What was found
MCN - DURING C20 CHECK DISCOVERED CORROSION ON THE AFT CARGO LOWER SILL STRAP FROM BS 774 TO BS 858, WL 158 AND BL 19R. NO CORROSION REMOVAL LIMITS WERE AVAILABLE IN THE BOEING 737-300 SRM. MAINTENANCE REMOVED AND INSTALLED NEW AFT CARGO DOOR LOWER SILL STRAP FROM BS 774 TO BS 858, WL 158 AND BL 19R IAW BOEING 737-300 SRM 51-40-02-0G FIGURES 3, 4, 6, 7 AND 8.