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The LearAvia Lear Fan 2100 turboprop was made of lightweight composite materials instead of the more usual aluminum alloy. It also featured a pusher design, in which two aircraft engines powered a single constant-speed three- or four-bladed propeller at the rear of the aircraft. A purpose-built gearbox allowed either one or both Pratt & Whitney of Canada PT6B free-shaft turbines to supply power via two driveshafts. The intent of the design was to provide the safety of multi-engine reliability, combined with single-engine handling in case of failure of one of the engines. Another interesting feature was the Y-shaped empennage at the tail. Two stabilizers pointed upward at an angle, similar to those on the V-tail Beechcraft Bonanza, and a stubby vertical stabilizer pointed downward. However, unlike the V-tail on the Bonanza, there was no pitch/yaw control mixing on the Lear Fan. The downward-pointing rudder also served to protect the propeller from ground strikes during takeoff and landing. The aircraft had a pressurized cabin and was designed for a service ceiling of 41,000 ft (12 500 m). It could accommodate two pilots and seven passengers, or one pilot and eight passengers. ==Design and development== Many years in development, it was not completed before inventor Bill Lear died in 1978. He begged his wife, Moya Lear, to finish it. 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.〔McCellan 2006.〕〔 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,〔 (officially recorded by sympathetic British government officials as "December 32, 1980" in order to secure funding that expired at the end of that year〔(Lear Fan 2100 (Futura) ). ''The Museum of Flight''. 2009. Retrieved 27 November 2009.〕). The Lear Fan, however, did not enter production. The US Federal Aviation Administration was not concerned about its use of innovative materials but did not 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. Gearbox wear was found to be unacceptably high. Development was abandoned in 1985.〔(Lear Fan Collapses ). ''Flight International'' 8 June 1985, p.30.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「LearAvia Lear Fan」の詳細全文を読む スポンサード リンク
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