Background
The aircraft departed Uchur in the morning on a supply mission to a geological camp located in the region of the Kovrik River. The crew successfully performed a first drop and continued along the Kovrik Valley in an attempt to make a second low pass.
Accident Sequence
While cruising at low height, the captain realized he was too low and elected to return. He made a sharp turn to the left, at which point control was lost. From a height of about 20–25 meters, the aircraft banked left, stalled, and crashed 1,900 meters from the drop zone. The aircraft was destroyed upon impact, and all nine occupants were killed.
Findings
The official investigation determined the probable cause to be poor pilot techniques and wrong decisions on the part of the captain, who failed to recognize that he was flying too low and at an insufficient speed while performing a sharp turn to the left in a mountainous area. Contributory factors included too low altitude to expect recovery when the stall occurred, the crew continuing flight at an insufficient height in a mountainous area, poor flight preparation, and wrong approach configuration.