PAK FA

[Trigger]

Just for the sake of argument, the F-22's bays are so big to accomodate an AIM-9L/M class missile with big 'ole fins on it. The plan is (as far as I understand it) for a finless variety of the R-73 to be utilised (well, nothing more than vestigial fins at least) so physically getting a missile in that space is possible. It would be like putting a -9X in the F-22's bay. . suddenly you have a lot of spare room...

Yeah, the fins on the -9M/L push it, but that side bay still has to accommodate the launch rail and the trapeze for the missile. You want to put a short range IR-guided AAM in that underwing fairing? An IR AAM has got to have a seeker lock along with a confirmation and consent before firing. That means that even with a helmet mounted sight, the missile still has to be extended from the aircraft into the slipstream before it can be fired. You don't eject-to-launch an IR AAM and there's no room in those fairings for the missile (even with thin-fins), it's railing, a trapeze and the door's own structure.

So far, the only "confirmation" that those are weapon bays has come from interweb forums (the same source as the promise of "plasma stealth" and UCAVs the size and price of a VW that can haul an F-15E's payload a thousand miles and loiter for days on end) and press articles. And we all know how accurate the press can be in these matters ("artificial intellect"). There's nothing on Sukhoi's website about it. And before someone cries "they want to keep details secret!", those fairings are visible to the entire world. And if it's such a secret, how do you know so much about it? In other words, that argument's a dog that won't hunt.

[Aggressor Supporter]

KEN'S LINK to the AFM boards contained a schematic where someone had calculated these fairings to be 4.5 metres long, which would make them long enough for both R-73 and R-77. Whether they're deep enough is another question, though.

Maybe this is Russia's idea of concealed weapons carriage outside of the internal weapon bays?

Yes, that and the real pics are the basis of my question and that is what I am assuming it is for. If it is not, then I guess we will eventually find out what that section is for. But if it is, then it will be interesting to see if the missile is suppose to pop out of the side of those fairings like the Raptor's or maybe protrudes out from the bottom or the front. From the real pic, it looks like there is no doors on the side or the bottom of it only some rivet details on the front.

[ChernayaAkula]

<...> IIRC, a fanboy drew that, so it's about as accurate as anything anyone here could come up with. <...>

I know, I know. I just thought that the folding fin Archers and the space in those bays was interesting. That all this (especially the internal arrangement) is mere speculation is perfectly clear.

<...> You don't eject-to-launch an IR AAM <...>

Not to stir up an argument (Real Aviation can rest in peace), but how does the Raptor get around this problem? This problem never occurred to me until someone else brought it up in some other thread.

Now, here's my (highly scientific ) idea on the weapons fairings.

Step #1: Missile receives target data via IRST.

Step #2: Cover made from radar-absorbent material is jettisoned. Maybe a hinge as on the F-4/15 tanks is used to ensure clean separation.

Step #3: Missile launch!

Step #4: Pylon holding "bay" cover and missile is jettisoned as well.

Step #5: Airframe is clean and stealthy again.

[Stratospheremodels]

Su-50 Facebook

It will soon have its homepage.

And thousands of friends.

[loftycomfort]

I know, I know. I just thought that the folding fin Archers and the space in those bays was interesting. That all this (especially the internal arrangement) is mere speculation is perfectly clear.

Not to stir up an argument (Real Aviation can rest in peace), but how does the Raptor get around this problem? This problem never occurred to me until someone else brought it up in some other thread.

Now, here's my (highly scientific ) idea on the weapons fairings.

Step #1: Missile receives target data via IRST.

Step #2: Cover made from radar-absorbent material is jettisoned. Maybe a hinge as on the F-4/15 tanks is used to ensure clean separation.

Step #3: Missile launch!

Step #4: Pylon holding "bay" cover and missile is jettisoned as well.

Step #5: Airframe is clean and stealthy again.

That's an interesting concept. In step 2, wouldn't the air slamming into the jet at mach 1+ rip the bay door right out? How would you prevent the ripped away, or jettisoned away, bay door from hitting the rest of the fuselage?

Terry

Edited February 11, 2010 by loftycomfort

[Av8fan]

Most of russian military jets don't have "official" names, they are designates by models only. The exceptions are usually media inspired, like Su-25 - rook , Su-47 Berkut, An-124 Ruslan or An-22 Antey, but such names are never mentioned in any militatry documentation

But unofficial names sometimes are quite funny. To the best of my knowledge the following aircraft types have well recognized names:

Su-24 - glazier's diamond (for scratchy sound of turbines in take-off mode)

Hmm..I think that should be changed to Mother in Law.. For scratchy sound of turbines in arrival mode..

Some interesting information.

I just wonder who will be first to market in 1/48th.

