What was found
RT SIDE ENGINE EXPERIENCED A LOW OIL PRESSURE LIGHT 1.5 HOURS INTO MISSION AND SUBSEQUENT PRESSURE LOSS. ENGINE WAS SHUTDOWN IN FLIGHT AND ACFT DIVERTED. THE ENGINE WAS RECEIVED AT THIS FACILITY FOR INVESTIGATION. THE PROPELLER SHAFT WAS HARD TO TURN AND A GRINDING NOISE WAS HEARD. THE CHIP DETECTOR WAS REMOVED AND FOUND IT WAS COMPLETELY ENCASED IN METAL CHIPS. THE POWER SECTION WAS REMOVED AND DISASSEMBLED. UPON REMOVAL OF THE 1ST STAGE CARRIER IT WAS DISCOVERED THAT THE HEAD WAS MISSING FROM ONE OF THE 6 INSTALLED MS 9490-34 BOLTS THAT HOLD THE SPLINE ADAPTER PLATE TO THE CARRIER. THE SUBJECT BOLTS AND FAILURES ARE ADDRESSED IN SB 14444 AND WAS ALSO INVESTIGATED BY THE TRANSPORT SAFETY BUREAU, AO-2010-006.