On April 17, 1994, at 0930 central daylight time, a homebuilt (Johnson) Avid Flyer, N312RJ, piloted by the registered owner/builder, was damaged beyond economical repair during a forced landing near New Richmond, Wisconsin. The private pilot, the sole occupant, reported no injuries. Visual meteorological conditions prevailed, no flight plan was filed. The local flight operated under 14 CFR Part 91, and originated from New Richmond, Wisconsin approximately 0928. The pilot stated: "Lifted off and stayed in ground effect to get speed up. Changed attitude to slow climb. Aircraft was climbing...Altitude unknown when engine had loss of engine power. Noticed I was descending." The pilot reported the power loss was gradual and he was unable to maintain altitude. He selected a field off the departure end of the runway and prepared for an off-airport emergency landing. The pilot stated he had to clear a row of trees before he reached the field, then had to lower the nose of the airplane to regain airspeed. He reported he felt turbulence just before the airplane touched down. The pilot indicated the left wing lifted and the right wing struck the field. He reported the landing gear collapsed when the airplane hit the ground hard, and the airplane skidded across the field. Postaccident investigation revealed no evidence of preimpact mechanical malfunction. Flight control and engine continuity were confirmed. There was fuel evident in both wing tanks, and in the fuel lines to the carburetors. The fuel appeared uncontaminated. Spark plugs appeared normal although two were broken off. The wooden propeller was shattered. The pilot stated there was no preimpact mechanical malfunction, he reported he believed the loss of engine power was due to carburetor ice. He stated there was no carburetor heat control installed on the airplane. A weather observation made at St. Paul Downtown-Holman Field (STP, located 27 NM west-southwest of the accident site) at 0845, indicated clear skies, 20 miles visibility, temperature 51, dew point 32, and winds out of the northeast at 6 knots. A chart which depicts conditions known to be favorable for the formation of carburetor ice (courtesy of Aviation Safety Bureau, Transport Canada) is appended.