ADA Tejas (LCA) News and Discussions

Which role suits LCA 'Tejas' more than others from following options?

  • Interceptor-Defend Skies from Intruders.

    Votes: 342 51.3%
  • Airsuperiority-Complete control of the skies.

    Votes: 17 2.5%
  • Strike-Attack deep into enemy zone.

    Votes: 24 3.6%
  • Multirole-Perform multiple roles.

    Votes: 284 42.6%

  • Total voters
    667
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Advaidhya Tiwari

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Is there a way to accomodate a SPJ inside the body of Tejas in Mk1 and Mk1A versions during their midlife upgrade?
The problem of MK1 is that it is too small to accomodate SPJ pods. That is why MK2 is needed. SPJ is not the only one excluded. Many other components also have been excluded due to small size

I've said this multiple times (somehow the point is not getting appreciated by ersakthivel & associates):
Thrust-to-weight ratio of the ENTIRE AIRCRAFT is the most important factor, not thrust-to-weight for the engine.
The hypothetical 20% increase in engine weight for 20% increase in thrust keeps the engine thrust-to-weight same, but gives a huge boost to the aircraft's thrust-to-weight ratio.
If I am right, there are few ways of increasing thrust of engine:
1) Increase the size of engine, either the overall dimensions or radius
2) Add another stage of compressor which increases length of engine
3) Improve material and thus have same size but increased thrust.

Now, if option 1 and 2 is exercised, the engine size will increase which will eat up the volume of the aircraft internals. So, the only way of increasing weight of engine by 20% and increase thrust by 20% is by changing the material of the blades to a better one and which weighs 20% more. It will be something like substituting the nickel alloy with tungsten or Uranium alloy.

But, yes, if the engine weight and thrust alone can be increased without increasing size, then the TWR of a plane will get a boost.
 

ersakthivel

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How does fighter design starts?

A hypothetical scenario,


ASR specifies,

Range, weapon load, close combat specs like ITR, AOA, TWR of entire fighter,Max G,STR, roll rate, climb rate etc,

Designers decide,
With the available engine tech, & engine TWR,
Whether it is possible,

Or,
Not.

Give feedback , arrive at a mutually agreed design goals,

Then, engine thrust, empty weight of the fighter needed to support the fuel, weapon load
Wing area needed to lift that mass & achieve those close Combat specs are arrived at,

This will be an iterative process, which will result in final empty weight of the fighter needed to support the wing area, and other parts get finalized,

Weight distribution of all LRUs, CG,drag calculations, CL, margin of stability or instability all play an important role in it.

Then design & prototyping progresses , ends up in a fighter type after decades of hard work, 1000s of test flights,


After that adding 300 kg to engine( for 20 % extra thrust of 16 KN,), at the tail, adding another balancing 300 kg of avionics at the nose,

Adding some more weight in fuselage to support these 600 kg at 9G, ,

Then wing size too needs increase, to generate better lift to support the weighter,

will get teja mk1 weigh up by say 700 KGS,

Then to support these 700 kgs , through out the combat range of the plane, we need more fuel , (some more weight gets added up, )

&

More importantly fuselage volume , to house that fuel & extra avionics weighing 300 kg.



This is called weight spiral.

Then we get a 7.5 ton empty weight tejas, with 96 KN engine thrust. 13.5 ton MTOW,

That means it is the same fighter like 6.5 ton tejas mk1, with 12.5 ton MTOW,

All specs will be same

, MTOW increases, but empty weight too increased, so no gain.


Engine thrust increases but fighter's TWR stays the same.No gain

But all calculations for CG, CL, margin of safety, drag need to be redone,

need to be revalidated, taking countless test flights & number if years.



It's like a guy strapping a 20 kg kerosene can on Ussain bolt's back,

Setting it on fire , in the hope of him completing 100 meters run in 5 seconds,

That's why ADA didn't choose that ruinously disastrous path advocated by Air Marshal Matheshwaran,by increasing stages & engine weight,

instead going for a better engine TWR GE 414 for mk2,

But our folks are getting their knickers in knots over stuffing 300 kg extra weight on Teja tail,

&


May be fly it in martian atmosphere with Maheswaran Sir in cockpit, to get a better tejas,

ROFL.

If canards were added to support super heavy radar in su 30 MKI, as alleged by some members,

It gives su 30 mki a cutting edge powerful radar, so worth it. & It was done along with many other IAF specific enhancements in a useful redesign.

