The US move to ground its entire fleet of Chinook helicopters after some cases of engine fires has not impacted operations of the iconic heavy-lift choppers by the Indian Air Force, which has sought more details on the issue from the Pentagon and aviation major Boeing. The 15 Chinooks, equipped with powerful contra-rotating tandem rotors, inducted by the IAF in 2019-2020 under a Rs 8,048 crore deal in September 2015, are relatively new to undergo such overhauls.