Date & Time: May 11, 1973 at 0437 LT
Type of aircraft:
Ilyushin II-18
Operator:
Registration:
CCCP-75687
Flight Phase:
Flight
Survivors:
No
Site:
Desert
Schedule:
Baku - Tashkent - Novosibirsk
MSN:
189 0012 02
YOM:
1959
Flight number:
SU6551
Country:
Kazakhstan
Region:
Asia
Crew on board:
8
Crew fatalities:
8
Pax on board:
55
Pax fatalities:
55
Other fatalities:
0
Total fatalities:
63
Aircraft flight hours:
21663
Aircraft flight cycles:
11787
Circumstances:
While cruising by night at an altitude of 7,800 meters in good weather conditions, the pilot-in-command initiated a turn to the left when control was lost. The airplane entered a dive and spiraled to the ground. At an altitude of 5,000 meters, some elements of the upper wing surface and the stabilisers detached and the airplane disintegrated in the air before crashing in a steppe located about 84 km south of Semipalatinsk. Wings and stabilisers parts were found at a distance of some 3.5 km from the crash site. All 63 occupants have been killed.
Probable cause:
The exact cause of the accident could not be determined. The assumption that the aircraft collided with an object was not ruled out. It is believed the crew may have start an emergency descent but the reason of this manoeuvre could not be established. FDR could not be read properly as it was seriously damaged in the crash.