As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW HEARD LOUD BANG FOLLOWED BY VIBRATION IN CONTROL COLUMN TRANSFERRED TO NRWC 645-DFW-01999. VIBRATION INSPECTION IAW WC 12-200-01, NO ABNORMAL DEFICIENCIES NOTED. THIS ACFT HAS BEEN INSPECTED TO THE EXTENT NECESSARY & FOUND TO BE IN A SAFE CONDITION FOR A FERRY FLIGHT.