Incident Summary
The pilot reported operating the airplane approximately 100 feet above the ground when initiating a downwind turn. During the turn, the airplane encountered a downdraft that pushed it closer to the ground. The pilot immediately applied full power, but the engine did not appear to produce full power, and the airplane continued to descend.
Landing and Damage
Due to the airplane's low altitude, the pilot stated he was unable to select a better landing area than a nearby frozen river. The airplane landed hard on the ice, resulting in damage to the wings, fuselage, and landing gear.
Pilot's Belief Regarding Engine Power
The pilot indicated that he believed the engine did not produce full power due to carburetor ice, which had accumulated since he had been operating the engine at a reduced power setting without carburetor heat.