On April 10, 1999, at 1650 hours Pacific daylight time, a Bellanca 7KCAB, N88212, was destroyed during a collision with the ground during practice aerobatic maneuvers near North Las Vegas, Nevada. The private pilot, the sole occupant, parachuted to safety and sustained minor injuries. The aircraft was operated by North Las Vegas Flying Club and was rented by the pilot for the local area personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the flight, which was conducted under the provisions of 14 CFR Part 91 of the Federal Aviation Regulations. The flight originated from the North Las Vegas airport at 1630. In the pilot's written statement he said he climbed to 6,000 feet msl and entered a left upright spin. After two turns, he initiated a forward movement of the stick to recover and found that the stick was jammed in the full aft position. He looked in the rear seat area and discovered that the rear seat back frame had fallen forward, looped over the stick, and was holding it in place. Following unsuccessful attempts to reach the seat back and recover from the spin, the pilot abandoned the airplane and parachuted to the ground. According to the pilot, the aircraft continued in the spin until ground impact. Additionally, the pilot said that a safety cable is supposed to hold the rear seat back frame upright during maneuvers to prevent the back from interfering with the rear control stick. The pilot reported that during the preflight inspection he observed that the safety cable was present. After the accident, a flight instructor told the pilot that the cable had been reportedly disconnected from its attach point by maintenance personnel to facilitate access to the aircraft battery and the ELT area behind the rear seat.