Air travel today may be taken for granted as an integral part of modern life, for both passenger and freight transport. But it comes at a cost which is both economic and environmental, and it is subject to limitations in the distances different types of aircraft can cover, the locations they can serve, and the payloads they can carry.
ESTOLAS (Extremely Short Take Off and Landing on Any Surface) is an exciting European Union (EU)-funded project which aims to reduce those economic and environmental costs, as well as make air travel more efficient, more cost-effective, and more sustainable. In one of the most radical re-thinkings in aviation history, ESTOLAS project team is focusing on combining the best features of an aeroplane, a helicopter, an airship and a hovercraft into a single hybrid aircraft.
Shorter and squatter in shape than a conventional aeroplane the ESTOLAS hybrid vehicle looks as revolutionary as it sounds. It still has wings, but instead of the long, thin body of a plane it has a disc-shaped main section. In addition to propeller engines, it also has a lifting rotor like a helicopter. Like an airship, it can use helium to provide additional lifting power, and like a hovercraft it has air-cushioned combined wheel-ski landing gear that allows take off and landing from any terrain.
"The new aircraft will provide numerous advantages," explains Project Coordinator Alexander Gamaleyev of Riga Technical University in Latvia. Take off and landing distances will be just 175 metres for the largest 'superheavy' ESTOLAS model, and as low as 75 metres for the smaller craft. As well as being capable of extremely short take off and landing, the ESTOLAS hybrid is also able to operate on any natural surface, be it runway, field, marsh, sea, river, lake or snow.
Load ratios will be 1.5 to 2 times higher than for conventional jet or propeller planes , fuel consumption will be lower and flight ranges could be extended to enable cargo delivery anywhere on earth without refuelling.
The result, says Mr Gamaleyev, is that the cost of air transportation should become similar to that of rail transport, while the hybrid's lower fuel consumption and reduced CO2 emissions should make it the most ecologically efficient form of air transport yet devised.
ESTOLAS team is examining the potential of four different sizes of hybrid aircraft small, medium, heavy and superheavy. The smaller models could be used to replace helicopters, providing a longer range and a greater payload capacity than a helicopter provides. The larger ESTOLAS models could be able to transport cargos using smaller airports than conventional planes can use, or even using open areas of land or water closer to the places or origin or destination.
It is expected that the ESTOLAS hybrid aircraft would have a wide range of uses. These would include providing more efficient and cheaper links not only between large cities with existing air transport facilities, but also between towns with no local runways or airfields. Providing support to the building and operation of oil and gas fields would be another key area of application, as would delivering a wealth of services such as defence, healthcare or emergency relief in hard-to-reach, remote regions. The new aircraft could also be used for business purposes and tourism.
Having designed and developed the concept of the hybrid aircraft, the next step for the ESTOLAS researchers will be to test a demonstration model of the aircraft in a wind tube. This will be followed, before the end of the project in April 2014, by radio-controlled flight tests.
The final stages of the project, adds Mr Gamaleyev, will include the development of a business plan to help move the ESTOLAS project from drawing board and test lab to commercial viability and everyday use. The shape of this is not yet clear, but options under consideration include establishing joint ventures with external partners, licensing, or seeking to attract venture capital.