What happened
During the flight, the aircraft experienced a catastrophic structural failure characterized by the separation of the left wing and the tail section. An investigation into the wreckage revealed that the main fuel supply line for the right engine had undergone a progressive rupture. Evidence of a long-term fuel leak was found surrounding the damaged line, and only trace amounts of fuel remained within the system at the time of the accident. Despite the loss of fuel, the right engine showed no signs of rotational damage, and the right propeller had not been feathered.
Structural analysis of the wreckage showed that the left wing D-tube rib at station 127 had suffered compressive buckling. The fractures observed on the left wing were oriented upward, while the horizontal stabilizer exhibited downward deformation. Prior to the accident, the pilot had expressed concerns regarding his proficiency in instrument flying and had requested additional training.
Findings
Investigators identified a progressive rupture of the right engine main fuel supply line as a critical factor in the incident. The investigation also noted that the right propeller remained unfeathered following the fuel loss. While the pilot had previously experienced an engine power loss 17 months prior where the incorrect propeller was feathered, the primary mechanical failure was linked to the fuel line degradation. Weather conditions at the time of the flight were reported as visual meteorological conditions, with cloud layers situated above 2,200 feet mean sea level.