Ahvenisto helicopter accident

Investigation

The board of inquiry appointed by the National Board of Aviation considered the cause of the accident to be a landing attempt made downwind and onto an unsuitable landing site, whereupon the pilot lost directional control of the helicopter. Contributing to the accident were also the high flight weight in relation to the conditions and the pilot's limited experience of helicopters, and of this difficult-to-fly aircraft type in particular. During the investigation more than a hundred eyewitnesses of and parties to the accident were questioned.

The helicopter's pilot was 29 years old at the time of the accident, and the owner of the helicopter described him as a solid professional and a very experienced pilot. The pilot had received a private helicopter pilot licence issued by the National Board of Aviation in 1979 and a commercial pilot licence in 1982. He had about 400 hours of flight experience on helicopters, but only 32 hours on this helicopter type.

According to the board of inquiry, the accident helicopter itself also had a latent defect. There was an installation error in the helicopter's control system that made the helicopter heavy to control if large movements were made with it. There was no entry about the defect in the helicopter's documents, and it had not been repaired.

In its report, completed at the end of 1984, the board of inquiry issued 14 safety recommendations, one of which was that more flight experience be required for flights carrying members of the public. At the time of the accident, 100 hours of flight experience were required to obtain a commercial pilot licence, with which one could also fly members of the public. Later the requirement for obtaining even a commercial pilot licence alone was raised to 200 hours.