Date & Time:
Dec 1, 1971 at 2148 LT
Type of aircraft:
Antonov AN-24
Operator:
Registration:
CCCP-46788
Flight Phase:
Landing (descent or approach)
Flight Type:
Scheduled Revenue Flight
Survivors:
No
Schedule:
Sverdlovsk - Ufa - Saratov
MSN:
57301705
YOM:
1965
Flight number:
SU2174
Country:
Russia
Region:
Asia
Crew on board:
4
Crew fatalities:
4
Pax on board:
53
Pax fatalities:
53
Other fatalities:
0
Total fatalities:
57
Aircraft flight hours:
10913
Aircraft flight cycles:
8544
Circumstances:
On approach to Saratov-Tsentralny Airport by night, the crew encountered poor weather conditions with fog, clouds from 100 to 1,000 meters and icing conditions. While approaching at an altitude of 400 meters with flaps and landing gear up, the aircraft nosed down to a 7-9° angle then rolled to the right. It descended with a high vertical speed before crashing in flames 13 km short of runway threshold. The aircraft disintegrated on impact and the wreckage was found 1,300 meters to the right of the approach path. All 57 occupants have been killed.
Probable cause:
The aircraft was approaching at an estimated speed of 240-260 km/h with flaps retracted when it rolled to the right and started an uncontrolled descent with a high vertical speed. It is believed that the loss of control was probably caused by an excessive accumulation of ice on fuselage and wings which adversely modified the aerodynamic characteristics of the aircraft. Investigations determined that the aircraft had flown in icing conditions for a period of 3 minutes and 50 seconds, resulting in an accumulation of 15 millimeters of ice. The reason why the flaps were not deployed could not be determined.
