Salvage and Investigation
The aircraft crashed into Torghatten, which is located 5 nautical miles (9 km; 6 mi) south-west of Brønnøysund Airport. The mountain is 271 meters (888 ft) tall and is a distinct height in an area which is otherwise rather flat. The aircraft hit the western side of the mountain at a point where the terrain is forty degrees steep. The center line of the flight path is 800 meters (2,600 ft) from Torghatten. The wreck was spread over an area 60 to 100 meters (200 to 330 ft) below the point of impact.
AFIS made several attempts to call up the aircraft. It received a call from a resident close to Torghatten which said they had heard aircraft noise followed by a crash. Brønnøysund Fire Department and an ambulance helicopter with a doctor was dispatched to Torghatten. The rescue work was made difficult by low clouds, small fires and explosions. The terrain was difficult and the lack of daylight made assisting the situation difficult. A helicopter with medical personnel and the airport direct arrived at 21:25, while a meeting place for the next of kin was established at the airport. At 23:30 the police stated that there was no hope of finding survivors and the scene changed from a search to an investigation scene. Due to the fog it was not possible to verify that all people had been killed until the next day. Seventy-five people from the Home Guard participated in the salvage.
The Accident Investigation Board Norway was informed about the accident at 21:10. Four members of the investigation commission were appointed, consisting of leader Lieutenant General Wilhelm Mohr, Pilot Hallvard Vikholt, Lieutenant Colonel Asbjørn Stein and Chief-of-Police Arnstein Øverkil. Because of poor weather conditions, the commission was not assembled in Brønnøy until 15:00 on 7 May. The same day the National Criminal Investigation Service arrived to assist AIBN. Six people appointed by the Canadian Aviation Safety Board, including representatives from de Havilland Canada and Pratt & Whitney Canada, were sent to aid the investigation. Four representatives from Widerøe were available for consultation with the commission. The investigation commission was later supplemented by Psychologist Grethe Myhre and Øverkil replaced by Arne Huuse.
The VOR/DME system was tested by the Civil Aviation Administration on 7 May and found to be working correctly. AIBN established a base of operations at the hangar at Brønnøysund Airport and used a helicopter to freight the pieces of the wreck there and bodies to Trondheim University Hospital for identification. Technical investigations started on 9 May. The aircraft was equipped with a flight data recorder and a cockpit voice recorder. Both were found intact and were decoded at the Air Accidents Investigation Branch in the United Kingdom. Improper use of the microphone made it difficult to hear the captain's voice, but it was possible to reconstruct the conversations and line of events. A memorial service was held on 10 May and was attended by Prime Minister Gro Harlem Brundtland. The last Home Guard personnel concluded their work on 11 May and the police concluded their investigations at Torglhatten on 13 May.
Read more about this topic: Widerøe Flight 710