China Flanker Thread II

Discussion in 'Air Force' started by sumdud, Jan 12, 2008.

  1. MiG-29
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    MiG-29 Banned Idiot

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    A couple of points, post stall is designed for air combat, and 3D nozzles are lighter than 2D nozzles.

    Flight tests of thrust-vectoring designs began in the early 1990s with airplanes like NASA’s modified F/A-18 and F-15, the Rockwell/MBB X-31, and a modified Air Force F-16. In 1994, the X-31 demonstrator was fitted with what German program managers called a “poor man’s thrust vectoring nozzle”—three paddle-like vanes that pushed into the exhaust stream—and the results were spectacular. Without thrust vectoring, the X-31 lost twice as often as it won against the F/A-18 in mock combat; with it, the X-31 didn’t lose once in 129 matches.
    How Things Work: Thrust Vectoring | Flight Today | Air & Space Magazine

    See these are american-german studies see more and see PSM which means post stall maneuvre

    Another demonstration of the advanced capability of
    TV and PSM was observed when the X-31 was tested
    against the F-18 in combat scenarios. X-31 is an experimental
    aircraft being developed and tested jointly by the
    U.S. and Germany [21]. The X-31 program is intended to
    highlight the tactical utility of Extended Fighter Maneuverability
    (EFM) at low cost [4]. It was observed that the
    F-18 had a better success rate when the X-31 was own in
    conventional configuration. However, when PSM was
    enabled, X-31 emerged as the winner.
    TV

    see PSM = Post Stall Maneuverability

    http://www.idearesearch.in/Papers/AP_aesi_agility.pdf

    3D nozzles are very light in fact they just add a few dozen kilos

    see

    Eurojet partner ITP of Spain is responsible for the design of the EJ200's TVN, and has attempted to optimise the device for simplicity of operation while adding as little weight as possible (about 40kg/88lb per engine). Eurojet pushes thrust-vectoring technology for Typhoon




    The flat nozzle made of metal is heavier than the circular one by approximately half a tonne. Mind you, the whole AL-31FP fitted with its circular swivel nozzle weighs a little bit more than 1500 kg only. So, the use of a flat nozzle implies an extra tonne at the rear of a plane (two-engine are meant here, which make up the most of modern fightershttp://vayu-sena.tripod.com/interview-chepkin1.html


    In the past, all jet aircraft to apply thrust vectoring have used mechanical thrust vectoring (MTV) techniques. This is done by mechanically deflecting the engine nozzle to direct the flow. Whilst effective, a MTV system is heavy and complex. The MTV nozzle on the F-22A Raptor (Fig. 2) weighs 30% of the total engine weight

    http://seit.unsw.adfa.edu.au/ojs/index.php/juer/article/viewFile/90/59


    So i will put it in context



    A Su-35 versus J-10 is not going to be the same than a J-11B versus J-10 on a dogfight and yes post stalll is used in air combat

    ---------- Post added at 06:06 PM ---------- Previous post was at 05:56 PM ----------

    the advantages of post stall are well known specially in Germany and the US, one of the biggest fallacies that emerged about post stall was when an american F-15 pilot boasted it could kill raptors doing post stall after a redflag debriefing.

    The reality was distorted, to start by american own reports say that F-22s have a kill ratio of 30:1
    on their favour meaning F-22 usually defeat their F-15 agressors.

    The chinese claimed the J-10 regularly kills Su-27s, meaning the Chinese fighter is superior to the flanker, however the flanker and fulcrum families have been upgraded with more powerful engines and TVC nozzles, so nowadays a Russian Flanker is far more advanced than the soviet Su-27s or J-11Bs and the likelyhood the J-10 will defeat the Su-35 are slim.

    plus


    The emergence of thrust vectoring has enabled significant improvements in combat aircraft performance. It has improved dog-fighting capability by allowing a condition known as super-manoeuvrability, where the conventional flight envelope is extended into the post-stall region. It has extended aircraft range by alleviating trim drag caused by elevator deflection (Mason 2002). It has reduced take-off distances by vectoring thrust downwards on rotation. Thrust vectoring can also be used to reduce the radar cross-section (RCS) of very low-observable aircraft by removing the need for conventional aerodynamic control surfaces (Gal-Or 1989). This concept was proposed for the conceptual X-44 MANTA (Multi-Axis No-Tail Aircraft) (Fig. 1), a long range bomber variant of the F-22 Raptor (Sweetman 2002). These factors combine to give thrust-vectored aircraft a significant tactical advantage.
    http://seit.unsw.adfa.edu.au/ojs/index.php/juer/article/viewFile/90/59
     
    #2011 MiG-29, May 28, 2012
    Last edited: May 28, 2012
  2. A.Man
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    A.Man Major

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    J-11BS or J-16? I Cannot Tell The Difference.

