by Purusharth Arora
On February 16, 2026, the honourable Defence Minister Rajnath Singh visited the Gas Turbine Research Establishment (GTRE), a Defence Research and Development Organisation (DRDO) laboratory in Bangalore, to witness something India had been chasing for over three decades, a full afterburner test of the Kaveri aero engine.
The demonstration confirmed that the engine's redesigned afterburner section could push wet thrust, the increased thrust produced by a method other than standard combustion, augmented for supersonic flight and combat manoeuvres, closer to the performance benchmarks of frontline Western engines.
Earlier versions of Kaveri's afterburner could only reach 73 kilonewtons (kN) of thrust, falling short of the 84 kN delivered by the American GE F404-IN20 engine that currently powers India's own TEJAS MK-1 fleet. That gap, though modest on paper, was enough for India to formally abandon the Kaveri programme and call in foreign help.
The successful test featured a redesigned afterburner module developed in collaboration with BrahMos Aerospace, targeting a peak thrust of 81–83 kN. Yet, as Mr. Singh made clear during his visit, this milestone is not an endpoint but an inflection point.
Calling for a nationwide aero-engine ecosystem and urging immediate investment in next-generation propulsion, including sixth-generation technologies leveraging artificial intelligence, machine learning, and advanced materials, placing the Kaveri’s progress within a larger strategic horizon.
It is, without question, a triumph of persistence. What follows, however, will not be determined by engineering constraints, but by political resolve.
The $55.3 Million Engine
The Kaveri engine programme, launched by GTRE to power the TEJAS, sanctioned in 1989, had an initial budget of $55.3 million (₹382.81 crore). As context, consider what was happening globally that same decade. General Electric (GE) was pouring over a billion dollars into the F404, the engine that would eventually find its way into India's own TEJAS fleet.
The Snecma (now Safran) M88 cost about $1.6 billion to develop and test, while Pratt & Whitney’s F135 was estimated at $1.0 billion in system development and demonstration costs. The Eurojet EJ200 from 1985 to present received a total of around $1.6 billion, and China’s WS-10 Taihang was part of a broader national jet-engine development push that reportedly received 10 billion RMB ($1.4 billion) over five years. India gave GTRE $55.3 million and expected a comparable result.
The consequences were predictable. While the GE F404 was being refined into an engine requiring fewer than two shop visits per thousand flight hours, with a higher bypass ratio for better fuel efficiency and a hundred kilograms less weight than Kaveri while producing equivalent thrust — GTRE was fighting problems it did not have the budget to solve.
GE tested 47 alloy formulations for the F404. Kaveri's initial $2.2 million materials budget allowed just three. In the late 1990s, Kaveri's indigenous turbine blades failed under high operating temperatures. The United States imposed sanctions on India following the Pokhran Nuclear test explosions in 1998.
This hampered the transfer of critical aero-engine technologies and components from the US and collaboration with Snecma, cutting off access to the single-crystal turbine blade technology that France had already mastered.
Testing infrastructure compounded these failures even further. From the programme's first day, GTRE had no domestic high altitude test facility, no flight test bed, no transonic chamber forcing critical performance tests to Russia's facilities at $12 million per cycle. Every problem caught late in Russia was a problem that should have been caught early at home.
The Tipping Point
The warning signs were visible as early as 1995. The Kabini core module, Kaveri's engine heart, ran its first test nine years into the program, already behind schedule. Flight tests planned for 1999 and TEJAS integration by 2000 both slipped into the future.
By 2004, the pattern had consequences. Repeated turbine blade failures forced component imports from Snecma, with high altitude trials in Russia exposing combustion instability at Mach 0.8. A flaw that domestic transonic facilities would have surfaced years earlier.
Fixing it consumed 14% of Kaveri's entire lifetime budget in a single corrective cycle. Combined with the engine's excessive weight and a thrust ceiling of 73 kN against the required 81–85 kN. In July 2007, facing mounting pressure, GTRE split the program into two tracks — K9+ to prove design concepts through flight trials, and K10 as the final production standard engine through foreign collaboration — an admission that indigenous development alone could not meet the timeline. The conclusion was unavoidable. Kaveri was not ready. The program ran out of runway because India had systematically denied GTRE the conditions under which success was possible.
The Cost of Delays
The 2004 Russian trials were the breaking point. That same year, India signed a $105 million contract with GE for 17 F404-GE-IN20 engines, the highest thrust variant in the F404 family, custom built for the Tejas with Full Authority Digital Engine Control (FADEC) and single-crystal turbine blades India could not manufacture itself.
The pivot, while a compromise and a quiet acknowledgment of Kaveri's failure, proved fortuitous in one sense, enabling the TEJAS to eventually evolve into a 4.5-generation fighter with super cruise potential, Uttam Active Electronically Scanned Array (AESA) radar, and Astra missiles. The aircraft found its footing, but on someone else's engine.
By 2008, with the Kaveri engine still falling short of required thrust, India took the pragmatic step of de-linking it from the TEJAS program. In parallel, Hindustan Aeronautics Limited (HAL) moved ahead with orders for 24 imported engines to power the aircraft’s first operational squadron, effectively acknowledging the programme’s limitations.
