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  • 2 months later...

PAK FA/T-50s in Syria

DWmVX3jWAAEAF2j.jpg

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Expectation: the newest 5th generation fighter jet will use only the most precision guided bombs that ever exist at the arsenal of Russian Army.

Reality: Ivan, hang up another dozen of FABs! No, not these, those ones, with rust, from 1945... Fuck, how i love this FABs!..

 

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There are a bunch of PGMs designed to fit into the internal bays, but I don't think any of them are mass-produced yet.  I don't think that even standard R-73s will fit into the canoe bays.

But the (hilarious) picture of the T-50 with iron strapped to it is from years ago during testing.  I don't think anybody on this side of the Atlantic has any idea WTF those things are doing in Syria yet.

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It's an interesting choice to operate them so close to american air assets - has anyone seen US SIGINT aircraft or similar going syria-wards? My 2p is they're just there to get "battle-proven" ticked off for their promotional material, we might even see them carrying dumb bombs (after all, radar signature of the floozy with dumb bombs is probably not representative of the radar signature when on proper operations). If any of the groups present in syria manage to shoot one down it'll be F-117-shootdown levels of hilarity (not as funny if the americans do it, and probably quite apocalyptic)

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1 hour ago, Xlucine said:

It's an interesting choice to operate them so close to american air assets - has anyone seen US SIGINT aircraft or similar going syria-wards? My 2p is they're just there to get "battle-proven" ticked off for their promotional material, we might even see them carrying dumb bombs (after all, radar signature of the floozy with dumb bombs is probably not representative of the radar signature when on proper operations). If any of the groups present in syria manage to shoot one down it'll be F-117-shootdown levels of hilarity (not as funny if the americans do it, and probably quite apocalyptic)

I feel like any incident resulting in the damage or loss of a Su-57 would spark  "Americans were behind it" conspiracy.

 

I've seen elsewhere that the Russians might be using the Syrian situation for sizing up the F-22 with the Su-57 and its new senors/radar, but the reversal of this would also be a potential outcome.

 

Also waiting to see if some pilot or airman manages to get a picture of both planes flying in the same frame, but I highly doubt either side would allow such an occurence.

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On 24.02.2018 at 1:51 AM, Krieger22 said:

How'd they even know that it was a -57? Are the flyboys really cleared to fly them that low?

Moderate tractor stealers have pretty nice cameras with good optics to record how moderate front-line hospitals and machine gun childrens are bombed. 

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18 hours ago, LostCosmonaut said:

This article claims (unsourced) that the Su-57 can use the R-37? Any truth to that? As far as I know the R-37 (AA-13) was stuck in development limbo and/or going to be used mainly on MiG-31BMs.

 

It may be possible to hang R-37M off of a wing pylon, but at a later date a dedicated variant of the R-37M called Izdelie 810 that fits in the internal bays will be produced.

It's worth noting that so far, none of the air-to-air weapons developed specifically for the SU-57 have been seen in public sources.  That doesn't mean that they don't exist though, just that the Russkies are keeping quiet about them.  I know that at least one expert thinks the K-74M2 has already entered testing.

I did a post on the PAK-FA's weapons here.

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  • 4 weeks later...

Old picture of some of the future air-to-air missiles for the PAK-FA:

V23qcu4.png

This picture was from 8 years ago or so.

At present, the K-74M (heavily overhauled R-73) is believed to have completed at least some testing.  The K-30 (clean sheet design with external similarity to ASRAAM) is believed to be cancelled.  K-77M (R-77 with conventional fins and much improved electronics) is believed to still be under active development.  K-77ME (R-77 with conventional fins and ramjet propulsion) is probably still under development, but according to Butowski the Russian government is not funding it and foreign customers are being sought.  K-37M and 810 (further developments of R-37) are still under development.

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  • 4 weeks later...

Paralay has made a comparison of the frontal areas of various fifth-generation jet fighters.  Sadly, no J-20:

9KXsbjU.jpg

This is probably approximately correct.  Paralay's photo-manip skills are pretty solid.

 

This picture helps emphasize some of the questions about the SU-57's aerodynamics and design.  What exactly is Sukhoi doing here?

The SU-57's vertical stabilizers are much, much smaller than the F-22's, and also much smaller than the SU-27's.  On top of that, it lacks the SU-27's ventral fins.  This is intriguing; even the J-20's designers didn't feel comfortable ditching ventral fins.  What exactly is the SU-57's alpha limit, and how much control does it have near that limit?  The answer is not obvious at all to me.  The fact that the inlets are not blended into the fuselage, instead forming a large "trough" does add some directional stability (I had speculated that this is the case earlier in this thread and have since found a textbook on fighter design saying that this is the case).  But the SU-27 also has semi-podded intakes, and it still requires enormous vertical stabs and ventral fins.

 

The LEVCONs surely add some additional control, but from everything I've read differential deflection of canards provides only very weak roll authority, and it's not obvious to me that LEVCONs would work any better in this role.

 

It's also worth noting that the common conceit, that the SU-57 is designed more for speed than other fifth gens, is not necessarily obvious from its shape.  While the F-22 looks blockier, the F-22 and F-35's shape minimizes wetted area, which reduces subsonic drag.  The SU-57 has a visually sleeker shape, but all of the exposed surface area from the podded engines and SRAAM canoes will increase the subsonic drag coefficient of the aircraft.

 

The fuselage of the SU-57 is clearly designed with lift generation in mind, but this design feature is also frequently misunderstood.  Generating lift with the fuselage is not automatically a good idea.  Engineers already figured out optimized lift-generating surfaces.  They're called wings and they're wing-shaped.  A fuselage, even a very flat one, does not make a particularly efficient wing because of its extremely low aspect ratio, which leads to high induced drag and a low lift to drag ratio.

 

That said, there are reasons why the designers might want the fuselage to act as a lift-generating surface.  A long, airfoil-shaped fuselage forebody (which the SU-57 clearly has) can be useful for reducing the shaking of the aircraft when it is flying fast at low altitude.  The unpredictable gusts of wind that trouble aircraft flying at low level can flow cleanly and with less disturbance around a lenticular cross section than they can a round one.

 

2Eax56f.png?1

 

In addition, long fuselage chines help reduce the center of gravity shift that occurs when the aircraft breaks the sound barrier.  I could not tell you why in the fuck this is, because it makes no sense to me, but it definitely is true.  The YF-12 and SR-71 had a measurable difference in supersonic pitch stiffness because the SR-71 had more extenstive chines than the YF-12.

 

Finally, the energy-robbing vortices created by the fuselage can be used to some benefit if they re-energize flow around other surfaces like the wings or tail.  This could be part of how the SU-57 manages high alpha control; the entire fuselage acts like a gigantic canard, and allows the wings and small vertical stabilizer to maintain much better lift and control authority than they would otherwise.  But again, this would imply some cost to the drag polar.

 

In aircraft design, everything is trade-offs.

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2nd flying Su-57 prototype T-50-2 (052 Blue) with an Izdeliye 30 turbofan engine on the left. It was indeed taken at Gromov Flight Research Institute earlier today.
Note the stylised "LL" (in Cyrillic) graphic on the vertical stabiliser,  acronym that stands for Letayushaya Laboratoriya - flying lab.

DbqBLWeXUAE8PRh.jpg

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