What was found
DURING HEAVY CHECK, FUEL TUBES AND CLAMP DETERIORATED AT FUEL PANEL 521BB. MAINTENANCE INSTALLED NEW TUBING AND CLAMPS UNDER FUEL PANEL 521BB IAW AMM 20-10-13, SEE CONTINUATION C1 FOR WORK ACCOMPLISHED. PN 170-06024-401, TUBE ASSY. ACFT REMAINS UNTIL HEAVY CHECK IS COMPLETED.