As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ONE OF FOUR B-468 FORK SPACERS SEPARATED FROM THE D495 FORK AND WAS FLOATING FREELY INSIDE THE HUB CAVITY CAUSING A RATTLING SOUND. SIGNIFICANT DAMAGE INCURRED TO THE FORWARD AND AFT HALVES OF THE INTERIOR CENTRAL WEB AREA OF THE PROPELLER HUB. SUSPECT CAUSE OF FAILIURE IS B-468 IS TOO HARD AND BRITTLE. CALL OUT FOR HARDNESS IS ROCKWELL 33-37 RC. SUBJECT PIECE TESTS AT 44.9 RC.