"We have invested Rs 150 crore more in the project to build two more prototypes of the LCH which will help in advancing the date of Intial Operational Clearance (IOC) from December 2015 to September 2015," HAL Chief RK Tyagi told PTI here.
He said with the addition of the two new protoypes, the testing of the programme would be fastened and the programme would be reviewed further to see if the IOC date can be advanced further.
"Two additional prototypes (TD3 and TD4) are planned to reduce development time leading to IOC. TD3 has been built and has commenced ground runs from September 7 and the TD4 fabrication is under progress," an HAL official said.
A total of 175 flights have been carried out on TD-1 whereas the second prototype has carried out more than 205 test-evaluation flights.
The two prototypes of the helicopter had taken part in the last edition of the Aero India show and hd also flown in the Iron Fist exercise in Jaisalmer last year.