What happened
On the night of April 29, 2022, a runway incursion occurred at Josep Tarradellas Barcelona-El Prat Airport involving a Vueling Airbus A320, registration EC-KLT, and a Ryanair Boeing 737-800, registration EI-EPA.
Twelve minutes prior to the event, the airport transitioned from a parallel runway configuration to an intersecting runway configuration. This change required air traffic controllers to manually update their information display systems. However, the local controller failed to update the arrival runway selection in the general information window. As a result, the controller's display showed the approaching EC-KLT as being much further from the threshold than it actually was.
Believing there was sufficient separation, the controller cleared the EI-EPA for takeoff from runway 06R. At the time of the incident, the EI-EPA was accelerating on the first third of the runway, while the EC-KLT was on approach to runway 02. The two aircraft crossed paths on runway 06R with a horizontal separation of only 285 meters and a vertical separation of 59 feet. The crew of the approaching aircraft was subsequently instructed to perform a go-around.
The investigation
The CIAIAC investigation focused on the air traffic control service provided by the Barcelona tower. Investigators examined the manual configuration change process and the reliability of the Advanced Surface Movement Guidance and Control System (A-SMGCS) alerts.
The investigation established that the controller was working with inaccurate distance-and-time-to-threshold data because the system was still calculating based on the previous runway. While a warning light had illuminated on the controller's screen due to the discrepancy, it went unnoticed for 12 minutes. The investigation also reviewed the crew's management of the conflict, noting that the approaching crew was heavily focused on their landing clearance and did not immediately detect the intersecting traffic.
Findings
- The primary cause was the issuance of a takeoff clearance for runway 06R while traffic was on approach to runway 02 at a distance of less than the required 4 NM.
- The controller's display erroneously indicated the arriving aircraft was 2.4 NM away when it was actually only 1.1 NM away.
- A failure to update the arrival runway in the general information window led to incorrect distance calculations.
- The controller did not detect the system's yellow warning light regarding the runway selection error.
- The A-SMGCS level 2 system correctly triggered a proximity conflict alert, but the controller's reaction was delayed, partly due to frequent false alarms from the system.
- The approaching crew's decision to continue the approach after initially spotting the traffic was noted as a contributing factor.