What was found
(CAN) FLIGHT WITH AN UNDETECTED FAILURE PILOT NOTICED AN EXTERNAL OIL LEAK FROM THE PROPELLER SHAFT AREA DURING PRE-FLIGHT WALK AROUND. INSPECTION REVEALED A CRACK ALMOST HALF WAY AROUND THE CIRCUMFERENCE OF THE PROPELLER SHAFT AT APPROXIMATELY 4 TO 4.5 INCHES FROM THE FRONT FLANGE. THE PROPELLER SHAFT IS TO BE SENT TO P&WC SERVICE INVESTIGATION AS SOON AS POSSIBLE. MANUFACTURER ENGINEERING IS CONDUCTING A PRELIMINARY VISUAL INSPECTION AT THE SHOP.