Point to note is additional lift & control surface like canards,

& an extensive redesign

was needed to support this extra 500 kg in a massive 30 mki , twin engine, beast of a plane , with truck loads of thrust, if the statement, "that canards were added to support radar weight" is true.

In case of Tejas , it is zero gain for a decade & thousands of correa invested in such a re engineering.


I don't know how long are these guys are going to hang on for this extra engine weight, thrust, tejas.

This will be my last post on this subject,
 
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ersakthivel

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On page no 421 in this thread, A full report on Air marshal Mateshwaran's speech at vayu round table is available,



https://defenceforumindia.com/forum/threads/ada-tejas-lca-news-and-discussions.1/page-421

Excerpt from this,

"Cost and time frames are absolutely unrealistic. And example: the Kaveri engine. 89 you get the CCS approval – project is approved for 450 crores saying that a 4th generation engine – no such engine existedanywhere in the world – and mind you we haven't made a single aero-engine that flies before that nor even today. No engine has been made – designed and made. And you want to jump to a 4th generation engine though original proposal was for a five-stage engine which people said 'Come on,have some sense. Look intoit again.' So they made it six-stage – even that was not existing anywhere in the world."
 

ersakthivel

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The poster in front of Tejas mk1 in Aeroindia says,

It has max endurance of 2 hrs 30 minutes
 

Advaidhya Tiwari

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Not a pipe dream.

I think Tejas might have it during peacetime patrols with minimum A2A(2 bvr and 2 wvr missiles load and 2×1200 and 1×800 fuel tanks.
There was no centreline fuel tank yet back then. Also, ferry range of Tejas is 1700km with internal fuel at high altitude. That means Tejas already has about 1 hour 45minutes of flight time in internal tank
 

ersakthivel

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Above quote of Air Marshal Matheswaran at Vayu Stratpost conference,

Underlines the perils of giving control of deep tech orgs like GTRE, ADA, HAL to IAF personnel ,

Who hv no technical credentials .

These guys, who hol forth on this subjects, about which they hv no clue will destroy whatever achieved so far.


French now says kaveri is stable enough for flight test,

Prat & Whitney , who inspected it years before, said it is a world class Engine, & they are ready to conoperate on it.

But our air Marshal says such 6 stage engine doesn't exists anywhere in the world.
 

ersakthivel

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https://defenceforumindia.com/forum/threads/ada-tejas-lca-news-and-discussions.1/page-422

Firstly, as testified by the IAF test pilots who have flown the Tejas through more than a thousand hours of flight-testing, the current version of the fighter, i.e. the Tejas Mark I, is already a world-class fighter that has achieved most performance landmarks that the IAF had demanded.

It flies at Mach 1.6 (about 2,000 kmph), a speed that the IAF is satisfied with.

Its state-of-the-art quadruplex digital flight control system makes it a maneuverable and easy-to-fly fighter,


unlike the unforgiving MiG-21 that it is slated to replace.

The Tejas has not had a single accident so far, testifying to the stability of its design.



Another key measure of a fighter's capability is the Angle of Attack (AoA) it can achieve.

The higher the AoA, the more lift that is generated, allowing a fighter to get airborne at slower. speeds from short airstrips, e.g. aircraft carriers.

The IAF had demanded an AoA of 26 degrees for the Tejas.

The Tejas has already been tested to 24 degrees, and is on course to achieve that target.



Says Air Commodore (Retd) Parvez Khokhar, who was for years the chief test pilot of the Tejas programme:

"The Tejas Mark I is far superior to the MiG-21 fleet that the IAF would have to operate to the end of this decade.


In key respects, it is a better fighter than even the Mirage2000.

The Tejas Mark I should enter the IAF's combat fleet in larger numbers and the Tejas Mark II scaled down.

(Now we hv best of the both worlds, with a sensible govt going for 123 mk1s,. mk1As, & mk2 being developed along the capabilities of f16plus.)

This would allow the air force to retire the MiG-21 fleet sooner."

(Parrikar got mk1A standard approved, to fulfill these wide words)



For this, the MoD must review its current plan to build just forty Tejas Mark I fighters, and embark upon another risky adventure to develop a more powerful, capable fighter.

Since this would take at least four years of development work, the IAF would not start receiving the Tejas Mark II until 2018.


