As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN DESCENDING THROUGH 20,000 FEET, PLANE PITCHED UP ABRUPTLY AND STARTED BUFFETING. SHUT DOWN THE ENGINE AND FEATHERED THE PROPELLER. THE BUFFETING CONTINUED. MADE AN ENGINE-OFF EMERGENCY LANDING. DURING INSPECTION, THE ELEVATOR SERVO TRIM ARM HAD BROKEN AT THE CLEVIS PIN. THE ELEVATOR TRIM TAB FLUTTERED VIOLENTLY, DAMAGING THE TRIM TAB, THE SERVO MOTOR AND ASSEMBLY AND THE WELDMENT CONNECTING THE ELEVATOR TO THE PUSH ROD.