PAK FA

[Wayne S]

They couldn't redesign the trunks after the fact. Look at the inlet shots--the fan is masked.

More and more pictures come out showing the shape, more interesting it does get. The intakes and area around them are very similar to the design put into the F-18E/F Intakes. See allot of similar theories of design.

Edited January 30, 2010 by Wayne S

[Waco]

Honestly, i swear, i don't see any F-22 blood in it. At all. Can anyone point out exactly what i am missing? YF-23ish, little bit yes. But not F-22.

You're kidding, right? General layout of the flight control surfaces, overall shape of the wing, overlap/sawtooth between the flaperons and the horizontal stabs...the entire outer mold line is pure F-22, including the line formed by the PAK-FA's LERX. It almost perfectly matches the upper line of the F-22s intake/chine. I'll grant that the wing is more swept than an F-22, but seems to very closely mirror the wing sweep of the YF-22. Additionally, the stabs look more YF-22ish, but that is consistent with the degrees of wing sweep. Even the actuator housing blisters derive from the F-22 bloodline.

What I personally don't see are any indications of this:

[Wayne S]

Has anyone seen true dimensions for it yet?

[foxmulder_ms]

The intake trunks look perfectly straight. Isn't having the jet fans visible from the front highly unstealthy?

:) I think it is like this:

Red: inlet (what you see from outside)

Black: turbine blades

Orange: trunk placement and diameter closer to inlet

Blue: trunk placement and diameter closer to blades

Trunk diameter and inlet diameter might be different so this lets a "~" shape trunk.

[MarkW]

You're kidding, right? General layout of the flight control surfaces, overall shape of the wing, overlap/sawtooth between the flaperons and the horizontal stabs...the entire outer mold line is pure F-22, including the line formed by the PAK-FA's LERX. It almost perfectly matches the upper line of the F-22s intake/chine. I'll grant that the wing is more swept than an F-22, but seems to very closely mirror the wing sweep of the YF-22. Additionally, the stabs look more YF-22ish, but that is consistent with the degrees of wing sweep. Even the actuator housing blisters derive from the F-22 bloodline.

Yeah, not trying to point fingers here, but aside from the inlet length, they have a strikingly similar planform. Ok, the stinger is different, but...

Side view I think not so much similarity, or not as much. I wonder what the drag counts look like. Is it "F-22 multirole" or more "JSF multirole" in design? Looks to me to be a good deal thicker than the F-22, and those wing root mounted things can't help. Probably still goes like a bat out of hell, but I'm really curious about range and sustained cruise performance.

This makes a good case about "straight" inlets, courtesy Waco--those F-22 inlets look pretty darn straight too, but you ain't seeing the fan from the outside.

[ST0RM]

What I personally don't see are any indications of this

From the front left/right and sides, it has the squatted look of the YF-23. But from the angle below as you have shown, I do see the Raptor likenesses.

-S

[Waco]

I dunno Storm, after watching the takeoff multiple times, I was struck by how much it reminded me of watching F-22 rotations and takeoffs...

[BAM'n'IVM]

Kind'a looks like a slightly squished Raptor with Sukhoi engines and forward fuselage. Pretty, though - and I don't often say that about Russian designs. Definitely not a "copy", but definitely thinking along the same lines.

[ST0RM]

I dunno Storm, after watching the takeoff multiple times, I was struck by how much it reminded me of watching F-22 rotations and takeoffs...

Well, you would be the expert. I only see them from the top and the occasional side bank shot :)

[Jonathan_Lotton]

Once again..the Russians have stolen a design...

This time..they stole a design from a video game..created by the Japanese.

The X-03 Wyvern, from Ace Combat 5.

Aside from the forward swept wings....its scary.

[GreyGhost]

Aviation Week preliminary analysis ...

>>> Clicky <<<

Gregg

[BrittMac]

The "moving LEX" is pretty neat.

I agree that it looks a lot like a Raptor in its vertical planform (looking at it from the bottom or top). From some angles it has some looks like the YF-23 as well. It will be interesting to see what the in-service version ends up looking like. I mean, really, this is just a prototype after all. I suspect it will end up looking a bit different in the end.

Not a bad looking bird either, I might add.

Does anyone else think the engines are "splayed" outward? Looks like that in the shot showing the bottom. Could be an illusion caused by the camera though. I dunno.

[Berkut]

General layout of the flight control surfaces...

