What was found
DURING A PHASE 4 INSPECTION PAINT BLISTERS WERE NOTED ON THE LT AND RT WING ROOT FAIRING LOWER AFT PANELS P/N 101-420024-43 AND 101-420024-8. UPON FURTHER INSPECTION BOTH PANELS WERE FOUND TO BE CORRODED THRU IN SEVERAL PLACES FROM THE INSIDE OUT. AFTER REMOVING THE PANELS IT WAS DISCOVERED THAT THE ACOUSTIC FOAM HAD BECOME SOAKED WITH WATER OVER TIME. THIS SET UP CORROSION OVER THE ENTIRE AREA OF THE INSIDE OF BOTH PANELS. ALSO WHERE THIS MATERIAL CONTACTED THE FUSELAGE ON THE LT SIDE IT CAUSED CORROSION THRU THE PRESSURE VESSEL. MFG HAS BEEN NOTIFIED AND SUPPLIED WITH PHOTO DOCUMENTATION.