Background
A contract dated 26 February 2016 (No. 2016-03/ACP) between Alrosa Airlines (JSC) and the Amakinskaya Geological Exploration Expedition of AK ALROSA (PJSC) established the basis for aeromagnetic survey flights. On 8 August 2016, the crew—consisting of a captain and a first officer—arrived from Mirny Airport to Polyarny Airport, both in the Republic of Sakha (Yakutia), to begin survey operations. Starting 8 August 2016, the crew, joined by an on-board operator from the expedition, performed daily survey flights. Crew rest was conducted in hotel accommodations with a minimum of 10 hours.
Pre-flight Preparation on 10-11 August 2016
On 10 August 2016, a flight application was submitted for the following day, specifying operations in airspace classes C and G. At the end of the flight shift that day, the aircraft was refueled with 1,050 liters of Avgas 100LL, bringing total fuel to 1,250 liters, which matched the flight task. On 11 August 2016 at 08:30 local time (23:30 UTC 10 August), the crew passed a medical examination and were cleared for flight at the Polyarny airport medical station. At 08:35 local (23:35 UTC), they received weather information from the duty forecaster at the AMSG Polyarny. Both the forecast and actual weather conditions were not impediments to the flight. Takeoff weight and center of gravity were within the limits specified in the Aircraft Flight Manual.
Flight Operations on 11 August 2016
At 00:34 UTC, the captain took off from Polyarny airfield. At 00:42 UTC, the captain reported to the Polyarny Tower controller that work had begun and that the next contact would be at 07:15 UTC. At 07:12 UTC, the captain contacted the Polyarny airport controller and requested permission to perform five passes over the runway for radio altimeter calibration. At 07:43 UTC, the captain reported to the Polyarny controller regarding the completion of that activity.