Accident Overview
A pilot performing maneuvers at altitudes between 1,800 and 2,300 feet experienced an engine roughness. The pilot applied carburetor heat, but when the condition did not improve, he turned it off. The flight continued and the pilot descended to a lower altitude for additional maneuvers. During this phase, he noticed a loss in engine rpm and applied full throttle, at which point the engine ceased operation. A forced landing was executed, resulting in a collision with trees.
Post-Accident Examination
After the accident, the carburetor heat control was found in the off position. All engine controls were observed to operate normally. The engine was subsequently run and displayed no evidence of mechanical failure or malfunction. No pre-impact anomalies were detected in the engine system.
Environmental Conditions
The aircraft was operating in atmospheric conditions that were conducive to visible carburetor icing at cruise power and serious carburetor icing at glide power. These conditions were noted as likely having an impact on engine performance, though no direct causal link was stated in the source.