What happened
On May 3, 2017, a Robinson R-44, registration RA-04156, operated by Light Air LLC, was conducting aerial surveillance of forest areas north of Beloretsk as part of a contract with the State Budgetary Institution Center for Forest Fire Prevention and Suppression of the Republic of Bashkortostan. The flight began with a transit from Ufa airfield, picking up two representatives from the client in the village of Zubovo.
Following the completion of the patrol mission, the pilot landed at Beloretsk at 15:45. Due to approaching darkness, the pilot determined that returning to Ufa was not feasible and planned to resume operations the following day, May 4, 2017. The pilot notified the airline's deputy director regarding the need for refueling the aircraft.
Later that evening, at approximately 23:30 local time, the aircraft was refueled using fuel from a drum brought to the site by an airline employee. The refueling process was completed by approximately 18:30, according to one report, though witness testimony placed the arrival of the crew for refueling around 23:30.