A SOCATA TRINIDAD IN CRUISE AT 16000 FT DECLARED AM EMER AND DIVERTED DUE TO LOSS OF ENG PWR CAUSED BY A FAILED TURBOCHARGER.

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THE 4 OF US WERE CRUISING ALONG ON AUTOPLT AT 16000 FT; BECAUSE THERE WERE 12000 FT MOUNTAIN PEAKS AHEAD OF US; SO I WANTED TO CLR THEM WITH PLENTY OF ALT TO SPARE. WE HAD JUST PASSED AN INTXN; AND WERE CLRED DIRECT TO ZZZ VOR. WE HAD PLENTY OF FUEL; AND WE WERE ALL WEARING OUR OXYGEN CANNULAS. EVEN THOUGH WE WERE ON AN IFR FLT PLAN; THE CEILING WAS ABOVE US AT FL200; AND IT WAS CLR DIRECTLY BELOW US. A LOOK AHEAD SHOWED WORSENING CONDITIONS AND SOME MOUNTAIN OBSCURATION; SO I WAS GLAD THAT WE WERE IFR. THE PLAN WAS PERFORMING WELL AS WE CRUISED ALONG AT 170 KTS TAS. WE EXPECTED TO ENCOUNTER SOME SIGNIFICANT RAIN BEFORE WE ARRIVED HOME; BUT THAT WAS NOT A BIG CONCERN BECAUSE OF MY IFR TRAINING. THE FLT FROM ZZZ1 TO ZZZ2 USUALLY TAKES ME 2.5 HRS. I LIKE TO LEAVE ZZZ1 EARLY IN THE AFTERNOON IN ORDER TO GET PAST THE MOUNTAINS BEFORE IT GETS DARK. BUT ON THIS DAY; WE GOT A LATE START AND ENCOUNTERED UNEXPECTED HEADWINDS. OUR GND SPD WAS ONLY 115 KTS; ACCORDING TO MY GPS. BECAUSE OF THIS; WE WERE ALMOST 3 HRS INTO THE FLT AND WE WERE STILL ALMOST 1 HR FROM HOME. THEN; WITHOUT WARNING; IT ALL CHANGED. SUDDENLY; IT FELT LIKE I PULLED THE THROTTLE BACK TO 'IDLE.' I CHKED THE THROTTLE CTL LEVER; AND MOVED IT BACK AND FORTH; WITH NO RESPONSE FROM THE ENG. I TRIED THE SAME WITH THE MIXTURE AND PROP CTLS; WITH NO IMPROVEMENT. EVEN THOUGH I HAD PLENTY OF FUEL IN BOTH TANKS; I SWITCHED TANKS AND TURNED ON THE ELECTRIC FUEL PUMP. THE MAGNETO SWITCH WAS IN THE 'BOTH' POS. I NOTED THAT THE MANIFOLD PRESSURE HAD DROPPED FROM 25 INCHES TO THE BOTTOM OF THE SCALE. ALL OTHER GAUGES (INCLUDING THE OIL PRESSURE GAUGE) WERE IN THE GREEN. MY EMER TRAINING HELPED OUT BECAUSE ALL OF THIS WAS DONE IN ABOUT 5 SECONDS. AS I WATCHED THE AIRSPD BLEED OFF FROM 170 KTS TO 150 KTS (AND DECREASING); THERE WAS NO MISTAKING WE WOULDN'T CLR THE MOUNTAINS AHEAD. WE WERE GOING DOWN INTO THE DARKNESS BELOW. FORTUNATELY; ZZZ3 ARPT CAME UP #1 ON THE LIST; ONLY 9.7 MI AWAY. ITS ALT IS 7000 FT (9000 FT BELOW US); SO IT WAS EASILY WITHIN GLIDING DISTANCE. THE GPS DATABASE TOLD ME THAT IT HAS A LONG (AND LIGHTED) RWY. A CALL TO UNICOM TOLD US THAT THERE WERE CALM WINDS BELOW. I CALLED CTR TO TELL THEM THAT WE HAD A LOSS OF MANIFOLD PRESSURE; WE WERE CANCELING IFR; AND WILL PROCEED TO THE NEAREST ARPT. I TOLD THE 2 PAX IN THE BACK SEAT THAT 'THE ENG DOESN'T SOUND RIGHT; SO WE'RE GOING TO STOP AT THAT ARPT OVER THERE FOR A PRECAUTIONARY LNDG.' I FIGURED THAT PANICKED PAX WOULDN'T HELP MATTERS ANY. AS WE APCHED THE ARPT; I MADE SURE TO KEEP MY BASE LEG IN TIGHT IN ORDER TO AVOID UNDERSHOOTING THE RWY. THE LNDG WAS SMOOTH; AND I EXITED THE RWY ONTO A TXWY WITH SNOW AND ICE ON IT. THE OUTSIDE AIR TEMP WAS 4 DEGS F. THE ENG WAS STILL RUNNING; SO I SLOWLY TAXIED TO THE RAMP. I GOT OUT OF THE PLANE; SLIPPED ON THE ICE; AND FELL DOWN. AS I WAS LAYING THERE; I SAW A STEADY STREAM OF OIL FLOWING OUT FROM UNDER THE COWLING. SO WHAT WENT WRONG? WE STILL DON'T KNOW; BECAUSE IT HAS BEEN 6 DAYS AND WE HAVEN'T BEEN ABLE TO GET ANYONE TO LOOK AT THE PLANE YET. ALL SIGNS POINT TO THE TURBOCHARGER. THE ENG NEVER QUIT ENTIRELY; BECAUSE WE COULD STILL TAXI WHEN ON THE GND AT 7000 FT. A TURBOCHARGER FAILURE AT 16000 FT WOULD DEFINITELY CAUSE A SIGNIFICANT LOSS OF PERFORMANCE. WE STILL DON'T KNOW IF THE OIL WAS DRAINING FROM THE TURBOCHARGER; ITS HOSES; OR THE ENG. ONE WITNESS AT THE ARPT SAYS THAT HE THINKS HE SAW FIRE COMING FROM UNDER THE COWLING AS WE WERE TAXIING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE ENG LOSS OF PWR AND ENG OIL WAS THE TURBOCHARGER WHICH EXPERIENCED A CRACKED CASE OR HOUSING. THE RPTR SAID THE AIRPLANE AND ENG WAS ALWAYS MAINTAINED IN PERFECT SHAPE AND WAS ONLY 20 HRS OUT OF THE ANNUAL INSPECTION AND THE TURBOCHARGER FAILURE WAS A SHOCK. THE RPTR SAID THE INSTALLATION OF THE GLOBAL POSITIONING SYS WAS A LIFESAVER AS IT PINPOINTED THE DIVERSION ARPT. THE RPTR STATED THE EXTRA TRAINING IN EMER PROCS WAS A GREAT HELP AND THE EXPERIENCE OF LOSING AN ENG AT NIGHT OVER MOUNTAINS WAS A LESSON TO NEVER LET IT HAPPEN AGAIN.