What happened
A business flight originated in Lavrentya, Russia, carrying an estimated 50 gallons of usable fuel. After a 40-minute flight, the aircraft arrived in Provideniya, Russia, with approximately 30 gallons of fuel remaining. During the stop in Provideniya, the aircraft was refueled with an additional 30 gallons. The pilot noted that while the standard departure fuel load is typically 120 gallons, no further fuel was available at that location.
Upon departing Provideniya, the pilot estimated the aircraft had a fuel endurance of 1 hour and 45 minutes. The flight proceeded to Gamble, Alaska, on St. Lawrence Island, arriving roughly 25 minutes after departure. Following the stop in Gamble, the aircraft departed once more. During this subsequent flight, the right engine lost power approximately 40 minutes after takeoff, followed by the loss of power in the left engine about 50 minutes after departure. The aircraft was not equipped with personal flotation devices for the passengers.
Findings
Investigation into the incident revealed that the pilot did not use a dipstick to verify the actual fuel quantity in the tanks prior to departure. Furthermore, the pilot failed to confirm the availability of fuel at the Gamble, Alaska, destination. The primary contributing factor was insufficient fuel reserves for the planned flight legs.