What happened
On the scheduled domestic route from Oulu Airport to Kuusamo, Finland, the Kar-Air flight KR482 initially cruised at FL70 above a cloud layer. During the descent phase, the aircraft entered icing conditions while passing through clouds between 6000 and 5000 feet. At approximately 07:24 GMT, the right engine of the aircraft type experienced a sudden loss of power. In response, the crew feathered the right propeller and transitioned to single-engine operations, initiating an emergency return to Oulu.
While Kuusamo ATC initially cleared the flight to FL60, the crew reported that the aircraft's climbing performance was insufficient for that altitude due to the ongoing icing. They requested and were granted a lower altitude of FL30. Despite using maximum continuous thrust on the remaining engine, the aircraft began losing altitude as ice continued to accumulate on the airframe. The crew attempted to descend below the cloud base, hoping the ice would shed or that they could identify a suitable emergency landing site.
As the aircraft approached the Pudasjarvi parish near Naamanka village, it had lost significant height, passing just meters above a trigonometric tower. While the pilot-in-command searched for a clearing, the aircraft type struck trees and impacted the ground in a swampy, sparsely wooded area 5 km north of Linattimajrvi at 08:04 GMT. The impact resulted in the destruction of the aircraft, leaving three persons badly injured and others with minor injuries.
Findings
Investigations determined that the primary cause was a sudden turbine breakdown in the right engine, which forced the flight into single-engine operations within icing conditions. A critical contributing factor was the accumulation of ice on the airframe, as the aircraft lacked necessary de-icing or anti-icing equipment. This buildup, combined with the aircraft's weight, rendered the single-engine performance insufficient to maintain altitude.