What happened
A geological survey mission departed from Seymchan at 03:05 local time, traveling through the region encompassing the Popovka and Byelaya Noch Rivers. While operating at an altitude of 760 meters and a speed of 250 km/h, the crew performed several maneuvers before decelerating to 80 km/h as they approached a mountain with a 40-degree slope.
During this approach, the tail wheel of the aircraft made contact with the ground, causing the plane to drift into the mountainside. In an attempt to regain airspeed and correct the descent, the pilot initiated a left-hand turn. This maneuver resulted in the aircraft bouncing against the terrain three times. Upon the third impact, the aircraft caught fire. The navigator and mechanic were ejected from the cockpit during the sequence and died immediately. The remaining two occupants of the four people on board sustained minor injuries. The aircraft was completely destroyed.
Findings
Investigations concluded that the accident was driven by improper flight maneuvers conducted near mountainous terrain due to a lack of discipline and negligence by the pilot-in-command.