India's quest to develop an indigenous jet engine remains one of the country's most persistent technological challenges, embodying a cautionary tale of ambitious aspirations met with complex realities. The Kaveri engine project, launched nearly four decades ago, stands as a symbol of both national determination and the formidable barriers to achieving self-reliance in critical defence technologies.

The Kaveri Project: A Chronicle of Delays And Cost Overruns

The Kaveri engine program began in 1986 with an ambitious goal: to power India's indigenous Light Combat Aircraft (TEJAS) with a indigenous heart. Originally budgeted at ₹382 crore and scheduled for completion by 1996, the project has evolved into a massive financial undertaking exceeding ₹3,000 crore by 2025. The cost escalation tells a sobering story—from ₹382 crore in 1986 to ₹1,300 crore by 2004, surpassing ₹2,000 crore by 2014, and officially reaching ₹2,839 crore by 2016. This represents a staggering 642 percent budget overrun without achieving its primary objective.

Despite decades of development, the Kaveri engine failed to meet the technical specifications required for the TEJAS fighter aircraft. The engine could only generate 70-75 kN of wet thrust, falling short of the required 90+ kN necessary for effective combat missions. Technical challenges included insufficient thrust-to-weight ratio, weight issues exceeding design parameters, reliability concerns with overheating and durability problems, and inability to match international standards set by engines like the General Electric F404 and SAFRAN's M88 turbofan.

Current Status And New Applications

As of 2025, the Kaveri project has undergone significant transformation. The engine received clearance for inflight testing in December 2024, marking a crucial milestone after years of development. Currently, a dry variant of the Kaveri engine is being developed specifically for the DRDO Ghatak stealth Unmanned Combat Aerial Vehicle (UCAV). This derivative engine produces approximately 49-51 kN of thrust, suitable for UAV applications but insufficient for manned fighter aircraft.

Godrej Aerospace has delivered the first two modules of the Kaveri derivative engine to the Gas Turbine Research Establishment (GTRE), with six additional modules scheduled for delivery in 2025. The company secured a contract in September 2022 to manufacture eight modules for the specialised 48 kN dry engine variant designed for autonomous air vehicles.

Fundamental Challenges In Jet Engine Development: Materials Science And Metallurgy Barriers

The development of advanced jet engines requires mastery of cutting-edge materials science, particularly in creating components that can withstand extreme operating conditions. Fighter jet engines operate at temperatures exceeding 1,500°C, necessitating specialised nickel-based superalloys, ceramic composites, and single-crystal turbine blades. India has struggled with producing single-crystal turbine blades, which are crucial for engine efficiency and longevity. These blades require advanced casting techniques, precise cooling systems, and proprietary coating materials—technologies that remain closely guarded by leading manufacturers like Rolls-Royce, GE Aviation, and Safran.

Limited Industrial Ecosystem

Countries that have successfully developed jet engines possess robust ecosystems encompassing research institutions, aerospace companies, and specialised suppliers. India's aerospace sector, while growing, lacks the comprehensive industrial base and supply chain necessary to produce the thousands of intricate components required for modern jet engines. This deficiency forces reliance on foreign imports for essential parts, significantly slowing indigenous development progress.

Testing Infrastructure Deficiencies

Advanced engine development requires sophisticated testing facilities, including high-altitude test beds, wind tunnels, and stress-testing laboratories. India has historically lacked these critical testing capabilities, necessitating engine testing in foreign facilities, particularly in Russia. This dependency not only increases costs but also creates logistical complications and potential security concerns.

Institutional And Leadership Challenges

According to industry analysis, the Kaveri project suffered from leadership issues that prioritised institutional protection over honest assessment of capabilities. Unlike the successful Light Combat Aircraft (LCA) program led by Dr. Kota at ADA, which embraced collaboration with industry and academia, the GTRE leadership was reportedly less open to external partnerships and honest evaluation of technical limitations. This closed approach delayed crucial international collaborations, with India approaching France's SNECMA (now SAFRAN) for technical assistance only in 2008, after 22 years of independent efforts.

The project also suffered from frequently changing requirements as the TEJAS design evolved, increasing the engine's weight by 1,000 kg and demanding higher thrust specifications that the Kaveri prototypes could not meet. Additionally, India's license Raj system obstructed private sector engagement, with meaningful private partnership beginning only in 2020—three and a half decades after the project's inception.

TOT Hiccups

The industry's exclusivity is further reinforced by the fact that only four to five countries have successfully developed advanced jet engines, with much of the technology being proprietary and closely guarded. No established manufacturer willingly shares complete technology transfer, making indigenous development the primary path for newcomers.

Recent Strategic Partnerships And Future Prospects

Recognising the limitations of independent development, India has embarked on strategic international collaborations. The most significant development is the partnership with France's Safran to co-develop a 110-120 kN afterburning turbofan engine for the Advanced Medium Combat Aircraft (AMCA). 

Simultaneously, India is finalising negotiations with GE Aerospace for the joint production of F414 engines for the TEJAS MK-2 program. This deal includes 80 percent technology transfer, a significant increase from the 58 percent offered in 2012, and covers 12 key technologies including thermal coatings and single-crystal turbine blade machining.

Conclusion

India's four-decade struggle with indigenous jet engine development reflects the complex intersection of technological ambition, institutional challenges, and strategic necessities. While the Kaveri project failed to achieve its original objectives, it has generated valuable technological capabilities and institutional learning. The shift toward strategic partnerships with established manufacturers, while maintaining intellectual property rights, represents a more pragmatic approach to achieving technological self-reliance.

The Kaveri story serves not as a failure but as a foundation for future success, demonstrating that technological sovereignty requires not just national will and investment, but also strategic partnerships, institutional reform, and long-term commitment to building comprehensive aerospace ecosystems. With current momentum and lessons learned, India stands positioned to achieve its jet engine dreams through a more collaborative and realistic approach.

IDN (With Agency Inputs)