What happened
On October 28, 2017, a Diamond DA40 NG, registration LN-FTM, was conducting a private flight from Kjeller to Trysil Airport. Upon arrival at Trysil, the pilot discovered the runway was covered in snow, a condition unexpected due to clear weather in other parts of the region. Because the pilot had not contacted the airport in advance, the runway status was unknown. After performing two flyovers to assess the surface, the pilot decided to land.
Following the landing, the pilot attempted to clear the runway using a private vehicle to create tracks in the snow. However, as the ground temperature rose from 0 °C to 4 °C, the snow became wetter and heavier. A subsequent takeoff attempt failed to reach rotation speed. After the runway was further cleared by a tractor, a second takeoff attempt was made. During this attempt, the aircraft began drifting to the left. Upon reducing power to idle to abort the takeoff, the aircraft swerved and slid off the runway, coming to rest in a parallel ditch. There were no injuries to the pilot or the three passengers, though the aircraft sustained damage to the propeller and nose gear.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the pilot's decision-making process and the environmental conditions at the aerodrome. The investigation noted that the pilot did not follow the requirement for Prior Permission Required (PPR) via telephone, which would have provided essential information regarding runway conditions. The investigation also looked into the impact of rising temperatures on the snow's consistency and the psychological pressures facing the pilot during the ground stop.
Findings
- The pilot landed at an airport without verifying the actual state of the runway surface.
- Rising temperatures caused the snow to transform into heavy, wet slush, significantly increasing the difficulty of the takeoff.
- The pilot was subject to several stressors, including the desire to return to Kjeller before dark, concerns for waiting passengers, and the pressure of a scheduled aircraft handover to another club member.
- The pilot's desire to complete the planned flight despite the deteriorating conditions contributed to the decision to attempt takeoff on an inadequately cleared runway.