What was found
DISCOVERED GALVANIC CORROSION COMMON TO THE ENGINE SHREDDER SCREEN PLATE (P/N 101-910049-107) ON THE LOWER AFT ENGINE COWLING WHERE THE CRES SHREDDER SCREEN IS SECURED. NO BARRIER APPLIED (I.E. ALODYNE PRIMER, OR SEALER) BETWEEN THE DISSIMILAR METEALS. THE CORROSION IS ALONG THE ENTIRE FAYING SURFACE OF THE SHREDDER SCREEN PLATE. SIMILAR GALVANIC CORROSION ALSO FOUND ON OTHER AIRCRAFT DELIVERED WITHIN LAST 12 MONTHS NEW FROM FACTORY. EXACT DISSAMBLY REQUIRED TO REMOVE AND TREAT THE SHREDDER SCREEN IS UNKNOWN BUT APPEARS TO BE EXTENSIVE DUE TO TFASTENERS IN COMMON WITH A CAPTRED STIFFENER/ANGLE.