Accident Overview
A witness observed the airplane entering downwind with smoke trailing. The pilot communicated to UNICOM that the engine had quit and that he needed to get down. The witness then observed the airplane making a tighter-than-normal base-to-final turn. The airplane nosed down and spun to the ground.
Post-Accident Examination
Examination of the airframe revealed no mechanical problems. The powerplant was removed to a testing facility. Teardown of the engine, accessories, and carburetor revealed no malfunctions. The carburetor, prior to teardown, was installed on a similar engine and was satisfactorily run in a test cell.
Terrain
The accident occurred in flat terrain.