What happened
During an approach to Hakodate Airport, the flight crew encountered adverse weather conditions. While the aircraft was at an altitude of approximately 6,000 feet, it collided with the side of Mt Yokotsu, situated roughly 18 km north of the destination airport. The impact caused the aircraft to break apart, and there were 68 fatalities among the occupants.
Findings
Investigations into the crash determined that the crew misidentified a navigational waypoint located about 5 nautical miles north of the Hakudate NDB as being positioned just past the station itself. Based on this error, the crew began their descent from 6,000 feet, intending to fly a single circular pattern to reach an altitude of 2,500 feet while passing over the navigation aid.
However, the outbound portion of this maneuver drifted further west than intended. Combined with significant southwesterly winds, the aircraft's position shifted more to the north than the crew had anticipated. This deviation led to the controlled flight into terrain as the plane struck the mountainside.