Accident Sequence
Shortly after a night takeoff from Almaty Airport, the aircraft climbed to an altitude of 120-150 meters at a speed of 355 km/h. It then entered a region characterized by very high outside temperatures ranging between +30 and +40°C. The flight encountered high winds and downdrafts. The airplane pitched nose down, descended, and struck the ground at a speed of 400 km/h, approximately 3,996 meters from the end of the runway. The impact occurred on a farm, causing an explosion and subsequent crash. Debris was scattered over an area 840 meters long and 130 meters wide. None of the 166 occupants survived the crash. Nine people on the ground sustained injuries, three of which were serious.
Investigation Findings
Official investigators determined that the accident resulted from the aircraft's encounter with an unpredictable and rarely experienced area of intense atmospheric turbulence. This turbulence included downdrafts of up to 14 meters per second (50 km/h) and tailwinds of up to 20 meters per second (72 km/h). Several contributing factors were identified: the aircraft was operated at a total weight close to its maximum allowable for the prevailing conditions; the airport's high altitude affected performance; and the high outside air temperature further degraded performance.
Probable Cause
The probable cause of the accident was the impact on the aircraft of an unpredictable, rarely encountered intense atmospheric turbulences area with downdrafts up to 14 meters per second (50 km/h) and a tailwind up to 20 meters per second (72 km/h). Contributing factors included the airplane being operated with a total weight close to the maximum allowable, the high altitude of the airport, and the high outside air temperature.