On April 22, 1997, at 2049 central daylight time, an unregistered, experimental homebuilt Rans S-12 Ariale airplane, owned by the pilot, was destroyed following an in-flight loss of control and subsequent impact with terrain near Purcell, Oklahoma. The student pilot and his passenger were seriously injured. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 personal flight, and a flight plan was not filed. The airplane was in the traffic pattern at David Jay Perry Airport practicing landings and takeoffs at the time of the accident. In the pilot's written statement, he indicated that the passenger, "had taken off to the north, turned crosswind, to the west, and stalled the plane. I attempted to assist and regain airspeed but we were too low and crashed." The pilot reported to the police that the passenger was operating the airplane when it, "lost airspeed and began falling." The pilot took control of the airplane from the passenger and attempted to recover by pointing the airplane downward to increase the airspeed. During the level-out, the airplane struck the ground. According to a witness, the airplane had made a "touch and go on runway 35 at David Jay Perry Airport. It turned crosswind at approximately 100 feet. While turning downwind at the same altitude and in approximately a 45 degree bank, the aircraft apparently stalled." He further stated, "the aircraft rolled to wings level and the nose was in an almost level attitude, approximately 20 degrees nose low at about 50 feet, when a second stall occurred." He lost sight of the airplane just before it impacted the ground. According to the FAA inspector, the pilot believed that the airplane was in the ultralight category and therefore, did not need to be registered. FAR Part 103.1 states that an ultralight vehicle is a vehicle that: (a) Is used or intended to be used for manned operation in the air by a single occupant; (b) Is used or intended to be used for recreation or sport purposes only; (c) Does not have any U.S. or foreign airworthiness certificate; and (d) If unpowered, weighs less than 155 pounds; or (e) If powered: (1) Weighs less than 254 pounds empty weight, excluding floats and safety devices which are intended for deployment in a potentially catastrophic situation; (2) Has a fuel capacity not exceeding 5 US gallons; (3) Is not capable of more than 55 knots calibrated airspeed at full power in level flight; and (4) Has a power-off stall speed which does not exceed 24 knots calibrated airspeed. The accident airplane was a two occupant vehicle, it had an empty weight of 475 pounds, a fuel capacity of 9 U.S. gallons, a cruise speed of 75 mph, and its power off stall speed was 35 mph. An exemption to Part 103, Exemption No. 3784 issued to the Experimental Aircraft Association, is available if the airplane is a two occupant vehicle, has a maximum fuel capacity of 10 gallons, a maximum power off stall speed of 35 knots, a maximum air speed of 75 knots, and a maximum gross weight of 496 pounds. An airplane may receive the exemption when it is to be operated for instructional purposes only, and the pilot in command must be a certified ultralight flight instructor. In addition, there must be a placard permanently displayed on the aircraft that states, "To be used for instruction only." There was not an exemption filed for the accident airplane. The pilot in command was a student pilot, and he did not possess a medical certificate. The passenger in the aircraft did not have an FAA pilot certificate or medical certificate.