Accident Overview
A nighttime takeoff from Lviv-Snilow Airport was followed by a climb during which the crew encountered a major technical failure on the left engine. The engine caught fire, and the airplane went out of control before crashing with a huge explosion in Vinniki, approximately 12 kilometers east of the airfield. The impact caused the aircraft to disintegrate. All 17 occupants on board were killed.
Engine Failure and Crash
The left engine experienced a critical failure shortly after rotation. Debris from the failure led to a fire, and the flight crew was unable to maintain adequate control of the aircraft. The airplane crashed in a residential area of Vinniki, resulting in a total loss of the aircraft.
Investigation Findings
The investigation determined that a turbine blade on the 1st stage of the high pressure turbine of the left engine broke off shortly after rotation. The blade failure was attributed to a conception failure: analyses revealed that the turbine blade had not undergone a standard thermic treatment, which reduced its resistance and hardness below the requirements specified in the technical specifications. The blade failure caused a sudden loss of power in the left engine, and debris smashed into the turbine chamber, rupturing a fuel line. Under pressure, fuel leaked into the chamber and ignited upon contact with high-temperature elements.