New Delhi, Sept. 4 -- Nearly a month after the pilot of a turbulence-hit Air India flight from Phuket to Delhi failed a dope test, the investigating agency, Aircraft Accident Investigation Bureau (AAIB), released a preliminary report on Friday, confirming the use of drugs by the pilot-in-command, calling it a "serious concern."

The agency said it has asked the regulator, the Directorate General of Civil Aviation (DGCA), to take appropriate action, news agency PTI reported. Releasing a preliminary report in connection with the 4 August incident, in which an Air India flight from Phuket to Delhi, operated with an A320 aircraft, suddenly dropped 300 feet in altitude and left several passengers injured, the AAIB stated that a detailed invest...