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Copyright © 2010 by B. Kohler
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TYPES OF WIG-CRAFT
WIG-crafts are not aircraft's. Specific
design criteria are complete different compared to an aircraft. For
example the take off. An aircraft uses a angle of about 14 degree for
maximum lift to shorten the take off distance. A WIG-craft has to be
started without this facility. To flare with high speed so low over a
surface the have to be auto stable. Over the years different types of
WIG-crafts where developed to optimize this type of craft.
Tandem W.I.G. ( Joerg Principe )
The tandem wing concept uses two small
wings in line. The wings are set in different angles in respect to each
other. This configuration provides excellent stability. No horizontal
stabilizer is necessary. The flaring height is relative low.
Reversed Delta W.I.G. ( Prof. Lippisch Principe )
Ekranoplan
The reversed delta wing is very stable by
it self, so that only a small horizontal stabilizer is necessary.
Fischer Flugmechanik ( Germany ) develop these crafts. These crafts can
also jump. The use V-hulls like on a speed boat. The most power is
necessary to get over the hump speed of the hull. Once flaring the
power can be reduced by 50 % for cruising.
Examples of Lippisch vehicles are the Airfisch series and the Flightship FS 8.
Ekranoplans where a Russian invention.
These crafts have wings with a very low aspect ratio of 1 to 4 with
endplates and flaps. At the start the blow air under the wings to
establish an air cushion. At cruising speed the propellers are tilted
in a more vertical position for more forwards trust i.e. speed.
Big
models use separate engines for trust and under wing blowing in front
of the wing. All Ekranoplans have huge horizontal stabilizers. These
crafts are also called PAR-WIG crafts (Power Augmented Ram Wing in
Ground Effect. Many have been built in different sizes, the largest
exceeding 500 tons. Russian companies are the only companies who can
deliver now.