The activities of the Accident Investigation Board are based upon the Norwegian Air Navigation Act of 1923. At that time, the board was under the administration of the Ministry of Defence and accidents were investigated by ad hoc boards.
In 1944, the Convention on International Aviation was ratified and a special organisation under the aegis of the UN was created - the ICAO, the International Civil Aviation Organisation. A total of 190 countries, including Norway, are members of this organisation. The international agreements are collected in 18 annexes. Annex 13 concerns investigation of aviation accidents and incidents, and the board always bases its work on this annex which describes the methods of aviation accident investigation.
A new regulation was introduced in 1988 for the investigation of aviation accidents, and on 1 January 1989 a permanent board, under the administration of the Ministry of Transport, was established. This board became an autonomous agency on 1 July 1999.
The regulation concerning official investigations states that:
The investigation has as its goal clarification of the sequence of events and causes, as well as discussing other significant conditions that could prevent accidents and incidents in order to improve aviation safety. The purpose of the investigation is not to apportion blame and liability.
The Investigation Board itself decides the scope of the investigations that are to be conducted, including the assessment of the expected safety benefit from an investigation in relation to the resources expended.