As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO FIELD DUE TO A LOUD BANG IN THE CAPTAIN'S CONTROL COLUMN. THE SUBJECT DISCREPANCY WAS DUE TO A BROKEN SPRING RETAINER ON THE ELEVATOR TENSION REGULAR WHICH ALLOWED THE SUBJECT TENSION STRING TO BECOME DETACHED. THE SUBJECT TENSION REGULATOR WAS REMOVED AND REPLACED AND OPS CHECKED PER MM 27-31-12 AND 27-31-00. ALL OPS CHECKS WERE GOOD.