GTRE to Test Dry Kaveri with New Afterburner on Tejas, 80kN Success Could Trigger Upgrading Entire Mk1A Fleet with Domestic Engines

In a major push for India's self-reliance in military aviation, the Defence Research and Development Organisation (DRDO) is set to test an upgraded indigenous jet engine on a Tejas Light Combat Aircraft (LCA).

The Gas Turbine Research Establishment (GTRE), a premier DRDO laboratory, has received the green light to integrate its Dry Kaveri engine, fitted with a newly designed afterburner, into a Tejas prototype for crucial flight validation.

This development is a critical milestone for the long-running Kaveri engine program, which began in 1989 with the goal of producing a domestic powerplant for Indian fighter jets.

A successful trial could pave the way for the Kaveri engine to replace the currently used American-made General Electric engines in the entire fleet of Tejas Mk1A fighters, of which the Indian Air Force (IAF) has 83 on order with plans for 97 more.

The engine at the center of the upcoming tests is a non-afterburning variant known as the Dry Kaveri, which was primarily developed for the DRDO's stealthy Ghatak Unmanned Combat Aerial Vehicle (UCAV).

In recent ground trials, this engine successfully produced 49-50 kilonewtons (kN) of thrust, exceeding its initial goals. By integrating a new, domestically developed afterburner, GTRE scientists aim to increase the engine's maximum thrust to approximately 80 kN.

This enhanced power output would bring the Kaveri closer to the 78.7 kN of thrust generated by the GE F404-IN20 engine that currently powers the Tejas Mk1 aircraft.

The ultimate ambition for a future version, dubbed Kaveri 2.0, is to achieve a thrust of 83-85 kN, making it a competitive, home-grown option for India’s frontline fighters.

The integration and flight tests will utilize an older Limited Series Production (LSP) model of the Tejas.

While the IAF has raised safety concerns about testing an uncertified engine on a single-engine aircraft and suggested using a twin-engine plane or an unmanned platform, GTRE is confident in proceeding with the Tejas testbed.

This crucial phase follows extensive development and earlier tests. Before the in-flight validation on the Tejas, the Dry Kaveri engine is scheduled for final high-altitude trials in Russia, set to begin in September 2025. These tests will be conducted at Russia’s Gromov Flight Research Institute using a modified Ilyushin Il-76 transport aircraft as a Flying Test Bed, where the Kaveri will temporarily replace one of the aircraft's four standard engines.

Despite the progress, significant challenges remain. At approximately 1,180 kg, the Kaveri engine is heavier than its foreign counterparts like the GE F404 (1,036 kg), which could affect the aircraft's agility.

GTRE is actively working on weight reduction by using advanced, lighter alloys and manufacturing techniques, with support from Indian public-sector undertakings like Mishra Dhatu Nigam Limited (MIDHANI), which specializes in critical aerospace materials.

The success of the Kaveri project is central to India's strategic goal of achieving autonomy in critical defence technologies, as the nation currently relies heavily on imported engines from the United States, Russia, and France for its military aircraft.

The upcoming tests represent a pivotal moment in demonstrating the maturity and viability of India’s indigenous aero-engine capabilities. Final certification for the Dry Kaveri engine is targeted for 2032.

 

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[R. Singh]

Seek 100% tech from Safran/Rolls Royce to make 85-90 KN engine for Tejas-1A and 110-130 Kn for AMCA !

 

[Sommyarup Roy]

Damn, if the thrust-to-weight ratio is comparable, then it's huge. Kaveri is flat-rated, so its performance is consistent across climates, so it can potentially be better than the GE F404.

 

[GMR]

Great! If it can achieve sustained 80 kN thrust, that's huge. Further refinements can help in exceeding the F404. All the best, keep up the heart; the result is at the doorstep.

 

[Sunny]

Unless the weight is reduced by at least 100kg and it achieves 85-90kn thrust, it will not qualify for Tejas Mk1A. Currently being overweight and underpowered compared to GE404 on Tejas Mk1, in its current planned specifications it will underperform and not meet requirements.

 

[Shafted mohammed]

I personally feel, by arm-twisting India on GE 404 engines, the US may end up as a big loser, as Kaveri is getting ready. Uncle Joe did, which the new administration continued; in fact, they put India against the wall. India already has an 80 KN thrust class engine to get the production of LCA Tejas MK1A going, and in the meantime, can use better materials and increase the thrust. This way, India can become self-sufficient in jet engines, and then in transport engines and commercial engines. GE, in the long run, would lose big.

 

[Sommyarup Roy]

Unless the weight is reduced by at least 100kg and it achieves 85-90kn thrust, it will not qualify for Tejas Mk1A. Currently being overweight and underpowered compared to GE404 on Tejas Mk1, in its current planned specifications it will underperform and not meet requirements.

GE engine is only 78 KN.

 

[Sunny]

GE engine is only 78 KN.

The General Electric F404-GE-IN20 variant for Tejas has 85 kN thrust.

 

[Apocalypse gupta]

The General Electric F404-GE-IN20 variant for Tejas has 85 kN thrust.

In the article, it is written that the IN20 variant for India has 78.7 kN thrust.

 

[abhinav srivastava]

They should further reduce the weight of Kaveri, but 100 kg overweight should not be a big concern. Tejas has 300 kg dead weight, which can be reduced.

