What was found
DURING HEAVY MAINTENANCE CHECK CENTER WING UPPER PANEL CORRODED AT LH APPROX STA 1214, XCW 3.0 AT S-17. AFTER FURTHER EVALUATION OF BLENDED OUT AREA AT LH APPROX STA 1214, XCW 3.0 AT S-17, BOEING FOUND BLENDED OUT LOCATION ACCEPTABLE AS A PERMANENT REPAIR IAW MD-11, MESSAGE: WGN-WGN-25-0035-4C.. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.