你好嗎？也很開心見到你。是的，終於學會寫中文了。倍感親砌！但很慢很慢。寫詩很好。Yes, with its long wingspan, Glider flys in a smooth, effortless, and often graceful way. Big birds like eagles can fly in the same way. Very cool, eh.
紅豆豆 發表評論於
你的名字很有趣:
A "glider" is an unpowered aircraft. However, the term is also used to refer to motorgliders, which are aircraft that switch off their engines in flight. The design of gliders enables them to climb using rising air instead of merely descending. This has created the sport of gliding, or soaring. The term "sailplane" is also used, implying a high soaring performance. Minimalist variations of the sport also occur in hang gliding and paragliding.
The term "pure glider" (or equivalently, but less commonly "pure sailplane") may be used to distinguish an unpowered glider from a motorglider, without implying any differential in gliding or soaring performance.
History
In ancient China, manned kites were used for military reconnaissance. The first glider seems to have been designed in 500 BC by Lu Ban, a contemporary of Confucius, although this was more of a toy than a genuine aircraft. Some records mention manned gliders in China by AD 500.
Abbas Ibn Firnas, invented (apparently independently of the Chinese) an early form of parachute in 875. It has also been claimed that before he died he developed a glider, and made a ten minute flight. Lacking a 'tail' his aircraft could neither steer nor land properly, and he was injured in the resulting crash.
The first heavier-than-air (i.e. non-balloon) aircraft to be flown in Europe, Sir George Cayley's Coachman Carrier (1853), was a pure glider. Otto Lilienthal, Percy Pilcher, John J. Montgomery, and the Wright Brothers are other pioneers who built gliders to develop aviation. After the First World War gliders were built in Germany for sporting purposes (See link to Rhön-Rossitten Gesellschaft). The sporting use of gliders rapidly evolved in the 1930s and is now the main application. As their performance improved gliders began to be used to fly cross-country and now regularly fly hundreds or even thousands of kilometers in a day, if the weather is suitable.
Military gliders were then developed by a number of countries, particularly during World War II, for landing troops. A glider was even built secretly by POWs as a potential escape method at Colditz Castle near the end of the war in 1944. The Orbiter vehicles or "space shuttles" do not use their engines after re-entry at the end of each spaceflight, and so land as gliders.
