As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(17590) OLD STYLE 2 PIECE PITCH CHANGE ROD CRACKED AND SEPARATED AT MATING JOINT IN FLIGHT CAUSING PROPELLER TO INADVERTENTLY FEATHER. THE PROBABLE CAUSE OF THIS IS DUE TO WEAK CONSTRUCTION. THE MANUFACTURER SHOULD CONSIDER MANDATORY REPLACEMENT OF ALL OLD STYLE 2 PIECE PITCH CHANGE RODS AT THE TIME OF NEXT DISASSEMBLY AND UPGRADING TO A NEW STYLE 1 PIECE PITCH CHANGE ROD TO PREVENT ANY POSSIBLE RECURRENCE. (K)