BENGALURU: Altogether 328 passengers on board two IndiGo planes had a close shave when a mid-air collision over the Bengaluru airspace was averted just seconds before it could occur on Tuesday (June 10), thanks to the on-board warning systems. Aircraft Accident Investigation Board has now begun an investigation into what it considers to be a very serious incident. The aircraft involved were flight 6E 779 Coimbatore-Hyderabad with 162 passengers on board and flight 6E 5505 Bengaluru-Kochi carrying 166 passengers, both flying above 27,000 feet. The Traffic Collision Advance System alarms went off alerting the pilots to the presence of the other aircraft.
An airline official said the planes came face to face when the Coimbatore-Hyderabad flight was at 27,300 feet and the Bengaluru-Kochi flight was at 27,500 feet, hardly four nautical miles (7.4 km) from each other and vertically separated by just 200 feet. The Air Traffic Control had asked the flight from Coimbatore to climb 36,000 feet while the flight from Bengaluru was directed to climb to 28,000 feet.
An official statement released by Indigo said, “The TCAS-Resolution Advisory system was triggered on two of our aircraft operating Coimbatore-Hyderabad and Bangalore-Cochin routes, respectively on July 10, 2018.” Confirming the incident, a Bangalore International Airport Limited (BIAL) spokesperson said,”The incident occurred some distance away from Kempegowda International airport.”
The TCAS monitors the airspace around a plane for other aircraft with active transponders. Whenever the system issues an alert, the pilot is supposed to act on it. It also gives instructions on the avoidance action to be taken to maintain the desired separation between the aircraft in proximity. The IndiGo statement also said the incident has been reported to the Directorate General of Civil Aviation. A DGCA official refused to comment on the incident stating that it was not appropriate to speak about it when investigations were now on by the AAIB.