

 

[flanker]

Look at the top of the tail. Is it the logo of the photographer or the real stuff?

Noticed just now? Trident is correct, it is just a "copyright" nick.

 

[sanjeev.k]

Tellingly, the Russkies aren't keen on the 2 seater 'FGFA', because of the RCS penalty.

I have always wondered whether the indian reporter (who attributed that statement to the Russians) got his facts/translation right? Evidently he's implying that the Russians have never heard of the FB-22/FB-23 (which did feature a 2nd weapon system operator without compromising forward stealth) ?

Actually cant they can go further ? - since they are going to be structural adjustments to develop the FGFA - they can add a few more apertures and basically create an F-35 like EODAS system (so the WSO can get a near 360 view of the airspace without having to be physically within an enlarged cockpit bubble). Yes there will be software challenges (probably not that simple to create a composite visual mosaic of the airspace from many IRST sensors)- but thats why my country is considering investing so many billions of $$$ in the FGFA (otherwise they might as well pack up their bags and go home).

 

[flanker]

A couple of "new" pictures i found:

http://www.ruaviation.com/docs/4/2010/11/2/14/

+ interview:

http://www.ruaviation.com/docs/3/2010/12/21/18/

 

[Wil]

Hello Boys (and Girls??)!

Some "old" pictures of PAK FA, but now processed with PS!

http://img717.imageshack.us/img717/8849/t501z.jpg

http://img513.imageshack.us/img513/1246/t502.jpg

http://img255.imageshack.us/img255/4530/t503.jpg

http://img833.imageshack.us/img833/4476/t504.jpg

http://img703.imageshack.us/img703/638/t505.jpg

http://img831.imageshack.us/img831/1228/t506.jpg

http://img688.imageshack.us/img688/8155/t508.jpg


It's very interesting to note the design "lifting body" of PAK FA. Therefore, the PAK FA has wings smaller than the F-22 Raptor and J-20. And it can, among other things, take off without the use of post-combustion.

(!!)

 

[lastdingo]

post-combustion.

"afterburner"

All fighters can do that - it just take s a little bit more runway.

 

[Wil]

All fighters can do that - it just take s a little bit more runway.

Hi!

The PAK FA can make short takeoffs (and climbing almost vertical) without "afterburner"...

http://www.youtube.com/watch?v=B5t6R9faLf8

How many planes can do this?

???

 

[SOC]

The F-14D (and presumably the F-14A+/B) could takeoff without afterburners.

 

[AeroFranz]

I'm assuming you refer to being catapulted from a carrier without using A/B.

I don't understand the few past posts. All you need to do to takeoff is reach a speed down the runway such that when rotated at the proper alpha, your lift is fractionally higher than weight (typically 1.1 or 1.2 times).

To be honest that entails having enough speed and tail control to rotate the aircraft as well. So, provided your tail size and deflection is sized properly, all it takes to takeoff is accelerating down the runway. If you don't have a whole lot of excess of thrust, then it will take you longer to acquire enough speed, but unless your drag is actually higher than your thrust (in which case you have bigger problems than just trying to takeoff!), you WILL eventually be in a position to takeoff.
The use of A/B simply increases the difference between thrust and drag, but modern fighters usually have plenty of excess thrust even in dry thrust. Use of A/B is probably useful when taking off with lots of ordnance hung under the airplane, in which case both weight and drag are increased.

 

[saintkatanalegacy]

well, that's where the levcons and slats come into play while on positive alpha

 

[flateric]

posted incognito at Paralay's forum. Picture origin is a Serbian(!) forum
so far I can confirm that this is authentic profile of "Izd.117" (whatever caption says) and attached 2D TVC nozzle drawing from Saturn's patent filed in 2008
I'm not quite sure if combo pic is authentic though - they seems to be just joined in PS

 

[Trident]

Interesting - so the accessories have been moved back to the bottom of the engine for the T-50, this fits in with that preliminary PAK-FA design with s-ducts, where this was also the case. That nozzle is particularly fascinating though, nevermind serpentine inlet ducts, what about serpentine nozzles (at least when fully closed, i.e. full dry thrust)!

 

[saintkatanalegacy]

well... it's only a semi S-duct for the inlet...

otherwise the main landing gear won't fit in...

it is also interesting to note that only roughly 1/3 of the compressor face would be visible(at least that's how my model looks like when I used paralay's schematics) :-[

 

[Sundog]

All fighters can do that - it just take s a little bit more runway.

Hi!

The PAK FA can make short takeoffs (and climbing almost vertical) without "afterburner"...

How many planes can do this?


???

Every modern fighter can do that. It's a matter of what their load is when they do that. If you think the display you witnessed in that video was performed with a full fuel load and ballast to simulate a full weapons load, you are mistaken.

 

[saintkatanalegacy]

my attempt of the nozzle patent

www.youtube.com/watch?v=sIV-LDfi99g

 

[flateric]

combo image found to be a fake by Paralay
while nozzle patent image is authentic, engine is not Article 117 (AL-41A1) but ordinary AL-31F with fake caption
whatever, this is not the only TVC nozzle patent filed by Saturn last years

 

[saintkatanalegacy]

may we see the patents? please ;D

 

[Husar]

Flat Nozzle patent
http://bd.patent.su/2383000-2383999/pat/servl/servlet64dd.html

 

[chuck4]

What is the point of this nozzle?

 

[SOC]

What is the point of this nozzle?

