Air Asia India’s Ahmedabad-Chennai flight and IndiGo’s Bengaluru-Vadodara flight narrowly escaped colliding on January 29. Both the planes came within a radius of eight kilometres. Their vertical distance was reduced to 300 feet above the Mumbai airspace. This information has come to the fore in a report by the Aircraft Accident Investigation Bureau (AAIB).
According to the investigation report released this month, the likely reason for this “serious lapse” was the air traffic controller’s lack of knowledge of the situation. It added that another possible reason was that the assessment of the situation at the Mumbai airport was done by the controller in advance.
Referring to the incident, the report said that most of the flights from Ahmedabad to South India go over Bhavnagar. However, on 29 January, the Air Asia India flight was on the route normally used by aircraft landing at Mumbai airport.
This situation was created due to the change of route by Air Asia India aircraft and the IndiGo flight coming from the opposite direction was on the direct route. When sufficient distance had been maintained, the air traffic controller’s automated system issued a predictive warning, the report said. However, the controller did not heed the visual inferred warning. It said that the controller, on account of his past experience, was assuming that the Air Asia India flight was on its normal route over Bhavnagar. So the controller thought that Air Asia India flight is not very close to Indigo flight.
accident was avoided
By the time the controller realized the situation, the Air Asia India flight had reached an altitude of 38,008 ft, while the IndiGo flight was flying at an altitude of 38,000 ft. Air Asia India’s flight got higher as its Traffic Collision Avoidance System (TCAS) issued a warning to the pilots. At the same time, Indigo’s flight remained at an altitude of 38,000 feet.