Two Mumbai-bound flights carrying close to 200 passengers came close to breaching the vertical safety distance prescribed by the aviation regulator.
But the abnormality was quickly corrected and both the flights landed safely. The incident took place around 10am when an Indigo flight from Bangalore was about to land in the city.
While the aircraft was preparing for its final approach, the pilot noticed a resolutionary advisory (RA) reported by Traffic Collision Avoidance System (TCAS) - anti-collision device installed in the aircraft.
The system issues a RA warning when an aircraft is 2.1 nautical miles or 40 seconds above or below another aircraft. In this case, the aircraft in close proximity was a city-bound Spicejet flight from Chennai.
"A pilot is supposed to correct the aircraft position acting on a RA warning which was done. There was no safety breach," said an ATC official.
An Indigo spokesperson confirmed the incident: "IndiGo Flight 6E-482 Bangalore-Mumbai had a Resolution Advisory triggered by TCAS."
However, the Spicejet spokesperson did not reply to HT's queries. Till the time of going to press, it was not clear whether both airlines had reported the incident to the Directorate General of Civil Aviation.