Dr. Lippisch and his X-112
The first proof of the concept by Dr. Lippisch
It was in the sixties, when Dr. Lippisch experimented with Ground Effect configurations. The result was the aerodynamic layout, in which the reversed delta wing was combined with a high positioned T-tail.
Until now, it is the only Ground Effect configuration, which proofed it’s inherent length and height stability in and out of Ground Effect theoretical and in operation.
Dr. Lippisch first designs were desigend as aircraft, for which the ability to safely operate in and out of Ground Effect was truly essential. On the other side, this original ability for free flight was great disadvantage to develop a Ground Effect Craft as a commercial useful product: The basic advantage of a Ground Effect Craft is it’s possible cheap operation.
To burden this advantage with the additional expenses to produce, register and operate a Ground Effect Craft as an aircraft,is completely unfeasible. Beside that, for very feasible reasons, a good Ground Effect Craft is a very bad aircraft, and vice versa.
X-113 over the North Sea
X-114
Continous works of RFB
Rhein-Flugzeugbau GmbH
In the late sixties, RFB with Mr. Hanno Fischer as a technical director started to evaluate Ground Effect Craft by order of the German MoD. With Dr. Lippisch as a consultant, they developed the X-113 as a successor of the X-112 in order to fullfil the task of the design evaluation.
After a successful series of tests with the X-113, a new design was started to cover the Navy requirement to
observe the baltic sea as per NATO requirement of that time.
Different to the X-113, the X-114 was a Katamran Design, where the fuselage was above the water, and the
sponsons had to give the displacement needed.
Also this craft was successfully operated.To improve sea worthiness during take off and landing, the X-114 was
modified to the X-114H with hydrofoils. Due an error of the test pilot that time, the X-114 got lost during trials,
while the Pilot survived uninjured.
At the end of the both programs, the conclusion was, that the technical and the military suitability was proven.
However, for civil applications, the registration of both craft as aircraft in those early years, was an extreme disadvantage, which prohibited the attempt to approach the market.
Airfish-1
Airfish-2
Airfish-3 in the Miami Bay
Ongoing R&D by Fischer - Flugmechanik
It was in 1979, when Hanno Fischer together with his partner Klaus Matjasic started to operate the R&D company Fischer – Flugmechanik. The initial target was the design, construction and operation of a small vessel, that should be unable for free-flight, and beeing able to receive a registration as a boat.
The first craft as a proof of the ship concept was Airfish-1 , which made it’s maiden flight in 1987. It cruised at 100 km/h on a power setting of 13hp. It raised the interest of an american company, and a cooperation to market this craft begun.
Based on this market interest, Fischer – Flugmechanik granted a license to RFB in order to continue the further devlopment on a basis of shared tasks, wherin Fischer – Flugmechanik proceeded with R&D and consulting, and RFB made the hardware.
Considering the recreational boating market, it was figured, that a production craft should have an significant smaller wing span, in order to fit into regular marina facilities.
As Lippisch designed craft with extremely small aspect ratio n had not been tested until then, it was decided to modify Airfish-1 by designing new wings for Airfish-1 to evaluate the characteristics of such small aspect ratio wing in flight tests. The modified craft was designated Airfish – 2, and was successfully tested in 1988 and 1989.
After those tests, FF and RFB were ready to design and build the prototype of the Airfish –3 , which was a kind of pre-production model for the 2 seated recreational craft. It made it’s maiden flight in 1990 and went through intense tests until 1992, when it was demonstrated during the Miami Boat Show.
As the American licensee breeched the contracts, and tried to build unauthorized copies of Airfish – 3, the program was discontinued.
Together with the downgoing of RFB, the Airfish design in complete came to a temporary stop.
Hoverwing 2 VT
R&D on the Hoverwing Technology
Fischer – Flugmechanik began to work on the design basis for bigger vessels, when in the early 90’s, after the reunification of Germany, a new situation occurred.
The German Ministry of Economics arranged a feasibility study to figure the best suitable product for the large shipbuilding industry at the baltic sea, which would be competitive on the shuipbuilding market despite the high production expenses in Germany.
The result was e requirement for a 80 seat Ground Effect Craft with a specified performance, which at that time was beyond the state of the art.
Based on that situation, the German Ministry for R&D supported a milestone program, in which initially all available know-how was concentrated in order to investigate possible technical solutions to fullfil the specification with a Ground Effect Craft. The end of the technical feasibility study Indicated, that none of the available designs could feasibly be scaled up to the recommended size.
But there were two suggestions for alternate designs, which appeared promising enough to be continued in the next milestone. Those were the design of Techno-Trans e.V. and the new design of Fischer – Flugmechanik, the Hoverwing.
Until 1996 Fischer – Flugmechanik continued the development of the new Hoverwing Technology together with it’s project partners, VBD Versuchsanstalt für Binnenschiffbau at Duisburg and others.
Then, in 1996 the new design appeared advanced enough to be tested with a manned test craft, which was a scaled down version of the projected 80-seated vessel. Under consultancy and supervision of Fischer – Flugmechanik, the Hoverwing 2VT was constructed by the VBD and several suppliers of components.
The maiden flight took place in 1997 on the inland waters of lake Baldeney nearby the city of Essen. After minor modifications, Hoverwing 2VT was transported to the Baltic Sea in order to compete with the alternate design of Techno Trans e.V.
Hoverwing 2VT continued several sea trials on the baltic, and the Markermeer in the Netherlands until 1999, in which it covered a distance of more than 3.000 km in all, without any damage or operational problem.