On October 22, 2000, about 1700 Eastern Daylight Time, an unregistered homebuilt airplane, a Weedhopper, was substantially damaged during a forced landing near Fordsville, Kentucky. The uncertificated pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91. According to a Federal Aviation Administration (FAA) inspector, the airplane departed from a private grass strip located at the pilot's home. The pilot stated that he liked to fly "in and out of the valleys" that surrounded his home. After departing, the pilot flew east, down a valley, at an engine power setting of about 5,600-rpm. As the pilot proceeded to fly over a friend's house, the engine power decreased to 2,700 rpm. The airspeed began to decrease, and the pilot lowered the nose after he "realized that I stalled it." As the airplane descended, about 50-60 feet above the ground, the engine power increased back to about 5,000 rpm. The airplane began to climb, but the engine power decreased again. The pilot lowered the nose and performed a forced landing to a road. As the airplane approached the road in a "sideslip," the pilot noticed an oncoming car and turned to the right to avoid it. The airplane struck a raised bank, rotated 180 degrees, and came to rest upright. A witness stated to an FAA inspector that he heard the airplane and "it did not sound good, kind of cutting in and out and missing." The witness then observed the airplane descend from the sky. At that time the "engine picked up speed and the [pilot] climbed up a little and then the airplane began to cut out again." The pilot had previously flown the airplane the night before the accident, and did not notice any problems with the engine or airframe. The pilot also fueled the airplane with about 3-4 gallons of fuel the day of the accident. Examination of the wreckage by the FAA inspector revealed that the airplane had two fuel tanks mounted on the airframe. One tank was ruptured and the other contained about 3 gallons of fuel. Examination of the engine revealed valve train continuity and compression confirmed at all cylinders. Battery power was applied to the airplane and spark was observed to all four sparkplugs. The fuel screen was absent of debris. The carburetor bowl and fuel lines contained fuel. When asked if the engine ever lost total power, the pilot replied that it quit just prior to the impact with the ground. No maintenance records were recovered. The airplane was equipped with a 2 cycle Rotax 503 engine. The manufacturer's operating manual stated: "Danger!: This engine, by its design, is subject to sudden stoppage! Engine stoppage can result in crash landings. Such crash landings can lead to serious bodily injury or death. Never fly the aircraft equipped with this engine at locations, airspeeds, altitudes, or other circumstances from which a successful no-power landing cannot be made, after sudden engine stoppage." "Warning!: Although these engine types have undergone considerable durability testing, this engine is not a certified aircraft engine. It has not received any individual safety or durability testing and conforms to no aircraft standards. It is for use in experimental and ultralight uncertified aircraft and vehicles only, in which an engine failure will not compromise safety...."