On June 18, 1999, at 1900 hours mountain standard time, a homebuilt Devor MXL II, N98MD impacted terrain while maneuvering in an open field in Tonopah, Arizona, approximately 10 miles west of Buckeye, Arizona. The experimental airplane, owned and operated by the pilot, sustained substantial damage. The uncertificated pilot was seriously injured. The local area personal flight was conducted under the provisions of 14 CFR Part 91 and originated on the pilot's property in Tonopah at an unspecified time. Visual meteorological conditions prevailed and no flight plan was filed. Another pilot witnessed the accident. He reported that the pilot took off to the south. The aircraft began a gradual climb to approximately 50 feet agl and turned east. The witness stated that the aircraft began losing altitude about halfway through the turn. The witness stated that it did not sound as if the throttle was set at full power and opined that the pilot did not apply sufficient power to complete the turn. The aircraft impacted the ground in a nose down attitude while traveling approximately 30 miles per hour, according to the witness' estimation. The witness stated that at no time did he hear the engine cut out or stop and there did not appear to be a malfunction with the flight controls. He further reported that the pilot had flown solo approximately four times prior to the accident. At the time of writing this report, the pilot was hospitalized and in a coma. No one else was able to provide information or further details. According to the Federal Aviation Administration (FAA) airman certification record files, the pilot has never held an FAA pilot's certificate.