What happened
During the initial stages of flight, the aircraft was observed taxiing normally with no audible engine irregularities reported by ground observers. However, following the takeoff roll, witnesses noted white smoke emanating from the left engine. The aircraft subsequently entered a steep left bank, reaching an angle of approximately 90 degrees. This maneuver was followed by a nose-down pitch and a rapid descent, which culminated in the aircraft striking trees and the ground.
Findings
Post-accident investigations identified a mechanical failure within the left engine's turbocharger assembly. Specifically, a segment of the pipe located near a flange, which connects to the turbocharger oil outlet, suffered a failure caused by fatigue. While this component failed, no other malfunctions were detected in the propellers or the right engine.
Investigators also noted that several controls were in the 'off' position at the time of the accident, including the magneto switches, the fuel selectors, and the mixture control arm on the left engine fuel control unit. The aircraft was occupied by the pilot and a passenger who held a pilot rating.