The GaN EW system could mask a B-52 if you told it to, so they’ve probably decided that RCS reduction is good enough with some newer RAM here and there.

One can dream… :rolleyes:

:rolleyes:

I think that you have missed the point of my example, and the point was to show you how drastically the “holes” and their arrangement can make the fighter plane heavy. The whole time I`m talking exactly about the volume, do I need to quote my self: “That way you have very “homogeneous” arrangement that doesn`t need so much strengthening with plenty of room for fuel without additional need to increase the cross section of the plane (that also brings the weight up) because if you have so many holes in the planes structure each above another you have to increase the volume of the plane to put the fuel somewhere (aside from the wings).”

It looks like you missed that part, but at least it`s a good thing you started to think in the right direction, yes the volume and strengthening 😉

Yes, they have internal weapon bays and that is the only thing they have in common because structurally they are very very different and I dedicated almost the whole post in explaining the differences but in vain if I may add.

Think about PAK FA internal weapon bays arrangement like this:

http://s25.photobucket.com/user/bharatrakshak/media/low-rcs.jpg.html

Its weapons bay is more like add on seen on the photo above, where you have all the upper structure/volume used for what it`s meant to be used, plus you get nice blended surface for additional body lift. Again, you don`t have the hole above the hole with holes at each side of the main hole/s that eats up the volume and need additional strengthening and additional increase in volume to store the fuel. That is what you get with F-22 and F-35. And all that big cross section leaves its mark on the performance of the plane, specially in the case of F-35.

Your PAK FA – Su-35S comparison is full of mistakes and pointless because we still don`t have official numbers for PAK FA and Su-35 empty weight.
It is better to compare Su-27 and PAK FA. We can be pretty sure that PAK FA will weight more even if it`s smaller, just like F-22. But it seems (acording to the people from Sukhoi) it`s not going to be that much heavier, F-22 heavier 😉

http://forum.keypublishing.com/attachment.php?attachmentid=224589&d=1380839905

Here is the acceleration chart our colleague made using flight manual data.
We can see that F-16 has excellent subsonic/transonic acceleration but as speed rises the planes with variable inlet geometry are leaving it behind and they continue to accelerate even when F-16 hits the “equilibrium”.
Can you explain why is that so?

Long story short, you have official statement from Mikhail Pogosyan that PAK FA with current engines have 3500 km subsonic combat range and more than 1500 km supersonic combat range. But you can try to dig something up and prove them wrong 😉

I can see this has departed the realm of productive discourse.

Let me put it to you this way… the F-22 is a design very highly optimized for kinematic performance, with a particular emphasis on supercruise performance.

For a while they discussed the possibility of an FB-22, a strike optimized variant.

If someone said the FB-22 would have far greater range and carrying capacity I wouldn’t have any problem believing it. Both of those changes would have been key in adapting it to a strike role.

What if someone announced, that in addition to featuring far greater range and carrying capacity, the FB-22 was also lighter, faster, and more maneuverable than the original F-22. Suddenly people would become more than a little… skeptical.

The simple fact is that the F-22 is very near what is achievable from a kinematic standpoint short of some major conceptual or technological breakthrough. Even aircraft like the Eurofighter, certainly no slouch, can’t match it at its strengths. That isn’t to say it will stand as some kind of benchmark for all time, but beating it by any significant margin will require a serious breakthrough.

There is no such thing as a free lunch.

If you add volume, add wing area, add avionics, add fuel, it is going to cost you somewhere.

As amusing as I find the idea that the F-22’s intakes simultaneously account for thousands of kilos of extra weight, and cripple its supercruise performance… I find that more than a little unlikely given that that would run 100% contrary to most of the F-22’s primary design goals and the F-22’s designers don’t appear to have been a bunch of idiots.

If you like to believe the F-22’s designers were just a bunch of idiots, how do you explain the obvious incompetence of the Su-35’s designers? How could they have screwed up so badly that only 2 years after the first flight of the final version of their new fighter that the PAK FA would fly… with all the same features and more, plus a bunch of LO features and internal bays… and all while weighing less and outperforming their new fighter in every way?

