As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE MAINTENANCE, A BULKHEAD AND DOUBLER WERE FOUND CRACKED IN THE EMPENNAGE. THE CRACKS WERE VISIBLE ONLY BY REMOVING THE FAIRING BETWEEN THE VERTICAL FIN LEADING EDGE AND EMPENNAGE AND SEARCHING WITH A MIRROR AND LIGHT. THE BULKHEAD AND DOUBLER ARE THE STRUCTURE USED TO MOUNT THE VERTICAL FIN, AND IT IS SUSPECTED THAT THE CRACKING WAS CAUSED BY FORCES ON THE FIN TRANSFERRING TO THE SURROUNDING STRUCTURE.