What was found
LEFT LOWER FUSELAGE SKIN JUST AFT OF RADOME HAS LIGHTNING STRIKE. REMOVED PAINT AT LIGHTNING STRIKE DAMAGED AREA IAW B747-400 AMM TASK 51-21-01-150-814. MECHANICALLY MEASURED LIGHTNING STRIKE AT LT FUSELAGE SKIN STA 176.5 1 INCH ABOVE STR 41L, ORIGINAL SKIN THICKNESS 0.056", D=0.012"X MAX 20% 0.011", FOUND TO BE OUT OF LIMITS IAW SRM 53-10-01-01-1 AND SRM 53-00-01-1A TABLE 11. PERFORMED DRILL OUT 0.126" ON LIGHTNING STRIKE AT LT FUSELAGE SKIN STA 176.5 1 INCH ABOVE STR 41L IAW SRM 53-00-01-2R-9 REPAIR STEP 3.A. OK TO NDT FOR OPEN HOLE. HFEC OPEN HOLE INSP NDTM PT 6 51-00-00 PROC 16 (ASSET 18-2213 DUE 10-20-26), NO CRACKS NOTED AT 1EA OPEN HOLE. REPAIRED DAMAGE AND NO FURTHER DEFECTS NOTED.