What happened
During normal flight operations, the pilot experienced an unexpected vibration within the aircraft. In response to this anomaly, the pilot initiated a precautionary landing procedure. The landing itself was executed with excessive force, resulting in a hard impact upon touchdown.
Following the incident, the aircraft was removed from the site without authorization from the National Transportation Safety Board (NTSB). This action prevented investigators from conducting a physical examination of the airframe and systems to determine the extent of the damage or the root cause of the vibration. Additionally, the pilot failed to submit a completed Aircraft Accident Report Form 6120.1 to the NTSB.
The investigation
Due to the unauthorized removal of the aircraft and the lack of submitted documentation, the NTSB was unable to perform a mechanical inspection or verify the condition of the components. Consequently, the origin of the reported vibration could not be determined through physical evidence.
Findings
The primary contributing factors included the unexplained in-flight vibration and the hard landing technique. The inability to examine the aircraft meant that the specific cause of the vibration remained unknown. The removal of the aircraft without authorization hindered the investigative process significantly.