C8/2003L Loss of separation minima north-east of Helsinki-Vantaa airport on 21 July 2003

On Monday, July 21, 2003 at 12:04 UTC (Finnish time –3 h) there was a loss of separation approximately 18 nautical miles Northeast of Helsinki-Vantaa airport, when an Airbus 319, registered OH-LVD, call sign FIN473, operated by Finnair Oyj, on a scheduled passenger flight from Rovaniemi to Helsinki and controlled by the Arrival radar, and a MD-83, registered OH-LPH, call sign FIN934, operated by Finnair Oyj, on a scheduled passenger flight from Manchester to Helsinki and controlled by the Approach radar, passed each other with a vertical separation of 200 feet and horizontal separation of 2.4 nautical miles.

The Accident Investigation Board Finland nominated July 28 a commission to investigate the incident. Investigator Ville Hämäläinen was nominated as the investigator-in-charge and investigators Erkki Kantola and Pekka Kanninen as members of the commission.

FIN473 was approaching from the VOR/DME ORIMAA. APP cleared it heading 185 and descend to FL 100. Next FIN472 received heading 360 and clearance to descend to FL 70. Then it was transferred to ARR frequency. FIN473 approached runway 22L extension from south. FIN934 was approaching from LAKUT reporting point. APP cleared it to follow Lakut3E transition and to descend to FL 90. Next APP gave FIN934 heading 070 and planned to vector it to the runway 22L via right base leg. APP did not think there was any conflicting traffic and cleared FIN934 to descend to 5000 feet on QNH 1018 with a new heading of 040. Thus FIN473 and FIN934 were on crossing flight paths.

The traffic controlled by ARR was in disorder due to a wrong turn direction given to the flight SK1706. After determining a new approach sequence ARR cleared FIN473 to descend to FL 60. The heading of FIN473 took it through localizer towards FIN934. Both APP and ARR controllers were focused to follow SK1706 and neither noticed that FIN934 and FIN473 were approaching each other so that the radar separation of 3 nautical miles would be lost. When ARR gave FIN473 a new heading towards the airport he noticed that both aircraft were at almost the same altitude and the separation was lost. He cleared FIN473 to expedite descent to 5000 feet without knowing that APP had cleared FIN934 also to 5000 feet. When the aircraft passed each other the vertical separation was 200 feet and horizontal 2.4 nautical miles.

The investigation commission recommended that the Civil Aviation Administration would consider, together with the ATC units and Avia College, to increase the co-operation training during the annual refresher training of the controllers. The commission also recommended that the CAA would study, with the ATC units, the possibility to improve the readability of the radar screens.

C8/2003L Report (pdf, 0.68 Mt)