Background
On 9 August 2022, the pilot-in-command (PIC) arrived at the operational point of JSC Aviation Enterprise Eltsovka, located in the settlement of Gornopravdinsk, Khanty-Mansiysk District, KhMAO-Yugra. Starting 10 August 2022, the PIC began flight operations as the commander of a Mi-8AMT helicopter, registration RA-22833. These flights were conducted for the client, the geological exploration company LLC Gorizont, under an aviation service contract dated 25 April 2019, number APE-4257-19.
Relocation and Cargo Operations
On 28 August 2022, the helicopter Mi-8AMT RA-22833 relocated from Gornopravdinsk to the area of the Untygey oil field. There, it performed cargo transport for the client between exploration wells Rotor-3 and Rotor-6 (designated as sites R-3 and R-6) and the oil and gas production workshop (TsDNG-2). Two ground specialists, aircraft technicians of JSC AP Eltsovka, were on board to perform operational maintenance.
Takeoff from the Gornopravdinsk landing site occurred at 05:21. After completing the day's work, at 14:44, the helicopter landed at site R-6 for crew rest and an overnight stay.
Pre-Flight Preparation on 29 August
According to an interview with the co-pilot conducted on 7 September 2022, the crew lived in a trailer at site R-6 with good conditions. Rest was at least eight hours. At approximately 03:00 on 29 August 2022, the crew began preparation for the next day's flights. A medical check was conducted under the PIC's supervision. The crew accepted the aircraft from the technicians and obtained weather information through the Metavia service; the PIC also checked the weather by telephone. At 04:00, they commenced the assigned task.
Medical Examination Procedure
On 29 August 2022, the pre-flight medical examination was performed by the PIC using an interview method with crew members. This procedure does not contradict the requirements of Federal Aviation Rules (FAR-128). According to FAR-128, when flights are conducted from aerodromes where no authorized medical worker is available, the pre-flight medical examination is not required, and the PIC decides on crew fitness for flight.