People are always able to find ways to justify things they want to be true and I can see that here. Time will tell…

When we talk about weight, it is very important to look at how that dimensions/volume/structure is distributed.

There is a saying in aero engineering, “the holes are heavy”!
When you have big holes you need a lot of strengthening to do in order for plane not to brake under heavy load. And having internal weapon stores is one good example of that.
Both, PAK FA and F-22 have them but there is a difference.
F-22 has very long and curvy air inlets (by itself it is additional weight) that represent major “hole” in planes structure. Below them is another major “hole”, main internal weapon store. And that is not all, at each side of the inlets there is one more “hole” for SRAAM`s.
My guess is that you need a lot of strengthening to do with such arrangement because you have a hole above the hole with the holes at each side of the main hole/s 😉
PAK FA has entirely different approach to the problem.
Air inlets are much shorter (less weight) and are not the part of the planes body structure in the way Raptors inlets are. They are more like “hanging” type of inlets. Smaller internal weapon stores for SRAAM`s are again “hanging” type of stores and are not in contact with any major “hole”.
And major hole (main weapons bay) above its self doesn`t have another hole, it has planes structure.

http://upload.wikimedia.org/wikipedia/commons/0/01/Sukhoi_T-50_Pichugin.jpg

http://www.kbvp.com/sites/default/files/images/F-22%20burners.preview.jpg

That way you have very “homogeneous” arrangement that doesn`t need so much strengthening with plenty of room for fuel without additional need to increase the cross section of the plane (that also brings the weight up) because if you have so many holes in the planes structure each above another you have to increase the volume of the plane to put the fuel somewhere (aside from the wings).

There is also the problem of the load distribution. If you do it well than you don`t need to strengthen the structure in the way you need to do it if you don`t distribute the load so good.

We also must consider that F-22 has extremely heavy nozzles that contribute to very high weight of the engine. Combined they alone produce more than 800 kg over the PAK FA engines of the first stage.

Regarding equipment, there are so many official statements that all electronic equipment is many many times lighter than the one used in Su-27 for example. After all, this is digitized fighter of the 21`st century.

Because of all that I don`t think it is impossible for PAK FA to be lighter than F-22 specially if this is claimed many times by the main people involved in the program.

I`m not claiming that it can supercruise at M 2,1 and I don`t think there is any official info about T-50 dry thrust, but the dry thrust at see level alone is not good enough for precise assessment.
You need to know L/D and T/D ratio. Plane with better ratios can have higher speed even if it has less thrust, but than again do we know that PAK FA really has less thrust in such cruise condition.
Engines lose power at high speed high altitude flight. I think that is very useful to have very efficient variable inlets for such flight condition (much better pressure recovery) and by a chance PAK FA has them. Not the case with F-22. So again, do we really know the thrust output at such flight conditions for both planes?

There is no precise number for amount of fuel PAK FA is carrying, but chief test pilot Sergey Bogdan said that it can carry even more than Su-35S. So, at least 11,5 tones. Again, the sole amount of fuel plane can carry is not enough for precise assessment. Aerodynamic efficiency and engine efficiency combined with fuel fraction can give much better picture and I don`t doubt for a second that PAK FA will have much better range than F-22.

Today you can make much better compromise than you could few decades ago.
Su-35S is very good example of that. That is the plane that can go as fast as 2500 km/h and can literally stand in one point in the sky close to 90° AoA, can take off from silly short distance with better range than any other operational fighter in existence. How can you explain that?
From what we could see and from what we have heard (coming from test pilots), PAK FA can easily mach and exceed Su-35S in any cardinal performance parameter.

In earlier post I tried to explain the reasons why PAK FA will have such take off and landing performance.

Yes, holes are heavy, but there is no way that comes close to explaining just how far off the numbers are.

