Forty of the forty-five people on board the aircraft died, making it the deadliest civil aviation accident in Norway until Vnukovo Airlines Flight 2801 in 1996.

Combined with false signals from the instrument landing system (ILS), this caused the pilots to misunderstand their location.

This in turn led them to take an incorrect landing path, causing the plane to hit ground in a hilly area.

Three years later, the investigation commission concluded that various measures should be put in place to improve navigation, to avoid similar situations in which pilots misunderstood their location.

[2] Braathens SAFE was the launch customer of the F28 and Sverre Sigurdsson was the first F28 to fly in revenue service, in early 1969.

[2] The norm for landing at Fornebu was to rendezvous with a radio beacon, Rumba, and conduct a fifteen-degree left turn for about half a minute.

This was a known fault with the system and pilots would therefore check the direction of the radio beacon at Asker to ensure they were in the correct position.

The aircraft descended below the lowest safe altitude and lowered its gear and flaps as if they were on the nominal bearing.

[9] Fornebu Air Traffic Control noticed that the aircraft disappeared from their radar and notified Asker and Bærum Police District at 16:36 that there was a potential crash.

The operation was also made more difficult as peaks and high ground were prioritized, while the aircraft was in fact located on a wooded gentle slope.

Because of the holiday season, people were on leave and it took time for the police to dispatch sufficient crew to carry out a proper search operation.

At 20:30 the police and air traffic control started to question if search area was correct and therefore decided to expand it.

[7] An investigation commission was appointed, consisted of three regular members, led by Lieutenant-Colonel Eirik Sandberg, Police Inspector Johan Fr.

They interviewed several hundred people, flew the flight with a similar aircraft in the same light and weather conditions and by February 1973 had collected more than two and a half meters of notes and documents.

When the beacon was transmitting false signals and they followed them without correlating by other means, the commission's test flights gave a course that would have resulted in a crash, had they not aborted.

The duration of the investigation was criticized by the press and next of kin, but the commission stated that it was necessary with a prescribed degree of diligence in the matter.

[15] The commission concluded that the probable cause of the accident was a navigational error which must have taken place before the aircraft had descended to 1,100 meters (3,500 ft).

The report stated that there were some shortcomings in crew procedures: a measurement for direction control had been moved to a less visible location, a radio compass was set at the wrong frequency so it received bearings from Lahti, a conversation related to the holidays with air traffic control and that the captain was not as rested as he could have been according to regulations.

[15] The commission could not find that the weather or the wind was a contributing cause,[6] although the darkness and fog could have hindered the crew from gaining a visual cue to their location.

The commission commented that air traffic control could have prevented the accident had it recognized that the aircraft was on the wrong path and alerted the pilots.

[16] A memorial to the victims was erected near the crash sites, located along a popular skiing trail between Myggheim and Sandungen.