What happened
On March 4, 2007, at Helsinki-Vantaa Airport, a conflict occurred between two commercial aircraft using intersecting runways. An Embraer EMB145, operated by Finncomm Airlines (callsign WBA152J), was on an ILS approach to runway 04R. Simultaneously, an Airbus A320, operated by Finnair (callsign FIN427), was preparing for departure from runway 33.
At 10:28:20 UTC, the air traffic controller cleared the A320 for takeoff on runway 33. Shortly after, at 10:28:30 UTC, the crew of the EMB145 reported being on short final, at which point the aircraft was approximately 1.8 NM from the runway threshold. Recognizing a potential conflict, the controller immediately ordered the A320 to abort its takeoff. The A320 ceased its departure roll after approximately 10 seconds, stopping about 300 meters before the intersection with runway 04R. Following the instruction, the A320 vacated the runway via taxiway Zulu. The controller then cleared the EMB145 to land on runway 04R, and the aircraft landed safely at 10:29:18 UTC.
The investigation
The investigation reviewed radio communications from both tower and ground control, as well as radar recordings from the Helsinki-Vantaa Winradar system. The analysis also incorporated assessments from the pilots of both aircraft and the air traffic controller. The investigation focused on the timing of clearances, the distance between the aircraft, and the adherence to operational manuals regarding runway separation.
Findings
- The air traffic controller issued takeoff clearance for the A300 in violation of the recommended separation standards outlined in the Helsinki Airport Operational Manual, which suggests that departures should not begin until an arriving aircraft is at least 2 NM from the threshold.
- The controller's error in assessing the impact between the arriving and departing aircraft was the primary cause of the incident.
- The controller's workload was increased by active ground vehicle training, maintenance work, and the resulting radio communications occurring in the area at the time.
- The controller was managing the entire traffic area and local approach alone, which may have contributed to the lapse in monitoring traffic flow.
- Despite the close proximity, runway separation was maintained as the A320 stopped before the intersection, and both flight crews were aware of the traffic situation.