As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FAILURE OF STARTER ADAPTER SHAFT GEAR IN FLIGHT CAUSED ENGINE SURGING AND LOSS OF POWER. PILOT THEN FOLLOWED APPROPRIATE AFM SHUT DOWN PROCEDURES. POST FLIGHT INSPECTION REVEALED FAILURE OF THE STARTER ADAPTER SHAFT GEAR ASSEMBLY RESULTING IN METAL CONTAMINATION AND FAILURE OF THE CRANKSHAFT GEAR AS WELL AS THE CAMSHAFT GEAR.