Sky
paragliders have just moved into their new factory and
office complex and to mark the occasion both Tim King and
myself (as well as 160 other people) were invited to the
opening to discover what goes into designing and manufacturing
paragliders and to party until the early hours.
Our tour started with an explanation of the design process
and the difference between reworking an existing design
and a new design. When a manufacturer develops a new design,
it is quite common to make some small improvements to it
and to repackage it after a year or two. This is relatively
easy and inexpensive. Often manufacturers will take innovations
from other gliders in their range (or even those developed
by a competitor) and enhance an existing design with them.
We then had a talk about the Sky designs; as we’d
been discussing the repackaging of a competitors DHV 2 glider,
it was contrasted with the Brontes.
We were taken through the design process, and the advanced
computer design package was demonstrated. It was surprising
how easily design changes could be made. The data files
produced by the software are completely compatible with
the computer controlled marking and cutting machine. This
machine would first load the cloth, and then mark up the
panels with the cutting reference and checking points. Once
this process had been completed, the cloth was cut. The
entire process took about 40 minutes and if required, 4
thicknesses of cloth could be processed at once!
One of the other guests asked what happened before Sky
had the machine, or if it was out of order for any length
of time. Martin Nemec, the director of the company showed
us the Stencil library that could be used to cut the panels.
This is the system in use by the some paraglider factories.
In order to make the production of the glider panels cut
in this way cost effective, 30 or 40 thicknesses had to
be cut at a time. It offers very little flexibility, and
the production of proto type designs is horribly expensive.
Before we moved onto the assembly room floor, we were
shown the paperwork that accompanied every single item produced
in the factory from bum bags to gliders. It gave a full
history of all materials and manufacturing processes used,
and meant that if there was ever a problem or query about
an item, its full production history was known. Once an
item had been finished and dispatched, the records were
duplicated onto the computer database for quick access and
cross-referencing.
We also had a brief chat about materials and how the latest
Porcher fabrics are now impregnated rather than coated.
This allows the use of lighter weight fabrics, which have
better durability. Sky are really impressed with the new
impregnated fabrics. They supply the local airport with
wind socks and previously, even with heavy cloths, the windsock
would be in tatters after a few months. We were shown one
made of the new impregnated Porcher. It had been in continuous
service for over a year and still looked new!
The assembly room floor is where the gliders are stitched
together. This is also where the reserves are put together,
and again these are made for other companies. If you open
up your reserve you might be surprised to find a Sky label
even though you didn’t buy a sky reserve.
The heavier cloth items like harnesses and flight decks
were put together in a different section of the assembly
room on bigger machines.
The next part of the factory was where the line sets were
made up. Before they are attached to the glider, there is
a blower that inflates four or five cells at a time and
a visual inspection is made of the inside, checking for
stitching defects. Once all the lines are attached and tension
applied (I think it was 15 kg), an electronic measuring
device is used to check the line lengths. It is accurate
to two tenths of a millimetre. The error on each line is
recorded on the gliders paperwork. DHV require that the
error is less than 10 mm, but Sky reject any line that is
out by more than 5 mm (the man in charge of this section
told us that it was very rare to find errors of more than
2 mm).
That wasn’t quite the end of the process. As a final
check, every glider is then taken outside and inflated before
being dispatched.
After the tour things really started to get messy with
a never-ending stream of drink, food, and a band. The enthusiastic
element was carted off at midnight to Ostrava, a town that
is famed throughout the Czech Republic for Friday and Saturday
nights out (we now understand where the rep came from!).
We run regular flying trips
to the Czech Republic with a chance to visit Sky's factory.
John Welch - March 2003
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