NTSB Factual Report

The pilot reported that he performed a takeoff and landed to a full stop. During his next takeoff he stated that he noticed that his airplane was not climbing and his RPM's were low. He clipped a small tree and elected to land in a nearby field. He said, "I now realize I never turned off carb heat before the second takeoff."

NTSB Probable Cause

The pilot not turning off the carburetor heat prior to takeoff resulting in the engine's reduced performance, and his failure to remain clear of the tree during takeoff.