Fuggiaschi (1952)

An Eskimo Army Sergeant is sent to his Arctic tribal village to gather information about a mysterious unmarked black airplane which shadows military planes in northern Alaska and equally-mysterious flashings lighting up the sky from Siberia across the Bering Strait. He soon discovers Soviet espionage at work. Along the way he must also deal with an ice-floe evacuation, an air-ice rescue, a fight with a polar bear and marriage to his fiancee.