On May 12, 1996, approximately 1700 hours Pacific daylight time, a homebuilt Crescenzi Kitfox , N2094J, being flown by a commercial pilot, sustained substantial damage during a collision with terrain while reportedly on base leg to a private airstrip approximately nine nautical miles west of Terrebonne, Oregon. The pilot sustained serious back injuries. Visual meteorological conditions existed at the time and no flight plan had been filed. The flight, which was personal, was to have been operated under 14CFR91, and, according to the pilot's statement to the Board, originated from the Redmond Municipal Airport, Redmond, Oregon, approximately 30 minutes prior to the accident. On site examination of the crash site by an FAA inspector revealed a total ground track distribution of 12 feet with extensive damage to the underside of the aircraft's fuselage. The pilot reported to the inspector that he originated from a private airstrip at his residence approximately two nautical miles north of the accident site and was trying to climb out of a downdraft when the aircraft impacted the ground. In his written statement to the Board, the pilot reported that he was "on an extended l(ef)t base for my airstrip maintaining a shallow descent" and that "suddenly a huge mass of air is pushing me down." He reported that the aircraft "impacted the ground in a level attitude" and that it "happened very quickly." The nearest charted airstrip is located 2 nautical miles west of the accident based upon the pilot's submitted accident site location in his report to the Board (refer to CHARTS I and II). The reporting officer who wrote the Deschutes County Sheriff's Report (Case number 96-7383) stated in part that upon his arrival at the accident site the wind was "gusting up to approximately 7 mph" and that "even after being told he had two compression fractures in his spine, (the pilot) was still attempting to get up and walk away from the hospital. He would not lie down on the gurney as requested by the medical staff. He continually was sitting upright and several times would attempt to walk away. When we asked Heller (the pilot) if he would submit to some field sobriety tests, it was then he decided that he was not able to sit up and had to lay down on the stretcher due to his injuries. Heller refused to submit to any form of FST's (field sobriety tests), even those that did not require that he stand or walk. Heller also refused to submit to a blood or urine sample to test for the presence of alcohol or controlled substances" (refer to attached report). Three paramedics attended to the pilot on the accident site. All three reported detecting the odor of alcohol on the pilot's breath (refer to attached statements).