Date & Time:
Mar 6, 1976 at 0058 LT
Type of aircraft:
Ilyushin II-18
Operator:
Registration:
CCCP-75408
Flight Phase:
Flight
Flight Type:
Scheduled Revenue Flight
Survivors:
No
Site:
Plain, Valley
Schedule:
Moscow - Yerevan
MSN:
186 0092 01
YOM:
1966
Flight number:
SU909
Country:
Russia
Region:
Asia
Crew on board:
11
Crew fatalities:
11
Pax on board:
100
Pax fatalities:
100
Other fatalities:
0
Total fatalities:
111
Aircraft flight hours:
21587
Aircraft flight cycles:
9082
Circumstances:
While cruising by night at an altitude of 7,800 metres, the electrical system failed, causing several instruments to fail, among them gyros. Control was lost and the airplane entered a dive and eventually crashed in a nose-down angle of 70° in an open field located 150 metres from the village of Verkhnyaya Khava, about 50 km northeast of Voronezh. Some debris of the airplane were found at a depth of 14 meters. It disintegrated on impact and all 111 occupants were killed.
Probable cause:
The 36 volts electrical system failed in flight, causing the automatic pilot system to fail as well as instruments such as gyros. Investigations were unable to determine the exact cause of the electrical system's failure. While flying by night and in a visibility reduced by clouds, the crew was unable to have visual references and lost control of the airplane after suffering a spatial disorientation.
