Seaplane
A seaplane is a powered fixed-wing aircraft capable of taking off and landing on water. Seaplanes 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. Seaplanes that can also take off and land on airfields are in a subclass called amphibious aircraft, or amphibians. Seaplanes 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.
The use of seaplanes gradually tapered off after World War II. This was in part due to investments in airports during the war, but mainly because landplanes were less constrained by weather conditions that affected seaplanes. In the 21st century, seaplanes maintain a few niche uses, such as for aerial firefighting, air transport around archipelagos, and access to undeveloped or roadless areas, some of which have numerous lakes. In British English, seaplane is sometimes used specifically to refer to a floatplane, rather than a flying boat.
Types
The word "seaplane" is used to describe two types of air/water vehicles: the floatplane and the flying boat.The term "seaplane" is used by some to mean "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 range in size from flying-boat type light-sport aircraft amphibians, such as the Icon A5 and AirMax SeaMax, to the 100,000 lb ShinMaywa US-2 and Beriev Be-200 multi-role amphibians. Examples in between include the Dornier Seastar flying-boat type, 12-seat, utility amphibian and the Canadair CL-415 amphibious water-bomber. The Viking Air DHC-6 Twin Otter and Cessna Caravan utility aircraft have landing gear options which include amphibious floats.
Floatplane
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. The 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. British usage is to call floatplanes "seaplanes" rather than use the term "seaplane" to refer to both floatplanes and flying boats.Design
Floatplanes have often been derived from land-based aircraft, with fixed floats mounted under the fuselage instead of an undercarriage.Floatplanes offer several advantages since the fuselage is not in contact with water, which simplifies production by not having to incorporate the compromises necessary for water tightness, general impact strength and the hydroplaning characteristics needed for the aircraft to leave the water. Attaching floats to a landplane also allows for much larger production volumes to pay for the development and production of the small number of aircraft operated from the water. Additionally, on all but the largest seaplanes, floatplane wings usually offer more clearance over obstacles, such as docks, reducing the difficulty in loading while on the water. A typical single engine flying boat is unable to bring the hull alongside a dock for loading while most floatplanes are able to do so.
File:UO-1 BB44 USS California.jpg|thumb|A Vought UO-1 floatplane of the U.S. Navy
Floats inevitably impose extra drag and weight, rendering floatplanes slower and less manoeuvrable during flight, with a slower rate of climb, than aircraft equipped with wheeled landing gear. Nevertheless, air races devoted to floatplanes attracted much attention during the 1920s and 1930s, most notably in the form of the Schneider Trophy, not least because water takeoffs permitted longer takeoff runs which allowed greater optimization for high speed compared to contemporary airfields.
There are two basic configurations for the floats on floatplanes:
- "single float" designs, in which a single large float is mounted directly underneath the fuselage, with smaller stabilizing floats underneath the wingtips, on planes like the Nakajima A6M2-N
- "twin float" designs, with two main floats mounted side by side outboard of the fuselage. Some early twin float designs had additional wingtip stabilizing floats.
Flying boat
A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy. Though a flying boat’s fuselage provides buoyancy, it may also utilize under-wing floats or wing-like hull projections for additional stability.Ascending into common use during the First World War, flying boats rapidly grew in both scale and capability throughout the interwar period, during which time numerous operators found commercial success with the type. Flying boats were some of the largest aircraft of the first half of the 20th century, exceeded in size only by bombers developed during the Second World War. Their advantage lay in using water instead of expensive land-based runways, making them the basis for international airlines in the interwar period. They were also commonly used as maritime patrol aircraft and air-sea rescue, particularly during times of conflict. Flying boats, such as the PBY Catalina and Short Sunderland, played key roles in both the Atlantic and Pacific Theater of the Second World War.
The popularity of flying boats gradually tailed off during the Cold War era, partially because of the difficulty in maintaining operations in inclement weather, when sea conditions may easily prevent takeoffs and landings while land-based aircraft are unaffected, in addition to investments in airports during the conflict that eased the introduction of land-based airliners that were larger and more efficient. Despite being broadly overshadowed, limited use of flying boats continued with some operators, such as in the cases of the Shin Meiwa US-1A and Martin JRM Mars. In the 21st century, flying boats maintain a few niche uses, such as dropping water on forest fires, air transport around archipelagos, and access to undeveloped areas. Many modern seaplane variants, whether float or flying boat types, are convertible amphibious aircraft, where either landing gear or flotation modes may be used to land and take off.
