A C421C IN CLB AT 10000 FT DECLARED AN EMER AND DIVERTED DUE TO THE R ENG FAILURE CAUSED BY A THROWN CONNECTING ROD.

Narrative

ACFT (CE421C XYZ) DEPARTED APA AT APPROX XA45. IFR FLT PLAN TO RIL. CLRNC FROM ATC; RESUME OWN NAV TO INTERCEPT (ROCKIES 3 DEP; DBL TRANSITION) CLB AND MAINTAIN FL200. AT APPROX 15 NM W OF APA; CLBING THROUGH 10000 FT MSL; THE R ENG MADE A 'POP' SOUND AND SMOKE APPEARED THROUGH VENTS IN TOP OF COWLING. NO IMMEDIATE INDICATION OF OIL PRESSURE LOSS OR HIGH TEMP ON ENG. PLT DECIDED TO FEATHER ENG AND SECURE DUE TO IMPENDING FAILURE. AT APPROX XB00; PLT ADVISED ATC OF R ENG FAILURE/FEATHER AND DECLARED AN EMER. PLT ADVISED ATC HE WANTED TO RETURN TO APA. AT APPROX XB10; ACFT LANDED ON RWY 17L AND TAXIED OFF RWY. NO INJURIES OR SUBSTANTIAL DAMAGE OCCURRED TO AIRFRAME. 5 PAX ON BOARD; 1 PLT CREW. PRELIMINARY INSPECTION OF ENG INDICATES CATASTROPHIC INTERNAL ENG FAILURE. HOLE IN TOP OF ENG CASE; R MAGNETO SHEARED FROM MOUNT AND INTERCOOLER DENTED FROM EJECTING PARTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ENG WAS A CONTINENTAL GTSIO-520-N WITH ONLY 500 HRS AND THE PRELIMINARY RPT WAS A THROWN CONNECTING ROD. THE RPTR SAID THE ENG WAS SENT TO THE MANUFACTURER FOR TEARDOWN AND THE FINAL RPT WAS NOT COMPLETE.