C19/2000L Loss of Separation over Espoo on 15 December 2000, Disappearance of Aircraft from ATC Radar
On Friday 15.12.2000 at 16.46 (Finnish time is used in this report) there was an air traffic incident over Espoo, where the required separation minima between two aircraft
were violated. An MD-83 airliner operated by Finnair Oyj, registered OH-LMG, call sign FIN2162, was approaching Helsinki-Vantaa airport and was about to reach its cleared
flight level (FL) 80, when it received a resolution advisory ” Climb” from its TCAS (Traffic Alert and Collision Avoidance System). The device showed that the other aircraft, an airliner of type IL62M, registered RA 86532, call sign AFL204, was at level flight 500 ft (about 150 m) below FIN2162, on its front left side at a distance of approximately half a nautical mile. AFL204 had been cleared to FL70. It appeared on ATC secondary radar (SSR/MSSR) screens for the first time at the same time when FIN2162 received the TCAS resolution advisory. The ATC radar data showed that AFL204 was then at FL76.
There were altogether 230 passengers and 17 crew members in the aircraft. No one was injured and no damage was caused.
The Accident Investigation Board (AIB), Finland was informed of the incident on 18.12.2000, when it received the incident reports filed by the captain of FIN2162 as well as Helsinki-Vantaa APP (approach) and DEP (departure) radar controllers.
The AIB decided to start an investigation on 20.12.2000 (decision No C 19/2000 L). Two experts of the AIB, airline pilot Jussi Haila and air traffic controller Erkki Kantola, were appointed as investigators. The incident investigation was based on the Act (373/1985) and Decree (79/1996) on the investigation of accidents, ICAO Annex 13 and EU Council Directive 1994/56/EC.
The material obtained by the investigators from Helsinki ATC included a list of 11 occurrences in which a Russian-built airliner had disappeared from ATC radar screen during the period 3.11.2000 - 15.12.2000. In addition, the Air Navigation Services department of CAA Finland provided a list on aircraft disappearances from radar between 30.8.2000 and 24.11.2001. The latter list contained 41 occurrences. The scope of investigation was therefore widened to cover the reasons for disappearance from radar.
Jouko Saikkonen, M.Sc., assisted in the investigation as expert in radar technology.
The captain and co-pilot of FIN2162 gave their statements of the incident on 2.1.2001. The APP controller gave his statement on 3.1.2001 and the DEP controller on 8.1.2001.
The pilot-in-command of AFL204 gave his statement in writing on 18.1.2001.
The final draft of the report was sent for comments to the Russian Aviation Authority, as required by ICAO Annex 13, on 18.5.2001. The draft was also circulated at the same time for comments at CAA Finland, Flight Safety Authority.
The investigation was closed on 16.8.2001.