As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AT CRUISE RPM, PILOT HEARD LOUD BANG FOLLOWED BY A SEVERE VIBRATION. REDUCING RPM MADE VIBRATION WORSE. A HIGHER RPM SETTING WAS USED AND AIRCRAFT RETURNED TO LAND SAFELY. UPON EXAMINATION, FOUND APPROXIMATELY 8 INCHES OF ONE PROPELLER BLADE SEPARATED FROM BLADE. SUBMITTER STATED THE BREAK WAS CLEAN AND SHOWED NO SIGN OF A PRE-EXISTING CRACK.