What was found
LOWER AFT INBOARD SECTION ON MAIN SPAR CAP HAS SEVERE EXFOLIATION CORROSION. CORROSION IS 1 INCH UNDER OUTBOARD END OF WING ATTACH DOUBLER AND EXTENDS OUTBOARD APPROXIMATELY 4 INCHES. CRACK CREATED BY CORROSION IS ABOUT .1250 INCH THICK AT AFT EDGE OF SPAR CAP. THE REST OF THE WING STRUCTURE HAD VERY MILD SURFACE CORROSION. ABOUT WHAT WOULD BE EXPECTED FOR A 32 YEAR OLD NON-TREATED OR PROOFED WING. TOP OF CAP IS AFFECTED AREA.