The Kaveri dry engine fitted to an IL-76 Russian aircraft during a previous flight test

Once the Kaveri Dry engine clears these simulated high altitude tests, GTRE will position the engine in the flying test bed (FTB), which is a modified Ilyushin (Il)-76 fixed-wing, four-engine turbofan aircraft

India’s dependence on Russia for conducting simulated high altitude tests and flight test bed testing are causing a further delay to the flight-testing of the Kaveri dry engine. A derivative of the bedevilled, indigenous Kaveri military gas turbine aero engine that has been under development at the Defence Research and Development Organisation’s (DRDO’s) Gas Turbine Research Establishment (GTRE) since 1989, the Kaveri dry engine is meant to power India’s first stealth, unmanned combat aerial vehicle (UCAV), the Ghatak.

Sources said that scientists and engineers at GTRE were ready with the engine for its eagerly awaited simulated high altitude tests. Designers working on the Kaveri Dry engine explained that simulated tests basically simulate high altitude conditions on the ground. Once the Kaveri Dry engine clears these simulated high altitude tests, GTRE will position the engine in the flying test bed (FTB), which is a modified Ilyushin (Il)-76 fixed-wing, four-engine turbofan aircraft. The Kaveri Dry engine will replace one of the Il-76's four engines in the FTB.

Sources also said that the government’s approval to ferry the Kaveri dry engine to Russia’s Gromov Flight Research Institute near Moscow, where the modified IL-76 is based, for the engine’s simulated flight tests was a formality. GTRE had hoped to complete all tests by 2024-25 and commence limited series production by 2025-26. The production agency is likely to be the public sector aviation major Hindustan Aeronautics Limited.

But, with Russia caught up in a conflict with Ukraine, the simulated high altitude flight test will take longer to fructify. The flight test had initially been delayed because of the COVID-19 pandemic.

For several years now, scientists and designers have been pushing for the acquisition of an Il-76 aircraft which will be used purely as an aero engine flight test bed.

India, which hopes to join the handful of global aviation majors who have mastered gas turbine aero engine technology, does not even possess a fully functional wind tunnel facility that is essential to study aerodynamic characteristics. Such a facility can simulate and test an engine designed to work at 40,000 to 50,000 feet above the ground and will give designers the freedom to scale up or down, test and validate the hundreds of components.

Scientists at DRDO confessed that the lack of such a facility means that an engine being indigenously designed has to be carted to Russia or elsewhere, making it a time-consuming process.

Since the 1990s, the Kaveri dry engine has been taken to Russia several times for testing.