As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING SCHDULED INSPECTION, MX FOUND 12 RIBS CRACKED IN THE HORIZ STABILIZER. CRACKS WERE FOUND TO BE EMINATING OUTWARD FROM A FASTENER HOLE ON THE ATTACHEMENT FLANGES OF THE RIBS WHERE THE BLIND FASTENERS WERE INSTALLED ON THE LOWER SKIN. ALL 12 RIBS WERE REPLACED IAW KIT 128-6200-1.