The two aircraft, both Airbus A-320s, were separated by only 200 vertical feet and flying directly towards one another above the southern city of Bengaluru, in Karnataka state, on Tuesday. The two planes were only 8 kilometers apart when their TCAS collision avoidance systems activated, NDTV reported.
TCAS, a system required for all Indian civilian airliners, directs pilots in the imperiled aircraft to engage in opposite maneuvers in order to escape the dangerous situation in flight. One plane might be told to dive away to the left, while the other would be told to climb and turn to the right, NDTV explained.
The near-miss occurred as one plane, bound from Coimbatore for Hyderabad, was climbing to 36,000 feet at the same time as the other plane, bound for Cochin from Bangalore, was ordered by air traffic control to climb to 28,000 feet. The two planes encountered each other at 27,300 and 27,500 feet altitude, respectively, according to sources cited by NDTV.
The Hyderabad-bound plane had 162 passengers and the Cochin-bound plane had 166, the Hindustan Times noted.
IndiGo has so far not commented on the circumstances that led to the incident.
The Aircraft Accident Investigation Bureau is investigating, though, and considers it to be a very serious incident, India Today reported.
The Hindustan Times noted that two other times recently, both in May, IndiGo planes nearly collided. In one instance, an IndiGo plane nearly collided with an Indian Air Force plane over the city of Chennai, and in the other an IndiGo plane narrowly missed an Air Deccan flight near the Bangladeshi capital of Dhaka.