As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A SMALL CRACK WAS FOUND AT ONE OF THE TWO DOWEL PIN LOCATIONS ON THE PROPELLER HUB MOUNTING FLANGE. THE CRACK APPEARS TO HAVE ORIGINATED AT A LARGE PIT ON THE MOUNTING SURFACE AND PROGRESSED INTO THE DOWEL PIN BORE. TOTAL LENGTH OF THE CRACK IS LESS THAN 0.0250". THIS IS A KNOWN ISSUE WITH THIS PART AND THERE ARE CHECKS IN PLACE TO PREVENT AND DETECT IT. NEW HUBS AND MOST OLDER HUBS HAVE 2 MODIFICATIONS INCORPORATED TO PREVENT THIS TYPE OF A DEFECT.