What was found
BOLT MAGNAFLUX INSP FOR ROUTINE 5-YEAR INSPECTION IAW MM. BOLT RETURNED AS UNAIRWORTHY DUE TO POSSIBLE CRACK INDICATION IN RADIUS UNDER BOLT HEAD. BOLT WAS INSTALLED NEW AT AIRCRAFT MFG IN RIGHT WING LOWER FORWARD POSITION. MAY POSSIBLY BE DUE TO MFG SURFACE DEFECT, WOULD REQUIRE PLATING REMOVAL AND FURTHER ENGINEERING INVESTIGATION TO CONFIRM IF ACTUAL DEFECT PRESENT. REPLACED BOLT WITH NEW RAPID-SUPPLIED BOLT.