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Thread: Qaher 313 flies....

  1. #31
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    Quote Originally Posted by crow11 View Post
    there is a video of it
    i dont know why people hate on it so much, im all for different planes, different unique designs - just like pre ww2 and ww2 now its just US, Russia and france that are making planes with china copying everything
    I don't think anyone 'hates' it, just that there's a healthy dose of scepticism about the design and its purpose. Not helped by the manufactured-hype about it being a 'stealth fighter jet' instead of just saying it's a test-bed.

    Aviation enthusiasts, those with a open press at least, have been subjected to 60+ years of 'artists impressions', models, mock-ups and CGI which have bred a level of cynicism as well as a sort of 'filter' for separating the feasible from the wishful.

  2. #32
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    Iran shows new footage of Q-313 'stealth' fighter

    ..

    When it was first revealed on 2 February 2013, the original aircraft was immediately met with almost universal derision from the international press with design features that showed the aircraft to be fundamentally flawed. These included (but were not limited to) features that suggested no fly-by-wire control of the aircraft, poorly positioned air inlets, and an almost comically small cockpit (complete with a Perspex canopy).

    While the recently broadcast footage shows the F-313 to be broadly similar in nature to the mock-up, some changes are apparent. While the original had shown a single-engined configuration, the new aircraft is a twin-engined designed. It has a beefed-up undercarriage, complete with a twin nosewheel; a two-piece canopy in place of the single-piece one of the mock-up; and is now at least large enough to accommodate a pilot.

    Even so, many of the previously revealed design flaws remain. These include too small and poorly positioned air inlets that would likely cut air flow to the engines at even the slightest angle-of-attack; a wing-chord that is too thick for high speed performance; a retractable sensor turret that would limit the aircraft's speed when deployed; engines that appear to have no exhaust nozzles; and an overall design configuration that looks far from stealthy in just about every aspect. Aside from the apparent design flaws, a feature of the footage that casts doubt over the veracity of the aircraft is that the rudders do not seem to move in sync with the nosewheel, as should normally be the case.

  3. #33
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    It's amazing how the nose wheel steering doesn't move the rudders and none of the other flight control surfaces apparently move either. It must be a stealth plane that uses stealth controls!

  4. #34
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    It flies!


  5. #35
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    Small intakes and small engines?

  6. #36
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    Quote Originally Posted by Freddy View Post
    Small intakes and small engines?
    It is amazing that those Iranian Scientists have completely by accident indigenously developed a Turbojet engine that happens to look like an overhauled J-85...
    Because sometimes in life we need a bit of fun

    https://www.youtube.com/watch?v=TXNAp3mKepc

  7. #37
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    Quote Originally Posted by Fedaykin View Post
    It is amazing that those Iranian Scientists have completely by accident indigenously developed a Turbojet engine that happens to look like an overhauled J-85...
    Yes very similar & the US it's self plans to keep using the J-85 through 2040. The most important thing though is that Iran can manufacture all the parts locally.
    Name:  Aero-Turbine-tapped-for-GE-J85-engine-overhaul.jpg
Views: 641
Size:  36.4 KB

    http://www.upi.com/Defense-News/2017...8981485436289/

  8. #38
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    Quote Originally Posted by Freddy View Post
    Small intakes and small engines?
    The problem is not the dimension of the intake , is how they are positioned: putting them OVER a LERX type structure do not seems a great move.

  9. #39
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    Quote Originally Posted by Marcellogo View Post
    The problem is not the dimension of the intake , is how they are positioned: putting them OVER a LERX type structure do not seems a great move.
    The position of air intakes above the wings make more sense if you take into consideration the Bavar 2 ground effect flying boat, some parts of the aircraft resemble the Qaher 313. Makes me think the intakes are where they are to avoid water being sucked in during take offs on water. Maybe there will be a hatch(es) that open up to allow more air in once the aircraft is in the air to deal with the problem you have pointed out.

  10. #40
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    Quote Originally Posted by Freddy View Post
    Yes very similar & the US it's self plans to keep using the J-85 through 2040. The most important thing though is that Iran can manufacture all the parts locally.
    Name:  Aero-Turbine-tapped-for-GE-J85-engine-overhaul.jpg
Views: 641
Size:  36.4 KB

    http://www.upi.com/Defense-News/2017...8981485436289/
    The reason for my scepticism is it has been shown more than once in recent years that a number of their fully indigenous programs actual incorporate a large amount of refurbished parts.

    At best they have reverse engineered 1950s turbojet that could be used to keep their F-5 fleet going a bit longer. Then again the IRIAF have not shown much interest in the various F-5 reverse engineering programs preferring overhauled examples from their current fleet. The Saeqeh had to make use of the worse surplus Vietnamese F-5 airframes rather than any from the active Iranian fleet.

    In the end this is for the benefit of a domestic audience.
    Because sometimes in life we need a bit of fun

    https://www.youtube.com/watch?v=TXNAp3mKepc

  11. #41
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    In the end developing advanced jet engines is the most difficult area of fighter aircraft development requiring decades of research and very deep pockets. Even China and India both with the will and pockets deep enough to fund RnD have struggled. There are areas like Avionics and electronics where Iran can make indigenous leaps in capability far easier as enabling technologies can be obtained with less trouble from abroad. The materials and fluid sciences that go into jet engine development is an order of magnitude more difficult.

    It should be remembered that nations proficient in high end fighter engine production burnt out a lot of metal in the early days and even more recently to get to where they are now.

