Incident Overview
A pilot experienced an unexpected loss of altitude while in cruise flight at 2,000 feet MSL. The engine, initially set to 27 inches of manifold pressure, was indicating only 19 inches. In response, the pilot maneuvered the airplane over a harvested corn field to conduct a precautionary landing.
Sequence of Events
When the pilot retarded the throttle to idle, there was no corresponding change in engine power. He then cut off fuel to the engine and initiated a left turn. During this action, the airplane gained altitude and slowed. At approximately 20 feet above the ground, while in a left bank, the engine ceased producing power. The airplane subsequently stalled and impacted the terrain.
Post-Accident Examination
Inspection of the engine revealed that the threaded end of the throttle push-pull cable had separated from the fork connector at the carburetor. This separation left the throttle open at approximately 18 inches of manifold pressure, preventing normal throttle control.
Probable Cause
The stated probable cause is the separation of the throttle cable from the fork connector, which resulted in an uncommanded throttle position and loss of engine power control.