As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
***CORROSION*** STA 500- STA 500A LBL 21 INTERCOSTAL AT FASTENER HOLES / REMOVED CORROSION ON INTERCOSTAL BS 500-500A LBL 21 IN AREA OF 1' X .75' X .020. FOUND TO BE OUT OF LIMITS IAW SRM 53-00-53-1A-2. LEAKED; DRILLED AND INSTALLED AND INSTALLED NEW INTERCOSTAL IAW SRM 51-40-05; SRM 51-40-02 AND BOEING DRAWING 143A7505