    The Chinese with their VERY deep pockets are making a fighter turbo fan that is reverse engineered from a US design that performance and reliability wise at best similar to a unit made in the mid 80's.
    Because sometimes in life we need a bit of fun

    https://www.youtube.com/watch?v=TXNAp3mKepc

  12. #42
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    Not seem me probable a direct derivation from it, one is a maritime sea surface effect vehicle, other a land based plane.
    For the rest both are remarkable example of IRGC lateral thinking, given that you can't compete in a symmetrical development , try a completely radical new approach to the problem.
    Your actual expertise in engine, light alloy/ composite materials allow you only to build a '70 plane: ok do it but (given that instead you are at fair good level in electronic and CAD design) do it stealth and with an innovative frame design other have tried but are instead gone for a more conventional solution.
    Probably it would not work anyway, but if it is succeed it would be a bang.

  13. #43
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    We can set two boundary conditions and check if the methodical design result would be the Qaher.

    1. Your engine technology is 3-4 decades behind that of your opponents.

    2. Your country to defend has one of the most mountainous topographies on this planet, where mountain chains are 2000m on average.

    The resulting design can be independent and no foreign companies or mainstream idol designs have influence on it.

    In such a case a result could be the following:

    Make use of the mountainous terrain to avoid detection by radar, IR and ESM. The design has to fly low in valleys to mask it. I wont go for the high altitude high speed game of air superiority fighters, hence no long range radar-tech/engine-tech driven BVR engagements. Now difference of speed at sea level is at best around 30% for a subsonic fighter and a advanced opponent fighter with advanced engine-tech due to the high drag. This lower speed difference compared to low engine-tech vs. high engine-tech engagements at high altitude helps to compensate.

    As for the deficits with the engine, a physical effect, the ground effect is taken into the design, which effectively creates more thrust. A possible turbofan variant of the J85 at 70s tech level without afterburner, optimized for low altitude, plus the bonus by the ground effect, decreases the gap in engine-tech. It may provides mach 0,9 for a draggy internal weapon VLO design.
    In a hunt, the opponents high engine-tech fighter, far from home base on short afterburner might do mach 1,3 with or without internal weapons, a short-lived difference of 30% for 30 years difference in engine technology.
    Its clear that this 1:1 hunt scenario is not everything and the opponents fighter will try to shot it down from higher altitude, look-down. However the topographie will always force it to get close in order to have a direct line of sight for radar/IR and weapons and the VLO design will futher hinder long rnage shots from look-down positions. With a intact IADS and LR-SAMs the initial engagements could be limited to that low-altitude hunt scenario where the kinematic advantage of the modern fighter is decreased.

    The Qaher is surely designed to make use of ground effect, its WIG like wingtips clearly point to it. Here is a technology where no experienced metallurgy is necessary, benefit by a physical effect affecting kinematics by developing a terrain avoidance system with digital maps and multiple redundant sensors. A mature terrain avoidance system for very low altitudes, state of the art.
    Additional advancing communication technology with data-links and sensor-fusion/IADS could provide the Qaher with the necessary situational awareness to do its low level operation, approach a target, pop-up, attack and dive back and leave the battle (this dive/low-level escape is also a method used by the B-2).

    The tandem wing design is also noteworthy for the ground effect optimization. A question is what range performance would be possible for such a ground effect operating aircraft with an non-afterburning J-85 turbofan variant. Would the ground effect operation at mach 0,9 max. provide it with the same range performance as a medium to high altitude operating fighter?
    The tandem wings have a interesting design, the forward wing/canard is conventional for a fighter, but the rear wing has a very thick leading edge. The benefit for such a thick wing profile is foremost the fuel that can be carried inside it, especially for a design that has internal weaponbays in the fuselage occupying space. The forward-wing apparently "breaks" the high speed airflow, so that the thick rear wing is just confronted with a low pressure region at the leading edge which could result into a thick wing as a airflow design result.
    The decision not to go with a supersonic VLO design and stick to a low-level mach 0,9 design would also be a brave one, supersonic sounds good but in a operation regime hypothesized for the Qaher the effort-benefit ratio would be too low. In high subsonic operation the design gets much cleaner and more efficient.

    Then there are always questions about the cost effectiveness. How much cheaper would be two turbofan modifications of the J-85 compared to modern engines (1/10 of a F404?)? How much cheaper is a small aperture low power AESA for 80km max. range against a 1m˛ target? How much easier design and hence cheaper is a VLO inlet like that of the Qaher? Just due to positioning it could provide the same VLO effect in its operation regime as complex fan-face avoiding supersonic designs. What high angle of attack penalties are expected for the inlet and how important are high AoA for its operation regime?
    If all these trade-offs and design elements are clarified we can judge if the methodical design result of the Qaher makes sense or not.

    Iranians are known for such unconventional designs and operation regimes, so this hypothesis might not be that far from reality.

    At this point the project remains up for debate, neither IRGC nor IRIAF have shown support for it and development seems to be slow. Lets see if we see a airworthy prototype soon.

  14. #44
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    Quote Originally Posted by PeeD View Post
    As for the deficits with the engine, a physical effect, the ground effect is taken into the design, which effectively creates more thrust.

    The tandem wing design is also noteworthy for the ground effect optimization
    As i remember ground effect doesn't create more thrust

  15. #45
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    Quote Originally Posted by moon_light View Post
    As i remember ground effect doesn't create more thrust
    He said effectively. Lessening the drag has pretty much the same result.

    Nic

  16. #46
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    Quote Originally Posted by Nicolas10 View Post
    He said effectively. Lessening the drag has pretty much the same result.

    Nic
    Exact. Add also the momentum thrust created by routing the flow downward with the induced lift and the continuous surface (sea) accelerating the flow (with the added massflow generated by sea-spray).
    The IGE however is only over a regular surface. Surface discontinuities such as overland will cancel the IGE effect at the speed of a plane.

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