INSUBCONTINENT EXCLUSIVE:
A total of 328 passengers onboard the two aircraft had a narrow escape
the pilots on both aircraft took emergency evasive manoeuvers to avoid a disaster.The two IndiGo aircraft, both Airbus A-320s, were
operating on the Coimbatore-Hyderabad (6E-779) and Bangalore-Cochin (6E-6505) routes respectively when in-cockpit alerts warned the pilots
of an imminent collision between the airliners over Bengaluru airspace.Sources indicate that the aircraft were vertically separated by just
200 feet as they headed towards each other
Travelling at several hundred kilometres per hour towards each other, the two aircraft were physically less than 8 kilometres away from each
other when collision avoidance systems onboard were triggered.The near-miss happened when 6E-779 was ordered by Air Traffic Control to climb
to 36,000 feet and 6E-6505 was asked to climb to 28,000 feet
At one stage of the flight, 6E-779 was at 27,300 feet and 6E-6505 was at just 27,500 feet with both aircraft headed towards each
other.According to IndiGo, ''The TCAS-Resolution Advisory system was triggered on two of our aircraft.''The airline has since informed the
Directorate General of Civil Aviation, the aviation watchdog, of the near-miss.IndiGo has not responded to queries from
TheIndianSubcontinent on the circumstances which resulted in the TCAS alerts being generated
The airline has also declined to share details on how close the aircraft were to each other.The Aircraft Accident Investigation Board (AAIB)
has begun an investigation.The TCAS, is used onboard airliners as the last defence against mid-air collisions
When the system generates a Resolution Advisory, as was the case on this occasion, a loud automated voice gives the pilots urgent
instructions on what to do immediately
These voice commands can be ''Climb, climb,'' ''descend, descend,'' ''increase climb,'' ''increase descent,'' ''level off'' among others.All
civilian airliners operating in India are required to operate TCAS systems which scan the airspace around the aircraft through a transponder
which detects signals from other aircraft which use compatible systems.A TCAS alert is sounded based on the rate which the aircraft in
conflict are approaching one another in addition to several other variables calculated by the system
TCAS works in a coordinated manner, so instructions given to two aircraft which are headed towards each other are usually diametrically
As an example, if pilots in one aircraft are ordered to climb, pilots in the other aircraft would be told to descend.In May, an IndiGo
flight from Kolkata to Agartala, and an Air Deccan flight from Agartala to Kolkata had a near miss while flying over Bangladesh.
