What was found
DURING ROUTINE INSPECTION OF THE MAIN CARGO DOOR HINGE, A CRACK WAS INDICATED ON THE FORWARD END OF BOTH HALVES, FUSELAGE/DOOR. ALSO, AT THE AFT END OF FUSELAGE HALF. NON DESTRUCTIVE INSPECTION CONFIRMED FINDING. REMOVED AND REPLACED HINGE IAW SB AEIO1-01 REV B. ACCOMPLISHED ON KITTY HAWK EA B7-51-003. NDI HOLES WITH NO CRACKS NOTED. RETURNED AIRCRAFT TO SERVICE. (M)