What happened
On the morning of the accident, an unscheduled domestic flight departed from Caranavi at 08:06 local time, bound for Rurrenabaque. Approximately seven minutes after takeoff, while cruising at an altitude between 3,500 and 4,000 feet near Alcoche, the aircraft experienced a failure of the left engine. Witnesses on the ground observed that the crew attempted to compensate by increasing power to the remaining engine.
Following the engine loss, the aircraft's flight profile became unstable, with the right wing appearing higher than the left. The plane began a leftward turn toward the wider section of the valley. During this maneuver, the aircraft entered an almost inverted position before recovering its upright attitude. The flight path involved two upward pitches of the nose followed by a complete 180-degree reversal in direction.
The flight ended when the aircraft struck the surface of a river with a high vertical descent rate and a level attitude. The impact lacked forward momentum and was severe enough to flatten the fuselage floor against the ceiling and crush the lower portion of the left wing.
Findings
Investigations determined that the left engine failure was the primary driver of the accident. The pilot was forced into a sharp 180-degree turn to the left because the valley narrowed ahead, making a rightward turn impossible due to proximity to a mountain peak. This specific maneuver was selected as it provided the only viable path toward a suitable section of the river for an attempted ditching.