Narrative:de Havilland DH-114 Heron LN-SUR, named 'Lars', took off from Trondheim at 08:30 for a domestic flight to Oslo. The flight climbed to a cruising altitude of 8000 feet, reaching Tolga radio beacon at 09:12. Light icing was experienced, which increased rapidly. The Heron started to lose altitude despite of the full use of the de-icing system. The captain elected to return to Trondheim. At 09:50 the aircraft struck Hommelfjell mountain at a height of bout 1350m, bounced in the snow and settled. Parts of the aircraft were used to rebuild Heron LN-NPI, which was damaged on January 26, 1957.
PROBABLE CAUSE: "Unusually heavy icing which the aircraft encountered. Severe downdraft immediately prior to the crash may have been a contributing factor."
» ICAO Accident Digest No.9, Circular 56-AN/51 (10-14)
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Trondheim-Værnes Airport to Oslo-Fornebu Airport as the crow flies is 393 km (246 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.