As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHILE ON FINAL APPROACH TO A WELL SITE, THE PILOT HEARD A LOUD BANG FOLLOWED BY A SEVERE AIRFRAME VIBRATION. AN AUTOROTATION WAS INITIATED AND A NORMAL LANDING ENSUED WITH NO FURTHER INCIDENT. THE ACFT WAS INSPECTED BY MX PERSONNEL BUT NO APPARENT DEFECTS WERE FOUND. THE ACFT REMAINS AT THE WELL SITE PENDING FURTHER INVESTIGATION.