[Trigger]

I know, I know. I just thought that the folding fin Archers and the space in those bays was interesting. That all this (especially the internal arrangement) is mere speculation is perfectly clear.

Oh, I know. I wasn't harping at you. You and Dmanton300 are both trying to come up with practical solutions to how that might could work. What I'm scoffing at is being asked to blindly accept such a concept with no good explanation.

Not to stir up an argument (Real Aviation can rest in peace), but how does the Raptor get around this problem? :unsure: This problem never occurred to me until someone else brought it up in some other thread.

By a trapeze.

Doors spring open, trapeze extends to let the Sidewinder's seeker get a look at the world, finds a nice hot exhaust, growls, pilot confirms and releases, missile comes off the rail to go do its thing, the trapeze snaps back down as the external doors close back up.

Yes, this would spike the radar signature the few seconds this is going on. But if you're close enough you gotta use heaters, chances are they already know you're there and you're probably close enough to show up on the other guy's radar anyway.

Agree with Terry, your concept's interesting...but yeah, airflow and the ejecting cover.

[Wayne S]

Yeah, the fins on the -9M/L push it, but that side bay still has to accommodate the launch rail and the trapeze for the missile. You want to put a short range IR-guided AAM in that underwing fairing?

I think the size in the pictures is deceiving, there must be area inside the wing also. Now if that door/cover is what will be used or is just there for test is another story.

An IR AAM has got to have a seeker lock along with a confirmation and consent before firing. That means that even with a helmet mounted sight, the missile still has to be extended from the aircraft into the slipstream before it can be fired. You don't eject-to-launch an IR AAM and there's no room in those fairings for the missile (even with thin-fins), it's railing, a trapeze and the door's own structure.

Helmet (JHMCS aim-9x) far as I know is used for lock-on-after-launch. Locked on wile on the rail would be high-off boresight.

I don't see why the Russians would need a seeker on a new missile to see before firing. Specially when they have shown to practice lock-on-after-launch with other platforms already.

Edited February 11, 2010 by Wayne S

[Raymond]

its possible its a new r-60 class missile, I suspect Ross might be right in that at the moment its just an aerodynamic faring simulating where the real thing may go, since this is just a prototype

IIRC in cases with missiles like the R-27ET, the IRST is the primary guidance; the missile itself is blind when launched, and picks up its own lock later. though dont know how useful that is for a self defense missile, its possibile it works on a similar idea

[Flankerman]

Su-24 - glazier's diamond (for scratchy sound of turbines in take-off mode)

Pin,

I thought the Su-24 was nicknamed 'Chemodan' (Suitcase) - because of its slab-sided appearance.

Ken

[Dmanton300]

Yeah, the fins on the -9M/L push it, but that side bay still has to accommodate the launch rail and the trapeze for the missile. You want to put a short range IR-guided AAM in that underwing fairing? An IR AAM has got to have a seeker lock along with a confirmation and consent before firing. That means that even with a helmet mounted sight, the missile still has to be extended from the aircraft into the slipstream before it can be fired. You don't eject-to-launch an IR AAM and there's no room in those fairings for the missile (even with thin-fins), it's railing, a trapeze and the door's own structure.

So far, the only "confirmation" that those are weapon bays has come from interweb forums (the same source as the promise of "plasma stealth" and UCAVs the size and price of a VW that can haul an F-15E's payload a thousand miles and loiter for days on end) and press articles. And we all know how accurate the press can be in these matters ("artificial intellect"). There's nothing on Sukhoi's website about it. And before someone cries "they want to keep details secret!", those fairings are visible to the entire world. And if it's such a secret, how do you know so much about it? In other words, that argument's a dog that won't hunt.

Isn't their talk of using an IRST as the primary seeker to obtain lock on and handing off to the missile at launch? Given that, you don't have to extend the missile into the airstream to give it a look around anyway (and look how much blind spot the seeker would have on the Raptor even when extended - a huge ARC is blanked by the fuselage and wing, no worse than many true but it's still a point). So, if you have that primary seeker in the form of an IRST obviating the need to extend for lock, there's no practical reason why an ejector can't be used even for an IR missile I'd think? And with the location of that supposed bay I presume you're ejecting down from it, rather than if, for the sake of argument, you tried it with the Raptor's bay, where you'd be ejecting sideways ito the immediate proximity of the wing.

Again, I'm not convinced it IS a bay for a missile, I'm just exploring the possibility that it could be. People may be keen on calling anything Russian a "knock off", but the fact is that Sukhoi are world class aerodynamicists and would probably have the challenges in hand! I think we may be presuming that fairing is a scab on, whereas I'm thinking of it as part of the airframe, which means that you have some internal space into the fuselage above it to play with as well.

