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Light Stealth Aircraft (LSA) - Concept Aircraft

Discussion in 'Indian Air Force' started by randomradio, Mar 19, 2016.

  1. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    Check the thrust of the two aircraft and also their weapon load outs. F-1 could lift same loads as M2K with lower powered engines if we equalised the internal fuel of the two as F-1 cud carry larger internal fuel load, from shorter runways and in combat it cud outperform M2K due to its lower wing span which resulted in lower drag than the very high wing area of M2K. F-1 made up for loss of wing area by high lift devices which cud be deployed when needed.
    I started this whole exercise with a SE design to keep costs and size low, went on to TE design with HTFE-40 engines and went further up to a 22.5ton design with two uprated Kaveri engines. In all these designs my goal was to outrange and outperform Rafale in every department using tech available within India, acquired by license production of aircraft for last over five decades. basic Idea was-use what we know and have easily available than try and create new exotic technologies which will bog us down.
    In trying to beat Rafale performance figures, I went mad and committed mistakes which were against the very basic idea of LSA itself. I wanted a small, simple, strong, agile, formidable fighter capable of operating from roads and grass fields as the stealth is not just about air but it starts from ground. I wanted to develop a first day and first strike aircraft for war. The whole world now knows that all the infrastructure for Rafale operations in India is confined to two air bases at the cost of $1.8billion. You knock off the infra even if you don't knock of the aircraft, and the whole fleet is on ground. The very basic idea of LSA was to use present infra available in Indian airbases and be highly mobile using container trucks for maintenance. My idea was to use roads as aircraft carriers. You take off from one road and land on another road and the entire maintenance also moves to new location when you are airborne for mission. Just like the "Present and intended Movement" of CBG is given to us Decklanders, same concept I wanted to apply on ground based on my own experiences. I totally deviated from the very design idea of my aircraft.
     
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  2. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    Stuck in this problem of trying to match Rafale in every aspect, I ended up doing one mistake after another. Another big contributor was the IN reqt of MRCBF. I tried to create an IN specific fighter and opted for TE design which ruined everything I had set out to achieve. So I went back to my very original design basics.
    Guess where did I find the solution solution? I found the solution in Mig-21Bis and Boundary layer control or BLC as we call it. I had planned to use EJ-230 for LSA for STOBAR deck launch reqts. But now even with 60/90Kn thrust Kaveri, LSA can go off the deck with payload and range superior to Rafale-M and F-18SH. Bucanner and F-4 Phantoms used BLC for CAT launch to reduce launch speeds and "sink-of-the-bow" by having higher positive launch speeds. A STOBAR carrier gives me an upward trajectory irrespective of the deck cycle in pitching. In fact the best way to launch from a STOBAR is when deck is pitching down as the negative slope of deck adds to acceleration. The final launch angle may reduce but the speed advantage gained by higher acceleration is such that it overcomes the lower exit angle due to nose down pitching of deck.
    In Sea Harriers, we never flew Alpha after launch but flew to 18* pitch angle and than rotated our nozzles for acceleration. Same is done even for Mig-29K operations. The pilot flies a body angle and not alpha. The exit body angle from Ramp gives an initial alpha of 10* which continues to reduce as the aircraft accelerates. In all my calculations for deck launch from STOBAR carriers, I was either short of speed by 4-5kts or had to restrict my MTOW. That put me in same situation as that of Rafale-M and F-18SH. Plus at limiting weight conditions for launch, there was no safety factor for either pilot inefficiency or degraded engine performance which happens across the fleet over a period of time. The safe launch from STOBAR must allow for 5% degradation of thrust and atleast 10 kts of speed as safety.
     
    Last edited: Nov 5, 2017
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  3. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    I did a detailed study of BLC and found that it can boost up Cl of the aircraft by few multiples. In MIg-21Bis, BLC is only over the flap and helps reduce the landing speed by 40kms/hr. It sucks away engine power as the air bleed needed reduces engine thrust. Mig-21BIS used it only for landing where the thrust requirements were low and additional loss of thrust was acceptable due to BLC. I have gone a step further. I have introduced BLC over the entire span of the TE of the wing with drooped ailerons. This will result in 4Kn thrust loss but helps knock out 21kts from takeoff safety speed. it also causes a loss of acceleration during climbout for acceleration to takeoff safety speed but the net gain is 15kts for zero height loss compared to deck. In CATOBAR launch we include 10feet hieght loss for perfect launch as safety factor. There will be no such requirement for LSA.
    But most interestingly, it gives me a STOL aircraft capable of operating from state highways and not needing express highways. This opens a new dimension to the whole survivability of LSA in war. The lower wing span and LCN number allows it to operate from deep interior roads easily.I have finally got what I needed from LSA. The BLC of LSA will be designed as such for TE solution,

