On November 1, 1996, about 1743 hours mountain standard time, a homebuilt experimental Rainey Rans S-12, N95HS, collided with the ground following an in-flight loss of control near Tucson, Arizona. The aircraft was owned and operated by the pilot and was on a local area personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was destroyed in the ground collision sequence. The certificated private pilot and the one private pilot passenger onboard sustained fatal injuries. The flight originated from Tyler Field, a private ultralight airpark in Marana, Arizona, at 1720. There were no witnesses to the accident. The aircraft was observed climbing out after takeoff toward the area of the accident site. Another ultralight pilot flying in the area observed the crashed aircraft on the desert floor and reported the event to 911. One witness stated that the ultralight flew over him and another person and, "as we were talking you hear the high pitched hum of its motor going behind us. Then it went completely silent and then we heard a bang or thud. I thought that it had just went over the hill and backfired or something." Another witness who arrived on scene stated that the ". . . engine had stopped in flight. The condition of the propeller blades were as such as the blades broke over the motor. If the engine had been running on impact, the blades would have been sheared off." In one statement made to the Federal Aviation Administration (FAA) airworthiness inspector, the individual stated that ". . . this pilot liked to fly high and he was in a hurry to get airborne before the sun set." The FAA inspector further stated in his report that "another pilot did tell me that this particular aircraft has a higher stall speed [than] most other ultra lights. Also two stoke Rotax engines can cold seize in a long climb." Both the pilot and the pilot-rated passenger had access to the flight controls. According to responding law enforcement personnel, the pilot/owner was found in the pilot's seat and the passenger occupied the normal passenger station. No definitive pathological evidence was found to make a determination of which pilot was at the controls of the aircraft at the time of impact. An FAA airworthiness inspector from the Scottsdale, Arizona, Flight Standards District Office responded to the accident site and examined the aircraft. The inspector reported that the aircraft impacted the ground in a near vertical nose down descent, and that the empennage was torsionally twisted. No broken or disturbed vegetation, or other ground scars were observed beyond the immediate area of the wreckage. The aircraft was examined with no abnormal conditions noted with the airframe control system or the engine. Following recovery of the aircraft the engine was examined by a power plant mechanic familiar with the Rotax engine. He reported that both spark plugs had no spark due to a broken wire in the ignition coil.