[pin]

I thought the Su-24 was nicknamed 'Chemodan' (Suitcase) - because of its slab-sided appearance.

True as well, "wardrobe" too for the same reason.

My only point that all these are nicknames rather than official designations.

On some Russian speaking forums T-50 was baprized as "PAK-Fighter" or "Flattened Frog" - the last one is almost ASIG compliant ;)

[Flankerman]

Has anyone seen a definitive set of dimensions for the PAK FA yet ???

Apart from guesstimates taken from photographs I mean. :)

I'm itching to scale up the couple of drawings that have appeared - and get started on a scratch-build.

Ken

[Aggressor Supporter]

That is an interesting theory on how the side missile bays might work posted by Moritz. But I have to say that looks to be impractical because to jettison the pods and rails would also be expensive especially over time. Along with probably having a limited launch envelope, the costs to replace the pod and rails due to training or testing and maybe not even recovering them if over enemy territory and them having a piece of your plane I think is impractical. If it does house a short range missile, I think the best way for it to launch is from a side door opening like the Raptor's although I don't see any indication of doors on the side of those fairings. Now if it isn't for a short range missile, maybe it is for sensors and maybe explains why there seems to be some rivet details on the front of it. If that is the case, then another question I would ask is where would the short range missile be? The two belly missile bays seems somewhat narrow and I would guess they can only hold two or three Amraam type missiles like in the schematic.

[Flankerman]

There is talk over on AFM that those two underwing 'missile bays' are actually vortex generators.....

The possible rationale behind the fuselage “chines†and wing strakes could be to generate two vortexes over each wing upper surface, thus enhancing lift (via more diffused vortex lift) at high angle of attack (AoA). In particular, the two inner vortexes (those generated by the fuselage “chinesâ€) would energise the airflow over the inner wing upper surface blending with the fuselage above the engine nacelles. The two outer vortexes (those generated from the wing strakes outboard the intakes lips) would transfer their kinematic energy to the upper outer panel wing airflow. Furthermore, given the expected path of such latter vortexes, they would also interact with the upper airflow over the all-moving horizontal tailplanes - thus replicating the superior longitudinal control provided in the Su-27 by its peculiarly located slab tailplanes.*

Text courtesy of Defpro.

Ken

[GreyGhost]

There is talk over on AFM that those two underwing 'missile bays' are actually vortex generators.....

The possible rationale behind the fuselage “chines†and wing strakes could be to generate two vortexes over each wing upper surface, thus enhancing lift (via more diffused vortex lift) at high angle of attack (AoA). In particular, the two inner vortexes (those generated by the fuselage “chinesâ€) would energise the airflow over the inner wing upper surface blending with the fuselage above the engine nacelles. The two outer vortexes (those generated from the wing strakes outboard the intakes lips) would transfer their kinematic energy to the upper outer panel wing airflow. Furthermore, given the expected path of such latter vortexes, they would also interact with the upper airflow over the all-moving horizontal tailplanes - thus replicating the superior longitudinal control provided in the Su-27 by its peculiarly located slab tailplanes.*

Text courtesy of Defpro.

Ken

That's what I said ... :)

I was just thinking the same thing, Trigger ...

They almost look like an aerodynamic feature rather than a housing ...

and ...

I wasn't going to bring up Plasma Stealth Emitters ... but ...

Hey, maybe even side looking radar ?

Gregg

Gregg

[ross blackford]

, Hi everyone, Perhaps we should all curb our speculation until some of us see the prototype or perhaps a pre-production example up close at MAKS. As MarkW would say, and not having a shot at you Mark, but we don't know what we don't know; none of us. We can speculate till the cows come home but in the end it's still just plain speculation, although if there is an announcement from the makers we could then probably discuss the purpose wisely.

Ken,

The Su-24 isn't the first twin engined medium bomber to be nicknamed 'The Suitcase'. Remember the Handley Page Hampden and Hereford. They had the nickname 'The Flying Suitcase' back in their day.

,

Ross.

[MarkW]

The idea that underwing pods of that shape would serve as overwing vortex generators shows such a mind boggling lack of basic aerodynamics understanding I'm simply stunned. Defence Pro? Oy vey...

I'm wondering about the tactical utility of some of these proposed antenna locations. Is the T-50 intended to be an ISR platform? How much time would it makes sense to be imaging directly off the wing a la JSTARS? If those indeed are radar antenna housings, they are HUGE. Exactly how much electrical power are we expecting those engines to produce?

I think a lot of energy is being put to what things could be, which is fun speculation, but not so much on the why.

Oh for cryin out loud, I inadvertantly agreed with Ross. What a world...

