At about 1730 Alaska time, the airplane sustained substantial damage during a forced landing on snow-covered tundra. The airplane was being operated as a VFR scheduled passenger/cargo flight under FAR 135. The airline transport pilot and two passengers were not injured. Visual conditions prevailed.
About 15 minutes after departure, the engine made a “very loud and unusual whining” noise, followed by partial loss of power. The pilot reported the problem to his dispatcher via the company radio frequency and began a turn toward a frozen pond for an emergency landing. During the turn, all engine power was lost and he selected an area of snow-covered terrain as a forced landing site. Just prior to touchdown, the left stabilizer struck the tops of small trees, resulting in substantial damage. After touchdown, the nose tire and fork broke free of the airplane. Preliminary examination of the engine by company maintenance personnel revealed a cracked crankcase.