As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE MAINTENANCE CREW WERE DOING A 600 HOUR INSPECTION ON THE AIRFRAME AS PART OF THE INSPECTION. THE FUSELAGE TO TAILBOOM SUPPORT REQUIRES A VISUAL INSPECTION. FOUND A SLIGHT BLACK MARK NEAR THE UPPER FUSELAGE SUPPORT FOR THE TAILBOOM. THE AREA WAS CLEANED UP AND INSPECTED AGAIN AND WITH A MAGNIFYING GLASS IT WAS DETERMINED THAT THE CHANNEL OR LONGERON WAS CRACKED.