    Engine bleed valve for BLC will be controlled by Nose gear air/ground sensor and Flap position sensor and BLC valve will start opening once flaps travel beyond 5* and fully open the valve at 10* flap position. With flaps deployed beyond 5*, nose wheel air/ground switch in ground mode, there will be no bleed air and full engine thrust will be available for acceleration even if one engine fails. As the aircraft exits the ramp and nose wheel air/ground switch goes to air mode, BLC valve will open to supply bleed air.

    · During Takeoff if engine fails beyond the 70m stop line, the pilot will be required to continue the takeoff NORMALLY and jettison all stores when the deck disappears from his view. This will ensure that all stores fall clear of the ship/deck and the aircraft exits the deck with internal payloads & CFTs only. This will reduce the takeoff weight by five tons. As the nose wheel sensor goes to air mode, the BLC will become active to reduce the target safety speed. The mathematical calculations show that aircraft will maintain positive ROC throughout and achieve its target safety speed by top of the trajectory.

    · During Aircombat with flaps selected to auto mode for combat, the BLC will be controlled by flap position switch only. This will add a completely new kind of advantage in combat to MSA-N and make it turn like a spinning top with one of the lowest stall speeds of any similar aircraft.

    · During Approach the BLC will be controlled by flap position sensor only and once landing flaps are selected, the nose wheel air/ground sensor will be removed from the logic circuit. This is to ensure that during bolter or inadvertent touch down touch down during go around on one engine or both engines, the BLC valve remains open and does not shuttle between open and close positions based on nose wheel contact with deck/Ground.

    · During Landing MSA-N will not need BLC however use of BLC will help in further improving the forward view angle with lower flap settings, drooped ailerons and full span BLC with increase roll control. The gains in terms of lower approach speed can be used to lower the approach alpha.
     
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  4. Foxtrot

    Foxtrot Captain SENIOR MEMBER

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    @vstol jockey : By when can we see the first prototype ? Its been quite a while now that you are working with this idea.
     
  5. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    Patience and desperations drive this world. I know when to do a press conference to announce my design and checkmate all other MII games.
     
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  6. randomradio

    randomradio Colonel Technical Analyst

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    If you destroy MRCBF, you will guarantee hundreds of aircraft orders. IAF's MII plans will all collapse on its own.
     
  7. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    As a Brahmin, I was told since my childhood that knowledge and education never fails a person and always come handy when needed the most. Creating an aircraft and trying to find similar parallels was an uphill task. On this very thread some of our dear members from France had raised doubts about the whole concept. But now what we have is that France has been doing the same for last seven decades.
    LCA in its present form is like Mirage series and LSA is like F-1 among them but with PBW instead of FBW. FBW restricts pilots inputs while PBW is like FBW in FBW Direct Law. It delivers what the pilot wants and does not apply any restrictions or modify the inputs of the pilot. In any aircraft design, when we use high lift devices, the net effect is a very strong nose down moment which needs to be countered in some manner. Tailless delta and Canards lack that ability. Only the Slats allow for higher lift and do not create the nose down moment. But they cause another problem, they need another device to help lower the pitch angle to allow the aircraft to land safely with reasonable gear size. or you will need a drooping nose like that of Concorde. Most tailess delta and canard designs have very high approach alpha to be able to reach the regime where the canards are effective in increasing Clmax value. When you deploy double slotted flaps with BLC, the center of pressure rapidly moves aft and creates a strong nose down moment which can only be countered by a tail plane. So if we want small, strong, agile fighter with high lifting capability using limited powered engines and capable of STOL, we will need high lift devices.
    LSA as a concept had always revolved around the idea of using the full architecture of an existing modern aircraft with revised airframe profile. I had manytimes quoted the time of 27months for development of M2K from the day the go ahead was given and the day the first prototype flew.But F-1 had beaten that also and much before. DA flew it in 20 months flat. using same example, I wish to use the architecture of LCA for SE LSA with high lift devices and ensure that money spent on N-LCA is recovered thru LSA-N.
    IAF is asking for 360* radars for AMCA and FGFA. LSA has this provision today and that too with DIRCM included. LSA has full 360* coverage for each of its sensors which even Rafale does not have and will never have. LCA was built as an aircraft from Out-to-In. LSA is being built as an aircraft from In-to-Out. The difference is that a 3D model of LSA airframe will first be created in its production standard with each and every equipment and sensor fitted in it and the fuselage length or anyother requirement like increase in wing area or span to meet specific performance targets will be finalised. In the present design, LSA far exceeds anything which the IAF can throw up as ASQR. after this 3D digital model meets all targets, will I start the CFD analysis.
     
