Date & Time:
Jan 31, 1971 at 0441 LT
Type of aircraft:
Antonov AN-12
Operator:
Registration:
CCCP-12996
Flight Phase:
Landing (descent or approach)
Flight Type:
Cargo
Survivors:
No
Site:
Plain, Valley
Schedule:
Tyumen - Surgut
MSN:
00 347 403
YOM:
1970
Country:
Russia
Region:
Asia
Crew on board:
6
Crew fatalities:
6
Pax on board:
1
Pax fatalities:
1
Other fatalities:
0
Total fatalities:
7
Aircraft flight hours:
391
Circumstances:
The airplane was completing a cargo flight from Tyumen to Surgut, carrying one passenger, six crew members and a load of 12 tons of herring from the Pacific. On final approach by night, at an altitude of 400 meters and a speed of 330 km/h, the captain requested 'flaps 15' when the airplane became unstable and rolled left and right. Few seconds later, the airplane entered a nose down attitude, reached the speed of 395 km/h and crashed in a left bank of 90° into an icy lake located 13,6 km from the runway threshold. The aircraft was totally destroyed and all sven occupants were killed.
Probable cause:
Loss of control caused by an excessive accumulation of ice on wing tips. The following factors were considered as contributing:
- Severe icing conditions,
- Misuse of the de-icing systems by the crew, especially with regard to air bleeding of the engines.
- Severe icing conditions,
- Misuse of the de-icing systems by the crew, especially with regard to air bleeding of the engines.
