What happened
On June 9, 2019, an Antonov An-2, registration RA-81519, was conducting agricultural spraying operations in the Tunkinsky District of the Republic of Buryatia. The mission, operated by Phoenix Airlines under a contract with the Zabaykalsky Forest Protection Base, aimed to protect forests from the Siberian moth using a biological agent. The aircraft was operating out of the Kyren landing strip in Class G airspace.
Prior to the accident, the crew had successfully completed two spraying sorties. According to the pilot, the third flight commenced at 08:00. The flight parameters were set at an indicated airspeed of 140 km/h with flaps extended to 5 degrees. The pilot reported that weather conditions during the initial flight segments and upon entering the Tunkinsky Gorge were stable, with no significant turbulence or cloud cover observed, and engine performance was within manual limits. However, upon entering the gorge, the aircraft suddenly encountered a strong downward atmospheric flow.
The investigation
The investigation reviewed the operational procedures and environmental conditions. It was noted that because no medical professional was stationed at the Kyren landing strip, the pre-flight medical examination was conducted and authorized by the pilot in accordance with FAP-128 regulations. The crew relied on internet-based services for receiving meteorological information. The investigation also confirmed that the flight route for the third sortie was identical to the two previous successful flights that day.