As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HAD A MAIN GEARBOX CHIP EVENT. PERFORMED CHECKS IAW MM TO INCLUDE OIL DAIN, STRAIN AND FLUSH. HAD FIVE SCALE TYPE CHIPS THE LARGEST BEING 1.5MM AND SENT IN FOR ANALYSIS. RETURNED AIRCRAFT TO SERVICE. AT RECEIPT OF ANALYSIS DATA PERFORMED A BORESCOPE OF PINION AND BEVEL WHEEL. FOUND FROSTING DAMAGE ON PINION GEAR AND REMOVED AIRCRAFT FROM SERVICE. (K)