    But to me, it makes no difference. J-11A, J-11B, J-11BS, J-16 or J15 that Sengfei is just reinventing the same wheel for different sizes.

    Chengfei is kicking the ass by making J-10, FC-1 and J-20. They are going to the top of the world.

    Chengfei still use Russian engines. So what?

    GM bought Honda engines. Honda paid money for Isuzu to make Passport under the name of Honda.

    [​IMG]
     
  3. Scratch
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    Scratch Captain

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    Honestly, I think you're vastly expending the argument beyond the point I originally adressed and go into fields I never questioned. As I have pointed out myself, I'm well aware of the the benefits of TVC like reduced trim drag or smaller RCS by a reduction in controll surface deflection, or more efficient turning because there's no controll surfaces moving into the relative wind to produce an aerodynamic force. I also totally aknowledge that modern day Flanker types are fitted with better aviaonics & stuff than MKKs. None of that stuff have I ever questioned.
    Although I wonder how you suppose TVC shortens the T/O run by deflecting thrust down. TVC does shorten a T/O run because by deflecting it (up) you have a force able to induce rotation before the aerodynamic control surfaces become effective. But if, upon rotation, you direct the thrust down (at the tail of the plane) you actually move up the tail, creating a pitch down motion, wich seems rather useless for T/O.
    Anyway, all that I'm saying is post stall maneuvering, while indeed offering great new possibilities to tackle an opponent, will in itself not be the holy grail in an operational environment.
    Those F-18 vs X-31 scenarios you mentioned seem to be 1on1 engagements. So if the X-31 drive managed to be so successfull mainly because of PSM stuff, I indeed do wonder would he have dared to pull the same stuff if there was another F-18 he would have to worry about. Because once he's stalling through the air, I do think he will make himself an easier target for that other guy.
    What PSM does foremost, is to change the direction in wich your nose is pointing, i.e. get you some good nose track. You will also be able to change the direction of your flight vector pretty well. But that comes at the cost of a greatly reduced length of that vector, a.k.a. slow speed. So that means you're now covering only very small pieces of distance at any one time. So you're rather stationary and predictable. And in a modern day fight, if there's more than the one guy you're shooting with your PSM stunt right know, that might mean trouble.
    And that's all I'm saying. Aside from all the benefits TVC brings, there will also be negative effects you have to keep in mind when using TVC in a certain way in certain situations.
     
  4. Air Force Brat
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    Air Force Brat Brigadier

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    I could be wrong about the weight of the nozzles, but three d is much more complex, and I would still say heavier, but you better call Col Moga and tell him he's doin it wrong. 1.The Raptor is supermanueverable, the F-35 is not. 2.The post stall regime makes you extremely vulnerable. 3 Air to Air missles receive a tremendous advantage when launched at higher speeds, no need to use fuel to accelerate to the velocity of the aircraft. 4 Off boresight aiming with the F-35, means its not necessary to manuever into the other guys six o'clock by using the helmet mounted sight. Those studies are now ancient history, while I agree to the concept of supermanueverable being superior, many of those advantages are lost when you bleed energy and are drawn into post-stall manuevering. More importantly when you deflect the raptor nozzles down, you pitch the nose down, when you deflect the nozzles up, you increase pitch, no sale on that, the only time deflecting the nozzles down will improve your takeoff performance is in a STOVL aircraft with front and rear nozzles. TVC is for pitch control on the Raptor,

    ---------- Post added at 12:48 AM ---------- Previous post was at 12:36 AM ----------

    I'm sorry Scratch, I didn't mean to duplicate your post, I should have read it before replying to mig, but you are of course correct, and that is precisely why Col. Moga did "not" perform the pugacheve cobra in his tactical display of the F-22, 1. It is tacticly useless. 2. You have to depart the aircraft, and he would not do that at low altitude, in front of the crowd because it is dangerous, and you are mometarily at least not in complete control of the aircraft. Those old studies of the X-31 and the F-18, were design to show the ability to target the adversary using supermaneuverability to "sight your weapons, just as you stated"/
     
  5. MiG-29
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    MiG-29 Banned Idiot

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    definitively you fall into contradictions and you are wrong, 3D is lighter than 2D flat nozzles, the advantages of 2D are in IR signature and the fact 2D can add some lift component, but in terms of thrust they waste more and the system is heavier, however they are better suited for Low observability and stealth.

