What was found
DURING C-CHECK AT AMS, FOUND CRACK IN STATION 500 FRAME WEB OUTER FLANGE BETWEEN RT STRINGERS S-10 AND S10A. TRIM CRACK AND SURFACE HFEC INSPECT TRIM LINE TO INSURE CRACK FREE CONDITION. INSTALLED TWO FILLERS, A REPAIR ANGLE, AND A REPAIR DOUBLER PER REF A OPEN HOLE HFEC INSPECT FASTENER HOLES COMMON TO REPAIR PARTS TO INSURE CRACK FREE CONDITION. CONTINUED INSPECTIONS ARE REQUIRED PER REF C SB 747-53A2265. REINSPECT AT REPEAT INTERVALS NOT TO EXCEED 3,000 FLIGHT CYCLES UNTIL THE AIRPLANE ACCUMULATES 20,000 FLIGHT CYCLES. THE REPAIR HAS BEEN APPROVED AS AN ALTERNATIVE METHOD OF COMPLIANCE TO PARAGRAHP B OF AD 91-11-01 AND HAS BEEN FOUND TO MEET THE TYPE CERT BASIS OF THIS AIRPLANE AS REQUIRED. (M)