What was found
CABIN STATION 1580, STRINGER 9R - 10R, FRAME OTBD FLANGE FOUND CORROSION. CORROSION EVALUATED & FOUND CORROSION MORE THAN 50% THROUGH. FRAME REPAIR CARRIED OUT IAW SRM 53-00-07-2R REV 117. THIS IS A CAT B REPAIR WITH A THRESHOLD OF 10000 FLIGHT CYCLES AFTER REPAIR. HFEC FOLLOW UP AT 120000 FLIGHT CYCLES INTERVALS. ALTERNATE FOLLOW UP INSPECTION AT 9000 FLIGHT CYCLES DETAIL VISUAL INSPECTION. REPAIR CLASSIFIED AS MAJOR.