What was found
DURING HEAVY CHECK MAINTENANCE FOUND SUSPECT CRACK AT RIB 12 RH HORIZONTAL STABILIZER. REMOVED AND REPLACED RIB AT FR12A ON R/H HORIZONTAL STABILIZER AND APLLIED TOPCOAT TO SURFACE FASTENERS AT RH HORIZONTAL STABILIZER,REF SRM 51-23-06, 51-40-08. A/C REMAINS IN CHECK.