Narrative:

Departing hpn at XA00 with flight following to gai. Class B clearance through new york class B airspace. All appeared normal climbing through 6500 ft to 8500 ft. Loud 'thunk' in left engine followed by yaw to left. Oil began pouring over left cowl and smoke appeared aft of engine. Feathered propeller and declared emergency with ZNY (approach). Hpn still in view and appeared to be nearest suitable facility. Elected to return to hpn and did so without incident. Note that engines were both completely overhauled 34 months ago and only have approximately 300 hours on them. There is a 4 inch square hole in top of left engine with jagged metal around it. Several small 3/4 inch square metal pieces sitting between cylinders. I'm glad I'm well trained with lots of recurrency experience. This is one situation where a second engine was essential. If this had been a single engine, landing would have been difficult with windscreen covered by oil. Callback conversation with reporter revealed the following information: reporter said during the callback that the engine had been replaced by the overhaul company that has a reputation of being very reliable. The cowling was damaged but a piston was missing and various other parts were found in the bottom of the cowling. The overhaul company concluded that a piston pin had failed. The reporter could not say enough about the benefit of regular recurrent training to be prepared for an incident such as this.

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Original NASA ASRS Text

Title: A BEECHCRAFT-55 ENG HAS CATASTROPHIC FAILURE. PLT ELECTS TO RETURN TO DEP ARPT.

Narrative: DEPARTING HPN AT XA00 WITH FLT FOLLOWING TO GAI. CLASS B CLRNC THROUGH NEW YORK CLASS B AIRSPACE. ALL APPEARED NORMAL CLBING THROUGH 6500 FT TO 8500 FT. LOUD 'THUNK' IN L ENG FOLLOWED BY YAW TO L. OIL BEGAN POURING OVER L COWL AND SMOKE APPEARED AFT OF ENG. FEATHERED PROP AND DECLARED EMER WITH ZNY (APCH). HPN STILL IN VIEW AND APPEARED TO BE NEAREST SUITABLE FACILITY. ELECTED TO RETURN TO HPN AND DID SO WITHOUT INCIDENT. NOTE THAT ENGS WERE BOTH COMPLETELY OVERHAULED 34 MONTHS AGO AND ONLY HAVE APPROX 300 HRS ON THEM. THERE IS A 4 INCH SQUARE HOLE IN TOP OF L ENG WITH JAGGED METAL AROUND IT. SEVERAL SMALL 3/4 INCH SQUARE METAL PIECES SITTING BTWN CYLINDERS. I'M GLAD I'M WELL TRAINED WITH LOTS OF RECURRENCY EXPERIENCE. THIS IS ONE SIT WHERE A SECOND ENG WAS ESSENTIAL. IF THIS HAD BEEN A SINGLE ENG, LNDG WOULD HAVE BEEN DIFFICULT WITH WINDSCREEN COVERED BY OIL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID DURING THE CALLBACK THAT THE ENG HAD BEEN REPLACED BY THE OVERHAUL COMPANY THAT HAS A REPUTATION OF BEING VERY RELIABLE. THE COWLING WAS DAMAGED BUT A PISTON WAS MISSING AND VARIOUS OTHER PARTS WERE FOUND IN THE BOTTOM OF THE COWLING. THE OVERHAUL COMPANY CONCLUDED THAT A PISTON PIN HAD FAILED. THE RPTR COULD NOT SAY ENOUGH ABOUT THE BENEFIT OF REGULAR RECURRENT TRAINING TO BE PREPARED FOR AN INCIDENT SUCH AS THIS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.