On May 6, 2000, at 1100 mountain daylight time, a Lewis Spitfire/Raven, experimental amateur built airplane, N17ST, impacted the terrain while executing a downwind to base turn at the Coronado Airport, near Albuquerque, New Mexico. The airplane was owned and operated by a private individual under 14 Code of Federal Regulations Part 91. The non-certificated pilot, sole occupant, received serious injuries, and the airplane sustained substantial damage. Visual meteorological conditions prevailed for the local flight, and a flight plan was not filed. The personal flight originated approximately 10 minutes prior to the accident. One witness reported observing the aircraft flying a traffic pattern for runway 3. He observed the aircraft "make a right turn from the downwind leg to base leg when it appeared to stall." Subsequently, the aircraft "pitched nose down into a steep angle all the way to impact." The FAA inspector responding to the site examined the airplane and found structural airframe damage. The wood propeller was shattered. Flight control continuity was confirmed. Fuel was found in the carburetors. The FAA inspector reported that he did not find any evidence of mechanical discrepancies that would have prevented airframe or engine operation prior to the impact. The pilot's spouse reported that the pilot's injuries precluded his submission of data during this investigation. The Safety Board did not take possession of the aircraft.