As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 ENGINE THRUST REVERSER REMOVED 12/16/00 DUE TO ACOUSTIC EXTENSION DUCT FOUND CRACKED DURING B-CHECK. SUBSEQUENT INSPECTION REVEALED CIRCUMFERENTIAL CRACKS ON THE INNER AND OUTER SKINS OF THE ACOUSTIC EXTENSION DUCT AT THE JOINTS OF BOTH FORWARD AND AFT ATTACH RINGS. THE SKINS ARE CRACKED 90 PERCENT AROUND THE CIRCUMFERENCES. CAUSE UNKNOWN. UNIT SENT TO MANUFACTURER FOR INVESTIGATION. NEW ACOUSTIC EXTENSION DUCT INSTALLED ON THRUST REVERSER.