As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A LAW ENFORCEMENT FLIGHT, PART 91 THE NR 1 ENGINE OIL COOLER SHAFT SHEARED CAUSING ENGINE OIL TEMPERATURE TO INCREASE TO ABOUT 120 C WHILE ALL OTHER ENGINE PARAMETERS REMAINED NORMAL. AIRSPEED WAS INCREASED AS RECOMMENDED IAW MFG MM TO SLIGHTLY ABOVE 80 KNTS FROM 60 KNTS. OIL TEMPERATURE DID NOT DECREASE. PRECAUTIONARY LANDING WAS MADE. REPLACED OIL COOLER HUB WITH MFG PN L792M3007215. PERFORMED LEAK CHECK AND OPS CHECK, ALL ENGINE PARAMETERS ARE WITHIN LIMITS.