A mid-air collision was averted over Mumbai's airspace when a Vistara aircraft came close to an Air India plane, prompting the Aircraft Accident Investigation Bureau to launch a probe.
On February 7, Vistara flight UK997, going from Delhi to Pune with 152 passengers on board, was just 100 feet away from Air India flight AI631, which was flying to Bhopal with 109 people.
The Air India flight captain has written in her report that the aircraft was indeed only 100 feet apart from the other plane after which it was immediately veered into a safer distance.
A collision was averted after an automatic warning alerted the pilots of the two planes of being in close proximity to each other, an official said. "It was a close shave," the official added.
The commander of the Air India flight acted swiftly and took the aircraft out of a possible harm's way, a senior official of the state-run airline said.
The two pilots of the Vistara flight have been grounded, pending investigation, while the Air India pilots have been cleared for flying by the investigator AAIB for not being at fault, the official added.
Vistara confirmed the incident and said both its pilots have been taken off duty for now.
"In this particular incident, the resolution advisory (Traffic Collision Avoidance System or TCAS) got triggered due to conflicting traffic. Our pilot followed the standard operating procedure to avoid it and carried out an uneventful landing. The matter is under investigation by the relevant authority," a Vistara spokesperson said.
TCAS is an on-board equipment that warns pilots of traffic near the aircraft and advises what action they can take to maintain a safe distance.
"The Air India aircraft was going as per the ATC (air traffic control) instructions. There was no confusion. But it seems that something had gone wrong between the Vistara pilot and the ATC as the Vistara aircraft kept descending while the ATC was giving different instructions. There was some kind of an argument between them," the Air India official said.
"The Vistara aircraft continued descending. So, finally, when our pilot saw the warning on board, she took corrective action and turned the aircraft from the collision point," the official said, adding, "The AAIB has cleared our pilot for flying."