As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
U SHAPED ALTERNATOR TO ENGINE ATTACH BRACKET FOUND CRACKED. CRACK WAS TANGENTIAL TO THE REAR BOLT HOLE IN A MOSTLY LATERAL DIRECTION. IF CRACK HAD CONTINUED, IT WOULD HAVE EVENTUALLY CRACKED ALL THE WAS ACROSS BRACKET, BEHIND THE REAR BOLT HOLE, ALLOWING THE REAR SIDE OF THE ALTERNATOR TO BE UNSUPPORTED. PROBABLE CAUSE WAS AN UNBALANCED ARMATURE IN THE ALTERNATOR; PN 3656624. CAREFUL ANNUAL/100 HOUR INSPECTIONS OF THIS PART ARE RECOMMENDED TO DETECT THIS TYPE OF PROBLEM BEFORE IT DAMAGES OTHER PARTS.