A disaster was averted at Calcutta airport on Wednesday morning when an aircraft entered the main runway for take-off while another was about to land.

The pilot of Air India’s Haj flight, which officials said was about two minutes from landing, spotted the aircraft a few hundred metres ahead and made a go-around after alerting the air traffic control (ATC).

After hovering for 15 minutes, the Haj flight with 449 passengers and 24 crew members landed at 8.20am. The directorate general of civil aviation has ordered an inquiry into the incident.

The aircraft on the runway was a Guwahati-bound flight of Alliance Air, a subsidiary of Air India. “The Alliance Air pilot has been taken off duty till the end of the probe,” said an Air India spokesperson.

“The ATC could not see the cargo flight entering the runway because of poor visibility. Hence, the pilot of the Haj flight could not be alerted,” said an airport official.

The runway visibility around the time the Haj flight was landing was below 750 metres and aircraft operations were being guided by the Category II Instrument Landing System.

“The pilot of the cargo flight was asked to stop at the secondary runway holding point as the visibility was low. Once the Haj flight had landed and vacated the primary runway, the cargo flight would have been given the clearance to enter the runway for take off,” an ATC official said.

“But the aircraft entered the runway through taxiway A while the Haj flight was landing. The pilot immediately realised the mistake and vacated the runway through taxiway B.”

Sources, however, quoted the pilot as saying that he did not receive any communication from the ATC.

“The pilot of the Alliance Air flights seems to have been at fault. We will get to know after the inquiry whether the pilot had ignored the ATC’s order,” said an official.

Police probe

A departmental inquiry has been ordered against three cops — a sergeant, a sub-inspector and a constable — who were spotted by their superior drinking behind Park Street police station on Tuesday night. The three cops, who were not on duty, were caught in the act when the deputy commissioner (II) of the special branch conducted a surprise check.