Date & Time:
Jun 12, 1980 at 1344 LT
Type of aircraft:
Yakovlev Yak-40
Operator:
Registration:
CCCP-87689
Flight Phase:
Flight
Flight Type:
Scheduled Revenue Flight
Survivors:
No
Site:
Mountains
Schedule:
Leninabad - Dushanbe
MSN:
9 91 04 03
YOM:
1969
Flight number:
SU088W
Country:
Tajikistan
Region:
Asia
Crew on board:
4
Crew fatalities:
4
Pax on board:
25
Pax fatalities:
25
Other fatalities:
0
Total fatalities:
29
Circumstances:
The three engine aircraft deviated from the prescribed flight path by 67 km while circumnavigating a thunderstorm over the mountains with neither crew nor ATC realizing the deviation. At this time, the radio compass did not work properly due to the interference caused by the proximity of the thunderstorm, and the wind component was different than forecast. When the crew reported overflying the outer marker, the aircraft was in fact still 43 km away from it. While descending in clouds, the aircraft crashed at a height of 2,840 metres into the slope of a mountain located 44 km northwest of Dushanbe Airport. All 29 occupants were killed.
Probable cause:
According to officials, the pilots have been hampered in their actions by the lack of visibility caused by poor weather conditions that remains a contributing factor. It is believed that the initial information provided by pilots to air traffic controllers were false and could have misled them. However, the assistance provided by air traffic controllers was insufficient and they did not proceed to any fix point control that should let them identifying the wrong position of the aircraft and thus informing the crew accordingly.
