As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) MAIN ROTOR RPM KEPT DECREASING AFTER ADJUSTMENT, OIL ALSO FOUND IN THE INPUT SEAL DRAIN TUBE. NO LONGER ABLE TO ADJUST IAW MM. UNIT REPLACED WITH SERVICEABLE FCU AND DEFECTIVE UNIT SENT TO MFG FOR INVESTIGATION AND WARRANTY REPAIR.