When IAF people associated with the tejas speaks a world of positives about mk1,

Few Air Marshal , ex chief types go on beating tejas down,

advocating it to be closed down(like Matheswaran) , & calling it is mig 21 plus,


is regrettable to say the least.
 
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ersakthivel

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How ironic,

After 10 years we are once again starting the same kaveri snecma jv rejected by IAF,,


IAF rejects French offer on engine for Tejas


Ravi Sharma

--------------------------------------------------------------------------------

‘Kaveri’ under developmentat the GTRE for 20 years

Snecma offer did not meet IAF requirements


--------------------------------------------------------------------------------
BANGALORE: It’s final: the indigenous Kaveri aero engine, under development at the Gas Turbine Research Establishment (GTRE) for 20 years with the specific objective of powering the Light Combat Aircraft (LCA) Tejas, will now not fulfil that task.

The LCA will not be operationalised with the Kaveri, since GTRE will not be able to satisfy the Indian Air Force’s requirement for a low altitude, high speed engine with a thrust of at least 90 kilo Newton (kN) within the extended timeframe, weight or volume.

GTRE officials told The Hindu that they hoped a Kaveri engine co-developed by the GTRE and the French aero engine house Snecma could at least become, in the distant future, the power for the Medium Combat Aircraft (MCA) that is still to be designed. “The IAF agrees that the MCA should be designed around a 90 kN thrust Snecma-GTRE Kaveri engine. The Kaveri could be tested on the LCA, but the aircraft won’t be operationalised.”

Conditions not met


The final blow for the Kaveri engine project, which was launched in 1989 as “the engine for the LCA,” andwhich has cost the exchequer over Rs. 2,000 crore in development, comes after the IAF rejected the offer from Snecma to co-develop the Kaveri along with the GTRE.

In 2005, after GTRE indicated that it would not be able to develop the core technology (hot end parts) for the Kaveri on its own, help was sought: France’s Snecma and Russia’s NPO Saturn made offers to collaborate with the GTRE, the former being pre-selected as the technical partner.

The IAF’s rejection of the French offer comes after a committee, headed by Air Vice-Marshal M. Matheswaran, pointed out that the Snecma offer did not meet the Air Force’sperformance (air staff) requirements, did not give the GTRE the core engine technology it was looking for, and did not help eliminate deficiencies in the Kaveri’s design.

“Assimilate” technology


Both Snecma and the GTRE contested the IAF’s stand, saying that the relevant design technology would, in stages, be assimilated to the Indian defence laboratories.

According to Snecma’schairman and chief executive officer Philippe Petitcolin, his company could pass on the design and manufacturing technology to Indian entities as soon as it “couldassimilate it.” Mr. Petitcolin told The Hindu that collaboration could save the GTRE at least 20 years in developing an aero engine.

The IAF committee, which also has members from other key constituents of the LCA programme, suggested restructuring of the GTRE, with research anddevelopment being made the area of focus. “GTRE hadunrealistically promised to make the Kaveri operational in seven years,” an IAF official said.

The Hindu : Karnataka News : IAF rejects French offer on engine for Tejas
 

ersakthivel

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1 December - The PV-3 flew for the first time for 27 minutes at an altitude of 2.5 km and at a speed of Mach 0.8. The PV-3 was equipped with a more advanced pilot interface, refined avionics and higher control law capabilities compared with the previous versions.
2007

Tejas PV-1 firing an R-73 missile during weapons trials in Goa
25 April - The first Limited Series Production LCA (LSP-1) made its first flight and it reached a speed of Mach 1.1.
PV-2 and PV-3 underwentsea-level trails at INS Rajali Naval Air Station, Arakkonam to study the effects of flying at sea-level, as all earlier trials have been conducted at Bangalore which is 3,000 feet above sea-level. The reliability of the LCA systems under the hot and humid conditions, as well as low level flight characteristics was tested.[6][7] It is due to this intense flight testing schedule that the LCA was not able to fly at the Paris air show-2007, as was originally planned.
7 September - TejasPrototype Vehicle (PV-1) made a successful maiden flight with two 800 litre drop tanks.
25 October - Tejas PV-1 fired a Vympel R-73 missile for first time. The trials were conducted off the Goa coast at INS Hansa Naval Air Station.
11 December - LITENING Pod was successfully tested on Tejas PV-2.
2008
7 February - Tejas Prototype Vehicle (PV-1) made a successful flight powered by fuel from two 800 litre drop tanks. It made a one hour and 24 minute long sortie. On internal fuel LCA can perform a 40-minute sortie.


