What was found
DURING HEAVY CHECK, MAINTENANCE FOUND RIGHT HAND HORIZONTAL STABILIZER RIB 12 AT FRONT AND MIDDLE SPAR CRACKED. REMOVED DAMAGED RIB 12 AT RT HORIZONTAL STAB. LOCATED, DRILLED, ALODINED AND INSTALLED NEW RIB 12 AT RT HORIZONTAL STAB REF SRM 51-40-08, 51-41-01, 51-41-02.