What happened
Flight XF352, a scheduled service from Yekaterinburg to Vladivostok with a stop in Irkutsk, was conducting its arrival procedure at approximately 02:05LT. While descending toward Irkutsk International Airport, the crew observed the runway at an altitude of 2,10-metres while traveling at 540 km/h. During the descent, the aircraft's speed dropped to 395 km/h as the landing gear was deployed. Following the gear extension, the Tupolev Tu-154 entered a left bank of approximately 20-23 degrees.
As the airspeed fell below the recommended 370 km/h, the aircraft's angle of attack increased to 16.5 degrees because the autopilot attempted to maintain altitude despite the loss of speed. This triggered an aural high angle of attack warning. The first officer disconnected the autopilot and applied left control input, which caused the bank angle to deepen significantly, reaching as much as -48 degrees. As the aircraft entered clouds, the crew lost visual reference to the horizon.
The captain assumed control but performed alternating left and right steering inputs. A sharp rightward deflection caused a positive angular acceleration of 4.4 degrees per second, prompting further leftward corrections by the captain. After the aircraft's vertical descent rate increased to 20 metres per second, an attempt to pull the control column resulted in a rapid pitch-up. This maneuver led the aircraft into a stall and a subsequent flat spin. The impact occurred in an open field 22 seconds later, causing a post-crash fire that destroyed the aircraft and caused 145 fatalities.
Findings
Investigations concluded that the accident resulted from an improper approach configuration by the flight crew. Key contributing factors included:
- Ineffective control inputs that induced a supercritical angle of attack, leading to the stall and spin
- Failure to maintain flight parameters as specified in the aircraft's operations manual
- Breakdown in crew resource management and established pilot-in-command responsibilities
- Improperly managed flight controls during the approach phase