Looking like that? Rear-hemisphere RCS reduction, if you ask me. It doesn't look so much like it's actually vectoring the thrust as it is repositioning the exhaust stream. Sync it with your ESM or RWR gear and you could adapt your nozzle profile to the most pertinent threat emitters.

 

[Fox_One]

How much certainty is that production aircraft will have 2D nozzles? Is it possible that in the end a compromise will be made for a conventional round nozzle, maybe modified with some serrated edges/flaps like F-35?

 

[saintkatanalegacy]

IIRC, the axissymmetric nozzles would be for the 1st phase engines while the flat nozzles are for the 2nd phase engines

anyways...

if the flat nozzles were installed... hmmm...

www.youtube.com/watch?v=dWkQRPzYrlQ

 

[Otaku]

my attempt of the nozzle patent

www.youtube.com/watch?v=sIV-LDfi99g

Just an observation, but I think you have it upside-down (check the official patent ;D).

The lower leaf is no.3 (in fig.1), which means the exhaust channel bends upwards:

 

[chuck4]

It seems this nozzle can never fully open up to the degree seen in normal axial symmetric nozzles or even in F-22's 2D nozzle. Does this mean it would restrict the use of afterburners?

 

[chuck4]

Also, how would T-50's maneuverability suffer from the loss of thrust vectoring? Also, as I understand it, the center of lift tends to move backwards when aircraft go supersonic, thus pitching the airtcraft down.. With this nozzle, the axis of thrust seems to move up as the the nozzle open up in response to thrust increase. This would also tend to pitch the aircraft down, worsening the effect of the move of center of lift. This would seem to me to combine to increase the control input needed from the FBW system during parts of the flight envelope, and thus worsen the aircraft's efficiency. Any thoughts?

 

[saintkatanalegacy]

Just an observation, but I think you have it upside-down (check the official patent ;D).

The lower leaf is no.3 (in fig.1), which means the exhaust channel bends upwards:

:'( ah well, I'll try again tonight

 

[kcran567]

I look at the t-50 and see the Russians wanted to take the best from each aircraft...

front end cockpit area very Northrop yf-23 like with a f-22 wing and Flanker style "centroplane" lifting fuselage for the weapons bays...add in the all moving vertical tails, adjustable LERX, and 3-d vectoring and you have a less stealthy, yet more maneuverable airplane than the f-22, but later versions should be more stealthy.

Excuse me but when i read things like that...what do you know about stealth? aerodynamics? How can you judge a plane you've seen on 2 videos only by bits?

Do you seriously think things are that simple?

No, you don't take best part from each plane; it doesn't work like that; a plane is an integral thing it is not because you take the 23 like front end with F-22 wings that it works.

When you design a plane you design it with all dimensions in mind.

World is not black or white and a simply study of performance of F-15 vs SU-27 shows you that lerx and tunnel on SU-27 is not equal to better performance;

Regarding those who believe that the t-50 and Flanker are related, only in the nacelle layout and centroplane. Think of it as a family stealthy "evolution" of the Flanker rather than a completely new jump into an entirely untested airplane configuration.

What is an untested airplane configuration for you? You think that because you have a tunnel it can't bring new flow fields?? That you master it an had only to tweak it??


I wish people would stop believe they can in one glance do the same work than 10 years of windtunnel,CFD and phd+20 years experienced people's work.


Not directed against you in an offensive way but with the release of J-20 i'm overflooded with those kind of people that already know what is good and is not good on a plane that hasn't even left the ground...and the S-duct stupid rants on pak-fa did set me on earlier..

Why reinvent the wheel? You must live in a world where no good ideas can be re-used, especially on the t-50. Unfortunately, the Russians have always borrowed ideas that worked, including the ones used on their own older aircraft.

 

[saintkatanalegacy]

like it's as easy as lego to do that :

 

[saintkatanalegacy]

I've been thinking a lot lately of the flat nozzles being located a bit forward than the axissymmetric nozzles coz these modifications would somehow increase the weight and consequently place the center of gravity further to the rear. Another would be the drag penalty associated with increasing the cross section of the aft section...

So I would somehow speculate some structural changes for the airframe once the 2nd phase engines are to be installed particularly shortening of the duct and possibly bringing the engines a bit forward... unless they decide to move the MLG backward ???

 

[LowObservable]

It's a neat design but could be an absolute sodder to mechanize, much less cool, unless you make the whole thing out of ceramic matrix composites.

 

[flanker]

Just heads up. There is an article in Air International regarding PAK FA. A few new pics that i personally haven't seen before. The information is ok, pretty accurate sum up with a few mistakes.

 

[saintkatanalegacy]

is the bottom half of the first picture suggesting an ejector flat nozzle arrangement?

 

[Austin]

NIIP AESA Ready for Test Flight ( via TakeOff Magazine )

 

[saintkatanalegacy]

should be interesting once the 3rd flying prototype is up

 

[saintkatanalegacy]

www.youtube.com/watch?v=wmqnWnERwIg

intake blocker

 

[sferrin]

I'll bet that would do wonders for airflow.

 

[saintkatanalegacy]

from what I've heard, the blocker won't be movable but I animated it anyway

 

[chuck4]

Don't believe the the shape illustrated for this "blocker" can work. Not sure how these radial and cylindrical vanes blocks radar waves traveling straight down the intake. If you can see the fan face straight down the intake through these "blockers", so car radar, no? You would need at least some shaping of the vanes so radar waves must bounce off them before hitting the fan face.