On August 28, 2001, at approximately 1340 mountain daylight time, a Bradley Rans S-7 homebuilt airplane, N91642, was substantially damaged during a forced landing following a loss of engine power near Fruita, Colorado. The airline transport pilot, the sole occupant aboard the airplane, was not injured. A private individual was operating the airplane under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local test flight that was originating at the time of the accident. No flight plan had been filed. According to the pilot, shortly after takeoff (approximately 30 feet above the ground), the engine began to lose power. He said the airplane lost the ability to climb at about 60 feet above ground level. The pilot said there was a fence and a barn directly in his flight path; he turned the aircraft left toward an alfalfa field to make an emergency landing. The engine continued to lose power and attempts to regain engine power failed. The airplane started to lose airspeed until the onset of a stall. The pilot reduced the airplane's angle of attack so that the airplane would not stall. The airplane contacted the ground with its right wing first, then rotated until its heading was 180 degrees from its flight path, subsequently coming to rest against a fence. The airplane's engine mount, both wings, and the horizontal stabilizer were bent, and the fuselage was wrinkled. Postaccident examination of the two cylinder engine by the pilot revealed that both piston rings had failed. The owner reported that the engine had approximately 4 hours of flight operation time.