What was found
ENGINE STARTED TO MAKE A KNOCKING NOISE WHILE IN-FLIGHT. AS THE ENGINE WAS THROTTLED, BACK NOISE BECAME MORE PRONOUNCED. AIRCRAFT WAS LANDED AT NEAREST AIRPORT. INVESTIGATION OF KNOCKING NOISE REVEALED THAT ONE TOOTH WAS MISSING FROM THE CRANKSHAFT GEAR. ENGINE TIME SINCE FACTORY REMANUFACTURE APPROXIMATELY 3,050 HOURS. TIME SINCE MAJOR OVERHAUL, APPROXIMATELY 350 HOURS. CRANKSHAFT GEAR WAS MAGNAFLUXED AT MAJOR OVERHAUL.