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  8. shaktimaan

    shaktimaan Lieutenant FULL MEMBER

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    I think its too late now, IAF is going to release rfi anytime now and dral is gearing up for MII... Even mod is not gonna agree now
     
  9. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    LSA-N model using HTFE-40/64KN engines or Honeywell F125x engines or 25ton TE MSA-N with folding wings using Kaveri engines show a remarkable ability of being capable of rejecting takeoff from a STOBAR carrier upto 90m of deck run or continue with takeoff even after failure of one engine after 90m of deck run at maximum structural weight and yet get away safely and that too with speed safety margin of ten knots and thrust+airframe deterioration margin of 5%. I had posted how the BLC will be controlled and that gives this fantastic results. LSA/MSA whenever built will completely redefine Naval aviation as we won't need huge carriers with nuke propulsion like what USN has with power requirements like their super carriers. Sastay main aur bahut kam main kaam ho jayega. Satyam Shivam Sundaram or SST-Sasta Sundar aur Tikau. . We will be able to carry and operate larger aircraft from smaller decks at much lower cost. The basis of calculation of these parameters is the parabolic trajectory taken by a shell when fired from the gun which assumes zero acceleration after leaving the muzzle. However in reality, an aircraft will be accelerating. The calculations have been done after calculating the total drag at ten alpha and half of that as rolling friction drag from deck during deck roll, Followed by thrust reduction of 50% after 90m of deck roll, followed by further thrust reduction of 5Kn for full span TE BLC requirements and full ten alpha drag figure when aircraft nose wheel goes to air mode. The ramp exit speed of the aircraft has been calculated base on two variables-aircraft's own acceleration plus the ships velocity. The launch speed is actually the ground speed and not airspeed which makes the whole calculation even more conservative. To explain further, most CBGs travel at arnd 15-17 kts speeds. if we have high wind speed available, the CBG can continue at its speed and launch the aircraft by just ensuring that the forward component of the wind is sufficient for launch even if winds are not exactly dead straight, but if the carrier needs to accelerate to launch its aircraft to generate sufficient wind on deck and turn into wind, the whole CBG will have to re-orientate itself to new FC-Foxtrot Corpn-flying course and its screen will need to also take new stations around the carrier before the aircraft can be launched. That includes the submarines which protect the CBG under water and cover the LLAs-limiting line of Approach for enemy conventional submarines.
     
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  10. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    Let anyone decide what they want to. I will fight it out and challenge every service to prove me wrong. Just for your info, the matter is now at the level of Vice Chief of Navy and I do not mind going directly to Chief also as the next Chief knows me personally very very well. He knows my credentials as an absolute professional and what devastation I can do and what I am capable of.
     
  11. randomradio

    randomradio Colonel Technical Analyst

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    We canceled MMRCA deal at the last minute. Nothing is ever too late.

    Our requirement is very high even if MII proceeds as planned. What LSA/MSA can do is kill SE MII first. It can even affect FGFA, AMCA etc.
     
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  12. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    It will based on what it has become now.
     
  13. shaktimaan

    shaktimaan Lieutenant FULL MEMBER

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    Your design is freezed now?? I am asking bcz as u r progressing u kept on finding issues/sol. in your design and i think you will find more issues when you will move to the next stage.
     
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  14. sunstersun

    sunstersun Lieutenant FULL MEMBER

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    honestly if this plane ever gets built, I'll consider anything possible.
     
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  15. vstol jockey

    vstol jockey Colonel MILITARY STRATEGIST

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    The design was frozen last year itself for SE design but than I deviated from the basic idea and ended up going round and round in circles.
     

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