As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A SCHEDULED MAINT VISIT WHILE PERFORMING A HORIZONTAL STABILIZER ROLLER INSP OF THE HORIZONTAL STABILIZER IB RIB AND BRACKET ASSEMBLIES, THE LT IB RIB WAS FOUND CRACKED. DETAILED INSPECTION INSTRUCTIONS OF THIS AREA ARE OUTLINED IN COMMUNIQUE' NR 70. MAINTENANCE REPLACED BOTH RIBS WITH NEW STYLE RIB ASSEMBLIES.