You are now claiming the PAK FA has “at least” 11.5 tons of fuel, which changes our comparison table to:

—————–F-22———–PAK FA
Length———18.92m———-19.8m
Wingspan——-13.56m———-13.95m
Wing Area——78m^2———–78.8m^2
Fuel————8,200kg———-11,500kg
Empty weight—19,700kg———18,000kg
Thurst (dry)—–232kN———–186kN or 220kN
Thurst (AB)—–312+kN———-294kN or 352kN

So the PAK FA is larger in every dimension, includes 40% more internal fuel (meaning a PAK FA on internal fuel carries as much fuel as an F-22 with two external 600 gallon tanks), two additional radar apertures, an IRST, DIRCM, and a jammer, and yet weights ~10% less and needs less thrust to supercruise faster and achieves vastly greater fuel efficiency…

Really in general this is less than credible. Some of these claims are perfectly plausible, but all at once? Not even close.

That isn’t to say the PAK FA won’t be a great plane, but this is getting to be another Mig-25 scenario where it is supposed to be the world’s greatest everything, all at once, but the world just doesn’t work that way.

Don’t think anyone dispute the cost factor. But it is design as a Hi value asset, in the very same class as F-22.
There seems to be aerodynamic improvment across the board. The sleekness dictate supersonic and supercruise performance. It also tell us the T-50 has a high lift, which comes from the blended wing/body design.
I personly find the Levcons very interesting, also the all moving horisontal stabz, so many large control surfaces on this bird. Speaks of exellent manuverebility.

However, i think the internal w-bay volume will be modest, and will hold max 6 missile.
I think Sukhoi and VSS requirements favor more volume for fuel.

And with its choice of a wing/body design, lots of internal fuel it will have.

The high cost may be justified as a high-end asset, but it raises questions about Russia’s future force structure. China is producing J-10s, and is developing the J-31. The US has the F-35. Russia will eventually need to develop a lower cost alternative to the PAK FA or see their overall force structure decline dramatically. Su-34, Su-35, PAK FA… all very much heavyweight aircraft.

As for the PAK FA’s performance, we will see. As I said before the numbers just don’t add up.

Take for example the claimed fuel capacity/range.

With a fuel capacity of 10,300kg the PAK FA is claimed to have a range of “Subsonic 4300km” and “supersonic 2000km.”

With a fuel capacity of 8,400kg the F-35 is claimed to have a range a little over half that, and that is with roughly half the installed thrust and a third less empty weight.

You could compare it to the F-22, which on a thurst and weight basis would be a more legit comparison, but then the difference is even greater…

I think it is safe to say the PAK FA’s specs are going to be subject to some serious revision before all is said and done.

In terms of weight, the PAK-FA development is ongoing. The F-22 added about 10,000lbs going from technology demonstrator yf-22 to production.

The PAK-FA is closer to a production representative vehicle, but aircraft do tend to gain weight moving from pre-production to production. There is a high probability the PAK-FA currently weighs less than the F-22. When the first are delivered to the customer, a comparison of weight will be more accurate.

It isn’t just the weight…

Almost certainly the weight number is way low, but also in terms of the range, speed, and handling capabilities. You can’t optimize a design for everything at once.

If you want great short-field performance and low/slow handling you are going to give up some performance at high speed, etc. The way people have been describing the PAK FA thus far it is like they took every spec and every feature anyone has discussed for any aircraft, increased them all by 20-100% and attributed them to the PAK FA.

…and cost will be another factor. This aircraft as described pretty much pegs the scale for cost. Two huge engines, huge airframe, huge avionics fit with more sensors, etc, than any other aircraft. It will be beastly expensive.

Madrat – You’re right. 120-plus F-35s have been delivered. How many of them are operational? (Isn’t that some kind of a record in itself?)

It’s interesting to see the Gripen E/F characterized as an unknown quantity, given that the S/W is the 21st evolution of a fully operational system, much of the weapon integration is essentially done, 1000+ F414s have been delivered and the aero configuration is modestly different from the C/D.

Indeed, you are comparing an upgrade to a clean slate design. Shouldn’t be such a hard concept to grasp. :rolleyes:

Nonetheless, by the time the first air-to-air only capable Gripen NG is delivered the F-35 will be wrapping up its SDD program and will have already delivered several hundred airframes.

The article has since been proven to be wrong. Those aircraft aren’t lost or anything of that sort.

Sputnik….