Hi every plane since 1940's...

overall shape of the wing,

I will give you that, from underside. The way it connects into fuselage is totally different and leading angle is also different. Which overall, says the design philosophy of PAK-FA. They wanted to make it faster, but not loose lift, hence the broad and highlifting fuselage.

,,,the entire outer mold line is pure F-22, including the line formed by the PAK-FA's LERX. It almost perfectly matches the upper line of the F-22s intake/chine.

Entire wow. If you say so. I am deffenitly seeing a totally different design than you.

Additionally, the stabs look more YF-22ish, but that is consistent with the degrees of wing sweep.

Stabs are tiny on PAK-FA and whole-turning. The area they sit on is vastly different.

Even the actuator housing blisters derive from the F-22 bloodline.

Okei, now it is my turn: You're kidding, right? Look at the bottom of any airliner. You will see tons of those blisters. Hint: Area rule. Overall, F-22 and T-50 is vastly different in aerodynamics. Vastly.

But seriously, this is not going to end well, and you know that Waco. I have made my points, you have made yours. So please, lets stop pointing fingers before the thread goes bad and into the toilet. It is a nice thread so far.

[Wayne S]

But seriously, this is not going to end well, and you know that Waco. I have made my points, you have made yours. So please, lets stop pointing fingers before the thread goes bad and into the toilet. It is a nice thread so far.

I don't think he was attacking it with that post, he is comparing it more to the YF-22/F-22 Then the looks of the YF-23.

Russia and America has always been pretty close in design mainly because we have the same need of Aircraft. Where most of Europe does not.

T-50 fallows pretty much how both countries designs were in the mid-late 80s.

T-50/PAK-FA looks like the Idea is to keep it in the bargain Basement price range, sports car "Vette"?. Where the F-22 is a "Ferrari" with out the Multi disk CD/DVD player but has the option for an I-pod.

[11bee]

deleted post....

Edited January 30, 2010 by 11bee

[Waco]

But seriously, this is not going to end well, and you know that Waco. I have made my points, you have made yours. So please, lets stop pointing fingers before the thread goes bad and into the toilet. It is a nice thread so far.

Thanks for taking it personally Berkut. I appreciate that. A very mature approach to the discussion.

So far, there's been a lot of comments that it looks like a YF-23, and you said that it in no way resembles an F-22. I took some pictures that I think illustrate very clearly that the outer mold line of the aircraft is very, very similar to an F-22. I didn't say it was a copy, I didn't say it was reverse engineering, I didn't say it was a ripoff. As I illustrated in the pictures, if you traced the outer mold line of both aircraft from a pure planform perspective, used only that outline and simply shaded in the middle, the silhouttes would look remarkably similar. How they arrived at the conclusion for that outer mold line, I cannot say. I'll wait for somebody with an engineering background to state in detail that similar technological challenges will arrive at similar looking solutions. Ben Rich, one of the primary designers of the F-117, wrote in his book Skunk Works that the outer-mold line was one of the most important facets in the design of a stealth aircraft. So I just thought it was interesting that the outer-mold line on the PAK-FA and F-22 is very similar.

To address a few of your other points, only because you have completely misunderstood what I posted:

Hi every plane since 1940's

While that may be true, there are a few similarities of the control surfaces layout that are similar and fairly UNIQUE to both the F-22 and PAK-FA: the chopped trapezoidal shape of the blended wing/upper fuselage, the shape of the stabs, the outward canted tails, the alignment of the stabs with the wings (rather than having some vertical displacement high or low from the wing surface area), and the overlap of the stabs with the wing control surfaces (necessitating that large corner cut on the flaperons).

Stabs are tiny on PAK-FA and whole-turning. The area they sit on is vastly different.

Stabs, not tail/rudders. To differentiate, what I was talking about was the horizontal stabilizors, or horizontal tails if you wish. Those are very similar in shape (again looking at the outer mold line) to the YF-22. What you are talking about are the vertical tails, or all-moving rudders. Those are obviously quite different.

Look at the bottom of any airliner. You will see tons of those blisters.

Not shaped exactly the same as the shape and placement on the control surfaces as the F-22. "Derived" was a strong word. I should have used reflective of the F-22 bloodline. The rounded diamond shape blended into the lower wing surface and placed exactly as they are on the ailerons and flaperons is not, however, found on the bottom of any airliner.