    Post-stall is very useful for two simple reasons, F-22 carries only two AIM-9s versus 6 AIM-120, the fighter has less short range missiles that can be cued by helmet sights.


    Translate this to numbers, if the enemy fighter dodges the AIM-120 or the IFF does not work properly you have to go into a WVR and ID it with balls eye, since F-22 is scarse dogfights are extremely dangerous.


    If the enemy fighter is a J-11, the F-22 pilot knows once you have no AIM-9s, you have to go to gun well J-11 has less chances of survival, Su-35, has equal odds in gun dogfight, it will be a match in supercruise and post-stall, not for nothing the Rusians call Su-35 generation 4.5++.

    Kinematically the F-35 is worst than F-22, it only carries a few AAMs and fewer AIM-9xs, in fact only two, if it can not id adversary, going close is not good, stealth means as long as you remain afar, far away it works, Su-35 has an IRST that can detect easily a target at 90km, for F-35 getting close is at its peril.

    Su-35 supercruises, F-35 does not and the Su-35 has also a HMS and newer off bored sight missiles.

    J-11 is not an equal of Su-35 and from 2013 Russia will recieve newer Su-30SMs and a new batch of Su-35s.

    post stall is an asset not for nothing F-22 has it, and it`s not old it simply you do not want to acknowledge you fall into the trap of thinking post stall is just cobra, but the reality there are more manoeuvres such as hook, chakra, mongoose or helicopte are other maneuvres that allow F-22 kill an adversary in ways a fighter having not thrust vectoring won`t be able to do it.

    J-11B is still very limited in that sense compared to the newer Su-35

    [video=youtube;qmIQAOG789E]http://www.youtube.com/watch?v=qmIQAOG789E[/video]

    ---------- Post added at 09:42 AM ---------- Previous post was at 08:49 AM ----------

    Going too fast means you can not change direction easily, if you are doing the helicopter maneuvre, the fighter can point the nose at any time at the adversary, the fighter without thrust vectoring will be unable to point the nose at you so quickly so victory is for the fighter with post stall capability.

    Modern thrust vectoring nozzles allow retofitting the thrust vectoring system relatively easily to the engines, in fact Eurofighter has such system it is light and can be easily be adapted to its engines, however budgetary pressures does not allow it.

    In Russia, they are building a very complex thrust vectoring 3D system on series aircraft, Su-35 and Su-30SM has a less complex and advanced but also is in series production in Russia and India for Su-30MKI.


    In theory, a J-11B with HMS and a good radar can repel J-10s and beat them, but in exercises they try agility and tactics, HMS and highly offbored missiles are equalizers but on fighters with weapons bays, weight and space are constraints and the scarsity of short range agile highly off bored missiles means post stall is an aid, F-22 has it for that reason.
    also remember AAMs are dodgeable, they fail too, and if you have only two AIM-9Xs or two IRIS-T you will end up dogfighting the enemy with guns.

    For F-35 and F-22 in order to win they have to do it at BVR and like F-4, they might need to go WVR where J-11s or J-10s carry more short range dogfight missiles, F-22 will supercruise to get rid of J-10s or J-11s, but Su-35 can go there.

    Su-35 is more dangerous simply because it can follow F-22 at supercruise and can dogfight it at post stall
     
    #2015 MiG-29, May 29, 2012
    Last edited: May 29, 2012
  6. Franklin
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    Franklin Captain

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    Yes, yes, yes MiG-29 we get the message. Those lazy bums at SAC better get off their asses and fit a 3D TVC nozzle on the WS-10A.
     
  7. CottageLV
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    CottageLV Banned Idiot

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    3D is not that necessary, plus they are very hard to service and have very short lifespan. The fly-by-wire codes have to be completely rewritten to fully squeeze out its potential. Currently 2D vectoring plates like those on F22 is suffice. But the bottom-line is the engine has to be strong, or else turning the nozzle won't do much for the 35 ton behemoths of the Su-27 family.

