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The Hughes D-2 was an American fighter and bomber project begun by Howard Hughes as a private venture. It never proceeded past the flight testing phase but was the predecessor of the Hughes XF-11. The only D-2 was completed in 1942–1943.〔Winchester 2005, p. 114.〕 ==Design and development== In 1937, Howard Hughes began the design of an advanced twin-engine, twin-boom interceptor in the hope of interesting the United States Army Air Corps (USAAC) in its procurement. The design was somewhat similar to the Lockheed P-38 Lightning that won the 1939 USAAC design competition. Hughes later testified to the U.S. Senate that Lockheed had stolen his design, although this was refuted by many others. Rather than abandon the project, as he later recounted in the 1947 Senate investigation, he "decided to design and build from the ground up, and with my own money, an entirely new airplane which would be so sensational in its performance that the Army would have to accept it." 〔Barton 1982, pp. 14-15.〕 Most of the airframe of the "DX-2" was made of Duramold plywood, a plastic-bonded plywood molded under heat and high pressure. This material was advantageous from an aerodynamic and a metals-shortage standpoint, but was difficult to work, and rejected as insufficiently robust by the USAAC. Initially, the aircraft was to have been equipped with a tail wheel but the landing gear was later changed to a tricycle configuration with the main undercarriage units retracting rearwards into the twin booms and the nosewheel retracting rearwards and rotating 90 degrees to lie flat in the small central fuselage. The powerplants were to have been a pair of experimental Wright Tornado 42-cylinder, liquid-cooled radial engines. The D-2 was built in secret at the Hughes Culver City, California factory with longtime associate, Glenn Odekirk, providing engineering inputs.〔Parker, Dana T. ''Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II,'' p. 50, Cypress, CA, 2013. ISBN 978-0-9897906-0-4.〕 The secrecy further alienated USAAC officers, especially when Hughes denied Materiel Command access to the plant. The USAAC had requested information about the project's progress, but did not enter into a formal contract until 1944. Final assembly and flight testing occurred at the Hughes Harper Dry Lake facility in the Mojave Desert. The finished D-2 looked like a scaled-up P-38 Lightning but, on paper, promised better performance; the Air Corps repeatedly compared it to the Lockheed XP-58 Chain Lightning. Difficulties encountered in obtaining the Wright Tornado engines led to the substitution of proven Pratt & Whitney R-2800s. Numerous designations were given to the project, including D-2, DX-2, DX-2A, D-3, D-5, XA-37 and XP-73. The names reflected difficulties in development, shifting mission emphasis, and the USAAC's uncertainty over how to use the aircraft. In June 1942, a USAAF memorandum stated: "Hughes Model DX-2A. Has been submitted as a convoy protector, convoy destroyer, pursuit airplane, fighter, and light bombardment type. Its longest life has been as a convoy protector, but the latest specification which will be used in the negotiations calls it a fighter. If the present airplane is completed as a military weapon, it will have armament substantially as on the XP-58. Its sole claim to being a bomber is the fact that it is equipped with bomb bay doors. Since it is to be purchased in its commercial form ... it is considered advisable to call it the XP-73 for the sake of administering the contract."〔Hansen 2012, p. 298.〕 The XP-73 was thus a temporary designation applied to the D-2 after the Material Command at Wright Field obtained approval to purchase "one Hughes DX-2 airplane in present commercial form as a prototype ..."〔Case History of Hughes D-2, D-5, F-11 Project, Compiled by Historical Section Intelligence, Air Material Command, Wright Field, August 1946.〕 Within three days, the D-2 had been redesignated as the XA-37 for purposes of administering a contract. However, Materiel Command engineers vehemently opposed the aircraft, partly because it was built of wood instead of aluminum, and in part because they believed Mr. Hughes had not the managerial and industrial capability to actually produce the aircraft. Neither of the above USAAF designations thus applied to any actual airplane; in the end, only two XF-11 prototypes and a mock-up were delivered. Because of Mr. Hughes's high political and public profile, the program was highly controversial. In July 1942, President Franklin D. Roosevelt's requested information and progress from USAAF chief General Henry "Hap" Arnold about the aircraft. Again in August–September 1943, the president and White House staff discussed Hughes's progress with Arnold, who then gave the order to purchase 100 F-11 derivatives. 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「Hughes D-2」の詳細全文を読む スポンサード リンク
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