As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE FROM BASE HOSPITAL AND ENROUTE TO SENDING HOSPITAL, PILOT NOTICED A PERSISTENT FUEL ODOR IN THE CABIN. THE PILOT THEN ABORTED THE MISSION AND RETURNED TO BASE MAINTENANCE HELIPAD. TROUBLESHOT THE PROBLEM. FOUND THE FUEL PURGE CANISTER FULL OF FUEL, THE MECHANIC DRAINED THE CANISTER. CONDUCTED OPERATIONAL CHECK FLIGHT AND RETURNED AIRCRAFT TO SERVICE.