As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER AN EMERGENCY LANDING, MAINTENANCE INSPECTED ENGINE AND FOUND THE DUEL MAGNETO HAD BROKEN OFF THE ENGINE ACCESSORY CASE. AFTER A RECORD SEARCH OF THE AIRCRAFT IT WAS FOUND TO HAVE TWO OTHER MAGNETOS INSTALLED IN THE PAST TWO YEARS. THERE MIGHT BE A PROBLEM WITH THE ENGINE IN QUESTION AND WAS REMOVED FROM SERVICE FOR FURTHER INSPECTION OF THE ACCESSORY SECTION.