As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AC WAS IN FOR HEAVY CHECK, LEVEL TWO CORROSION WAS FOUND ON LT ENGINE NUMBER FOUR HEAT SHIELD AND INTERNAL STIFFENERS ON BOTTOM. MAINTENANCE REMOVED AND REPLACED THE HEAT SHIELD (P/N 170-39554-001) AND INTERNAL STIFFENERS (P/N 170-34584-001) PER THE EMB SRM. AC OUT OF SERVICE FOR HEAVY CHECK COMPLETION.