What happened
On December 15, 2015, at approximately 23:00, the crew of a Mil Mi-8T, registration RA-24402, operated by LLC AK Vityaz-Aero, began pre-flight preparations at the Nikolayevka-2 settlement. The flight, designated as YF-9146, was a commercial operation on behalf of OJSC Kamchatgazprom, intended to transport passengers and baggage to the VZhK settlement.
Following a medical examination and pre-flight briefing led by the pilot-in-command, the crew received meteorological information from the company dispatcher. The weather conditions were deemed suitable for the mission. Before departure, the aircraft was refueled to a total of 2,520 liters (2,072 kg). The flight load consisted of 22 passengers and 689 kg of baggage.
At 23:30, the helicopter departed from Nikolayevka-2, utilizing the ground effect over the runway to gain speed. The flight lasted 1 hour and 40 minutes, concluding with a landing at VZhK at 01:10. After landing, the crew unloaded the baggage and passengers, then notified the Petropavlovsk-Kamchatsky airport controller of their arrival and scheduled their next radio contact for 03:00. Following the arrival, the aircraft was refueled with an additional 720 liters of fuel.
The investigation
An examination of the flight documentation revealed that the calculated takeoff weight of the Mil Mi-8T was 12,139 kg. This figure exceeded the maximum allowable takeoff weight by 139 kg. Additionally, the aircraft's center of gravity at takeoff was recorded at +208 mm, which remained within the operational range of -80 mm to +370 mm.