In the 30ies building gliders was a "wood and fabric" story.
Most gliders have been built locally. They were mainly of the Zoegling family, the
conventional German version and the so called British version (with 4 tubes for the tail). Grunau
Babies and Gruene Posts have also been built.
No photo survives of the Raab factory, or of glider manufacturing in the KEA factory. KEA
was a military factory and no pictures were allowed anyway.
The only picture of glider building in the 30ies is the following:
A Zoegling glider is being built in the small workshop of the Faliron
Aeroclub, around 1937.
In the 40ies we do not have gliders built (except the Glaros that figures in most on
our pictures of the 40ies).
In the 50ies we have many Cavka gliders being manufactured by the KEA factory. We have no
pictures again.
After the 50ies until today, all gliders in Greece are imported. There are only two
exceptions, both were experiments.
First experiment was a sea glider.
Around '68 Platon Kourouvakalis (just Plato to make things simple) and C.Pikros made
preliminary drawings of two wooden sea gliders, a two-seater and a simpler single-seater.
Plato's drawing was the two-seater, and he started building it. Finally, Plato designed
all the flying machine, C.Pikros designed the part under the water surface.
In this 1969 photo Plato is seen under the wing of the sea glider, with J.Konstantakatos and P.Kalogerakos.
Here is Plato again with N.Barzelai and C.Pikros. The young boy is Kalogerakos junior.
The first flights of the "Gliding Fish" (Anemopsaro) were in the Faliron Bay
in front of the Royal Yachting Club.
After the flights, we were met by coast guard officers. Fully manned rescue vessels were
also arriving. The coast guard had received telephone calls that a airliner has been seen
diving in the bay.
Later the "Gliding Fish" went to Ioannina lake, in NW Greece, for some more
flights.
We found no problem in flying the ship, no problem in taking-off or landing.
The main problem, that we did not expect, was the immense drag of the tow-rope in the
water. For more than a hundred meters of rope, the power boat could hardly attain take-off
speed. After take-off you had to pull hard to unstick the rope from the water.
A drum on the power boat could unreal the rope. But the whole operation was complicated
enough. The sea glider was abandoned.
Next experiment was the ð12
In 1976 we started thinking of a low performance sailplane for soloing around the
airport. As low performance was considered an L/D of around 20 and a minimum sink of
around 0,8 m/s.
The first preliminary drawings was the ð10, a 10m span light sailplane using the high
lift airfoil FX63-137. As the existing data for the airfoil were only for low Re number,
professor Wortmann himself was asked on the matter. His answer was strait: "Do not
use FX63-137, this is suitable only for wingtips". After these divine words, the wing
profile was changed to the conventional FX61-184 and the span had to grow to 12m. So was
born the ð12.
Fiberglass was chosen as the building material. The plug for the fuselage was built with
much enthusiasm and with much amateur work mostly by C.Pikros himself. Then work came to a
stop. The member of the ð12 team on whom the fiberglass work depended started looking at
the project with less amateur attitude.
The fuselage plug. From the left: D.Augerino, B.Katiniotis, C.Pikros.
In 1980 the ð12 team was joined by aeronautical engineer T.Spathopoulos and the
project was adopted by the ship owner P.Laskaridis. At this stage a new conservative
decision was made.
As nobody in the team had experience in dealing with vacuum bags, the fiberglass wings
were abandoned in favor of a conventional aluminum wing. A couple of experienced metal
workers started building first the jigs then the three pieces wing. At the same time the
fuselage mold was built and at last the fuselage shell was laid up.
The fuselage mold.
Building the aluminum wing. Here is the center section. Around the end of 1984 the wings were almost ready. All the metal fittings of the fuselage were built. The pilot's seat and the instrument panel too. The total weight of the sailplane was about 130 kg.
Aeromodeler C.Friedman, who has worked for the final fuselage shell, is
seen adjusting the canopy frame.
On the other hand there were also some failures. The stabilator was built by a young
engineer of the team, using an aluminum spar and polystyrene foam covered with fiberglass
and a lot of filler to smooth its surface. It was extra heavy. Bending the canopy' s
acrylic sheet in a bath of heated oil was also complete failure.
These were independent pieces that could be easily rebuilt. But the project had already
used a lot of money (e.g. many years of rent for the workshop). At the same time the
people involved had acquired careers with few time to spare. The ð12 project was
abandoned for good. It has been a very instructive experience for the whole team.