What happened
The flight included an intermediate stop at another airport to pick up a passenger. The landing at this intermediate location was completed without any noted discrepancies. Upon continuing to the accident airport, the pilot performed a landing that both the pilot and passenger described as normal. However, during touchdown at the accident airport, a snapping sound was heard by those on board. This was immediately followed by the left main landing gear rotating under the fuselage and separating from the aircraft.
The investigation
Mechanical examination of the landing gear assembly identified that the failed landing gear attach bolt had become distorted. Further inspection showed that the threads on both the bolt and its associated nut were stripped. Additionally, investigators found that the attachment hole for the landing gear had become elongated.
An examination of the dirt runway surface was also conducted. The investigation found no potholes, ruts, or other defects in the surface. No unusual tracks or markings were observed on the runway until the area near where the aircraft came to rest.