What happened
During a mission supporting the 121st geodetic expedition, an aircraft was performing a flight between Zyryanka and Seymchan when it encountered heavy cloud cover. The weather conditions had dropped below established minimums, yet the crew proceeded with the flight instead of returning to the departure airfield. During this period, the aircraft drifted approximately 25 km away from its planned trajectory.
While flying through the clouds over mountainous terrain, the aircraft struck a steep slope on Mount Khapchagai, which stands at an elevation of 1,554 metres. The impact occurred at an altitude of roughly 1,200 metres, approximately 61 km northwest of Seymchan. The crash resulted in 5 fatalities, including one of the two pilots, and left four of the six passengers deceased. The remaining survivors sustained serious injuries. Search teams located the wreckage and the survivors on 23SEP68.
Findings
Investigations into the accident concluded that the primary factor was the crew's decision to continue the flight despite encountering weather conditions that were below the required visibility minimums, rather than returning to their point of origin.