Violation of standard operating procedures led to close call between two aircraft at Mumbai: Airports Authority

Violation of standard operating procedures (SOP) resulted in a close shave between an Air India and IndiGo aircraft on Saturday, according to a preliminary investigation into the incident.

Various units of air traffic control manage the country’s airspace. Air traffic eight miles from Mumbai airport is handled by the control tower and its responsibilities include co-ordinating arrivals and giving clearance for departures.

A preliminary investigation into Saturday’s incident suggests violation of the revised SOP for time-based spacing between arrivals under the TTT procedure, Airports Authority of India said in an operational circular to all controllers issued on Monday.

Post the incident, the AAI management has instructed its air traffic controllers to strictly follow the SOPs. "The incident has been viewed with utmost seriousness by the Directorate-General of Civil Aviation and higher management of AAI," it said.

The incident occurred when an IndiGo aircraft arriving from Indore landed seconds before an Air India aircraft took off for Thiruvananthapuram. The incident breached the required safety margin and is being probed by the DGCA. Both Air India and IndiGo said their pilots had received clearance from air traffic control for departure and arrival, respectively.

"Air traffic controllers are now extra cautious while spacing aircraft. Another factor influencing separation between aircraft is the weather. With the advance of the monsoon, pilots request deviations and are unable to maintain the flight path assigned to them," said a person familiar with the issue.