    ---------- Post added at 10:07 AM ---------- Previous post was at 10:05 AM ----------

    I think only the early basic versions fly at 30 tons, the recent ones, especially the Su30 and 35, all fly at 35 tons.
     
  8. 70092
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    SAC make about 20 variants of J-8 and still make them at the moment, and the Airforce still order them as charity orders to just keep SAC afloat...

    Judging by their track record, I think they could still produce Su-27 variants by 2050...
     
  9. Scratch
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    I will say again that I see this only as a valid point for a (notional) 1on1 engamement where there's no second attacker easily able to shoot you once you've entered that flat spin (& did become rather predictable) and when you've got enough altitude below you to afford loosing that altitude.
    Most combat planes have a cornering speed of about I'd guess 400-450 kts indicated, so that's when they'll turn best. And I still doubt that planes would be able to enter those PSMs at these kinds of speeds controlled. The wings can probably bear those forces when you do a pitch up style maneuver, but I doubt the vert stabs could take the side loads of a relative wind of 400kts 90°off, furthermore that force would reduce the speed at wich the tail could come around considerably, thereby reducing the advantage of that PSM stuff.
    That in the end means you need a somewhat lower airspeed at entry. And that means either slow down at the merge prior the maneuver, wich will cost a few seconds in wich the other guy can maneuver further, or fly around slower all the time, wich makes you less responsive and more easily outmaneuverable.

    Again, as for the rest of what you say, most of that I have never questioned or neglected. Although I don't think a fighter with fewer WVR AAMs will generally loose WVR combat on the ground that it has fewer missiles.
     
  10. MiG-29
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    MiG-29 Banned Idiot

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    The number of missiles is a big issue, however in the current concept the F-22 is supposed to kill F-15s first without being seen.

    The F-22 is supposed to do that to J-11s or Su-35s, but here is where the americans claim the winner is always who remain unseen until the last moment, watch the video at minute 8:00 to minute 12, see a F-15 pilot named Capt John Teichart say at minute 9:00 "i could never see them" here is the basic concept behind F-22, however
    [video=youtube;-XlMcwKRCEE]http://www.youtube.com/watch?v=-XlMcwKRCEE[/video]

    That is why the F-22 carries so few AIM-9 and does not carry an IRST or HMS.

    However the trend is to get better and better IRST systems and other types of detectors that could allow a fighter like J-11B to down a F-22.

    However if we are to believe the french, Rafale put a fierceful fight against the F-22 in WVR.

    So here is what everyone is doing is to detect stealth fighters and get in close where the F-22 might become like the F-4 in vietnam.

    So if you read in the future J-11B is trying to get AESA radars better IRSTs is to give a slim chance against stealth fighters.

    But let us point the F-22 has post stall capability, F-35 has not.

    Now with or without post stall, a fighter needs a wingman, when you have 2 versus one the odds are against the one flying alone, but dismissing post stall is just a trick of you, it will depend in the way the pilot flies and the tactics he uses plus it also depends in the ability of the rival


    F-22 outnumbered can down 4 enemy jets without loses, but remember here the enemies are F-15 type jets, which is an equivalent of J-11.

    In the original case, J-10 is more capable than J-11Bs according to Chinese reports, if you would change the Su-35 versus J-10 the difference will be Thrust vectoring, change that to F-22 versus J-10 and the J-10 won`t even see the F-22 even if the F-22 is outumbered.

    will post stall play a part yes it will, will thrust vectoring play a part yes it will, will HMS play a part, yes it will, and today Su-35 has HMS, thrust vectoring and Supercruise .


    Now i will tell you why F-22 does hooks and supercobra.

    According to those who say post stall makes you predictable is because if you have 1 versus 2 post stall is predictable since it will slow you down.

    to start cobra can be used as a way to slow down and force a enemy overshoot F-22 and over pass F-22, but if there is a second fighter you say F-22 slows down so much the second jet can kill it.


    if that would be the case, then F-22 should be killed more often by F-15s since F-15s outnumber F-22s and F-22 lack AIM-9Xs and HMS, but it does not happen because TVC nozzles simply increase roll rates, turn rates beyond what the F-22 does without it, F-22 is not that much superior to F-15s and F16s without thrust vectoring, in fact sometimes it has inferior numbers but post stall and stealth means an inferior AIM-9P and the lack of a HMS allow F-22 overcome F-15s easily.

    The point here is timing and training, there are instances when post stall is not needed or simply dangerous, but it is definitively an asset
     
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