A Brief History of Wing-In-Ground Vehicles

Ground effect was originally observed in maritime birds flying close to the sea surface to travel longer distances with less effort.  In World War II, German flight crews flew close to the sea surface to extend the range of their bombers, as well as presumably trying to avoid Radar detection.  RAF flight crews found empty Lancaster bombers difficult to land on short runways because of ground effect.

After the War, two parallel streams of development took place.  The Russian Ekranoplans and the German/US reverse delta WIG's.

KM Ekranoplan

The Russian developed machines, generally referred to as Ekranoplans, used rectangular wings in combination with a large T-Tail.  The drawback with the rectangular lift wings is that the lift is concentrated to a line running across the vehicle, meaning it is a bit like flying a see-saw.  This lack of longitudenal stability, has occasionally caused incidents, such as the KM nose diving into the water and an Orlyonok breaking into two.  The lift to drag ratio also tended to be no better than a commercial aircraft, so this format has not found favour elsewhere.

Lippisch-X112Alexander Lippisch in German and the US, developed machines generally based on a forward swept delta wing format, in combination high-elevator tail with either single or twin rudders.  This system proved naturally more stable as the lift is distributed more evenly along the vehicle's length and its lift to drag ratio is much better than the Ekranoplans, thus making them more fuel efficient than not just them, but commercial aircraft as well.  As a result, these machines are beginning to find commercial success in archepelagos as a lower cost alternative to helicopters and a more practical alternative to fixed wing aircraft.

More on ground effect vehicle history can be seen at: