Accident Overview
On an unspecified date, an Antonov An-2 aircraft, registration RA-40204, was performing a flight from Sterlitamak to Orsk and back via Zilair and Akyar. The flight was part of an oil pipeline survey mission for the company Transneft. While flying at low altitude in marginal weather conditions, the crew initiated a turn. During the turn, the single engine impacted the ground and the aircraft crashed in a snowy field located 2 km southwest of Gai, approximately 25 km north of Orsk.
Impact and Damage
The aircraft was destroyed by impact forces. All three occupants were killed. There was no post-crash fire.
Weather Conditions
At the time of the accident, visibility was reduced to 800 metres, with local reductions down to 300 metres. The cloud base was at 90 metres, and freezing fog was present.
Probable Cause (Official Findings)
The probable cause of the accident was spatial disorientation by the crew when turning in visibility restriction conditions (fog) and "whiteout" of the snow-covered underlying surface, which resulted in an uncontrolled descent and ground impact. Contributing factors included: incorrect evaluation of weather conditions by the crew, leading to an unreasonable decision to conduct a VFR flight; flight operations at an unauthorized low height above ground; lack of IFR operation skills; formal training and checks for minima reduction by the pilot-in-command; and weather conditions during operations that did not comply with assigned minima requirements.