|
The de Havilland Canada DHC-2 Beaver is a single-engined, high-wing, propeller-driven, STOL aircraft developed by de Havilland Canada, primarily known as a bush plane. It is used for cargo and passenger hauling, aerial application (crop dusting and aerial topdressing), and has been widely adopted by armed forces as a utility aircraft. The United States Army purchased several hundred; nine DHC-2s are still in service with the U.S. Air Force Auxiliary (Civil Air Patrol) for search and rescue. A Royal New Zealand Air Force Beaver supported Sir Edmund Hillary's expedition to the South Pole. Over 1,600 Beavers were produced until 1967 when the original line shut down.〔("de Havilland Canada DHC-2 Beaver." ) ''Canada Aviation and Space Museum''. Retrieved: November 20, 2009.〕 Due to its success, the Royal Canadian Mint commemorated the Beaver on a special edition Canadian quarter in November 1999. ==Design and development== After the war, de Havilland Canada management turned to the civilian market for work, aware that military contracts were unlikely to guarantee business. The company had recently hired Punch Dickins, a famous bush pilot, as Director of Sales who began an extensive program of collecting requests from other pilots, to understand what they needed in a new aircraft. Almost without variation, the pilots asked for tremendous extra power and STOL performance, in a design that could be easily fitted with wheels, skis or floats. When de Havilland engineers noted that this would result in poor cruise performance, one pilot replied "You only have to be faster than a dog sled". Other suggestions were seemingly mundane but important in the bush plane world; full-sized doors were installed on both sides of the aircraft so it could be easily loaded no matter which side of a dock it tied up on. The doors were also made wide enough to allow for a 45 Imperial gallon drum to be rolled up into the aircraft. On September 17, 1946, de Havilland officially put together a design team consisting of Fred Buller, Dick Hiscocks, Jim Houston and W. Jakimiuk, led by Phil Garratt. The new aircraft was designed to be all-metal (unlike older designs like the famous Noorduyn Norseman), using "steel from the engine to the firewall, heavy aluminum truss frames with panels and doors throughout the front seat area, lighter trusses toward the rear and all monocoque construction aft". At the time de Havilland Canada was still a British-owned company and there were plans to fit the evolving design with a British engine. This limited power, so the wing area was greatly increased in order to maintain STOL performance. When Pratt & Whitney Canada offered to supply war-surplus Wasp Jr engines at a low price, the aircraft ended up with extra power as well as the original long wing. The result was unbeatable STOL performance for an aircraft of its size. After much testing and with adjustments and improvements, the innovative airplane was ready for the sales circuit. Since de Havilland Canada aircraft were all named after animals, it was decided that the new bush plane was much like the hard-working beaver. The first flight of the DHC-2 Beaver was in Downsview, Ontario by Second World War flying ace Russell Bannock on August 16, 1947. The first production aircraft was delivered to the Ontario Department of Lands and Forests, a design partner, in April 1948. Initial sales were slow, perhaps two or three a month but as the plane was demonstrated sales started to improve. A key event in the Beaver's history occurred the next year, when the US Army started looking for a new utility aircraft to replace their Cessnas. The competition quickly boiled down to the Beaver and the Cessna 195 but the Beaver outperformed the 195 and with the outbreak of the Korean War, led to orders for hundreds of aircraft. Soon orders increased from around the world. When production finally ceased in 1967, 1,657 DHC-2 Beavers had been built. The Beaver was designed for flight in rugged and remote areas of the world. Its short takeoff and landing capability made it ideal for areas normally only accessible by canoe or foot. Because it often flies to remote locations, often in cold climates, its oil reservoir filler is located in the cockpit and oil can be filled in flight. A series of upgrades to the basic design were incorporated. One major customer introduced the use of flat steps replacing the earlier tubes, a feature that is now almost universal. In 1987, the Canadian ''Engineering Centennial Board'' named the DHC-2 one of the top ten Canadian engineering achievements of the 20th century.〔Cooper, Russ. "Winged Workhorse." ''Canadian Geographic'' magazine, July/August 2007, p. 26.〕 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「De Havilland Canada DHC-2 Beaver」の詳細全文を読む スポンサード リンク
|