Its ability to operate on water with little need for airport infrastructure is a clear advantage for its development in an increasingly environmentally conscious world.
Seaplanes are a special type of aircraft, the peculiarity of which is that they are able to land and take off over expanses of water. They emerged at the dawn of aviation and until the middle of the 20th century were highly regarded because of the little or no infrastructure required for their operation.
They are particularly interesting as they straddle the line between naval and aeronautical engineering. They are currently a growing segment of commercial air traffic with a promising future.
They are usually classified into two different types:
The first type consists of conventional aircraft in which the landing gear has been replaced by floats and the fuselage does not touch the water. They are sometimes referred to as "float planes". One example is the DHC-6 Twin Otter, considered by many to be the best-selling aircraft in Canadian history. This model of aircraft is even capable of landing on beach sand, as it does when operating at Barra Eoligarry Airport in Scotland (IATA: BRR, ICAO: EGPR).
The second type of seaplanes is composed of aircraft in which the fuselage is shaped like a ship's hullThis ensures the necessary buoyancy during docking manoeuvres, or when taxiing over water during take-off or landing. This special type of aircraft usually has a high-wing configuration with the engines on top of it (in order to keep the engines as far away from the water as possible). They are sometimes referred to as "hydrofoils". Examples include the Canadair CL-215 seaplanes belonging to the Spanish Air Force, which are particularly effective in firefighting or in other activities such as the fight against drug trafficking or the control of illegal immigration.
It is wrong to think that seaplanes must necessarily be small aircraft. The world's largest amphibious seaplaneThe Chinese-built AG600 Kunlong has a length of 36.9 metres and a wingspan of 38.8 metres (classified as ICAO code letter D). With a maximum take-off weight of 53.5 tonnes and a maximum range of 4,500 kilometres, it is capable of carrying up to 50 passengers and 12,000 litres of water (in its firefighting version). In this promotional video its first test flight can be seen:
As a curiosity, we can mention the Beriev Be-200 (in Russian: Бериев Бе-200) model, alias ‘Altair’: the only jet seaplane in the world, with a wingspan of 32.7 metres. In the following photograph, you can see it taking off from the water and in this one video is shown in action.
Finally, within this second type of seaplane is the Hughes H-4 Hercules, considered by many to be the greatest eccentricity of its creator, the millionaire Howard Hughes. It was 66.65 metres long and had a wingspan of 97.54 metres, the longest in the world at the time (1947). Although it was built mostly of wood, it managed to take off and land only once.
It is common for either of the two types of seaplanes described (floatplanes or hydrofoils) to be capable of operating at conventional aerodromes. In such cases, they are usually referred to as "amphibious aircraft". As a curiosity it can be mentioned that, in the design of a new seaplane model, "the anchor" should never be forgotten.
Some of the world's leading seaplane manufacturers include: Aztec Nomad and Viking Air (both Canada), Dornier (Germany), ShinMaywa (Japan) and Beriev (Russia). In the United States, they include Aviat, Bombardier, Cessna and Seawind.
Interestingly, neither Airbus nor Boeing are among them, although historically, the latter produced the Boeing 314 "Clipper" model until 1941. At the time, it was the world's largest series-produced commercial transport, designed for transoceanic flights. It was capable of accommodating 74 passengers in seven luxurious compartments. In addition, it had a dining room for 14 people and a bridal suite at the rear, near the tail of the aircraft.
Mass passenger transport by seaplane lost popularity in the 1950s because they were more inefficient than conventional aircraft, which, in the past, were aerodynamically better as well as being able to carry large numbers of passengers directly to airports on the ground.
However, the future may be different and promising; I would even dare to say spectacular. Currently, many ‘land-based’ airports face problems due to the impact of their presence on the land located in their vicinity. In particular, increasingly restrictive noise legislation imposes enormous constraints, often exacerbated by the lack of space available for the development of those aerodromes that are ‘cornered’ by the urban development of the city they serve.
In response to the difficulties described, a number of measures have already been taken in the following areas transoceanic seaplane conceptual developments. They are based on the "flying wing" concept, which is more aerodynamically efficient than the typical "fuselage-wing" configuration.
Early conceptual designs estimate a length of 80 metres, a maximum height of 20 metres and a wingspan of 160 metres for this type of aircraft (twice the maximum value set by ICAO for F-code aircraft, which are the largest). An Airbus A380, currently the largest commercial airliner, has a wingspan of 79.75 metres (half that) and a length of 72.73 metres. These new seaplanes could carry up to 2000 passengers, while an Airbus A380 can carry a maximum of 853 passengers in its highest density configuration.
Aircraft of such dimensions obviously do not have adapted ground infrastructure The ICAO would have to develop specific regulations for them beforehand. This problem does not exist at sea due to the large amount of free space available.
On the other hand, this type of aircraft would have their engines on top, which is advantageous in terms of noise emissions. However, when taking off or splashing down over expanses of water, probably far from the coast, noise pollution will not be a conditioning factor for the normal performance of their operations.
Its large size improves aerodynamic efficiency while favouring operation in heavy swell conditions. If necessary, floating breakwaters can be arranged, which is technically feasible, even in high seas.
Seaplanes are the most environmentally friendly of all "powered flying machines" because they do not need infrastructure other than natural water bodies for their operations.. Nor does a seaplane imply exclusive use of water surfaces, which it often effectively shares with other users. Nor should it be forgotten that 70 % of our planet's surface is water.
Who knows, maybe one day we will see transoceanic seaplanes taking off from Malaga, Barcelona, New York, Lisbon, Buenos Aires, Hong Kong, etc. The future holds the answer.
