Background
The helicopter, a Robinson R-44 with registration RA-04347, was owned by Uryumkan LLC and based at Svetly. On October 21, 2016, after a previous flight, the helicopter was refueled with 176 liters of Avgas 100LL, for which a quality certificate was provided.
First Flight
On October 22, 2016, the pilot-in-command (PIC) filed a flight request for a route from Svetly to Zolotorechinsk (Krichinovsky section) with a planned departure between 00:00 and 02:30 local time. The crew consisted of the PIC and a second crew member, who was a founder of Uryumkan LLC and held a valid private pilot certificate. Since no medical professional was available at Svetly, the PIC determined crew fitness in accordance with regulation FAP-128. The PIC conducted a preflight inspection, as reported by witnesses on the ground. The flight was initiated at 00:30 with the PIC and two passengers on board. Communication with air traffic control was established via VHF radio just before takeoff. The flight to Zolotorechinsk proceeded without issues, and the PIC reported landing and the end of communication at 02:04.
Second Flight
At 10:40 on the same day, the PIC departed from Zolotorechinsk for a night flight without notifying air traffic control. The flight was conducted in Class G airspace. According to witnesses, the purpose was an operational necessity to travel to a site called Dzalay-Kaday, located approximately 30 kilometers east of Zolotorechinsk. The crew consisted of two people, and one passenger was on board. The takeoff mass was 1133 kilograms, which did not exceed the maximum takeoff mass of 1134 kilograms specified in the Robinson R-44 flight manual. The center of gravity was 2380 millimeters, within the allowed range of 2370 to 2490 millimeters.