A Norwegian investigation into a runway excursion incident of a Boeing 737-800 at Oslo Gardermoen Airport, Norway showed that the airport had not sufficiently assessed the risk of the combination of a shortened runway and poor friction during precipitation.
On May 25, 2015, SAS Scandinavian Airlines flight SK4425 departed Tromsø, Norway on a flight to Oslo Gardermoen Airport with 184 persons on board. The aircraft, a Boeing 737-800, landed on runway 01L, at Oslo Gardermoen Airport in tailwind conditions and rain. The runway was shortened from 3600 m to 1928 m due to asphalt resurfacing. The last 300 m of the runway surface consisted of concrete. A published NOTAM informed that the concrete surface was “slippery when wet”.
The AIBN stated that the aircraft landed after being stabilized at 1000 ft and 500 ft. The flight crew on LN-RCZ was unable to achieve sufficient deceleration after landing and the aircraft departed the runway. The aircraft came to rest approx. 50 m into the Runway End Safety Area (RESA). After colliding with runway light fixtures, the aircraft sustained minor damage. There were no injuries.
It was the AIBN’s view that multiple factors contributed to the incident. The flight crew decided to land with a landing configuration not suitable for the actual weather and runway conditions, in addition to late engagement of full thrust reversers after landing.
Several crew on previous flights had reported very slippery conditions on the last part of the runway. A landing ahead of the investigated landing also experienced trouble with achieving sufficient deceleration. This landing was performed with optimum landing configuration.
The airport operator had not, to a sufficient extent, assessed the risk of the combination of shortened runway and poor friction during precipitation. In this case, these factors in addition to tailwind condition resulted in reduced safety margins.
Based on the measures implemented after the incident for both the airline and the airport operator the AIBN does not issues any safety recommendations.