C5/2003L Loss of separation minima north-east of Helsinki-Vantaa airport on 28 April 2003

On Monday 28 April 2003 at 03.48 UTC (Finnish time -3 h) there was an aircraft incident approximately 20 NM north-east of Helsinki-Vantaa airport. A Finnair Oyj Airbus 321, call sign FIN360, registered OH-LZB, on a scheduled passenger flight from Oulu to Helsinki-Vantaa, and a Finnair Oyj MD-11, call sign FIN98, registered OH-LGC, on a scheduled passenger flight from Bangkok to Helsinki-Vantaa, passed each other with a horizontal distance of 1.9 NM and vertical distance of 700 feet. The aircraft were controlled by the approach radar controller. The Accident Investigation Board Finland set up 6 May 2003 an investigation and appointed airline pilot Jussi Haila as the investigator-in-charge and air traffic controller Erkki Kantola as a member of the commission.

The FIN98 was approaching from south and had reached 5000 feet on QNH 1003 as cleared. FIN360 was approaching from north-east and closing in on a preceding slower FIN520, ATR72. The approach controller ordered FIN360 to turn approximately 90° left from its approach heading to maintain horizontal separation between the aircraft. The trainee working in the approach radar position had cleared FIN360 to 5000 feet on QNH before this. The instructor supervising the trainee ordered to leave FIN360 at flight level 60. The controllers working at arrival and departure radar positions informed approach position that there is not required separation between flight level 60 and 5000 feet on QNH but the approach controller did not react to the information.

The pilots of FIN360 had changed QNH sub-scale settings to their altimeters after being cleared to 5000 feet which was below the transition level 55. After being recleared to flight level 60 they changed back to the standard setting 1013 and descended to flight level 60. The altitude of FIN360 was 5700 on QNH and the altitude of FIN98 was 5000 feet. The closest horizontal distance between the aircraft was 1.9 NM according to the radar recording. The vertical separation should have been at least 1000 feet or the horizontal separation 5 NM.

The cause of the incident was the inadequate planning and controlling of the approaching traffic and the passive working method of the instructor in respect to the fact that it was only the tenth operational training shift of the trainee. A contributing factor was the fact that the approaching traffic volume was quite heavy when compared to the trainee’s experience.

The investigation commission made no safety recommendations.

The comments received for the final draft have been taken into account in the report.

C5/2003L Report (pdf, 0.6 Mt)