As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHEN COMPLETING AN OUT OF PHASE INSPECTION ON THE ACFT, IT WAS DISCOVERED THAT THE REAR MUFFLER ON THE RT ENGINE HAD SEPARATED INTERNALLY. THE OUTER SHROUD OF THE MUFFLER HAD BECOME COMPLETELY DETACHED FROM THE END PIPES AND THE INTERNAL PIPE. THE MUFFLER HAD BEEN REPAIRED 61 HOURS PREVIOUSLY. IT WOULD APPEAR THAT THE CRACK INITIATED FROM THE REPAIR WELD.