In a written reply to Rajya Sabha, Parrikar said the total expenditure incurred on development of Kaveri engine so far is Rs 2,101 crore.
"Aero engine developed by DRDO has not achieved the required thrust to power Light Combat Aircraft (LCA). Therefore, it has been decided to use Kaveri derivative engine ("dry" engine) for powering Indian Unmanned Combat Aircraft," he said.
The project for development of Kaveri engine was sanctioned in 1989 with probable date of completion in 1996, which was extended to 2009. Government has further approved its continuation within the cost ceiling.
Non-availability of skilled or technical manpower in the field of aero-engine technology and increase in scope during development were also some of the reasons, he said.