What happened
On April 23, 2015, a Mi-8T, registration RA-22919, operated by LLC AK Vityaz-Aero, was scheduled to perform a commercial flight transporting passengers and cargo. The planned route involved multiple stops, beginning at the Kozyrevsk landing site and traveling through various points including Anavgay, the Balygingan River, and the Tikhaya River, before concluding at Esso.
Pre-flight preparations began at the Kozyrevsk landing site at 02:30. During this period, the pilot-in-command assessed the crew's health and authorized the flight. Meteorological information regarding the weather at the Esso site and along the flight path was obtained via telephone from a dispatcher. The crew also calculated safe altitudes for the various route segments and completed refueling operations. At the time of departure, the aircraft was reported to be in serviceable condition following routine maintenance.
The crew departed from Kozyrevsk at 03:51. The flight proceeded for approximately 20 minutes toward the "47km" landing site, located on the bank of the Bystraya River. Upon arrival at the "47km" site, the aircraft was loaded with 1,740kg of weight, consisting of three passengers and 1,500kg of cargo. Following this loading, the actual takeoff mass was recorded at 11,240kg, with a center of gravity offset of +180mm, which remained within the limits specified in the flight manual.