What was found
DURING ROUTINE PROPELLER REMOVAL FOR OVERHAUL, DETERMINED 6 AN470 4-4 RIVETS COMPLETELY SHEARED OFF AND MISSING FROM RIGHT FRONT ENGINE SUPPORT AND CHANNEL ASSY, PN 1213433-14, AND SUPPORT, PN 1213433-17. FURTHER INSPECTION REVEALED NO OTHER DAMAGE OR SHEARED RIVETS IN ANY OTHER OF THE 3 REMAINING MOUNTS. THE ENGINE HAD BEEN OVERHAULED AT AN EARLIER DATE. SUSPECT CAUSE: TORQUE MAXIMUM PERFORMANCE TAKEOFF AND PROP VIBRATION. SUBMITTER SUGGESTS CLOSER INSPECTION IN AREA.