What was found
(CAN) AFTER TAKEOFF, FLIGHT CREW HAD CHIP DETECTOR LIGHT ILLUMINATE ON RT ENG. CREW REDUCED POWER AND IMMEDIATELY RETURNED TO LAND. MAINT WAS SENT TO INSPECT CHIP DETECTOR, DISCOVERED SEVERAL CHUNKS OF FERROUS METAL ON CHIP DETECTOR PLUG. OIL FILTER WAS REMOVED AND INSPECTED, FOUND TO CONTAIN AN ABNORMAL AMOUNT OF METAL. UPON ROTATING PROP, A GRINDING/RATTLING NOISE WAS OBSERVED COMING FROM GEAR CASE. ENG WAS REPLACED AND UNSERVICEABLE ENG TORN DOWN. INITIAL FINDINGS WERE THAT HIGH SPEED PINION GEAR HAD SHED A GEAR TOOTH WHICH WAS WHAT WAS FOUND ON CHIP DETECTOR. NO FURTHER REASON FOR PINION GEAR FAILURE HAS BEEN DISCOVERED. MORE INFORMATION WILL FOLLOW IF ANY CAUSE OR CONTRIBUTING FACTORS CAN BE DETERMINED.