Flight Planning and Weather
On 11 February 2018 at 11:24, a flight plan for helicopter Mi-8T (registration RA-22330) was filed with the Novosibirsk ZC of the Unified Air Traffic Management System. The plan scheduled flights from 03:00 to 16:00 on 12 February 2018 in Class C and G airspace, with landings on sites selected from the air. Airspace use was permitted at 11:26 on 11 February. At 01:52 on 12 February, the crew received a weather forecast by telephone from the AMSG Tomsk for meteorological areas 1–9 of the Tomsk RPI. The forecast did not preclude the flight.
Pre-flight and Departure
At 02:00, the crew underwent a pre-flight medical examination at the Aviamed center in Strezhevoy, as recorded in the pre-flight medical log. They arrived at the aircraft at 02:20. According to the pilot-in-command, there were no remarks regarding the helicopter's maintenance or condition (the onboard log was destroyed in a subsequent fire). On 12 February, the crew performed eight flights under the original flight plan, all without incident.
Medical Evacuation Request
During the flights, while communicating by radio and later by telephone at the "Koltogorskiy prichal-9 km" landing site, the pilot-in-command received a request from a dispatcher for a medical evacuation flight: to transport a sick woman and two escorts (a police officer and a paramedic) from the settlement of Prokhorkino to Aleksandrovskoye. The planned route was: "Koltogorskiy prichal-9 km" – Oktyabrskoye (Prokhorkino) – Aleksandrovskoye – "Koltogorskiy prichal-9 km". On the leg from "Koltogorskiy prichal-9 km" to Oktyabrskoye (Prokhorkino), the occupants were the police officer and the paramedic. On the leg from Oktyabrskoye (Prokhorkino) to Aleksandrovskoye, the occupants were the police officer, the paramedic, and the patient. Figure 1 in the source depicts the flight route for 12 February.