failed, but the VLJ concept became popular again 30 years later. In 1976, Lear sold an option to his LearStar concept to Canadair, a Montreal aircraft manufacturer. The idea was to design an executive aircraft which would bring together a supercritical wing with Lycoming's new turbofan engine. However, the concept was only a very rough outline, prepared by a consultant. Although Canadair took up its option, Lear eventually realized that the Canadians had simply been interested in using his reputation and skills at promotion to penetrate the market. Canadair's design had little relation to Lear's concept, and Lear had no role in its development. Nevertheless, the Canadair Challenger business jet was to have a long career, with several variants. Bombardier Aerospace, by that time the parent company of Canadair, acquired Lear Jet in 1990. One of Lear's most innovative projects was his last — a revolutionary aircraft called the LearAvia Lear Fan 2100, a seven-passenger aircraft whose single pusher propeller was powered by two turbine engines. The fuselage of this aircraft was made of lightweight composite materials, instead of the more typical aluminum alloys. The Lear Fan was ultimately never completed; at the time of his death Lear asked his wife, Moya, to finish it. With the help of investors she attempted to do so, but the aircraft failed to obtain FAA certification and so was never put into production. Other notable inventions Lear developed the 8-track tape music cartridge in 1964. Lear's invention was an improvement on the four track Muntz Stereo-Pak tape cartridge, marketed by Earl "Madman" Muntz in California in 1962, itself a version of a 3-track system, Fidelipac. The 8-track was a commercial success that provided good audio quality and was easily adapted to vehicle and home use. The Lear Jet Stereo 8 Division offered home, auto, and portable versions. A popular theory is that Learjets also included an 8-track players. In 1965, a partnership between Ford, RCA, and Lear offered the first pre-recorded 8-track music cartridges. RCA released the first Stereo 8 Tape Cartridges in September 1965, issuing 175 titles. In 1968, Lear started work on a closed circuit steam turbine to power cars and buses. He built a transit bus, and converted a Chevrolet Monte Carlo sedan to use this turbine system. It used a proprietary working fluid dubbed Learium, possibly a chlorofluorocarbon similar to DuPont Freon. A prototype racing car was built to