What was found
DURING SCHEDULED AIRFRAME INSPECTION, FOUND EXTENSIVE CORROSION DAMAGE TO THE COVER MOUNTING FLANGE AREA OF THE RT WING CENTER SECTION UPPER SKIN AUXILLIARY FUEL CELL COVER DISH. SIMILAR DAMAGE NOTED ON OTHERWISE CLEAN AND HANGARED LOW-TIME LATER SN B200 AND ACFT IN THIS AREA. MORE DETAILED INSP OF THIS AREA ADDED IN LATEST MM REVISION PHASE INSP GUIDES. RECOMMEND THE AUX FUEL CELL COVERS AND NACELLE FUEL CELL COVERS HAVE 12-MONTH INSP ADDED TO THE MM SPECIAL INSPECTIONS GUIDE. ALSO RECOMMEND A SB INCORPORATING "BEST PRACTICES" SUMMARIZED FOR CONTROLLING CORROSION IN THESE AREAS.