What happened
On November 20, 2009, an Airbus A320, registration I-LINH, operating as flight JET52G from Verona Villafranca to Catania Fontanarossa, was climbing through approximately 9,000 feet when it encountered a potential collision risk. The aircraft was executing a standard instrument departure (SID) and had been cleared to climb to FL150.
Simultaneously, two Tornado aircraft from the Italian Air Force, operating under the callsign Lince 01, were conducting a visual flight rules (VFR) operational mission at FL 105. As the A320 climbed, it crossed paths with the military formation. While the air traffic controller provided traffic information regarding the position of the Tornado aircraft, the vertical separation between the two groups was not clearly communicated to the A3/20 crew.
At approximately 08:41 UTC, the A320 crew received a TCAS Resolution Advisory (RA) command to "Descend." The flight crew immediately disconnected the autopilot and performed a rapid descent to avoid the conflict. The encounter resulted in no injuries and no damage to the aircraft, but highlighted a significant breakdown in separation management.
The investigation
The ANSV investigation examined radar data, the A320's Digital Flight Data Recorder (DFDR), and radio communications between the aircraft and the Garda Approach/Radar controller. The investigation focused on the coordination between the radar controller and the procedural controller, as well as the accuracy of the traffic information provided to the crews.
Investigators found that the A320 was climbing at a high rate of 3,600 feet per minute, which reduced the time available for the crews to visually acquire the other aircraft. While the controller provided updates on the horizontal distance of the Tornado aircraft, the vertical position of the military jets was not explicitly communicated to the A320 crew until the aircraft were already in close proximity. Furthermore, the investigation noted that the military aircraft were flying on a route that deviated significantly from their authorized path.
Findings
- The primary cause of the event was the ambiguous identification of jurisdictional responsibilities regarding the provision of separation services by the Garda Approach/Radar controller.
- The air traffic controller acted more as a passive observer rather than actively managing the risk of conflict between the IFR and VFR traffic.
- The flight crews of both the A320 and the Tornado aircraft failed to take sufficiently conservative actions to increase situational awareness.
- The classification of the airspace as Class D contributed to the risk, as separation is only required between IFR and IFR traffic in this designation, whereas the interaction between the IFR airliner and VFR military jets required more stringent monitoring.
- Meteorological conditions, specifically low visibility at the departure airport for the military aircraft, may have created a false sense of security regarding the stability of the traffic flow.