Mitsubishi Motors regarding their MU-2. An agreement between the companies was reached in mid-1964: the MU2 would be fabricated in Japan but assembled by Mooney in the United States. The existing Kerrville facility and workforce was insufficient, so Mooney purchased near the airport in San Angelo, Texas ( to the northeast of Kerrville), set up an assembly line in an existing hangar, and built new support facilities. The MU2 sold slowly. This was partly because the same sales force that was selling the M20 line was also trying to sell the much more expensive MU2. It cost about US$400,000, and marketing and selling such an airplane was different than selling a small four-seater. The company's management was also over-stretched. In 1967, Mooney acquired production rights to the Aircoupe from Alon Aircraft Company. Owners John Allen and Lee Higdon, who had left Beech Aircraft to start their own company, took managerial positions at Mooney. Production began in 1968 with a total of 38 units. That year Allen and Higdon both left Mooney, Allen returning to Beech to assist with the Beechcraft Duke. In 1969 the tail of the plane was updated and it became the M10 Cadet, but only 9 units were sold that year. 50 were built in 1970 before the model was terminated, marking the end of the Aircoupe. Despite strong sales of the M20, Mooney was short of cash. The development of the M22 Mustang had cost more than expected, and was ultimately unsuccessful. The collaboration with Mitsubishi had come with substantial financial assistance but proved too much for the company to handle. It went into chapter 7 bankruptcy in early 1969; American Electronics Laboratories quickly acquired Mooney in March of that year and invested US$600,000 to keep it operating. Sales that year were less than half of the previous year's figures, although a new model, the M20E Chapparal, was released with electrically-operated flaps and landing gear. AEL was unable to turn the company around and sold Mooney to Butler Aviation International in December 1969. AEL owned Mooney for just over 9 months and lost nearly a million dollars during that time. Butler Aviation also acquired the troubled Aerostar company and combined it with Mooney in an attempt to save both. The Mooney name was dropped in 1970, as was the M20 designation; the planes were called Aerostars. 1970s Butler Aviation closed the Mooney plant in early 1971