Tejas Mk1A upgrade: DRDO plans 90kN Kaveri 2.0 core overhaul to replace GE engines

Conceived more than four decades ago and split from the Light Combat Aircraft (LCA) project in 2008 following performance shortfalls, India’s indigenous Kaveri jet engine is undergoing a complete structural rebirth.

Facing persistent global supply chain bottlenecks that delayed deliveries of foreign powerplants and stalled local aircraft production, the Defence Research and Development Organisation’s (DRDO) Gas Turbine Research Establishment (GTRE) has uncoupled the revived Kaveri 2.0 from heavier stealth-fighter engine plans.

Instead, engineers are engineering a newly designed 90-kilonewton (kN) core specifically built to swap out imported engines on the Indian Air Force’s frontline fighters during their mid-life upgrades.

The GTRE is managing a deliberate two-pronged engine strategy. While a heavier 120kN to 140kN engine is being co-developed with French aerospace firm Safran for the fifth-generation Advanced Medium Combat Aircraft (AMCA) under the Advanced High Thrust Class Engine (AHTCE) program, Kaveri 2.0 is charted as a dedicated medium-thrust workhorse.

The redesign represents a fundamental architectural shift rather than an incremental modification. The earlier Kaveri Derivative Engine (KDE) delivered between 49kN and 52kN of thrust, falling short of modern fighter operational requirements.

Kaveri 2.0 targets 55kN to 60kN of "dry" thrust and 90kN to 100kN of maximum "wet" thrust with an afterburner — a performance threshold matching the American-made General Electric F404 engines currently powering the Tejas Mk1A.

To achieve this jump in performance, GTRE is completely rebuilding the engine core, focusing heavily on a redesigned High-Pressure Compressor (HPC) to maximise pressure ratios and fuel efficiency. The new core incorporates single-piece blisks (bladed disks) machined from advanced titanium alloys to eliminate air leaks, drop structural weight, and raise the thrust-to-weight ratio.

Additionally, single-crystal turbine blades will be integrated into the assembly to tolerate higher internal operating temperatures and boost thermal efficiency.

The transition to an indigenous 90kN engine carries direct strategic weight for the Indian Air Force. With the current GE F404 engines slated to reach their mid-life replacement cycle in the 2030s, a fully qualified Kaveri 2.0 provides an in-house alternative that reduces foreign hardware dependence and insulates the fleet from international supply chain disruptions.

Elements of the Kaveri technology baseline are already in active service. A dry, non-afterburning derivative of the engine successfully powers DRDO’s Ghatak stealth unmanned combat aerial vehicle (UCAV).