Piper PA18 accident near Newman Lake, Washington, January 1, 2016

The NTSB's narrative final · quoted from the NTSB record

The private pilot performed two low passes to the snow-covered airstrip, during which the airplane's flaps were extended and carburetor heat was on. After completing the second low pass, the pilot retracted the wing flaps, turned off the carburetor heat, and applied engine power to go around. The engine subsequently experienced roughness and a partial loss of power. The pilot turned the carburetor heat back on, but engine power was not restored. Unable to maintain altitude, the pilot elected to land on the airstrip he had been overflying. During the landing, the airplane nosed over due to the depth of the accumulated snow, which resulted in substantial damage. A postaccident examination of the carburetor revealed full control continuity to the carburetor heat/air box, the butterfly valve reached full travel, and full control continuity from the cockpit throttle and mixture controls to the carburetor was confirmed. An engine run revealed no anomalies. Although the airplane was operating in conditions that were conducive to a serious risk of carburetor ice accumulation at a descent power setting, the engine was operating at a takeoff/go-around power setting at the time of the loss of power, and it is unlikely that carburetor ice would have accumulated during this time. Therefore, the reason for the partial loss of engine power could not be determined.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.