The Wright brothers used ground effect when they flew their first aeroplane in 1903. In fact it took them a further six years to design a wing shape and find a lightweight propulsion system with enough power to lift them out of ground effect. The wing-in-ground effect technology works well with three well-known but surprisingly little appreciated principles of aerodynamics:

Firstly, the aerodynamic efficiency and lifting capacity of a wing increases dramatically when operated in less than one-half of its wing span above water or ground, in what is termed "ground effect". Ground effect is the phenomenon caused by the presence of a boundary between the ground surface and the wing, which aletrs the flow of air stream around the wing and restricts the down-wash off the top of the wing. This down-wash is normally responsible for creating considerable "induced drag" when it mixes and eddies with the air that has passed under the wing. In ground effect, the air that has passed under the wing is far more compressed and is generally less turbulent than when the wing is in free flight. This allows much more efficient mixing with the top surface airflow at the trailing edge of the wing. When an appropriately designed wing is operated very close to a surface, lift is increased by as much as 45% and drag is decreased by up to 70% as compared to the same wing operating in free flight. Typically, an aircraft at normal flight attitudes will carry around 5 kg/kw of engine power. A well designed ground effect craft will carry up to 20 kg/kw of engine power, ie, 400% increase in power to weight efficiency over conventional aircraft. The efficiency of a ground effect craft increases with size. A 2 tonne 4 seat ground effect craft, while still more efficient than a similar light aircraft is nowhere near as efficient as a 50 or a 500 tonne ground effect craft.

Secondly, the Coanda effect, also known as "boundary layer attachment", is the tendency of a stream of fluid to stay attached to a convex surface, rather than follow a straight line in its original direction. The Coanda effect has important applications in various lift-enhancing devices on aircraft, where air moving over the wing can be "bent down" towards the ground using flaps and a jet blowing over a curved surface to increase the lift.

Thirdly, the lifting capacity of the wing is increased if the airstream over the wing is accelerated by the high-velocity exhaust engine. Therefore by a combination of deflected engine thrust, traditional aerodynamic lift and augmented propulsive lift, it is possible to make a more efficient ground effect flight.

The history of man taking advantage of ground effect with conventional aircrafts dates back to World War II when German aviators flying the Europe-South American route found that as much as fifty percent of their fuel could be saved if they trimmed their craft to fly just above the sea's surface, thus extending their bomber's operational range further into the European theatre as the conflict developed. However, the aircraft is designed to fly most efficiently at high speed and at high altitude. It is not purpose designed to operate efficiently in the region of ground effect. A considerable amount of research and development work has been carried out since the end of World War II in an effort to produce a stable, purpose-built ground effect vehicle to establish commercial design criteria for high efficiency operation primarily in the marine ground effect environments. This work is still continuing mainly in Russia, Germany, China, Korea and Singapore.

Wing-in-ground (WIG) effect have been actively researched and developed since the early 1960's despite the fact that in that period these crafts have not reached the acceptance level as mainstream transport vehicles for either civilian or military applications. Two main streams of R&D in WIG crafts originated from the former Soviet Union and the Germany. The nett result has been the emergence of two fundamental wing shapes, the "square planform" and the reverse delta triangular "Lippisch" type. The former’s school is known as the Erkranoplane and the Soviets dominated this school. The German school is named after Dr Alexander Martin Lippisch (1894 - 1976).

Dr Alexander Martin Lippisch was born on 2 November 1894 in Munich, Bavaria, Germany, the son of Franz and Clara (Commichau) Lippisch. His father was an artist. Alexander was educated at the Technische Hochschule Berlin, Germany. He enlisted in Germany's armed forces in 1915, and served until 1918 as an aerial photographer. He was awarded a doctoral degree at the University of Heidelberg at the age of 50 in 1943. Dr Lippisch was the inventor of the forward delta wing and tailless aircraft, which finally led to the first rocket engine driven aircraft. It was the well known Me-163 used during the end of World War II as interceptor aircraft by the German Air Force.

Dr Lippisch intended to fill out the gap of transportation existing particularly in countries with many water regions of lakes and rivers, or countries with sea shores and where no expensive airports can be built. Though most ships and modern aircrafts are catered for mass goods transportation, they are however slow and expensive respectively. To counter this situation, a proposed idea by a line of dedicated designers gathered to construct high speed ships such as the hydrofoils boats. High waves, however limits the efficiency of hydrofoils whenever met the cruising limit of approximately 60 knots. Another solution was to use the hovercraft. The hovercraft, however, needed two engines, namely one to produce the air cushion and a second one to give the vehicle its horizontal speed. In addition, they are limited in flight altitude and have only a small maneuverability.

Dr Lippisch pioneered the reverse delta wing design for the ground effect crafts. He designed a revolutionary new ground effect craft, the X-112. It had a reverse delta-wing planform with negative dihedral at the leading edge and a large T-shaped tail, for stability. This configuration proved to be inherently stable in ground effect flight and many recent designs have been based on the original Lippisch concept. Dr Lippisch named his reverse delta wing ground effect craft as Aerofoilboat. With his design, the aerofoilboat stays nearly as economical as a ship is, to be maneuverable like a ship but as fast as an aircraft. The aerofoilboat does not need an engine to produce an air cushion, but only a propulsion to provide a forward thrust to get the air speed. The aerofoilboat's reverse delta wing design is capable of producing a ram aerodynamically in short distance over the water. The air cushion produced in this way amends the flight quality of the craft to an astonishing extent. Alexander Martin Lippisch died on 11 February 1976 in Cedar Rapids, Iowa, of a heart and lung Ailment.

