Comprehensive repairs of the main runway of Calcutta airport will be taken up in the first week of September, airport officials said on Tuesday.

“A proposal will be sent to the Airports Authority of India (AAI) headquarters in Delhi to make the extended portion of the secondary runway operational by the first week of September. Once it becomes operational, the main runway can be closed for maintenance,” a senior airport official said. The decision to send the proposal was taken at a co-ordination meeting held on Monday by the AAI.

The secondary runway has been extended by 440 metres on the northern side, which would enable bigger aircraft to land on and take off from this runway.

“The turning pad at the edge of the secondary runway is ready and some other landing equipment will be installed this month,” the official said.

Maintenance of the main runway has been hampered since July. Maintenance work for 24 hours every month is mandatory. But only 11 hours of maintenance was undertaken in July. According to officials, lack of co-ordination among the departments of the airport is responsible for the disruption in maintenance schedule.

The pending work includes repair of craters, strengthening of the parts of the runway surface that are used frequently, resetting of runway lights and trimming of grass along the runway border.

Lack of maintenance has resulted in the runway surface peeling off often.

The main runway could not be closed for repairs because of low visibility on the secondary runway and other operational problems, an airport source said.

Airlines have told the airport authorities that once the extended portion of the secondary runway becomes available for operations, they would not have objections to the main runway being shut down.

The minimum visibility of the secondary runway is 3,600 metres since it does not have the Instrumental Landing System (ILS), said officials.

The secondary runway will also be extended on the southern side by another 400 metres. Once the work begins, the installation of the ILS would also start.

After the ILS is installed, the minimum visibility required for landing on the runway will come down to 750 metres.