As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT, ACFT EXPERIENCED A VIOLENT SHAKING DUE TO RUDDER OSCILLATION. SUCCESSFUL LANDING ACCOMPLISHED. FOUND RUDDER TRIM TAB BOLT SHEARED AND FALLEN OUT. TAB WAS FREE TO FLUTTER INDUCING LARGE RUDDER INPUTS. ALL TAB CONTROL COMPONENTS WERE INTACT AT WALK-AROUND