Ekranoplan Vs AirFish

In sharp contrast with the design of the AirFish reverse delta wing planform, the Ekranoplan type ground effect vessels are all square planform vessels. Changes to the fore and aft pitch of this type of ground effect crafts is damped at the trailing edge, through the air under the wing's resistance to further compression between the craft and the water surface. In the case of the Ekranoplan square planform design, this line of "compressive stability" runs across the craft in a straight line, and puts a critical stability control point into the fore and aft moment. This must be carefully controlled by the trail plane and elevator, much like flying balanced on a see-saw.

The situation in a Lippisch's reverse delta wing planform is quite different. The trailing edges of both wings extend from the rear of the craft and pass the craft's center of gravity to the front. The critical stability line is not across the craft but at a tangent to it. This makes the fore and aft pitch stability much more forgiving. This in turn reduces the pilot skill demands, and also allows stretching the overall performance envelope to include kinetic jumps. Not so with the Ekranoplan square planform.

The highest efficiency on record for a square planform, power assisted ram vessel is around 10 kg/kw. For a Lippisch reverse delta planform this figure is as high as 20 kg/kw. But more importantly from an operational point of view, the most efficient surface clearance height of square planforms are around only 10% of the wing span or less. On the contrary, a Lippisch type ground effect craft has surface clearance of up to 50% of the wing span. These performance limitations will always relegate the Ekranoplan type vessels to sheltered waters and rivers.

From Aerofoilboat to AirFish

Dr Lippisch’s design has evolved into AirFish family of ground effect crafts which are the most efficient form of transports available today. Rhein Flugzeugbau GmbH (RFB) pioneered the German concept in Germany since 1964. Dr. Alexandria M. Lippisch was then under employment of German scientific institutes and as a consultant of RFB. Together with his protégé Mr Hanno Fischer, they championed the design and construction of several well known ground effect crafts such as the experimental crafts X-113, X-114 and X-114H (X-114 with hydrofoils). These WIG crafts were built to military specifications and requirements and are capable of free flight in addition to flight in ground effect operation. The X-114 operating in ground effect still hold the world record of having the highest lift-to-drag ratio of any subsonic aircraft. 

Ing. Hanno Fischer has developed around 12 different types of aircrafts like the Fantrainer, Fanliner, RW 3 and the military used WIGs X113, X114 and X-114H. After leaving RFB, Mr Hanno Fischer founded his own research company, Fischer Flugmechanik, where he focussed on the development of commercial WIGs without free flight capability for the civil passengers transportation market. Mr Hanno Fischer and his protégé Mr Klaus Matjasic designed and built the AirFish family of WIGs, including AirFish-1, AirFish-2 and AirFish-3, based on his experience with Dr Lippisch. As a last resort, these crafts are also capable to perform short jumps to avoid obstacles while cruising in ground effect. These are the predecessor of the AirFish-8, an 8-seater WIG craft that is of our current focus.

Subsequently, WigetWorks acquired all patents, industrial property rights and know-hows from the Airfoil Development GmbH and Fischer Flugmechanik, covering the complete technology developed in connection with the design, testing and manufacturing of all AirFish types of WIG crafts. Wigetworks will continue the development and commercial production of WIG crafts on the basis of AirFish Technology and with the continuing support of the German designers. The technology acquisition would grant WigetWorks worldwide exclusive rights and license, with the rights to grant sub-licenses and to sell and distribute the AirFish Technology.

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Enormous Potential of WIGs
A large number of hard facts underlie the huge potential of WIGs, and the corresponding enormous opportunities for WigetWorks:


The fastest ships are wave piercing catamarans and the top speed threshold for all marine crafts appears to be stubbornly stuck at about 50~60 knots for several decades now. At its top speed, the fuel consumption of a ship or catamaran is many times more than when it is traveling at its efficient cruising speed. Obviously hydrodynamic drag will always be present as long as the hull is in contact with water. Consequently the most efficient marine craft is clearly one that is not in contact with water. This is the motivation of hovercrafts and hydrofoils, even though both of these still cannot avoid contact with the water. The most exciting innovation that came out of the marine transport industry in the last 100 years seems to be the Hovercraft. But this is more than 40 years old. This technology turns out to be disappointing in terms of its high cost and poor maintainability.

There is an obvious lack of viable transport over the water, other than expensive helicopters in the speed range of 50 knots to 100 knots. A typical small aircraft such as Vanilla Cessna 152, cruises at about 100 knots. It is uneconomical and unsafe for aircrafts to fly at speed below 100 knots.

While air-travel is statistically the safest mode of transportation, a few known crashes often strike deep fear into the psyche of commuters. Recent waves of terrorism have significantly threatened the safety of air-travel, and many would probably be glad to give air-travel up if not because it saves them time. There is a lot of unproductive down-time associated with air-travel, for example, the need to check in at the airport 2 hours before take-off, waiting to collect luggage at the congested carousel after landing. Furthermore, most airports are far away from the commercial centers or tourist destinations hence further commuting by roads or by slow boats is often necessary, adding to further journey fatigue.


Smugglers and pirates are becoming more sophisticated, and many now own high speed boats, in some cases even equipped with small armament. For a country like Australia that has a very long coastline, coastal patrol is a difficult and expensive task. Illegal migrants arriving by boats are on the increase.