What happened
On April 1, 2012, an ATR 72-201, registration VP-BYZ, was scheduled for flight UTA120 from Tyumen (Roschino) Airport to Surgut. The aircraft had arrived earlier that night from Surgut on flight UTA-119. Following the arrival, the aircraft remained parked at the terminal for over seven hours during which it was exposed to rain and wet snow in near-freezing temperatures. No de-icing or anti-icing procedures were applied to the airframe prior to departure.
At approximately 01:32:58, the crew initiated the takeoff roll with flaps set to 15 degrees. The aircraft lifted off at 01:33:28. Shortly after reaching an altitude of 690 feet and a speed of 150 knots, the crew began retracting the flaps. Once the retraction process was finished, the aircraft experienced an uncommanded right bank. The flight crew disengaged the autopilot and attempted to correct the roll using the ailerons and rudder, but the aircraft subsequently banked heavily to the left.
The aircraft struck the terrain at 01:34:35 while in a steep left bank of approximately 55 degrees and a pitch-down angle of 11 degrees. The impact resulted in the total destruction of the aircraft and a subsequent ground fire. Of the 43 fatalities recorded, 33 people (comprising 29 passengers and 4 crew members) were killed, while others on board sustained serious injuries.
Findings
- The aircraft was subjected to freezing precipitation for more than seven hours while parked at the gate.
- No de-icing or anti-icing treatment was performed on the aircraft before the takeoff roll.