Date & Time: Oct 1, 1970 at 1927 LT
Type of aircraft:
Antonov AN-12
Operator:
Registration:
CCCP-11031
Flight Type:
Cargo
Survivors:
No
Schedule:
Mys-Kamennyy - Tyumen
MSN:
7 3 450 03
YOM:
1967
Country:
Russia
Region:
Asia
Crew on board:
7
Crew fatalities:
7
Pax on board:
1
Pax fatalities:
1
Other fatalities:
0
Total fatalities:
8
Aircraft flight hours:
3637
Aircraft flight cycles:
1768
Circumstances:
After delivering various equipment for a local oil exploitation company, the crew was returning to Tyumen and departed Mys-Kamennyy Airport at 1911LT in snow showers reducing the visibility to 1,8 km. During initial climb, the crew was cleared to climb to 6,600 meters when four minutes later, the captain declared an emergency and stated that both left engines failed. He was cleared to fly back to Mys-Kamennyy Airport and started a return circuit. At a distance of 18 km from the airfield, he reported runway in sight and lowered the gear shortly later then reduced his altitude to 250 meters at a distance of eight km. At five km, he reported that the aircraft was losing altitude when he was instructed to turn right. Shortly later, at a speed of 220 km/h, the airplane crashed in an icy swamp located 2,2 km short of runway and 450 meters to the left of its extended centerline. The aircraft was destroyed and all eight occupants were killed.
Probable cause:
Investigations were unable to determine the exact cause of the failure of both left engines. Nevertheless, the assumption that this was caused by the presence of ice crystals or pellets clogging a fuel line or a fuel filter was not ruled out as well as a valve failure. Poor weather conditions were considered as a contributing factor.