What was found
AAIRCRAFT 8306, DURING C CHECK IN MSP, MAINTENANCE FOUND CORROSION COMMON TO THE FUSELAGE BOTTOM SKIN COMMON TO THE WASTE BOX CUTOUT. THE CORROSION IS LOCATED IN 4 SPOTS ON THE WASTE COMPARTMENT CUTOUT DOUBLER AND EXTENDS TO THE SKIN IN 1 AREA. MRT OF EACH ZONE IS; A: 0.035 DOUBLER AND 0.008 REMOVED FROM SKIN, B: 0.045, C: 0.085, D: 0.090. THE SKIN P/N IS C01342101-113 AND THE DOUBLER P/N IS C01342310-107. BOTH ARE MADE FROM 0.125 2198-T82 SHEET. CORRECTIVE ACTION: REMOVED CORROSION AND INSTALLED 2 REPAIR DOUBLERS AND 2 REPAIR TRIPLERS AND REPLACED WASTE BOX DOUBLER PER ER/A 613419-14.