On October 29, 1997, at 1415 hours Pacific standard time, a Striplin Lone Ranger Silver Cloud, N4478Y, nosed over while making a forced landing approximately 1 mile from the end of runway 22 at the Agua Dulce, California, airport. The forced landing was precipitated by a loss of power. The aircraft was destroyed and the pilot received minor injuries. The experimental homebuilt aircraft was owned and operated by its private pilot/builder and was on a local area personal flight. Visual meteorological conditions prevailed and no flight plan was filed. In his written report to the Safety Board, the pilot reported that he had just departed the Agua Dulce uncontrolled airport and was en route to the private landing strip at his home in Leona Valley, California. He reported that at 500 feet above ground level (agl) the engine began to shake violently. The pilot indicated that he throttled the engine back which reduced the vibration; however, when he applied power again, the engine continued its violent vibration. The pilot reported that he did not believe that he had sufficient altitude to return to the Agua Dulce airport and elected to make a forced landing in a vacant field. He reported that he "landed hard and bounced coming to rest upside down." An aerobureau flight crew from Los Angeles County Sheriff's Department responded to the accident site and interviewed the pilot. He reported to the deputies that his engine began to "die" after takeoff, and he headed toward a field just south of the crash site. He stated that he was too high and fast to land in the field and he turned around to land downwind in the accident site field. During the interview, the pilot said he was 30 feet agl when the airplane stalled, fell to the ground, and nosed over. Witnesses to the accident reported that around 1415 they heard an aircraft flying over their home making strange noises. They believed that the noises were coming from the engine. The witnesses observed the aircraft circle at a low altitude and over fly their home. They saw the aircraft turn 180 degrees and head for a field that was directly in front of their home. The witnesses reported that at the last moment the pilot appeared to turn the aircraft abruptly to land and the right main landing gear struck the ground followed by the nose and the left main. The nose gear collapsed and the aircraft came forward and flipped over onto its back. An Federal Aviation Administration (FAA) inspector from the Van Nuys, California, Flight Standards District Office conducted an on-site investigation of the accident. He reported that the aircraft landed on a soft dirt field. According to the inspector, on rollout, the aircraft's nose wheel sank into the soft dirt allowing the aircraft to nose over onto its back, which separated the empennage from the aircraft fuselage. Due to the damage of the aircraft, the FAA inspector could not verify control continuity to the elevator and rudders, nor could he confirm the engine problem that the pilot and witnesses identified. The pilot/owner reported that a postaccident examination of the aircraft engine revealed that the vibration was caused by the "belt reduction drive unit - [because] the belt rolled forward out of its grove [sic]." He further reported that the belt reduction drive unit was a home fabricated unit.