History
Aviation's earliest pioneers looked to bodies of water to serve as runways for take-offs and landings, a practice that began in earnest in the 1910s. Seaplanes pioneered transatlantic air routes, and were used in World War I. They continued to develop before World War II, and saw widespread use. After World War II, the proliferation of land airstrips made water landings more applicable in special circumstances. The practice continued via niche applications, like accessing otherwise remote areas, fighting forest fires, and serving as maritime patrol vessels.Early pioneers
The quest for an aircraft that could take off or land from water began with float planes, which are not flying boats.In 1876, Frenchman Alphonse Pénaud filed the first patent for a flying machine with a boat hull and retractable landing gear, but failed to build one. Austrian Wilhelm Kress is credited by some with attempting to build the first successful seaplane Drachenflieger, a floatplane, in 1898, although its two 30 hp Daimler engines were inadequate for take-off, and it later sank when one of its two floats collapsed.
On 6 June 1905, Gabriel Voisin took off and landed on the River Seine with a towed kite glider on floats. The first of his unpowered flights was. He later built a powered floatplane in partnership with Louis Blériot, but the machine was unsuccessful. Other pioneers also attempted to attach floats to aircraft in Britain, Australia, France, and the US.
On 28 March 1910, Frenchman Henri Fabre flew the first successful powered seaplane, the Gnome Omega-powered hydravion, a trimaran floatplane. Fabre's first successful take off and landing by a powered seaplane inspired other aviators, and he designed floats for several other flyers. The first hydro-aeroplane competition was held in Monaco in March 1912, featuring aircraft using floats from Fabre, Curtiss, Tellier and Farman. This led to the first scheduled seaplane passenger services, at Aix-les-Bains, using a five-seat Sanchez-Besa from 1 August 1912. The French Navy ordered its first floatplane in 1912. On May 10, 1912 Glenn L. Martin flew a homemade seaplane in California, setting records for distance and time.
In 1911−12, François Denhaut constructed the first seaplane with a fuselage forming a hull, using various designs to give hydrodynamic lift at take-off. Its first successful flight was on 13 April 1912.
Throughout 1910 and 1911, American pioneering aviator Glenn Curtiss developed his floatplane into the successful Curtiss Model D land-plane, which used a larger central float and sponsons. Combining floats with wheels, he made the first amphibian flights in February 1911 and was awarded the first Collier Trophy for US flight achievement. From 1912, his experiments with a hulled seaplane resulted in the 1913 Model E and Model F, which he called "flying-boats".
In February 1911, the United States Navy took delivery of the Curtiss Model E and soon tested landings on and take-offs from ships, using the Curtiss Model D.
There were experiments by aviators to adapt the Wright Model B to a water landing. The first motion picture recorded from an airplane was from a Wright Model B floatplane, by Frank Coffyn in 1911. The Wright Brothers, widely celebrated for their breakthrough aircraft designs, were slower to develop a seaplane; Wilbur died in 1912, and the company was bogged down in lawsuits. However, by 1913, the Wright Brother company developed the Wright Model CH Flyer. In 1913, the Wright company also came out withe Wright Model G Aerboat, which was a seaplane with an enclosed cabin ;the chief engineer of this version was Grover Loening.
In Britain, Captain Edward Wakefield and Oscar Gnosspelius began to explore the feasibility of flight from water in 1908. They decided to make use of Windermere in the Lake District, England's largest lake. In 1909, the duo attended the Blackpool Aviation Week, where Wakefield “put forward the theory of flying from water, but was ridiculed by the experts.” The rejection spurred the two men into collaborating on their own individual hydro aeroplane designs. To test their floatplanes, they decided to make use of Windermere in the Lake District—England's largest lake. Gnosspelius’ first attempts to fly attracted large crowds, although the aircraft, named Gnosspelius No.1, failed to take off due to its underpowered engines. The unsuccessful demonstration prompted Gnosspelius to re-design the floats that had been crafted for him by boat builders Borwick & Sons, and had incorporated features of Borwick's successful speed-boat hulls. Meanwhile, Wakefield ordered a floatplane similar to the design of the 1910 Fabre Hydravion. Meanwhile, Wakefield ordered a floatplane similar to the design of the 1910 Fabre Hydravion. By November 1911, both Gnosspelius and Wakefield had aircraft capable of flight from water and awaited suitable weather conditions. Gnosspelius's flight was short-lived, as the aircraft crashed into the lake. Wakefield's pilot, however, taking advantage of a light northerly wind, successfully took off and flew at a height of to Ferry Nab, where he made a wide turn and returned for a perfect landing on the lake's surface. By November 1911, both Gnosspelius and Wakefield had aircraft capable of flight from water, and awaited suitable weather conditions. Gnosspelius's flight was short-lived, as the aircraft crashed into the lake. Conversely, Wakefield's pilot took advantage of a light northerly wind, and successfully took off and flew at a height of 50 feet to Ferry Nab, where he made a wide turn and returned for a perfect landing on the lake's surface.
In Switzerland, Émile Taddéoli equipped the Dufaux 4 biplane with swimmers and successfully took off in 1912. A seaplane was used during the Balkan Wars in 1913, when a Greek "Astra Hydravion" did a reconnaissance of the Turkish fleet and dropped four bombs.