Overview
On 2 June 2015, a Mil Mi-8T helicopter registered as RA-22580 operated by OAO UTair-Helicopter Services performed a commercial air transport flight under contract No. 100/15AR dated 15 April 2015 with the customer OOO MIDGLEN Logistics Sakhalin. The flight was conducted in accordance with mission assignment No. 811895-15 and flight request No. 3, both dated 1 June 2015.
Flight Planning
The planned route departed from Airdrome Lensk, with intermediate stops at landing sites Quarry No. 3, Quarry No. 5, and Quarry No. 2.1, before returning to Airdrome Lensk. Refueling was scheduled at Talakan Airfield. On 1 June 2015 at approximately 23:00 local time, the crew—consisting of the pilot-in-command, co-pilot, and flight engineer—arrived at Lensk. At 23:05, crew members underwent a medical check and were cleared for flight duties. At 23:10, the PIC received a weather briefing from the forecaster of AMSG-2 Lensk. Based on a 2P weather forecast, the crew performed flight calculations.
Preflight and Departure
On 2 June 2015, after completing preflight preparations, the crew took off at 00:13 from Airdrome Lensk with one passenger on board. The first landing at Quarry No. 3 occurred at 01:08.
Cargo Operations and Subsequent Flights
Following passenger disembarkation and cargo loading between 01:15 and 03:03, the crew executed three flights on the route from Quarry No. 3 to Quarry No. 5 to deliver cargo. At 03:43, the crew departed Quarry No. 5 for Talakan Airfield for refueling. Refueling and helicopter maintenance were conducted at Talakan from 04:21 to 05:04.
No further flight details or incidents are documented in the provided source.