What was found
WHILE IN-FLIGHT, OIL PRESSURE AND TACHOMETER DROPPED TO ZERO. WAS ABLE TO LAND ON PRIVATE GRASS STRIP WITHOUT INCIDENT. DETERMINED THE OIL PUMP DRIVE GEAR FAILED CAUSING FAILURE OF OIL PUMP, TACH DRIVE, AND ALTERNATOR GEAR. ON AN EARLIER DATE, FORCED TO MAKE AN EMERGENCY LANDING WITHOUT INCIDENT IN SAME TYPE AIRCRAFT. IT WAS ALSO DETERMINED THE OIL PUMP DRIVE GEAR HAD FAILED.