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. INTERCOSTAL IS CORRODED OUT OF LIMITS AT STATION 1285-1307 AT LEFT BUTT LINE 36. RECEIVED AND MATCH DRILLED NEW INTERCOSTAL IN ACCORDANCE WITH SRM 51-40-05. INTERCOSTAL WILL BE INSTALLED ON NR 2749.