As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING POWER-UP FOR TAKEOFF, THE PILOT REPORTED HEARING A LOUD POP. HE PULLED POWER OFF AND TAXIED TO THE LOCAL FBO. AFTER SHUT DOWN, ONE BLADE WAS IN FEATHER. THE PROPELLER WAS REMOVED AND BROUGHT TO OUR SHOP. UPON TEAR DOWN, THE PITCH CHANGE KNOB ON THE BLADE HAD BROKEN OFF. NO OTHER DAMAGE WAS NOTICED. CAUSE IS UNKNOWN AND THE BLADE HAS BEEN SENT TO THE FACTORY.