Accident Overview
A non-scheduled domestic flight departed Caranavi at 0806 hours local time, bound for Rurrenabaque. Seven minutes into the flight, while over Alcoche approximately 21 km from Caranavi, the aircraft experienced a failure of the left engine at an estimated altitude of 3,500 to 4,000 feet.
Flight Details
Ground witnesses reported that following the left engine failure, power was increased on the remaining engine. The aircraft then assumed a flight attitude with the right wing leading, and within seconds began turning left toward the widest part of the valley. During the turn, the aircraft briefly attained an almost inverted attitude but subsequently recovered.
Witness Observations
According to witness accounts of the flight path, the nose of the aircraft rose twice before the aircraft completed a 180° change in direction. Moments later, it crashed into the river. The aircraft struck the water surface in a level attitude with a high rate of vertical descent; there was no forward movement at impact. The force of impact was severe, flattening the lower surface of the left wing and the fuselage floor, which was forced upward to the ceiling.
Probable Cause
The official investigation determined that the primary cause of the accident was the failure of the left engine and the execution of a sharp 180° turn to the left of the original flight path. This maneuver was deemed necessary because the valley ahead narrowed, and a turn to the right was not possible due to the aircraft's proximity to and altitude below a mountain on that side. The turn toward the river was considered the only option that allowed the aircraft to reach the most suitable area for ditching.