What happened
The pilot reported that the aircraft began to drift to the left immediately after touchdown. In an attempt to maintain directional control, the pilot advanced the propellers into the beta range and applied correction using the right spoiler and right rudder pedals. However, the aircraft experienced an immediate drop or turn to the left, resulting in a collision with a snowridge on the runway surface.
Following the impact, both engines were feathered. The aircraft then slid along the length of the snowridge. During this slide, the left wingtip struck the ground, as did the left side of the fuselage. The left main landing gear subsequently collapsed. The drag strut was found sheared flush with the barrel, which caused the gear assembly to fail completely.
The investigation
A metallurgical examination was conducted on the failed landing gear components to determine the cause of the structural failure. The tests revealed that the rod had been subjected to an overload condition. Crucially, the analysis confirmed that the component had not been weakened by corrosion, cracks, or fatigue prior to the accident.
Findings
The investigation determined that the primary sequence of events began with the aircraft drifting left after touchdown. The subsequent impact with the snowridge subjected the landing gear to forces beyond its design limits. The metallurgical evidence confirmed that the failure was due to the overload from the impact rather than any pre-existing mechanical defect or material weakness.