What was found
MCN - MAJOR REPAIR - DURING C-21 CHECK A .5 INCH CRACK WAS FOUND ON PREVIOUS REPAIR AT FASTENER HOLE OF LOWER FUSELAGE SKIN BS 454, RBL 3. MAINTENANCE TRIMMED OUT DAMAGE ON PREVIOUS REPAIR AT FASTENER HOLE OF LOWER FUSELAGE SKIN BS 454, RBL 3; PERFORMED HFEC INSPECTION OF CUTOUT TO VERIFY NO CRACKS EXIST; FABRICATED A FILLER, A STRINGER FILLER, 5 EACH STRUCTURAL FILLERS, A DOUBLERS, AND A TRIPLER; INSTALLED REPAIR PARTS IAW ER 15-5331-03311-ES1.