As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING COMPRESSOR REPLACEMENT THE COMPRESSOR TENSIONING BRACKET WAS FOUND TO HAVE CRACKED ON ONE OF THE 2 ARMS AND SERVICEABLE REPLACEMENT PART INSTALLED. CLOSE EXAMINATION REVEALED THAT THE PARTS ARM SLOTS HAD BEEN WATER JETTED DURING MFG WHICH LEAVES A ROUGH SLOT SURFACE THAT SEEMS TO BE THE SOURCE OF THE STRESS RISER WHERE THE CRACK DEVELOPED. SUGGEST THAT THE MFG DRESSES AND POLISHES THE WATER JETTED SLOTS TO PREVENT CRACK DEVELOPMENT AND INCREASE MATERIAL THICKNESS TO IMPROVE PART SERVICEABILITY. (K)