As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PROP BRUSH BLOCK FAILURE EXPERIENCED. SLIP RINGS WERE SEVERELY PITTED ALONG WITH SIGNS OF BURING AND MELTING OF BRUSH GEAR. NO CURCUIT PROTECTION WAS ACTIVATED. INSPECTION SCHEDULE REQUESTED FROM OPERATOR. MAINTENANCE INSPECTIONS OF BRUSH BLOCK ARE PERFORMED AT 500 AND 1000 HR INTERVALS. SEARCH SHOWED NO OTHER INCIDENCE OF THIS FAILURE TYPE ON FILE AT TIME OF ENTRY.