Now to counter-arguments. Logically, there are some significant differences between the two aircraft. The huge, widely spaced engine tunnels are far more reflective of Flanker ancestry, as pointed out in the AvWeek article linked above. The long goose neck and standard Flanker wanker are also Su-27 ancestry. The nose cross section looks similar for the top half, but the PAK-FA's chopped lower section lops off the bottom part, resulting in an assymetric pentagon of sorts. The F-22s is more diamond shaped.

I think the different leading edge sweep is far more telling. Sukhoi is clearly aiming for a very high top end speed on this sucker.

Despite the differences, I think Sukhoi appears to have taken Ben Rich's quoted approach, and as a result, the outer mold lines are remarkably similar. Inside that outer planform, there are a lot of differences, most notably with the layout of intake trunking, engine housing, and weapons bays.

Now if you'd like, can we return to the nice thread? I was rather enjoying the comments, discussions, and comparisons of where Sukhoi adopted existing aviation design principles and where they have new innovations. Before I was called out, that is.

Personally, I am still most interested in the moveable leading edge extension. I'm curious if its function is, as I suspect, to perform like the forward canards of the later-Flanker models. It could be something entirely different though, more in line with controlling aerodynamic flow over the upper wing and into the engine inlets.

[Berkut]

Maybe I missed something in the other 2,000 posts on this subject but where exactly are the weapons bays? The Raptor has it's primary bays between the engine intakes. Doesn't look like there is enough room on the PAK and if there is, I think it would cut into space available for fuel tanks.

Two weaponbays between engines. Around 5 meters in length each. + Rumors of weaponbays for missiles firing backwards.

Next flight will be on monday.

[Waco]

The Raptor has it's primary bays between the engine intakes. Doesn't look like there is enough room on the PAK and if there is, I think it would cut into space available for fuel tanks.

Actually, it's more appropriate to say that the F-22's weapon bays are under the intake trunking. Check out some pics of the new Hasegawa models intake trunking and you can see how the tubes kink inward from the intakes and then move upward to pass over the weapons bays.

PAK-FA's weapon bays are between the intakes, arranged in tandem rather than side-by-side like the Raptor.

[Berkut]

Thanks for taking it personally Berkut. I appreciate that. A very mature approach to the discussion.

Sigh, it is actually you that took it personal just now. I was just trying to get the discussion done, over, zakonchit, finito. Because if you look at the amount of threads locked, there is a same pattern over and over again. And that pattern closes threads. It takes just one person in this thread to not argument well, and then the thread will be locked due to the hell that will brake loose.

It is not that i don't want to have the discussion, it is just that this can get explosive (not because of you or me, but someone else) very very fast. And i personally would like to see this thread continue.

[Raymond]

[Flankerman]

the T-10 we all know that the first prtotypes were so much different from what we know now as Su-27

Yes - but that was only done because the T-10 did not meet its performance targets.

Mikhail Simonov took the very brave and bold decision to completely re-design the T-10 - and it emerged a year later as the T-10S - with a veryy different layout.

Given the advent of modern CAD and fluid dynamics computers, there is no reason to suppose that the T-50 will need any changes - a couple of tweaks maybe, but not a re-design.

Mind you, the F-22 was very different to the YF-22, so maybe it will change in the light of flight testing.

But I would be very surprised if it followed the T-10/T-10S route.

Ken

Edited January 30, 2010 by Flankerman

[Jeff]

So, how stealthy is the PAK FA? From the frontal and side cross section, it seems to me the RCS is even lower than the F-22. The only thing that bothers me with the PAK FA is the intake seems to expose the blades of the engine. Maybe they have some RAM coating or zig zag edge along the length of the intake tube to solve that problem.

[Sebastijan]

The only thing that bothers me with the PAK FA is the intake seems to expose the blades of the engine.

It is interesting to see how many people are bothered with that but yet there have been no detailed photos where intake could be seen. I'm sure the intake trunking is such that fan blades cannot be seen...

[MarkW]

Two weaponbays between engines. Around 5 meters in length each. + Rumors of weaponbays for missiles firing backwards.

What about the bumps on the underside of the wing just outboard of the gear? The ones suspiciously sized for short range AAMs?

[MarkW]

I think the different leading edge sweep is far more telling. Sukhoi is clearly aiming for a very high top end speed on this sucker.

Or it could be driven by planform issues. The F-117 wing sweep, for example was not driven by speed. This is likely a compromise sweep angle.