As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MCN - DURING C11 CHECK DISCOVERED LEVEL 2 EXFOLIATION CORROSION ON HAT CHANNEL AT BS 1688 TO BS 1716 AND BL 5.5L. NO CORROSION REMOVAL LIMITS WERE AVAILABLE IN THE SRM. MAINTENANCE REMOVED, FABRICATED AND REPLACED HAT CHANNEL AT BS 1688 TO BS 1716 AND BL 5.5L IAW BOEING 757-200 SRM 51-40-02-0G FIGS 8 AND 12.