B1/2006L Aviation accident at Suomussalmi Juntusranta on 8 July 2006

On 8 July 2006, at around 17:45-17:50 an aviation accident occurred at Juntusranta, in the municipality of Suomussalmi. A Cessna 172, registration OH-CEB, owned by Suomussalmi Flying Club and on a fire survey flight, collided with terrain and was completely destroyed. The pilot and the navigator were killed instantly. On 10 July 2006, Accident Investigation Board Finland (AIB) appointed investigation commission B 1/2006 L for this accident. Investigator Juhani Hipeli was named investigator-in-charge with investigator Hans Tefke as member of the commission. Investigator Kari Ylönen was invited as an expert to assess the alerting and rescue activities.

The pilot and the navigator were on a fire spotting flight, tasked by the Emergency Response Centre (ERC) of North Ostrobothnia and Kainuu to locate and inspect some reported smoke. A storm front had passed over the area and lightning had caused two small forest fires in the area of Juntusranta. Once they had located the fires, the pilot was to guide the ground units to the fire. At times, the pilot flew unusually low. After having directed the ground units to the second fire, he then continued flying low, almost at treetop level. Thereafter, while still at a very low altitude, he was observed banking sharply to the left. His airspeed was estimated to be fairly low and, based on the engine sound, his power setting was estimated as being low as well. Prior to colliding with the terrain, the aircraft disappeared behind treetops. An eyewitness who had spotted the aircraft a moment earlier heard the sound of the crash and reported it to the ERC.

A significant causal factor was that the pilot was flying unreasonably low. Another important factor, which the pilot probably did not even realize was a risk, was that he was evidently using his mobile phone even at a low altitude. Some of the conversations he carried out were with the ground firefighting units, but others were private calls. He was too inexperienced to realize the risks of low level flying, which increase if one is simultaneously engrossed in another activity. It is very demanding to complete a turn at low level and, therefore, a simultaneous telephone call can be fatal. The investigation also revealed that aviation authorities do not monitor and oversee the flight operations and procedures of fire survey flights. The custom of the flying club, according to which the pilot carries out all radiotelephony with the ground units while flying the aircraft, is too taxing on the pilot.

The direct causal factor of the accident was loss of control caused by inadequate flight attitude monitoring, which in a low level turn resulted in an immediate collision with the terrain. Contributing causal factors included the pilot’s almost nonexistent experience in low level flying, the high wing aircraft and the probable use of the mobile telephone during low level flight, all of which affected flight attitude monitoring. Furthermore, fatigue and the after-effects of alcohol possibly affected the pilot’s performance and alertness. Underlying factors include the abovementioned workload custom which taxed the pilot during the flight as well as the fact that fire survey procedures are up to operators themselves to decide.

The investigation commission issued six recommendations. It recommends the Finnish Air Rescue Society, being the umbrella organization of air rescue and fire survey flight associations, establish and maintain operational and safety customs among its member associations that fulfil the requirements of aerial fire survey operations. The Finnish Civil Aviation Authority is advised to update fire survey flight regulations and to introduce hour-based alcohol use rules for Finnish General Aviation as well as to instruct the use of mobile phones in aviation. The Ministry of the Interior is advised to install the authorities’ terrestrial trunked radio network (TETRA) terminals in aircraft which are normally used for fire survey flights. The Civil Aviation Administration Finavia is advised to introduce and adopt the mobile phone locating service as an official tool at Air Rescue Co-ordination Centres. The Ministry of Transport and Communications is advised to increase citizens’ awareness of, among other things, the directive of the Finnish Communications Regulatory Authority which regulates the use of mobile phones onboard aircraft.

B1/2006L Report (pdf, 1.24 Mt)