As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT DECLARED EMERGENCY ON ACCOUNT OF LOW OIL QUANTITY. #1 ENGINE WAS SHUTDOWN. SINGLE ENGINE TIME WAS 5-10 MINUTES. FLIGHT LANDED WITHOUT INCIDENT AND WAS NOT OVERWEIGHT. MAINTENANCE FOUND THE HANDCRANK DRIVE COVER UNINSTALLED ON THE ENGINE. REINSTALLED IAW AMM 72-63-00-400-002-A.