As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TROUBLESHOOTING FOR A LOOSE TAIL ROTOR GUARD IN TAIL ROTOR GEARBOX HOUSING, PULLED THE GUARD OUT OF THE GEARBOX AND FOUND FERTILIZER PACKED INTO CAVITY. WHILE SCRAPING FERTILIZER OUT OF CAVITY, FOUND CORROSION HAD EATEN THROUGH MAGNESIUM HOUSING. THE PACKED FERTILIZER WAS KEEPING THE OIL FROM LEAKING OUT.