An Antonov 26B-100 passenger plane sustained substantial damage in a runway excursion accident at Deputatskiy Airport, Russia. The airplane operated on a passenger flight from Yakutsk Airport (YKS) to Deputatskiy Airport with 21 passengers and five crew members on board. The weather at Deputatskiy Airport at the time of landing included a 4 m/s wind from 290 degrees, visibility 5000 meters, light snow, solid cloud cover at 2100 m, an air temperature -20ø C, and a pressure of 732 mm Hg. The flight was cleared to land on runway 10. The An-26 touched down slightly left of the runway centreline and drifted further to the left. The left hand main landing gear ran into a 20-50 cm high snow bank at the edge of the runway. The airplane ran off the runway and came to rest on snowy terrain. The nose undercarriage collapsed and the right hand wing twisted forward, causing the no. 2 engine to touch the ground. Conclusion (translated from Russian): The cause of the accident without casualties to the aircraft AN 26B RA-26061 was a runway excursion, resulting in damage to the entire structure. The accident was made possible due to a combination of the following factors: – error in piloting technique, expressed in correcting the approach up to the moment of landing, which led to a landing at an angle to the runway centreline and significantly to the left of the centreline – a mismatch between the runway condition and the unpaved runway regulations REGA RF-94, in terms of distance between cleared and uncleared surface of unpaved runways with a slope less than 1:10; – the aircraft swung left when the left main landing gear entered fresh snow 30-50cm in height as a result of burying both left main landing gear wheels in the snow.