Incident Overview
An aircraft engaged in a geological support mission crashed on the icy surface of Yessey Lake, approximately 5 kilometers from the village of Yessey, while approaching Yessey Airstrip. There were no casualties in the accident.
Sequence of Events
During the approach, the pilot-in-command performed a fourth turn. The pilot then elected to correct the aircraft's roll. However, the control input increased the roll angle to 45 degrees. The aircraft lost height and impacted the frozen lake.
Official Findings
The investigation determined that the probable cause of the accident was an inappropriate roll correction by the pilot on approach. This action caused the aircraft to bank excessively, leading to a loss of altitude and the subsequent crash.