What was found
DURING ANNUAL INSPECTION, THE SPINNER BULKHEAD WAS FOUND CRACKED AROUND 5 OF THE 6 ATTACHING POINTS. THIS AREA IS SUPPORTED WITH A DOUBLER. TWO OF THE 6 ATTACHING POINTS WERE FOUND COMPLETELY BROKEN, AND NO LONGER PROVIDING SUPPORT OF SPINNER. A REVIEW OF AIRCRAFT RECORDS REVEALED TWO PREVIOUS FALURES OF THIS PART. FAILED PART REVEALS SEVERAL ELONGATED BOLT HOLES. SUSPECT CAUSE, IMPROPER TORQUE OF ATTACHING HARDWARE, AND/OR POSSIBLE PROPELLER OR ENGINE VIBRATION. THE FAILED PART WAS INSTALLED 12-93 WITH 400 HOURS TIS.