A parallel Worlds

Sunday February 8 2009 / Science & Technology

There has been more and more interest in personal aviation over the last few years, and that is likely to continue as prices come down and the quality and quantity of flying machines on offer increases.

One of the more interesting concepts, all the more so in the present economic climate as it is cost efficient, is ground effect technology.

ground effect principles

Ground effect wingships are particularly suited to remote regions (like Alaska), where there are few roads and much water, which limits transport option to air travel (fast, but expensive) or water travel (slow, cheaper, can be uncomfortable). Ground effect wingships can offer fast and comfortable transport at a more reasonable price than air travel.

Ground Effect is the name given to the dramatically improved aerodynamic performance of a wing when it operates close to a ground plane.

Video: The principles of Wing in Ground Effect

Wing in Ground Effect (WIG) is the official term adopted by the United Nations International Maritime Organization (IMO) and the United Nations International Civil Aviation Organization (ICAO) for a marine craft using ground effect as a means of lift.

Ever since the beginning of manned flight pilots have experienced something strange when landing an aircraft. Just before touchdown it suddenly feels like the aircraft just doesn't want to go lower. It just wants to go on and on due to the air that is trapped between the wing and the runway, forming an air cushion. The air cushion is best felt in low wing aircraft with large wing areas. This phenomenon is called (aerodynamic) ground effect. The Wright brothers probably had not even flown out of ground effect in their early flights, they benefited from ground effect without even knowing it existed.

One of the most well  known WIG planes was the mighty Russian 'Ekranoplan'

In the Second World War pilots knew that when they lost an engine on the way back from the enemy that they could reach home by flying just a few meters above the sea, thus needing less power. The very well known Spruce Goose, the largest aircraft ever, never even left ground effect in its only 90 second flight! When an aerodynamic wing is close to a ground plane, such as water, lift is increased by as much as 45% and induced drag decreased by up to 70%.

This is vastly different to normal operation of an aircraft wing in free flight away from the ground. The main benefits when a craft is operating within ground effect are that speed, payload and fuel economies are considerably more efficient than with traditional boat, plane and helicopter transport.

Ground Effect Sea Eagle

For more information about Wing in Ground Effect principles and craft:
The WIG Page
Bentley Yachts- The Future of Yachting

Suggested by
Ian Skellern