Wednesday, May 19, 2010

A new video with PAK FA was published in Internet


  1. Beautiful aircraft.

    Good to finally see all the moving control surfaces. Also the short take-off looks effortless.

  2. to Tass:

    first time the 'skinned joint' (donno the right word in English) between controllable LERX and wing was shown, the TWS too, only from the right side however.

  3. looks good but I hope the in production PAK FA is a lot stealthier than this prototype specially from the bottom part of this aircraft around the engine.

  4. to Anonymous,

    I think it's a pretty good bet that the designers know what they're doing.

    To me, the F-22 and F-35 look fat in comparison.


    to Igor,

    now that you mentioned it, I just noticed it

  5. Hail the Russian Enggineering and this master piece.............

  6. So if the radar and avionics are ready, this version with the S 117 engine might really be inducted into RuAF around 2015 right?

  7. To Sancho,

    there not ready yet as they're still in the test stage. It shouldn't be a big technical problem to have everything ready by 2015, more a matter of political support.

  8. To Igor,
    According to this article PAK-FA will use the flat nozzles in the future like the F-22 does. Will the new nozzles allow for 3D-TVC. I know the F-22 doesn't have 3D-TVC b/c the nozzles are way too close together, but there pretty far apart on PAK-FA. Here's the link:
    Also do you think the fuselage of the production model will be flattened and smooth like the F-22 or even the Berkut? Or would it take too much time to make the necessary changes?

  9. to anon May 30, 2010 11:46 PM:

    1) The first prototype has 2D nozzles with diagonal axis of deflection, just like Su-30MKI has. It allows to mimic true 3D nozzles to some extend. The same principle could be realized with the flat nozzles too. However, I dont think the flat nozzles will be ready for serial production till 2015 when first PAKFA fighters come to service. It's something that kept for the second step engine.
    2) the composite structure of fuselage and the (hidden) riveting technology on PAK FA is not significantly different from F-35 for example. It's just the same level of tech processing.

  10. I think Anon means to ask if the bottom of the aircraft will be left with engine intakes sticking out and bulges and edges underneath the aircraft or if it will be filled in and flattened.

    A bit like that variant of the Flanker that had part of the gap between the engines filled in and a belly mounted recon pod fitted... the extra space used for more fuel and extras one expects.

  11. GarryB,

    ah, right... that's can be different on the serial plane. That's all I can say. Instead of just flattening with internal bay reworking they can change it in a different way. For example to make it more rectangular with integrated fuel tanks. They already hinted the final look may be rather different. I even expect horizontal blades dropping when TVSs come to mature controllability.

  12. Sort of like the opposite of what external conformal tanks have done to the latest F-16 model...
    I always thought that a good upgrade for the Su-27 would be to rotate the intakes 90 degrees and push them together so that what are now the tops of the intakes are side by side together in the centre of body. This would mean if you looked into the intakes you couldn't see the engines because of the curve of the intake channels.
    You could then cover over the gap between the engines and fill the gap with extra internal fuel plus towed decoys etc and then just cover the belly with conformal AAM launch positions for minimum RCS.
    The question of course is that would that reduction in RCS warrant the reduction in engine performance.

  13. To GarryB:
    The bottom of the aircraft will remain the same on the one-seater as it is air superiority fighter and the aerodynamic scheme chosen simply doesn't allow this kind of changes. In MoD requirements paper that was leaked in jpg. scans there was a requirement: "To work out methodology to evade GBAD threats" This means aircraft will remain unstealthy from certain angles in the downside, but not from the front.

    On the rear side they are working, but this also seems not be a priority as of now.

    On the 2-seater/strike variant we may speculate...

  14. Here you can see some tailless model, maybe a PAK FA modification.

  15. The stealthy nozzles seem to be in development for new engines that should be ready in 8-10 years from now. Integrating them into 117 ones may provide great difficulties. I may be wrong on this, as there was info that they were drawn already. However testing of such systems usually takes a lot of time, and to fully test them before 2015 is questionable.

  16. Thanks Andy for your input, I personally don't have a problem with all the bits and bumps under the aircraft, bits and bumps are actually OK as long as they don't reflect radar back to the emitting radar.
    The perfect RCS is not a perfect sphere, it is more like a diamond shaped flat plate angled at a steep angle to the radar looking at it.
    Going tailless will reduce unnecessary weight and complication and also greatly reduce RCS.
    An example of a similar effect of thrust vectoring is where the Flankers started out with canard foreplanes, with the Su-27M, the Su-33 and what is now the Su-34 all having canards in their design. The new Su-35S however has a flight control system developed with TVC engines that makes canards redundant so they were removed to reduce weight etc. On the Su-33 it improved low speed handling and I understand that on the Su-34 it improves low level high speed flight comfort by actively trying to level out the bumps with such a large wing area.
    Regarding the engines I have read that the direct result of the reduction in size of the PAK-FA from something the size of a Flanker to something slightly smaller has meant that the original 5th gen engines (the Al-41) is now too big to fit in the PAK-FA so some of the 5th gen changes applied to the design of the Al-41 have been applied to the Al-31 to create the 117 and a new slightly smaller 5th gen engine is being developed for the PAK FA. The result should be that the 117 can be retrofitted to the Flanker family while the new engine will be for the PAK FA a little while after it enters full service, at a time when new models are being worked on like the two seat model with India and a naval model as well as any other types like strike or jamming or recon or interceptor etc etc.
    The person talking about it mentioned that it would be good to have a new more powerful engine become available at about that time anyway due to expected weight increases as more things are added.

