What happened
On 19 March 2022, an aircraft was performing a landing at Optand Airport in Jämtland County when it veered from the runway centerline. After departing the paved surface, the aircraft traveled approximately 50 meters into the snow-covered runway strip. During this excursion, the aircraft encountered a section of thicker, harder snow, which caused the plane to overturn and come to rest on its back. While the aircraft sustained significant damage, there were no injuries to the occupants.
The investigation
The investigation focused on the environmental conditions and the state of the runway strip. At the time of the accident, the runway strip had been partially cleared of snow, with the cleared surface extending only 1.3 meters from the edge of the paved runway. Investigators noted that while Swedish Transport Agency regulations (TSFS 2019:26) require a runway strip width of at least 10 meters to ensure adequate bearing capacity, there is a lack of specific regulatory clarity regarding snow removal requirements for these strips during winter operations. It was determined that the depth of the snow in the uncleared area was a primary factor in the aircraft's inability to remain upright.
Findings
Investigators identified that the initial deviation from the centerline was likely caused by a combination of a landing bounce and a sudden gust of wind from the west. The proximity of the nearby tree line may have contributed to turbulence or wind shear during the landing phase.
Furthermore, the investigation found that the pilot's insufficient control measures and delayed inputs, likely due to limited flight experience, failed to prevent the excursion. The severity of the aircraft damage was directly attributed to the thickness of the snow on the runway strip, which caused the aircraft to tip forward and eventually land on its back.