A PIREP PA32-300 IN CRUISE AT 11000 FT DECLARED AN EMER AND DIVERTED DUE TO LOSS OF PWR CAUSED BY EXHAUST GAS OBSTRUCTIONS.

Narrative

2 1/2 HRS INTO ROUTINE IFR FLT IN VFR CONDITIONS ABOVE BROKEN/SCATTERED CLOUD LAYER (TOPS 4000-8000 FT) AT 11000 FT MSL. FIRST NOTICED POOR ALT HOLD OF AUTOPLT AND SHUT IT OFF; THEN FOUND I COULD NOT HOLD ALT MANUALLY; EVEN AT FULL PWR AND AT HIGH ANGLE OF ATTACK. AIRSPD WENT DOWN TO 80 KTS. ATC NOTIFIED AND REQUESTED 9000 FT. OUTSIDE AIR TEMP WAS QUITE COLD (-20 DEGS C); TRIED ALTERNATE ENG AIR WITH NO EFFECT; TRIED LEANING; RICHENING; MAGNETOS WITH NO EFFECT. FUEL FLOW NORMAL AND GEM ENG MONITOR SHOWED ALL CYLINDERS SIMILAR; AND RESPONDED NORMALLY TO LEANING. OIL PRESSURE MAY HAVE DROPPED; BUT OIL TEMP DID NOT GO UP SIGNIFICANTLY ATTITUDE AND NAV INSTS WERE NORMAL. DECLARED EMER AND REQUESTED VECTORS TO NEAREST ARPT SCRANTON-WILKESBARRE. IN THE DSCNT THROUGH THE CLOUDS; TRACE ICE (RIME) ACCUMULATED ON THE PLANE. WX RPT INFLT APPROX 30 MINS EARLIER HAD NO PIREPS OF ICING. LANDED WITHOUT ANY DAMAGE OR INJURIES; AND NO ICE WAS ON THE PLANE ON THE GND. OIL QTY REMAINING WAS LOW; AND BOTTOM OF PLANE OIL SOAKED. BREATHER FROZE UP?? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE GRADUAL LOSS OF PWR WAS CAUSED BY OBSTRUCTIONS IN THE 3 EXHAUST MUFFLERS. THE RPTR SAID EACH MUFFLER IS FED BY 2 CYLINDERS SO THE EXHAUST GAS TEMP WHILE HIGH WAS THE SAME IN EACH CYLINDER. THE RPTR SAID A BAFFLE BROKE LOOSE IN EACH MUFFLER AND BLOCKED THE EXHAUST OUTLET PIPE FROM THE MUFFLER. THE RPTR SAID THE TECHNICIAN AT THE LAST ANNUAL INSPECTION RPTED SMALL SEGMENTS BEING BROKEN OFF THE INTERIOR BAFFLE OF THE MUFFLER BUT IT APPEARED AS NORMAL WEAR. THE RPTR STATED THE ENG WAS A LYCOMING 10-054OK1G5D. THE RPTR SAID ALL 3 MUFFLERS WERE REPLACED AND ENG OP WAS RESTORED TO NORMAL.