Calcutta, Jan. 21: Planes circled in the sky, some were diverted and many could not take off as the lights along the main runway at Dum Dum airport went off for close to three hours.
Apparently, a cable was damaged during installation of a modern system that would help all-weather operations.
The lights failed after 5 pm, when the main runway is thrown open after work through the day for putting in place the instrument landing system, which accurately guides aircraft to runways in poor visibility.
Airport director Rajendra Paul said the runway was supposed to be handed over for operations at 5.30 pm. 'However, one cable was damaged while the work for installing instrument landing system was going on and the main runway could not be handed over,' Paul said.
The damage in the cable was spotted and rectified after searching for over two kilometres, he added.
A high level inquiry has been ordered into the incident.
In Dum Dum, the main runway is the only strip that can be used after sundown. With the flight schedule going haywire on a busy evening, the airport authorities took desperate measures. The secondary runway was made available and flights took off till 6.53 pm after which low visibility put paid to the emergency measure.
Forty-five minutes later, the authorities gave up and the Air Traffic Control (ATC) declared an emergency. All security personnel were instructed to rush to a pre-determined point as operations ground to a halt.
The lights finally came back on at 8.10 pm and the ATC gave the thumbs up for normal functioning 20 minutes later.
The first casualty seems to have been a Jet Airways flight from Mumbai, which was expected at 7.10 pm and had to be diverted to Chennai. It arrived in Calcutta at 10.14 pm.
Earlier, a Chennai-Calcutta Indian Airlines flight was recalled to base shortly after take-off at 5.30 pm as the ATC at Chennai airport learnt about the Calcutta glitch.
A Singapore Airlines flight scheduled to land at 8.35 pm had to circle the city airport before it was cleared to land. It touched down only after 9 pm, airport officials said.
Authorities had tipped off Dhaka, so that the last Bangladesh Biman flight, due here at 7.50 pm, took off only after it got clearance at 8.30 pm. Biman sources said the flight touched down in Calcutta around 10 pm.
The sources said a Lufthansa cargo flight had also been temporarily grounded at Dhaka because of the glitch at Dum Dum airport.