AN AIR AMBULANCE SMT LANDED ENRTE.

Narrative

AT APPROX XA30 LCL ACFT DEPARTED T65 ON A 135 AIR AMBULANCE MISSION. AFTER MAKING A NORMAL DEP; WE CONTACTED APCH. AT THAT TIME; I GAVE HIM MY POS AND ALT AND REQUESTED MY IFR CLRNC TO ABC. AFTER ABOUT 10 MINS INTO THE FLT; WE EXPERIENCED A LARGE NOISE; BOOM! AT THAT TIME; ALL MY ENG GAUGES SEEMED TO BE NORMAL. OUR CONDITIONS WERE NIGHT TIME AND IMC. AFTER TALKING TO MY MEDICAL TEAM AND LETTING THEM KNOW WE HAD A PROB; AS WELL AS THE AIR TFC CTLR. I ADVISED THEM WE NEEDED TO DIVERT TO XXX. SHORTLY AFTER THAT TIME; APPROX 4 MINS; MY OIL PRESSURE DROPPED. AS THE ENG STARTED TO RUN ROUGH; I FEATHERED THE R ENG. AFTER COMPLETING THE EMER CHKLIST. APCH HANDED ME OFF TO TWR. AT THAT TIME; I ASKED HIM TO MAKE A PHONE CALL FOR ME AND TO HAVE CRASH FIRE RESCUE STANDING BY. AFTER SAFELY LNDG AND TAXI BACK TO FBO; I WAS ABLE TO TALK TO THE CRASH FIRE RESCUE PEOPLE AND EXPLAIN WHAT HAPPENED. AT NO TIME WAS AN EMER DECLARED. THE REASON FOR THE RPT IS THAT I DID LATER MY COURSE AND THEN CONTACTED APCH; AS WELL AS GOING INTO SINGLE ENG.