As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) POST FLIGHT WALK AROUND REVEALED OIL LEAK OF TAIL ROTOR GEARBOX. DISAASEMBLY SHOWED THAT INPUT SEAL DUST SEAL LIP HAD PEELED OFF AND WENT INTO THE SEALING LIP ALLOWING GEARBOX TO LOOSE IT''''S OIL DURINGA 40 MINUTE FLIGHT. CHIP DETECTOR WAS CLEAN AT THIS POINT, HOWEVER AFTER POST REASSEMBLY GROUND RUN, CHIP LIGHT ILLUMINATED. INSPECTION SHOWED EXCESSIVE METAL ON DETECTOR.