Yes u are probably right, its a Complete machined bar, but it has to be very wide if not so very deep..

Its all about the distance from the neutral axis.

Maybe you are calling that wide and I am calling it deep.

But just thinking how Sukhoi get around the issue of life hour on the airframe it self.. Do they aim for the same figures as the improved Su-35S, or perhaps Sukhoi even raise the bar further. 🙂 Well it remains to be seen.

Who knows (except outside Sukhoi and the Russian defense ministry).

As Berkut state. Internal structure re-enforced bars are not something that materialize from thin air..

Indeed – it is a question of 2AH^2.

But I believe there is sufficient depth above the bay to allow sufficiently large “H” to avoid the need for a large “A” (larger A = heavier)

Its strenghtning bar, probably made of Titanium and Allue alloy. Its a large section cover wing to wing inside the airframe, in short holding everything togther. There must be several of such section. One in front of the forward W-bay, one in between the two, and one in the aft of 2nd W-bay.

If not, pls explain to us how this is done then?

It would not be a strengthening bar – typically these frames would be full on machined parts.

I was looking at pics of the F-22 wingbox forgings pre-machining just the other day… can’t remember where now…

Are you joking? You do understand that the main wingspar is running right in between the bays?

🙂 Not joking. You could well be right, there is reason to increase the spar depth for moment of area reasons.

But…

given the fuselage extends quite a bit upward above the wing plane around the centreline – I’m not sure it is necessary to intrude into the whole bay. The Flanker series obviously got away without having a lower cross-member between the engine nacelles – how much deeper is PAK-FAs body?

The break is also well aft of the quarter-chord point. Then again, the landing gear is in-line with the break indicating the presence of a big structural member.

From a structural POV – the lightest solution would have had the lower surface of the fuselage aligned with the lowest point of the nacelles. It would also increase weapons bay depth at little weight addition (but would come at a bit of a Mach-Area sacrifice).

If this is accurate – they shouldn’t need the spar lower flange to go through the bay. But it would be quite a bit lighter if they did so.
http://forum.keypublishing.com/attachment.php?attachmentid=216858&d=1369158154

There is no logical reason for having a long ass bay.

Apart from fitting long assed weapons into it.

And if that is a “placeholder” then clearly russians are morons for having same type of placeholder on Su-47.

That was just the size of the S-47 full bay, due to the nose gear and due to the close mounted engines.
http://www3.picturepush.com/photo/a/8992721/img/8992721.jpg

Which needless to say, was also a prototype

I think a brand new run of B-1s, using modern materials and processes would be a good replacement for the B-52, with the new bomber replacing the B-2…

no need to go all crazy tech for a long range bomber with a long loiter time over a mild to benign air environment. modernised B-1 would fit the bill nicely

Errr…. why?

They’d be safer incorporating racks into C-17s so they could eject bombs/missiles out the back door. Buying additional C-17 frames could augment transport capability when needed.

In fact I am somewhat amazed that there haven’t been more studies on it. Especially considering B-52 replacement studies were on the go since the 1960s and that there have been at least 4 B-52 re-engining studies since the mid-90s!

Of course, it couldn’t exactly be renamed the B-17 😉

i do not see your point about size and market. y20 will take over all il76 market and some c130.

Operating cost is a function of aircraft weight. While purchase cost of a Y-20 *may* be appreciably lower than say, the il-76 or even the C-130, its operating costs would be light years above a C-130. Air-forces and governments will be acutely aware of my point about size and market!

Then there is the question of field length. No matter how cheap your plane is to buy, or how cheap it is to fly, if it cannot actually land and take-off from where you need to, then its as useful as a chocolate teapot.

The Y-20 is simply not comparable to the C-130 in terms of field length. Is it comparable to the il-76? Well, we’ll just have to wait and see on that one.

If any, Russia would need actually three to four carrier battle group with capabilities similar to the british QE Class.

Need?

What you need depends greatly on what you intend to do around the rest of the world!

market is chinas!

Hmmm….

Just drawing together some general info from wiki – note this doesn’t consider payload-range, STOL or rough-field capabilities.

C-235, 5 tonnes
C-295, 9.25 tonnes
C-27J, 11.5 tonnes
C-130H, 20 tonnes
A400M, 37 tonnes
XC-2, 37.6 tonnes
il-76, 42 tonnes
An-70, 47 tonnes
Y-20, 66 tonnes
C-17, 77.5 tonnes
An-124, 150 tonnes

In Design
KC-390, 23.6 tonnes
Y-9, 25 tonnes

I wouldn’t call that a cornered market!

I notice no-one has considered the paradigm shift yet. That is, destroy the seeker head or damage the control surfaces with your AESA set.

If you have the power & energy to take down the initial BVR volley of missiles (due to the longer target time), you are back to WVR warfare.

If you’ve a distributed array on your aircraft, and you have the power to take down any missiles, you are back to aerial warfare with a gun.

If you have the power to take down entire aircraft, you are the winner.