What was found
UNUSUAL CLANGING SOUNDS HEARD DURING A TRAINING FLIGHT. IMMEDIATELY TURNED TO BASE AND GAINED ALTITUDE TO ASSURE SAFE LANDING AT JNX. AFTER 2 MILES, A DUAL ECU FAIL BECAME ACTIVE DUE TO LOW OIL PRESSURE. CONTINUED FLIGHT AT IDLE. AT 3 MILES FROM BASE, OIL PRESSURE DROPPED TO ZERO. THE PILOTS LANDED THE AIRCRAFT SAFELY WITHOUT ANY OTHER INCIDENT, AND THE ENGINE AUTOMATICALLY SHUT DOWN DURING TAXI ON TAXIWAY. ENGINE WAS UNCOWLED AND FOUND A HOLE IN THE CRANKCASE. UPON DISASSEMBLY OF OIL PAN, THE MECHANICS FOUND A JOURNAL BEARING BOLT HEAD HAD SHEARED AND BOUNCED AROUND INSIDE THE CRANKCASE, CREATING 3 HOLES OF SIGNIFICANT SIZE AND SOME CRACKS.