What happened
On August 11, 2016, an Antonov An-2, registration RA-17812, operated by ALROSA Airlines, was conducting aeromagnetic surveying operations in the Sakha Republic. The flight was part of a contract with the Amakinskaya Geological Survey Expedition. The crew, consisting of a captain, a co-pilot, and a flight operator, had been performing daily flights in the region since August 8, 2016, with at least 10 hours of rest between shifts.
Prior to the flight on August 11, the aircraft was refueled with 1,050 liters of Avgas 100LL, bringing the total fuel load to 1,250 liters. After passing medical examinations at the Polyarny airport medical center at 08:30 local time, the crew received meteorological information indicating that conditions were suitable for the mission. The aircraft's takeoff weight and center of gravity were within the limits specified by the flight manual.
At 00:34 local time, the pilot took off from Polyarny airfield. Shortly after, at 00:42, the pilot notified the air traffic controller that the survey work had commenced and requested to reconnect with the tower at 07:15. Later that morning, at 07:12, the pilot contacted the controller to request permission to perform five passes over the runway for the purpose of calibrating the radio altimeter.