What was found
DURING C CHECK, LT WING NR 4 SLAT ACTUATOR PISTON END ATTACH FITTING LOOSE FASTENERS ALSO INTERNAL ANGLES 2 EACH PLUS RIB ARE CRACKED. REMOVED NR 4 SLAT IAW B-727 M.M. 27-81-11. CUT-OUT AREA IN AFT LOWER. SKIN IAW B-727 SRM 57-50-3 AND REMOVED 2 DAMAGED REPAIR ANGLES AND 2 RIBS IAW B-727 SRM 51-30-2. FABRICATED 2 RIBS IAW B-727 SRM 57-50-2. PARTS ALODINED AND PRIMED IAW B-727 SRM 51-10-2 AND INSTALLED IAW B-727 SRM 51-30-2.