What was found
(CAN) - NOSE WHEEL WOULD NOT COME DOWN FOR LANDING, CONFIGURATION. A/C LANDED ON MAINS WITH NOSE WHEEL FULLY RETRACTED. UPON INSPECTION NOSE WHEEL UPLOCK BEARING FOUND SEIZED WHICH RESULTED IN NOSE WHEEL NOT DISENGAGING FROM UPLOCKED POSITION. - BEARING WAS SERVICED AT PREVIOUS 100 HOUR INSPECTION AND A/C DUE FOR ANOTHER 100 HOUR INSPECTION. - SUSPECTED CAUSE: A WET SPRING ALSO, OPERATOR'S FLIGHTS ARE MOSTLY DONE OFF OF GRAVEL STRIPS. THERE WAS A LARGE ACCUMULATION OF SAND & SILT ON LANDING GEAR. OPERATOR REGULARLY PRESSURE WASHED GEAR AND GREASE JOINTS AND HINGES. BUT UPLOCK WAS OVERLOOKED AND NOT CHECKED REGULARLY ON WALK AROUNDS.BEARING ARE NOW INSPECTED ON A/C DAILY PREFLIGHT INSPECTIONS.