As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRFRAME EXPERIENCED VIBRATION WHEN AIRSPEED WAS GREATER THAN 300 KNOTS. *S/D* CHECKED AIRCRAFT PER TROUBLESHOOTING MAINTENANCE MANUAL. NO DISCREPENCIES WERE NOTED DURING GROUND CHECKS OR BY SUBSEQUENT FLIGHT CREWS SINCE THE INITIAL WRITE-UP. NO VIBRATION OR FLUTTER NOTED. AIRCRAFT OK FOR CONTINUED SERVICE.