Kolkata: Three flights averted a possible danger when radio communication between the pilots and the Netaji Subhas Chandra Bose International Airport here snapped for 11 minutes.
Airport officials Saturday said three high frequency communication channels used for voice interaction did not function between 9.17 am and 9.28 am on Friday.
A Delhi-Kolkata GoAir flight took off and attained a height of 6000 ft while two Jet Airways flight from Port Blair and Delhi were ready to land during that period.
The Jet Airways flight from Delhi was at an altitude of 8,000 ft and that from Port Blair was 7,000 ft above the city then.
The planes were visible in the monitor of the ATC radar but telephone communications with pilots regarding alteration of heights were not possible posing a major safety threat, the officials said.
The ATC could restore contacts with the flights via an emergency frequency after four minutes and the pilots were asked to remain at their respective heights.
The system was fully restored 11 minutes later, the officials said adding several planes ready for departure were delayed due to the communication system snag.
The airport's Regional Executive Director Suddhasatwa Bhaduri said the communication channels got disturbed for a brief period as upgradation of ATC towers is going on.