As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE HEAVY MAINTENANCE VISIT, THE FUSELAGE CROWN SKIN AREA BETWEEN BS 600 AND BS 660 AND BETWEEN S-4L AND S-4R WAS FOUND TO HAVE DAMAGE. A MAJOR REPAIR IS REQUIRED TO CORRECT DAMAGED AREA. *S/D* CAUSE NOT IDENTIFIED. REPAIRED CROWN WITH EXTERNAL DOUBLER.