Edited February 11, 2010 by MarkW

[Berkut]

This is going nowhere. We might as well start discussing how a wing works, or why earth is round...

[Berkut]

So far, the only "confirmation" that those are weapon bays has come from interweb forums (the same source as the promise of "plasma stealth" and UCAVs the size and price of a VW that can haul an F-15E's payload a thousand miles and loiter for days on end) and press articles. And we all know how accurate the press can be in these matters ("artificial intellect"). There's nothing on Sukhoi's website about it. And before someone cries "they want to keep details secret!", those fairings are visible to the entire world. And if it's such a secret, how do you know so much about it? In other words, that argument's a dog that won't hunt.

1: Please show me where Gr00mi, Nemetc or other insiders talk about plasma stealth. "The same source" - sorry, but that is weak argument.

2: Exactly what info do you expect Sukhoi to be releasing? It is a military subject, of course they won't tell you things. We didnt see the plane untill some weeks ago. Do you really expect them to release info on left and right?

Have you heard a story about a flight mechanic that linked to this site?. It really doesn't matter at all what is visible or not. What is not visible is far far more important. Do you see for example a lot of info regarding coatings on F-22? And don't get me started about APG-77....

PS: I knew that plasma stealth would be mention at some time... You can laugh as much as you like about plasma stealth...But it is actually a heavy researched topic in Soviet Union/Russia. Does these pictures tell you anything?

This isn't some ATS stuff, but actual research.

Making plasma cloud to cover whole aircraft at all time is very hard. However, plasma cloud application can be used on radars...Look at radars, they are flat like frying pan. However, if you cover that frying pan in a plasma cloud, chances of reflecting is much less.

Edited February 11, 2010 by Berkut

[Fuji]

This is going nowhere. We might as well start discussing how a wing works, or why earth is round...

I understand your frustration, but remember many model builders have no clue as to what theyre building and how it works. Its all about the coolness factor. They gotta learn somehow.

As for those things under the wings. Some sort of antenna rig sounds feasable. The updated J-10s have got some new antenna rig as part of the underwing and seem to be incorporated into the pylon system, maybe.

http://i18.photobucket.com/albums/b146/Kha...AAFJ-10B025.jpg

http://g2globalsolutions.com/review/wp-con...9/07/j01b-2.jpg

http://www.fyjs.cn/bbs/attachments/Mon_090...5bf88c7a56f.jpg

http://www.airforceworld.com/pla/gfx/j10b/j10b-31-2.jpg

http://cnair.top81.cn/fighter/J-10B5.jpg

[Trigger]

Does these pictures tell you anything?

Aside from "Google works" and "Hey, guys! They approved our budget!"? Okay, here goes...

"That boy's head's like Sputnik! Spherical, yet pointy in parts!"

"Gee officer, I have no idea how that dead hooker got in my trunk."

------

Back in the days of Real Aviation, the concept of plasma stealth on the next generation Russian fighter was used by some to marginalize the F-22. Yeah, Russian scientists have studied it and it's not practical for an airplane. It ended up a punch line, much like the F-14 single-handedly winning the Cold War.

I don't expect Sukhoi to be releasing a whole lot of information, which is why I'm skeptical of the fairings housing missiles. if they can, fantastic. Just show me.

Edited February 11, 2010 by Trigger

[MarkW]

Underwing vortex generators and plasma stealth...

Ok, where are the flight test pr*n pictures?

[schurem]

Oh, I know. I wasn't harping at you. You and Dmanton300 are both trying to come up with practical solutions to how that might could work. What I'm scoffing at is being asked to blindly accept such a concept with no good explanation.

By a trapeze.

Doors spring open, trapeze extends to let the Sidewinder's seeker get a look at the world, finds a nice hot exhaust, growls, pilot confirms and releases, missile comes off the rail to go do its thing, the trapeze snaps back down as the external doors close back up.

Yes, this would spike the radar signature the few seconds this is going on. But if you're close enough you gotta use heaters, chances are they already know you're there and you're probably close enough to show up on the other guy's radar anyway.

Agree with Terry, your concept's interesting...but yeah, airflow and the ejecting cover.

You know, and im sorry that this doesnt have jack **** to do with PAK FA, but won't the sidewinders motor completely blast the raptors innards and flank skin to smithereens if its fired from the position in that picture?

Whats up with that?

and on a side note, i really like the more lighthearted tone this forum keeps in these matters as opposed to the /other/ one ;-)

[Trigger]

You know, and im sorry that this doesnt have jack **** to do with PAK FA, but won't the sidewinders motor completely blast the raptors innards and flank skin to smithereens if its fired from the position in that picture?

Whats up with that?

I think there's a small blast deflector on the rail right behind the AIM-9's motor that redirects the plume out away from the airframe.