Pleas understand it did not undergo fly test. It only was tested at high altitude simulated environment (at ground)It's passed the high altitude test and ready for production.
Aero India 2023: GTRE completes high-altitude testing of Kaveri derivative engine
India's Gas Turbine Research Establishment (GTRE) – an agency under the state-owned Defence Research and Development Organisation (DRDO) – has completed high-altitude...www.janes.com
Motors (CIAM) in Russia, simulating an altitude of 13,000 m (42,651 ft).