What happened
On August 3, 2018, under a service agreement between RN-Vankor LLC and UTair-Helicopter Services, two separate flight missions were scheduled at the Vankor site. The first mission involved a Mi-8AMT, registration RA-25640, tasked with transporting passengers and baggage along a route including Vankor, 104 km, NPS-1, NPS-2, and Tarko-Sale airfield. The crew consisted of a pilot-in-command, a co-pilot, and a flight technician.
The second mission involved a Mi-8AMT, registration RA-22427, assigned to transport cargo via external sling from Vankor to Suzun. The crew for this aircraft also included a pilot-in-command, a co-pilot, and a flight technician.
At 02:18:23, the crew of RA-22427 began engine starts at the northern parking area. After completing engine starts, the crew performed a hover and notified air traffic control of their movement to the cargo parking area. At 02:31:31, the aircraft landed at the cargo parking area, located approximately 350 meters from the northern parking area. Without shutting down the engines, the crew began the process of attaching the cargo to the external sling. Simultaneously, at 02:35:28, the crew of RA-25640 initiated engine starts at the northern parking area. By 02:41:41, the crew of RA-22427 reported via radio that they were performing a control hover while attaching the cargo.