As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE IN HEAVY MAINTENANCE, LT HORIZONTAL STAB RIB 13 HAS A CRACK AT FRONT SPAR BEHIND LAST UPPER RIVET. REMOVED CRACKED RIB FROM LT HORIZONTAL AND INSTALLED NEW RIB TO LT HORIZONTAL REF SRM 51-41-01 AND 51-41-02. DRILLED AND TREATED NEW RIB REF SRM 51-40-02 AND 51-23-04.