The three planes, which were parked here since January 17, flew to airline's base for Boeing family of aircraft in Mumbai for routine maintenance after getting necessary clearance from the civil aviation regulator -- Director General of Civil Aviation (DGCA), airline sources said.
DGCA Arun Mishra said he allowed the airline to operate ferry flight so that routine maintenance could be carried out for the grounded planes.
"It was a short ferry flight. They didn't carry any passengers, only two pilots were allowed inside each aircraft. We gave them permission to fly as the aircraft needed maintenance, which could be done in Mumbai where the airline has its base for Boeing aircraft. Also the company was paying high parking charges at the Delhi airport," Mishra told PTI.
Air India, last month, grounded all its six Boeing-787 Dreamliner planes after a global directive by US regulator, Federal Aviation Administration to stop operations of all the 50 such planes delivered so far to various airlines.
Three planes were parked here at Indira Gandhi International airport while one each at Chennai, Bangalore and Mumbai airports.
Regulators across the world ordered grounding of all 50 planes after fire broke out in a parked Japan Airlines 787 on January 7 while another aircraft of All Nippon Airways was forced to make emergency landing after a smoking battery on January 16.