LCA Tejas Multirole Aircraft

Discussion in 'Indian Air Force' started by Dark_Prince, Apr 14, 2010.

  1. vstol jockey
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    vstol jockey Colonel STRATEGIST

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    The present F404IN20 engine is a big stretch on the original engine. The MTOW of a fighter for an adequate performance in dry thrust should not be 2.5 times the dry thrust of the aircraft. Aas far as possible, try and achieve a TWR of 1 for the MTOW in Air Defence Role. MK1A with an empty weight of 5.5tons+4xIDerbyER of 116Kgs each with another 40 kgs for pylons and missile rails will weigh 624 kgs and 2xPython-5 will weigh 300 kgs. The centreline D/T with 800 ktrs will weigh another 725kgs. with 2400kgs as internal fuel and gun ammo, MK1A will have a an MTOW of 9659kgs which is same as 95KN. At 50% fuel and six missiles, aircraft will have a TWR of 1.19 with a combat weight of 8100kgs, which is massive. Considering that D/T is dropped after fuel is consumed and aircraft has only 1500kgs of fuel internally.
    Now let us do the same maths for MK2 with 62.5/98 engine with 50cms increase in length. Let us assume that Mk2 will have 3 tons of internal fuel and will be 400 kgs higher weight compared to MK1A due to bigger engine and bigger airframe weight. With combat weight of 8500 kgs MK2 will have a TWR of 1.18 but will have higher wing loading compared to Mk1A. So tell me which will be a better fighter? Mk1A will have superior TWR to even M2K and Mig-29UPG. You can well imagine what will be its ITR & STR.
     
    Last edited: Dec 28, 2016
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  2. Agent_47
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    Agent_47 Admin - Blog Staff Member MODERATOR

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    This spec is comparable to Gripen NG.
    Empty weight : ~ 6600 kg
    MTOW : 15000 kg
    Engine : Kaveri 90-95 Kn

    [​IMG]
     
  3. Sathya
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    Sathya 2nd Lieutant FULL MEMBER

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    I think it's not ge 414 but Kaveri snecma engine for mark 2
     
  4. HariPrasad
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    HariPrasad 2nd Lieutant FULL MEMBER

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    Then for what we have ordered GE 414?
     
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  5. HariPrasad
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    8500 against 8100 is a rise of about 5% against which Engine dry thrust increases 20%. i.e 52 kn to 62.5 Kn and that should make Mk2 much better in T/W ratio.
     
  6. vstol jockey
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    vstol jockey Colonel STRATEGIST

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    The combat weight TWR of Mk1A will be 1.19 for 8100kgs while it will be 1.18 for MK2 for combat weight of 8500kgs. But Mk2 will have higher wing loading. It is very difficult for me to believe that with increased length Mk2 will weigh just 6 tons. It will be minimum 6.2tons with just 50cms increase in length due to airframe and 100kgs due to engine weight.
     
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  7. Sathya
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    Sathya 2nd Lieutant FULL MEMBER

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    We have ordered only a small batch, further orders were never placed,.
    By now initial batch should have been delivered . I guess initial delivery were supposed to happen in 2013 December .
    We haven't received it yet . Don't know the current status .

    Similarly there is Snecma Kaveri offset if we had gone for ..
    So the planned re engine option of F404 in older batches is already set to get ready .. Why will go for F414 , when we can have our own engine .

    Either way we have two options .
    If we are using both then I guess
    Kaveri for MK1A and GEF414 for Mk2 LCA
    I hope Kaveri is successful and gets integrated in both.
     
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  8. Picdelamirand-oil
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    Picdelamirand-oil Lt. Colonel STRATEGIST

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    This was the expected specifications to day this has changed

    KEY DATA
    • Length overall 15.2 m
    • Width overall 8.6 m
    • Basic mass empty 8000 kg
    • Internal fuel 3400 kg
    • Max takeoff weight 16500 kg
    • Max thrust 98 kN
    • Min takeoff distance 500 m
    • Landing distance 600 m
    • Max speed at sea level > 1400 km/h
    • Max speed at high altitude Mach 2
    • Supercruise capability: Yes
    • Max service altitude > 52.500 ft
    • G-limits -3G / +9G
    • Hardpoints 10
    • Combat turnaround air-to-air 10 min
    • Full engine replacement 1 hour
    http://saab.com/globalassets/commer...oad-section/facts/gripen-e-fact-sheet--en.pdf

    Finally the airframe is not better than a Mirage 2000
     
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  9. vstol jockey
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    vstol jockey Colonel STRATEGIST

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    Gripen-E is a third rate fighter and I really do not know why some people are peddling it. LCA MK1A with better avionics and reduced weight will be far superior to it any day. In fact many have been misled by its weapon load. With MTOW of 16.5 tons, 8tons empty, 3.4 tons internal fuel, it will have capability to lift only 5 tons of weapon load. This is what Mk1A will lift after reduction in weight. 5.5tons empty, 2.4 tons internal fuel and 13.5 tons MTOW gives a payload of 5 tons. The fuel fraction of Mk1A will be 0.304 compared to 0.298 of Gripen-E.
     
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  10. rockstar
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    rockstar 2nd Lieutant FULL MEMBER

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    Whats the Kaveri current thrust and expected thrust with the help of Safran?
     
  11. vstol jockey
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    vstol jockey Colonel STRATEGIST

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    The figures are not known to anyone but it is expected that it will at least have a thrust similar to F414INS6 or may be more depending on whether it will be flat rated or not. If it is flat rated, it may be limited to about 60/95 other wise I expect it to be around 65/108 level.
     
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  12. HariPrasad
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    HariPrasad 2nd Lieutant FULL MEMBER

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    They said that weight is reduced to 6150 kg and target is 6000KG. I believe that it will improve the fitness ratio and wave drag (Because of improvement in length) and other aerodynamic improvement will come from canopy redesign. So Mk2 will be a better aerodynamics plane that should compensate for low wing loading. Of course canopy redesign can be incorporated in Mk1+ also.
     
    Last edited: Dec 29, 2016
  13. HariPrasad
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    HariPrasad 2nd Lieutant FULL MEMBER

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    I think it is 8.5 and not 9.
     
  14. Picdelamirand-oil
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    Picdelamirand-oil Lt. Colonel STRATEGIST

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    It's data from SAAB.
     
  15. HariPrasad
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    HariPrasad 2nd Lieutant FULL MEMBER

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    Ok But what I had read was 8.5.
     

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