  17. to Garry B:

    Note the 3D TVS is something used to be maximally effective on a single-engine plane. A two-engine fighter, like PAK FA, can handle it with 2D TVSs which are deflected obliquely, like Su-30MKI does.

  18. With respect I disagree. 3D thrust vectoring on a single engine aircraft is powerful but can only act against the air. 3D thrust vectoring on a twin engine aircraft can be used to perform a lot more manouvers because it has something to work against.
    For example a single engine aircraft with three D thrust vector control can sweep the tail around in any direction independant of whether its flight control surfaces are generating lift or drag but to have full roll control and be able to steer the nose of the aircraft in the precise direction you want independant of the direction of travel two engines make it much easier.
    Simply as an example of what thrust vectoring alone can do look at the rear firing experiments with R-27s and R-73s.
    The R-27 when fired backwards stalled as it approached zero speed because the large wings were not generating lift and could not hold the nose pointing at the target, so it stalled and the nose dropped and the lock was lost.
    The R-73 on the other hand was able to keep its seeker (nose) pointed at the target and maintained its lock as it passed through the initial phase of flying backwards, then falling, then accelerating forwards to the rear of the launch aircraft.
    If it had been a twin rocket missile with TVC it could have rolled and manouvered but with one TVC rocket nozzle all it could do was keep its nose pointed at the target area.

  19. Hi, I read in forum recently that the Pak Fa will not carry KAB bombs and that Sukhoi insiders had stated that on some Russian forums. Does anybody know about that, could that be true?
    What strike capability is left then?

  20. to Sancho:

    KAB-1500 doesnt fit the internal bay, but KAB-500 and KAB-250 do it.

  21. to GarryB:

    Not only KTRV but Bazalt too has a totally new line of guided bombs, specially optimized for 5th gen fighter - RBK-500, RBK-250, RBK-100. Look here

  22. Interesting Igor, thanks. I hadn't seen that.

    On a slight tangent have you heard anything about the further development of the Ugroza guidance kits for unguided rockets?
    They would transform an attack helo like the Havoc where 80mm rockets might be used in a volley at a group of trucks with laser guidance you could take on 18-20 light vehicles with one 20 round rocket pod at a range safe from small arms fire but not breaking the bank in cost.

  23. GarryB:

    - I can only confirm, they are doing these researches, remember some source speak about this. However, the unguided missiles are an excellent weapon by itself. The good side of it: steadiness for jamming and low cost. So I more expect the use of these 'guided unguided rockets' from the UCAVs then from helos or strike planes. This would be really devastating.

  24. Unguided rockets will remain the best way to deal with area soft targets, but with vehicles more and more often getting some form of light armour for splinter protection soon a helo taking on a supply column might need the ability to get direct hits to have an effect.
    Some forget that for every tank on the battlefield there are dozens of other lighter targets that don't require the power or cost of an anti tank missile but would need the accuracy of a guided munition to reliably kill.
    Guided unguided rockets gives a Helo the huge advantage of standoff capability, which is obviously beneficial to the lifespan of that helo if it can loft 80mm rockets at targets 6km away so it is at the edge of MANPADS range rather than the normal range of 2-3km depending on the rocket type.
    The near future armament of the Mi-28N could be 16 Hermes missiles with a range of 20km and two pods of a total of 40 x 80mm rockets that can be used on point targets out to 6-7km, plus the gun. That is 56 guided missiles to hit rooms in a building, tanks, bunkers, trucks, etc etc.

  25. to Igor

    "KAB-1500 doesnt fit the internal bay, but KAB-500 and KAB-250 do it."

    That's what I thought, but they meant Pak Fa couldn't carry KAB bombs at and what surprised me.

  26. Well KAB bombs include both TV and laser guided bombs... I suspect that original unmodified KAB TV guided bombs might require a lock on to target before release that might not be possible with internal carriage.
    A common air to air missile like the R-73 couldn't be stored internally because it also needs a target in seeker view before launch.
    The solution is a lock on after launch weapon.
    AFAIK the air launched IR guided AAM solution will be related to the new short range SAM called Morfei which will also be lock on after launch too.
    Shouldn't be an issue for laser guided bombs but TV guided bombs might need modification.

  27. Putin meets 'Stealth': PAK FA T-50 fighter jet:

  28. I wonder if they will make special versions of the Ugroza rocket kits for UCAVs?

    It seems to me that for a UCAV that glide range is more important than actual velocity.
    Even for HEAT charges the actual velocity of the warhead is not really important so that the Ugroza kits for unguided rockets could perhaps have shorter rocket motors and use the extra length for longer span wings to allow perhaps an initial lofted trajectory and then a pitch down and glide to a long range target maybe 10-15km away.
    In fact a useful rocket for UCAVs and even strike aircraft like the Su-34 would be an active jammer drone that could be launched from the S-13 rocket pods (122mm calibre rocket pod) that could have an active radar jammer disposable rocket that can be launched when the launch platform is threatened.
    I remember reading about a 122mm rocket that could be used like that that is fired into enemy airspace so that air defence radars and EW assets can be detected at attacked.
    Perhaps a 5 shot rocket pod load could be 1 jammer drone and 4 rockets with glide wings and anti radiation seekers, or perhaps 5 drones and a wing load of some Kh-25/-31/58 ARMs.