Radar link failure at Kolkata airport gives jitters to ATC

Multiple radars and a vital VHF-radio link at Kolkata's Netaji Subhash Chandra Bose airport went off today due to a glitch in BSNL network, giving jitters to the air traffic control officers for the second time in a fortnight.
The glitch in the BSNL network was for about 35 minutes, from around 12:40 PM to 1.15 PM, sources said.
During this period, when there was no signal from four ADS-B (Automatic Dependence Surveillance-Broadcast) radars at Agartala and Patna, AAI staff at Pune and Patna ground stations were communicating through the other aircraft--asking the pilots to relay the message to the nearby aircraft, they said.

The problem was with the radar that keeps an eye on the planes beyond 200-nautical miles of Kolkata, they said.
ADS-B is surveillance technology in which an aircraft determines its position via satellite navigation and periodically broadcasts it, enabling it to be tracked.
Earlier this month, Kolkata airport had faced the problem of communication link failure, forcing the Kolkata Air Traffic Control to approach the Nagpur and Varanasi ATCs to track the movement of aircraft.