LearAvia Lear Fan 2100
The aircraft was designed by Bill Lear, but not completed before his death in 1978. It was planned for production to be carried out in Belfast, Northern Ireland, in a new factory built with money from the British Government in an effort to boost employment. After the cancellation of a planned test flight on December 31, 1980 due to technical issues, the first prototype made its maiden flight on January 1, 1981 (a date officially recorded by sympathetic British government officials as "December 32, 1980" in order to secure funding that expired at the end of that year).
The Lear Fan, however, did not enter production. Structural problems were discovered during the pressurization of the all-composite fuselage. The US Federal Aviation Administration refused to issue the prototype with an airworthiness certificate because of concerns that, despite two engines, the combining-gearbox that drove the single propeller was not adequately reliable. Development was abandoned in 1985 after only three aircraft were built.