So An hour & half with two 800 litre drop tanks on February 7,2008.
This is before centerline fuel tank. & 1200 liter fuel tanks were tested.

So 2 hours, plus endurance is not a pipe dream by ,"empty vessels, perhaps"
 

ersakthivel

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In negative stability (Relaxed Static Stability, RSS) fighter like Tejas,


Center of Lift (CP or CL) is in front of Center of Gravity(CG),

So that the fighter is UNSTABLE in pitch axis & goes with the wish of pilot trying agile manuoveres,

They need precise analog or digital flight control systems that keeps the fighter fom going out of control, by giving
inputs to control surfaces every milliseconds,


In contrast,

In the old world positive stability fighters,

CG in front of CP, so that fighter resists pilot's attempts at agile manuoveres & tries to return back to stable flight,


that are directly , physically controlled by pilots input to control surfaces.


Because sophisticated analog or digital flight control systems were not in existence then.

"experts" who advocated ,that 300 kG extra engine weight in tejas needs , no structural re engineering, because of 16℅ extra thrust,


Can go to the link below to learn more,

https://forums.bharat-rakshak.com/v...d=788e6782db9d2125e02389b40222afad&start=2080

All concerns regarding increase or decrease if weight in relation to CG, CP, margin if instability are debated there.

Just look at the quality of discussion & learn some decorum as well.


Before analog & digital fly by wire systems came into existence all fighters were stable in flight profiles.

With the advent of trans sonic & super sonic fighters, wing sweep angle increased ,


Because of the need to restrict air frame with in trans sonic shock cone.

So the fighter's mass began to coalesce around its fuselage, due to wing spans getting shorter in relation to fuselage length.

So fighters became more stable & increasingly hard to manoeuvre in pitch angle,

Due to the increase in Stability margins,

To obviate this RSS fly by wire deltas design became dominant,

From this point onwards weight distribution in fighters had to be precisely calculated with regards to CG, CP, margin of instability
 
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Enquirer

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Once again the fraud of the forum strings together sentences from different websites with zero understanding of the basics!

Commercial airlines don't need maneuverability like a fighter jets, and as such they take advantage of the laws of physics and have CG fore of CP!

Fighter jets, need to be agile - able to turn around quickly and as such are intentionally made unstable.

Notice how the logic (that even that moron peddled unknowingly) corroborates my statement that Su-30MKI with heavier radar will be more stable than Su-27! But this idiot refuted that and then is bullshitting nonstop with confusing nonsense!
 

Prashant12

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DRDO wants to sell super radar technology for fighter jets to industry, invites applications


India’s defence research and development organization (DRDO) wants to sell tech that it says it has developed for a `super radar’ for fighter jet aircraft and has asked the Indian Industry to submit proposals for transfer of technology (ToT).

The Electronics and Radar Development Establishment (LRDE) has said that it is ready with its “Active Electronically Scanned Array Radar (AESAR)” technology and has four licenses to offer to the Indian industry. The lab has asked interested companies to submit their profiles to apply for the project.

The AESAR is a key requirement for all future jet fighter purchases by India, with efforts also on to integrate it to the indigenous Light Combat Aircraft (LCA) Tejas that are on order by the Indian Air Force. In a recent note, DRDO gas said that its fire control Radar can be configured for use on any fighter class aircraft and has sought Expression of Interest (EOI) from prospective bidders.

“Active phased array technology in the Radar enables user to achieve high mission reliability with multi-target tracking capability. The radar operational modes are designed to assist the fighter pilot in the execution of various combat missions in air-to-air, air-to-ground and air-to-sea operations,” the DRDO note says.

AESA radars are at the heart of modern fighter aircraft and are integrated on all cutting edge jets like the Dassault Rafale and Boeing F/A 18 besides the fifth generation F 22 and F 35 fleet. These radars enable jets to detect enemy targets from a standoff distance without getting exposed. They can also track and target multiple threats simultaneously, giving one jet the ability to take down several targets. An AESA radar will also be a defining parameter for the upcoming contest to supply 110 fighter jets to India under a Make in India scheme.

Israeli company ELTA is equipping 58 of the Indian Air Force Jaguar jets with AESA radars as part of the upgrade plan. No other Indian Air Force fighter had the AESA radar yet but India is processing a global tender for AESA radars for a new fleet of 83 LCA MK 1A fighters for which also ELTA has been down selected.

