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The Boeing 314 Clipper was a long-range flying boat produced by the Boeing Airplane Company between 1938 and 1941. One of the largest aircraft of the time, it used the massive wing of Boeing’s earlier XB-15 bomber prototype to achieve the range necessary for flights across the Atlantic and Pacific Oceans. Twelve Clippers were built; nine were brought into service for Pan Am and later transferred to the U.S. military. The remaining three were sold to British Overseas Airways Corporation (BOAC) by Pan Am and delivered in early 1941. (BOAC's 3 Short S.26 transoceanic flying-boats had been requisitioned by the RAF). ==Design and development== Pan American had requested a flying boat with unprecedented range that could augment the airline's trans-Pacific Martin M-130. Boeing's bid was successful and on July 21, 1936, Pan American signed a contract for six. Boeing engineers adapted the cancelled XB-15's wing, and replaced the Pratt & Whitney Twin Wasp radial engines with the Wright Twin Cyclone.〔Bowers December 1977, pp. 14–15.〕 Pan Am ordered six more aircraft with increased engine power and capacity for 77 daytime passengers as the Boeing 314A. The huge flying boat was assembled at Boeing's Plant 1 on the Duwamish River in Seattle, and towed to Elliott Bay for taxi and flight tests. The first flight was on June 7, 1938, piloted by Edmund T. "Eddie" Allen. At first the aircraft had a single vertical tail, and Allen found he had inadequate directional control. The aircraft returned to the factory and was fitted with the endplates on the ends of the horizontal tail in place of the single vertical fin. This too was found to be lacking and finally the centerline vertical fin was restored, after which the aircraft flew satisfactorily.〔Bogash, Robert A. ("In Search of an Icon: The Hunt for a Boeing B-314 Flying Boat, Pan American NC18601 - the Honolulu Clipper" ) ''rbogash.com.'' Retrieved: July 31, 2011.〕 The 314 used a series of heavy ribs and spars to create a robust fuselage and cantilevered wing, obviating the need for external drag-inducing struts to brace the wings. Boeing also incorporated Dornier-style sponsons into the hull structure.〔Bowers November 1977, pp. 28–35, 60–61.〕 The sponsons, broad lateral extensions at the waterline on both sides of the hull, served several purposes: they provided a wide platform to stabilize the craft while floating on water, they acted as an entryway for passengers boarding the flying boat and they were shaped to contribute additional lift in flight. Passengers and their baggage were weighed, with each passenger allowed up to free baggage allowance (in the later 314 series) but then charged $3.25 per lb ($7.15/kg) for exceeding the limit.〔Klaás 1989, pp. 17, 20.〕 To fly the long ranges needed for trans-Pacific service, the 314 carried of gasoline. The later 314A model carried a further . A capacity of of oil was required for operation of the radial engines. Pan Am's "Clippers" were built for "one-class" luxury air travel, a necessity given the long duration of transoceanic flights. The seats could be converted into 36 bunks for overnight accommodation; with a cruising speed of (typically flights at maximum gross weight were flown at ) in 1940 Pan Am's schedule San Francisco to Honolulu was 19 hours. The 314s had a lounge and dining area, and the galleys were crewed by chefs from four-star hotels. Men and women were provided with separate dressing rooms, and white-coated stewards served five and six-course meals with gleaming silver service. The standard of luxury on Pan American's Boeing 314s has rarely been matched on heavier-than-air transport since then; they were a form of travel for the super-rich, priced at $675 return from New York to Southampton (comparable to a round trip aboard Concorde in 2006).〔("British Airways Concorde." ) ''Travel Scholar'', Sound Message, LLC. Retrieved: August 19, 2006.〕 Most of the flights were transpacific, with a one-way ticket from San Francisco to Hong Kong via the "stepping-stone" islands posted at $760 (or $1,368 round-trip).〔Klaás 1989, p. 20.〕 The Pan Am Boeing 314 Clippers brought exotic destinations like the Far East within reach of air travelers and came to represent the romance of flight. Transatlantic flights to neutral Lisbon and Éire (Ireland) continued after war broke out in Europe in September 1939 (and until 1945), but military passengers and cargoes necessarily got priority, and the service was more spartan. Equally critical to the 314's success was the proficiency of its Pan Am flight crews, who were extremely skilled at long-distance, over-water flight operations and navigation. For training, many of the transpacific flights carried a second crew.〔Klaás 1989, p. 64.〕 Only the very best and most experienced flight crews were assigned Boeing 314 flying boat duty. Before coming aboard, all Pan Am captains as well as first and second officers had thousands of hours of flight time in other seaplanes and flying boats. Rigorous training in dead reckoning, timed turns, judging drift from sea current, astral navigation, and radio navigation were conducted. In conditions of poor or no visibility, pilots sometimes made successful landings at fogged-in harbors by landing out to sea, then taxiing the 314 into port. 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「Boeing 314 Clipper」の詳細全文を読む スポンサード リンク
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