A seaplane is a powered fixed-wing aircraft capable of taking off and landing (alighting) on water. Seaplanes that can also take off and land on airfields are in a subclass called amphibious aircraft. Seaplanes and amphibians are usually divided into two categories based on their technological characteristics: floatplanes and flying boats; the latter are generally far larger and can carry far more. These aircraft were sometimes called hydroplanes, but currently this term applies instead to motor-powered watercraft that use the technique of hydrodynamic lift to skim the surface of water when running at speed.
Their use gradually tailed off after World War II, partially because of the investments in airports during the war. In the 21st century, seaplanes maintain a few niche uses, such as for dropping water on forest fires, air transport around archipelagos, and access to undeveloped or roadless areas, some of which have numerous lakes.
The word "seaplane" is used to describe two types of air/water vehicles: the floatplane and the flying boat.
- A floatplane has slender floats, mounted under the fuselage. Two floats are common, but other configurations are possible. Only the floats of a floatplane normally come into contact with water. The fuselage remains above water. Some small land aircraft can be modified to become float planes, and in general, floatplanes are small aircraft. Floatplanes are limited by their inability to handle wave heights typically greater than 12 inches (0.31 m). These floats add to the empty weight of the airplane and to the drag coefficient, resulting in reduced payload capacity, slower rate of climb, and slower cruise speed.
- In a flying boat, the main source of buoyancy is the fuselage, which acts like a ship's hull in the water because the fuselage's underside has been hydrodynamically shaped to allow water to flow around it. Most flying boats have small floats mounted on their wings to keep them stable. Not all small seaplanes have been floatplanes, but most large seaplanes have been flying boats, with their great weight supported by their hulls.
The term "seaplane" is used by some instead of "floatplane". This is the standard British usage. This article treats both flying boats and floatplanes as types of seaplane, in the US fashion.
An amphibious aircraft can take off and land both on conventional runways and water. A true seaplane can only take off and land on water. There are amphibious flying boats and amphibious floatplanes, as well as some hybrid designs, e.g., floatplanes with retractable floats.
Modern production seaplanes are most often light aircraft, amphibious, and of a floatplane design.
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Seaplane Facts for Kids. Kiddle Encyclopedia.