As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT GROUNDED FOR HEAVY MAINTENANCE. AFT LOWER CARGO STRINGER 39L IS CORRODED BETWEEN STATION 1250-1307. CORROSION FOUND TO BE OUT LIMITS IN ACCORDANCE WITH SRM 53-00-03 FIGURE 101. INSTALLED FABRICATED STRINGER SECTION 39L STATION 1250-1274 AND 1274-1307 IN ACCORDANCE WITH SRM 53-00-03.