词条 | seaplane |
释义 | seaplane aircraft ![]() A seaplane must have sufficient buoyancy to float on water and must also have some means for supporting its weight while moving along the water surface at speeds up to flying speeds. It must be able to take off and land with a margin of stability and control on the part of the pilot; its structure must be strong enough to withstand the shock of landing; and its water resistance must be low enough to permit reasonably short takeoff runs. Ways of meeting these requirements were provided by Curtiss in two forms. He developed the float seaplane, which is essentially a land plane with buoyant floats or pontoons substituted for the landing wheels, and the flying boat, in which the main float and the fuselage are combined in a single boatlike body. In either case float design includes a stepped bottom to facilitate takeoff. As speed and lift increase, the seaplane lifts onto its step so that it is barely skimming the water with friction at a minimum. Single-float seaplanes and single-hull flying boats require side floats or wing-tip floats to keep them upright. Twin-float seaplanes do not require the auxiliary floats, nor do twin hull flying boats and single hull boats with stub wings, or sponsons, located at the waterline. The addition of a retractable landing wheel gear to a float seaplane or flying boat, also accomplished by Curtiss, created the amphibian aircraft capable of operating from land runways or water. A post-World War II development was the pantobase, or all-base, airplane incorporating devices for operating from water or from a variety of unprepared surfaces such as snow, ice, mud, and sod. |
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