On April 20, 1999, about 1600 eastern daylight time, a Cessna 150M, N66560, registered to Brittania Flight Center, Inc., operating as a 14 CFR Part 91 instructional flight, crashed while attempting an emergency landing, following a loss of engine power near Rockledge, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The airplane received substantial damage and the student pilot, the sole occupant, sustained minor injuries. The flight originated from Winter Park, Florida, about 1 hour before the accident. According to eyewitnesses, the airplane engine's sound lessened and stopped completely. The engine sounded quiet as the pilot appeared to look for a landing area. The airplane crashed in a residential area. According to the student pilot, he was flying his solo cross-country flight from Winter Haven's Gilbert Airport to Cocoa's Merritt Island Airport. About 10 miles west of Merritt Island, he radioed Merritt unicom for traffic advisories and to relay his intentions. He stated he was in cruise flight at 1,800 feet msl, 2,300 (engine rpm), and mixture leaned "appropriately". Immediately after his radio transmission, he noticed an uncommanded reduction in engine rpm, and a loss of power. He got no response to increasing his throttle setting, so he began emergency procedures for an engine failure, except that he does not remember using carburetor heat. His two options for a forced landing site were a road or a field. The road contained too much traffic and the field was ringed by high tension wires and contained playing children. According to an FAA inspector, the airplane struck a tree and came to rest in the front yard of a private residence on its side, right wing up. The FAA inspector could not estimate the amount of fuel aboard, but stated the left tank contained enough fuel that the fuel line and vent line had to be plugged to prevent spillage when the wing was removed. The gascolator and carburetor contained fuel. Fire rescue personnel responding to the accident mentioned they sandbagged the storm sewer drain to prevent a "significant amount" of fuel from entering the storm drain. The carburetor squirted fuel through the venturi when the throttle linkage was manually pumped. The airplane was equipped with properly vented fuel tank caps. Testing of fuel for water content was negative. Disassembly examination of the engine and its components revealed no mechanical failures or malfunctions. Aircraft records revealed an appropriate supplemental type certificate (STC), for automotive fuel use. The spark plugs and combustion chambers exhibited abnormally dark coloration, and it is the FAA inspector's opinion that the coloration is the result of, "..a fuel rich mixture which would be consistent with carburetor icing". Reference to carburetor icing charts reveals that an ambient temperature of 24 degrees C and a dew point of 9 degrees C, as reported by Titusville (TIX) and Melbourne (MLB) for the time period of the accident, would put the flight's probability within the region labeled, "visible icing at glide and cruise power." A copy of the chart is included in this report under, "Other Pertinent Forms and Reports".