What was found
(CAN) MAY 7, 2002. THE AIRCRAFT DEPARTED YVR ON A NORMAL POSITIONING FLIGHT TO YYJ. ABOUT 15 MILES OUT OF YYJ, THE CREW NOTED A ROUGHNESS IN THE LT ENGINE FOLLOWED BY OIL COMING OUT OF THE COWLING, AND ELECTED TO PERFORM A PRECAUTIONARY SHUTDOWN. LANDED IN YYJ WITHOUT FURTHER INCIDENT. INVESTIGATION REVEALED THAT THE 3/8 INCH DIAMETER STUD P/N 38-13 AT THE 1:00 POSITION ON THE NR 2 CYLINDER HAD FAILED JUST BELOW THE CASE SURFACE UNDER THE CYLINDER MOUNTING FLANGE. LOSS OF THIS STUD CAUSED RAPID FAILURE OF THE OTHER 3 STUDS ON THE UPPER FLANGE OF THIS CYLINDER, UNSEATING THE BASE SEAL AND RELEASING OIL. THE LOWER STUDS WERE ALL INTACT AND HOLDING THE CYLINDER IN PLACE.