Investigation Summary
Flight 253 was a scheduled morning service from Trondheim to Oslo. Approximately 42 minutes into the flight, near Røros, the aircraft encountered rapid icing conditions. The ice accumulation was so severe that it not only compromised aerodynamic lift but also covered the windshield and the radio antenna, severing communication and hindering navigation. The pilots attempted to turn back toward Trondheim, but a combination of heavy ice and a downdraft forced the aircraft down. The Heron struck the snow-covered slopes of Hummelfjell at roughly 300 km/h. The impact was softened by a snow dune, which likely prevented further fatalities. The subsequent rescue operation was hampered by a blizzard and visibility as low as 20 meters, preventing aerial searches from locating the wreckage. The survivors were eventually found after Rolf Kirkvaag and another passenger left the site to seek help and encountered a rescue party.
Final Conclusions
The investigative commission, which included representatives from the Royal Norwegian Air Force and de Havilland, published its final report on 9 May 1957. It concluded that the accident was caused by extreme icing conditions that no contemporary ice protection system could have managed. The investigation cleared the pilots of any error, noting that their decision to turn back was timely but ultimately insufficient due to the rapidity of the ice buildup. The commission also found that while the weather briefing at Værnes did not predict these conditions, a personal consultation with a meteorologist might have provided a more accurate forecast.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Ice Protection System
The Heron was equipped with a de-icing system that the commission found to be superior to contemporary aircraft, yet it was overwhelmed by the rapid rate of atmospheric icing.
Radio Antenna
Ice accumulation on the external antenna caused a total loss of radio communication, leaving the crew unable to receive navigation assistance or transmit distress signals.
Interesting Facts
- 01The aircraft was named 'Lars', carried serial number 14093, and was registered on 8 February 1956.
- 02The impact occurred at approximately 300 km/h (160 knots).
- 03The engines were sheared off upon impact, but the fuselage remained largely intact after sliding into a snow dune.
- 04Visibility at the crash site during the rescue attempt was estimated at only 20 meters.
- 05This was the first fatal accident in the history of Braathens SAFE.
Safety Actions & Advisories
Meteorological Consultation
The commission recommended that pilots confer in person with meteorologists regarding the entire flight route to better predict localized severe weather.
Survival Equipment
The investigation recommended that airlines equip aircraft with additional first-aid and survival equipment for accidents in remote areas.