As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE COMPRESSOR REMOVAL TO FACILITATE OTHER MAINTENANCE THE CRACKED TENSIONING ARM WAS DISCOVERED AND A NEW REPLACEMENT PART INSTALLED. SUSPECT METAL FATIGUE BUT THE SECOND TENSIONING ARM MAINTAINED UNIT FUNCTIONALITY HAD NO APPARENT DEFECT DEVELOPING. SUGGEST INSPECTING SLOTS OF THE TENSIONING ARMS IN DETAIL, WHENEVER REMOVING THE BELT TENSIONER, FOR CRACK DEVELOPMENT BEFORE ARM BREAKS. (K)