As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCN - MAJOR REPAIR - DURING C-05 CHECK EXFOLIATION CORROSION WAS FOUND ON TOP LT WING IN SPAR SKIN AT BS 575, WBL 81.5. MAINTENANCE CUT OUT DAMAGED AREA OF LT WING IN SPAR SKIN AT BS 575, WBL 81.5; FABRICATED A -5 FILLER AND 4 EACH REPAIR PLATES (DOUBLERS); INSTALLED REPAIR PARTS IAW B737-300 SRM 57-20-01 FIG 202.