The integration of an AESA radar was a key parameter for the air force to clear the order for 83 LCA Mk 1A fighters, after years of blocking the indigenous fighter on concerns that it would not be combat worthy.

https://economictimes.indiatimes.co...invites-applications/articleshow/65597037.cms
 

Advaidhya Tiwari

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DRDO wants to sell super radar technology for fighter jets to industry, invites applications


India’s defence research and development organization (DRDO) wants to sell tech that it says it has developed for a `super radar’ for fighter jet aircraft and has asked the Indian Industry to submit proposals for transfer of technology (ToT).

The Electronics and Radar Development Establishment (LRDE) has said that it is ready with its “Active Electronically Scanned Array Radar (AESAR)” technology and has four licenses to offer to the Indian industry. The lab has asked interested companies to submit their profiles to apply for the project.

The AESAR is a key requirement for all future jet fighter purchases by India, with efforts also on to integrate it to the indigenous Light Combat Aircraft (LCA) Tejas that are on order by the Indian Air Force. In a recent note, DRDO gas said that its fire control Radar can be configured for use on any fighter class aircraft and has sought Expression of Interest (EOI) from prospective bidders.

“Active phased array technology in the Radar enables user to achieve high mission reliability with multi-target tracking capability. The radar operational modes are designed to assist the fighter pilot in the execution of various combat missions in air-to-air, air-to-ground and air-to-sea operations,” the DRDO note says.

AESA radars are at the heart of modern fighter aircraft and are integrated on all cutting edge jets like the Dassault Rafale and Boeing F/A 18 besides the fifth generation F 22 and F 35 fleet. These radars enable jets to detect enemy targets from a standoff distance without getting exposed. They can also track and target multiple threats simultaneously, giving one jet the ability to take down several targets. An AESA radar will also be a defining parameter for the upcoming contest to supply 110 fighter jets to India under a Make in India scheme.

Israeli company ELTA is equipping 58 of the Indian Air Force Jaguar jets with AESA radars as part of the upgrade plan. No other Indian Air Force fighter had the AESA radar yet but India is processing a global tender for AESA radars for a new fleet of 83 LCA MK 1A fighters for which also ELTA has been down selected.

The integration of an AESA radar was a key parameter for the air force to clear the order for 83 LCA Mk 1A fighters, after years of blocking the indigenous fighter on concerns that it would not be combat worthy.

https://economictimes.indiatimes.co...invites-applications/articleshow/65597037.cms
This is a fantastic news. I wonder how DRDO got AESA completed in just 5 years from start! But that is damn fast.
 

ersakthivel

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Once again the fraud of the forum strings together sentences from different websites with zero understanding of the basics!

Commercial airlines don't need maneuverability like a fighter jets, and as such they take advantage of the laws of physics and have CG fore of CP!

Fighter jets, need to be agile - able to turn around quickly and as such are intentionally made unstable.

Notice how the logic (that even that moron peddled unknowingly) corroborates my statement that Su-30MKI with heavier radar will be more stable than Su-27! But this idiot refuted that and then is bullshitting nonstop with confusing nonsense!
Yo mud headed expert,

Read the following,

Before starting your ,"fortune telling",

"Combined with relatively low wing loading andpowerful basic flight controls, it makes for an exceptionally agile aircraft, controllable even at very low speeds and high angle of attack. "

You hv been yelling from the roof top that,

LOW WINGLOADING is some insignificant spec.

Correct your lying ways, before calling others fraud.





The Su-27's basic design is aerodynamically similar to the MiG-29, but it is substantially larger. The wing blends into the fuselage at the leading edge extensions and is essentially a cross between a swept wingand a cropped delta (the delta wing with tips cropped for missile rails or ECM pods). The fighter is also an example of a tailed delta wing configuration, retaining conventional horizontal tailplanes.

The Su-27 had the Soviet Union's first operational fly-by-wire control system, based on the Sukhoi OKB's experience with the T-4 bomber project. Combined with relatively low wing loading and powerful basic flight controls, it makes for an exceptionally agile aircraft, controllable even at very low speeds and high angle of attack. In airshows the aircraft has demonstrated its maneuverability with a Cobra(Pugachev’s Cobra) or dynamic deceleration – briefly sustained level flight at a 120° angle of attack
 
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