The Comptroller and Auditor General’s (CAG) 2010–11 report would later underscore the scale of the problem. It revealed that by 2009, only two of six critical milestones had been achieved, with timelines slipping from an initial 1996 target to 2009.
The audit also flagged a staggering 642% cost overrun (₹1,892 crore), an overweight engine (1,235 kg against a target of 1,100 kg), and persistent gaps in core technologies such as the compressor, turbine, and control systems. Taken together, these findings offered a clear institutional verdict of India running out of patience before GTRE had run out of potential.
From the 2000s to 2025, India has spent over $1.9 billion buying F404 (Indian spec) engines from GE, with no technology transfer, no intellectual property rights, no co-development. Kaveri's entire four-decade budget across the same period was just $239 million
India spent eight times more buying the foreign replacement than it ever invested in building their own indigenous engine.
Fall Seven Times, Stand Up Eight
Yet the delinking did not end Kaveri's story. Two years after the formal delinking, Kaveri prototype K9 was successfully flight tested at the Gromov Flight Research Institute in Moscow on November 4, 2010, reaching 6 km altitude at Mach 0.6, with engine control and performance described as excellent. While India deepened its foreign engine dependency, GTRE quietly kept working.
A dry non-afterburning variant, the Kaveri Derivative Engine (KDE), was repurposed to power DRDO's Ghatak, a stealth Unmanned Combat Aerial Vehicle (UCAV), achieving 49–51 kN in high altitude testing in 2022. In March 2026, the Defence Procurement Board recommended acquiring 60 Ghatak UCAVs, giving the KDE a real production order, not just a deadline.
Meanwhile Godrej Aerospace shifted from delivering modular components to fully assembled engines, a subtle signal that Kaveri's knowledge base was moving from laboratory to factory floor. The BrahMos-redesigned afterburner pushed wet thrust to 81–83 kN, finally closing a gap that had defined the programme's failure for two decades. India's indigenisation drive within GTRE now stands at 85%, targeting 88% by mid-2026. The resilience of the engineers didn't disappear after 2008. They adapted, narrowed their scope, and kept building
New Terms, Old Patterns
The resilience finally begun attracting partners on terms India has never negotiated before. Three foreign engine manufacturers are now competing for India's next-generation engine business. Both France’s Safran and Britain’s Rolls-Royce offered India full ownership of Intellectual Property Rights (IPR) and 100% technology transfer, enabling true sovereignty and export freedom.
However, United States’ GE, from early 2000s reflected a transactional relationship with only 58% Technology Transfer (ToT) for the F414 engine. The contrast in terms offered by the US and the Europeans is telling.
And yet, that very competition has altered the game. The credibility of the European offers appears to have nudged GE toward a more accommodating stance, culminating in the landmark GE-HAL agreement for co-production of the F414-INS6 engine for the TEJAS MK-2, reportedly involving an 80% transfer of technology.
Safran too secured the agreement to co-develop the engine for India's Advanced Medium Combat Aircraft (AMCA) and transferring core metallurgy and design expertise to local Indian firms, ensuring deep industrial capability.
What makes this moment significant is not merely the signing of contracts, but the larger shift in Indian power. The long timelines for AMCA and Indian Navy's Twin-Engine Deck-Based Fighter (TEDBF) gave India room to negotiate from strength. The Safran deal now awaiting final approval from India's Cabinet Committee on Security (CCS), while the GE approved deal now focuses on powering the Tejas program.
Commitment Runs Both Ways
With deals in place, Kaveri’s survival becomes critical as the foundation that makes the Safran partnership meaningful. Technology transfer only works if someone can receive it. GTRE's engineer, the ones who spent decades wrestling with turbine blade failures, combustion instability, and thrust shortfalls are that receiving end.
Their accumulated knowledge, built through failure as much as success, is the institutional memory that allows India to sit across from Safran as a genuine co-developer rather than a passive recipient. If Kaveri is quietly deprioritised now that foreign deals are signed and moving, the engineers who built that preparation would disperse. The Safran deal is only as valuable as GTRE's ability to receive it.
But Safran's history with India invites justified scepticism. The company was penalised for defaulting on offset obligations tied to the Mirage upgrade and Rafale deals, part of a pattern where nearly half of India's offset contracts have faced penalties.
The Ministry of Defence's own assessment described such promises as "over-ambitious." Given this track record, the onus is on Safran to demonstrate through transparent milestones and accountable execution that this partnership is different in practice, not just on paper.
The Question Yet To Be Addressed
India currently operates 29 active fighter squadrons against a sanctioned strength of 42. Until it develops a competitive indigenous turbofan engine, that gap will remain hostage to foreign approvals, diplomatic whims, and supply chain constraints. The record-high 2026–27 DRDO budget and the Safran partnership represent India's most serious attempt yet to address this challenge. But record budgets have existed before: more money is necessary, yet by itself, it has never been sufficient.
GTRE's engineers have proven themselves capable. The key questions this moment raises—whether GTRE will receive serious funding to become a genuine co-developer, and whether Safran's unprecedented offer will differ in practice from its previous commitments—will determine if India's aerospace story enters a new chapter or repeats an old one.
IDN - Views expressed above are the author's own
