On April 1, 1995, at 1030 eastern standard time, a Cessna 150, N3546V, lost partial engine power during a low pass over Waisley Airport in Erie, Pennsylvania, and collided with trees during the emergency descent. The pilot was not injured. The airplane was substantially damaged. Visual meteorological conditions prevailed. The local personal flight was conducted under 14 CFR Part 91. The pilot reported that during a low pass over the grass strip at Waisley Airport, the airplane's engine "...started to miss, spit, and sputter." The pilot stated that prior to the low pass he applied heat to the carburetor and left it on. The pilot said that he decided to make a precautionary landing and made a downwind pattern for the runway. The pilot reported, "Did a short downwind pattern, altitude indicated 1250 FT. agl on line up to runway. I was short of field, added a little power, 46V started to balloon, possibly from ground affect, 46V engine back fired twice, airstrip (Elev 950 FT-Runway L-2000 FT) 46V would land long, fearing collision to occupied house on west end of runway, gave 46V full throttle, turned slowly to left (to prevent stall)." The pilot stated that the airplane had "...a poor climb rate..." and would not clear obstacles around the runway. The pilot stated that he made an emergency landing off the airport and during the descent, the airplane collided with trees. Postaccident examination of the engine did not reveal any anomalies. No contaminates were found in the fuel. The engine was started and run for about five minutes with no anomalies noted. No airframe anomalies were found. The pilot stated that he thought "...there was carburetor icing present." At 0952, the Erie Weather Observation Facility recorded a temperature of 39 degrees Fahrenheit and a dew point of 21 degrees Fahrenheit. According to Icing Probability Curves, conditions which are known to be favorable to the formation of light induction system icing at glide or cruise power existed. (See attached Icing Probability Curves.)