What happened
On October 16, 2012, an Airbus 320, registration N40IAV, operating as Avianca flight AVA9777, and a Jetstream 41, registration HK-4775, operated by Easyfly, experienced a serious airprox incident within the Bogotá Terminal Area (TMA).
The event began when the pilot of the Airbus 320 requested a routing change to avoid inclement weather near the VULAM waypoint, but the request was not addressed by the North Sector controller. Shortly after, the Jetstream 41 was authorized to proceed via VULAM to the Bogotá VOR. Simultaneously, the Airbus 320 was cleared to descend to FL190.
As both aircraft descended, they converged on intersecting headings. The separation between the two aircraft reduced to just 2.7 nautical miles horizontally and 600 feet vertically. The situation escalated when the controller, attempting to resolve the conflict, mistakenly issued a turn instruction to a different flight number, confusing AVA9777 with AVA9767. The conflict was only resolved when the Airbus 320 crew reported a Resolution Advisory from the TCAS system and initiated a right turn.
The investigation
The GRIAA investigation focused on the coordination between the Bogotá Arrivals and Bogotá North Terminal sectors. The investigation established that the North Sector controller failed to comply with operational manuals by transferring responsibility for the flights without ensuring separation.
Key findings included a lack of formal coordination between the two sectors, as controllers were communicating verbally rather than using established intercom channels. Furthermore, the investigation found that the North Sector controller had ignored a request from the Arrivals planner to redirect the Jetstream 41 and had not acted on the Airbus 320 pilot's request to fly direct to the Bogotá VOR, both of which could have prevented the convergence.
Findings
- Communication errors: The air traffic controller confused the identification of flight AVA9777 with AVA9767, leading to delayed and inaccurate instructions.
- Operational failure: The North Sector controller failed to ensure separation and did not implement requested routing changes that would have mitigated the risk.
- Coordination deficiencies: There was an absence of a formal operational agreement between the Bogotá Arrivals and Bogotá North Terminal sectors, and coordination was being conducted via unrecorded verbal exchanges.
- Pilot non-compliance: The investigation concluded that the crew of the Airbus 320 failed to comply with instructions provided by the arrivals controller.