India’s Aircraft Accident Investigation Bureau is probing how two aircraft came within just seconds from mid-air impact.
Officials said an IndiGo Airbus A320 jet came within 15-35 seconds of a smaller Air Deccan 18-seater Beechcraft 1900 D close to the India-Bangladesh border.
The planes were travelling in different directions to and from Kolkata Airport.
The IndiGo jet was beginning its descent when the traffic collision avoidance system kicked in.
The Deccan Air plane was still climbing after just taking off from the airport.
Investigators say the two aircraft came within 700 feet of each other, which is less than the minimum 1,000 feet prescribed before evasive action is required.
"The IndiGo aircraft was at the prescribed air level. The pilot followed the standard operating procedures and reported the matter to ATC and the company," an IndiGo spokesperson said of the May 2 incident.
