What was found
MCN - DURING C18 CHECK DISCOVERED CORROSION ON THE RT INBOARD MID-FLAP, INBOARD CARRIAGE, INBOARD AND OUTBOARD FORE FLAP SEQUENCE CARRIAGE TRACKS. NO CORROSION REMOVAL LIMITS ARE AVAILABLE. MAINTENANCE REMOVED AND REPLACED THE RT INBOARD MID-FLAP, INBOARD CARRIAGE, INBOARD AND OUTBOARD FORE FLAP TRACKS IAW BOEING SOPM 20-50-01.