What was found
CABIN INTERNAL STRUCTURE, FRAME CRACKED AT FASTENER LOCATION WHERE AC DISTRIBUTION DUCT SUPPORT BRACKET IS SECURED TO FRAME, STATION 1520, BETWEEN STRINGER -8L & -9L. MARKED CUT OUT DAMAGE SECTION OF FRAME & INSTALLED REPAIR DOUBLERS IAW SRM 53-00-07, REPAIR 1. INITIATED DIP TO RE-INSPECT REPAIR 12,000 FLIGHT CYCLES FROM INSTALLATION OR 50,000 AIRFRAME FLIGHT CYCLES, WHICHEVER COMES FIRST & AT INTERVALS OF 12,000 FLIGHT CYCLES THEREAFTER IAW SRM 53-00-07 REPAIR 1 TABLE 203 ZONE 3.