SAS925 and KLM1174 were on crossing courses over Svensheia in Southern Norway. Both flew at the assigned altitude, flight level 340. The air traffic controller on duty discovered the conflict late and the risk of collision was avoided by the flight crew following their respective TCAS RA instructions (Resolution Advisory). Through this investigation, the Accident Investigation Board believes it has identified the causes of the violation of separation minima, which can be linked to the Air Traffic Control Service. There were system weaknesses related to the layout of the Flight Progress Board and distribution of Flight Progress Strips, which made the air traffic controller's conflict search difficult. Furthermore, it was identified that the ground-based safety net STCA (Short Term Conflict Alert), that was supposed to notify the air traffic controller if the defined separation minima were in the process of being violated, issued warning later than assumed.
Statens havarikommisjon for transport
<a rel="nofollow" class="external free" href="https://www.aibn.no/Luftfart/Rapporter/2011-25-eng">https://www.aibn.no/Luftfart/Rapporter/2011-25-eng</a>