 

[PK]

Unless the weight is reduced by at least 100kg and it achieves 85-90kn thrust, it will not qualify for Tejas Mk1A. Currently being overweight and underpowered compared to GE404 on Tejas Mk1, in its current planned specifications it will underperform and not meet requirements.

It can still be used on the trainers such as the upcoming HLFT-42 even if it falls slightly short on some parameters with respect to the short term future outlook. That still saves us a lot of dependence on imports.

 

[Anubhav Sharma]

Sorry to say, but Russia is the only option as the US has already derailed the F404 engine and Apache deal by various months. Rolls-Royce is in cahoots with the US and will not work against their will. The M88 is already a pretty older model, and they haven't fulfilled the offset obligations of Rafael. Although I support diversification, in this time of war we don't have unlimited time.

 

[Sunny]

In the article, it is written that the IN20 variant for India has 78.7 kN thrust.

On the GE website it's mentioned 85kN.

 

[Sunny]

It can still be used on the trainers such as the upcoming HLFT-42 even if it falls slightly short on some parameters with respect to the short term future outlook. That still saves us a lot of dependence on imports.

For that the requirement specified is of 95-100kN engine.

 

[Bikramjeet Goswami]

Great! If it can achieve sustained 80 kN thrust, that's huge. Further refinements can help in exceeding the F404. All the best, keep up the heart; the result is at the doorstep.

Cannot achieve sustained 80 kN thrust; afterburner uses up a lot of fuel, and the Tejas, being small, doesn't carry a lot of it.

 

[Suyash]

On the GE website it's mentioned 85kN.

It looses thrust in our weather conditions as it isn't a flat rated engine. That's why 78.7

 

[The Dark Knight]

Cannot achieve sustained 80 kN thrust; afterburner uses up a lot of fuel, and the Tejas, being small, doesn't carry a lot of it.

It performs just like F404, nothing more, nothing less.

 

[Diganta Ghosh]

The main problem is the thrust-to-weight ratio and engine life. Dry thrust is almost reaching 50 kN, and wet thrust is also above 80 kN. The next Kaveri 2.0 should incorporate more advanced technologies to ensure it matches the F414 level efficiently.

 

[DefStock]

85kN is very good for UCAV Ghatak and Tejas Mk1s, but contracts already signed for F404s. GoI making big mistake delaying AMCA engine contract. That will take 6-7 years for first prototype and it's still not signed.

 

[DefStock]

GE engine is only 78 KN.

Yes, stable, long-duration 85kN will qualify it for Mk1A easily. I wonder if GTRE can finish the final certification by 2026.

 

[sanket]

Great news! My every word is becoming true. Now I was the first saying Kaveri would be tested and can take 8 to 10 years development time with refinement. As always, I have been saying the MiG-29 fighter jet would have been an ideal test bed, and IAF should have handed over one of the MiG-29s to GTRE.

Tejas LSP being single-engine would be risky, but GTRE is more confident. I think this time it would have been a good comparison between RD-33 and Kaveri. Data collected from integrating and testing the engine in all parameters, after that Kaveri will be refined further with weight reduction, plus increasing the thrust to 85 to 90 kN with flat-rated tech. Kaveri will give stable thrust in local humid conditions without dropping further thrust unlike all other foreign engines which tend to drop 8 to 10% thrust.

I have been saying for several times it will take 8 to 10 years for refinement of Kaveri. In the mid-life upgrade of Tejas Mk1A, Kaveri will find its integration and ending dependency on foreign GE-404 power plant. Now all pressure is on GE for smooth supply of GE-404 and removing hurdles of ToT/local license manufacturing of GE-414.

Tejas Mk1A project now has various options from Kaveri, and it was pressure tactics on using the French offer of the M88-4 engine. With past experience from Safran, I don't think Safran has any chance in the engine project. It's all over for Safran. RR is going to win the AMCA engine development deal. It's all over, RR written, only formality to announce. With the success of Kaveri engine development, it will end the drama of GE/Uncle Sam forever. Comedian jokers, countdown begins for winding up your comedy show for entertaining the platform and somewhere else.

 

[Parveen Gahlot]

That's the good news (if it's true). I don't think it should be tested on LCA LSP. It should be done on a two-engine jet like MiG-29 or any other. We should build a high-altitude testing facility and arrange a plane for a testbed at any cost ASAP. Yes, I agree that the weight-to-power ratio is low, but firstly we would be able to generate so much power, then we can try different combinations for weight reduction as well. Sign the deal with RR for a new engine, and that could also help the Kaveri engine as well.

 

[Pankaj]

It's a great achievement by the country to induct an indigenous engine in a fighter jet, and it must have been done two or three years ago. Anyway, it's a matter of pride for all of us.

 

[Sambit Ranjan]

85kN is very good for UCAV Ghatak and Tejas Mk1s, but contracts already signed for F404s. GoI making big mistake delaying AMCA engine contract. That will take 6-7 years for first prototype and it's still not signed.

80kN is achieved only after integration of afterburner. Ghatak won't carry Kaveri with afterburner.

 

[Akshat]

Sorry to say, but Russia is the only option as the US has already derailed the F404 engine and Apache deal by various months. Rolls-Royce is in cahoots with the US and will not work against their will. The M88 is already a pretty older model, and they haven't fulfilled the offset obligations of Rafael. Although I support diversification, in this time of war we don't have unlimited time.

Sorry to say but India doesn't trust Russia now. That's why they have been specifically kept out of most of our indigenous projects over the last 10-15 years, except maybe using some of their test facilities.