What was found
UPON APPROACH TO LANDING THE LEFT ENGINE PROPELLER WAS OBSERVED TO ENTER AN OVERSPEED CONDITION FROM 1900 TO 2420 RPM. THE ENGINE WAS SHUT DOWN AS A PRECAUTION AND LANDING WAS MADE WITHOUT INCIDENT. UPON INSPECTION OF THE ENGINE, THE FUEL CONTROL WAS REMOVED AND THE DRIVE COUPLING WAS OBSERVED TO BE DAMAGED, AND THE FUEL CONTROL DRIVE BEARING WAS ROUGH AND HAD EXCESSIVE PLAY. THE ROOT CAUSE OF THE DAMAGE APPEARED TO BE THE FAILED FUEL CONTROL DRIVE BEARING, WHICH RESULTED IN DAMAGE TO THE DRIVE COUPLING AND A SUBSEQUENT INCREASE IN FUEL BEYOND WHAT THE GOVERNORS COULD EFFECTIVELY CONTROL ONCE THE FUEL CONTROL INPUT RPM SLOWED BEYOND WHAT IT SHOULD HAVE BEEN AT THAT POINT.