What happened
The incident occurred immediately after departure while the aircraft was in its initial climb phase. During this period, the left engine exploded, prompting the flight crew to initiate a return maneuver. As the aircraft executed a turn with an angle of bank reaching 115 degrees at a speed of 80 knots, the left wing entered a stall condition. The wing subsequently struck the terrain, causing the airframe to cartwheel and impact the ground approximately 600 meters from the runway threshold. Upon impact, the aircraft caught fire. The accident resulted in eight fatalities, including the stewardess and seven passengers. The flight deck consisted of a pilot and a copilot.
Findings
The official investigation determined that the loss of control was triggered by a stall induced by violent yawing moments. The pilot was unable to recover the aircraft from this state. Several mechanical failures contributed to the event. Specifically, hold-down studs on the number six cylinder of the left engine failed, forcing the cylinder off and carrying away the lower third of the engine ring cowling. This displacement disturbed airflow over the tail surfaces, creating buffeting and increasing drag on the affected side. Additionally, severe vibration was generated by the continued rotation of the propeller on the inoperative engine. A key contributing factor identified was the absence of individual propeller pitch controls, which would have allowed the crew to increase pitch on the failed engine to reduce rotational speed and mitigate windmilling effects.