As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE BEGAN RUNNING ROUGH AND BECAME SMOOTH AGAIN DURING DESCENT. TROUBLESHOOTING FIRST FOUND BRASS METAL PARTICLES IN AIR FILTER AND OIL. CRANKSHAFT WAS APPARENTLY BROKEN OR CRACKED BUT STILL TOGETHER. AFTER NUMEROUS GROUND RUSN AND KNOCKING NOISES HEARD, THE CRANKSHAFT BROKEN AND ROD THROWN THROUGH CASE. THE BREAK WAS BETWEEN NR 3 AND NR 4 ROD JOURNALS. SENG BACK TO ENGINE COMPONENTS FOR WARRANTY AND ANALYSIS. (K)