Avia Economia, Part 3

You Motorheads will like this Part :-)

Primary Gliders are designed to be dismantled. The fuselage breaks
down into two pieces. The horizontal stabilizer un-pins, as does the
rudder. Control cables are fitted with turn-buckles at key points,
allowing the cables to be divided, their free ends coiled and stored
in suitably marked bags, along with a dash of rat poison. The wings
of course, are designed to come off, the control cables are coiled &
bagged as mentioned above.

The break-down of a Primary Glider is mostly common sense but it also
reflects the components that make up its structure, and in doing so
defines the logical sequence of the manufacture of those components,
such as the rudder, stabilizer, aft fuselage and so on. This is worth
mentioning here because a Primary Glider is not a project with a
definable end. As soon as the first one is finished you will find
there is enough interest to begin collecting materials for another --
and enough people to keep it flying. But this post is about what to
do with your Primary when it's NOT flying.

You store it in its trailer.

In its dismantled state a Primary Glider occupies a space about 16
feet in length, 5 feet in height and four feet in width. Add an extra
foot to those dimensions for 'working room' and you have the
approximate dimensions of the glider's required storage space. Your
task is to turn those dimensions into a trailer.

Weight of the glider is not a factor here. At an absolute maximum a
Primary Glider will weigh no more than 180 pounds, assuming it is
built with ballast weights and a heavy skid. A more realistic figure
would be about 130 pounds. The weight you need to worry about is that
of the trailer's chassis & body. Here again, the weight is not very
much but its CG must be taken into account.

As a rule, start with the largest wheels you can find, with 15" or 16"
rims being preferred. Do a rough estimate of the trailer's weight and
locate the axle accordingly. When under-weigh a glider trailer can be
an awkward tow. It may be necessary to re-locate the axle or even to
add a ballasting mass. Be sure to take the required tongue-length
into account and provide the trailer with a steerable third-wheel and
jack-stands or stabilizers to keep the trailer firmly in place when
loading and unloading the glider.

The fun part of this assignment has to do with what you decide to
build the trailer from. Aluminum monocoque construction should be
high on your list since it provides an opportunity to introduce
Chapter members to riveting and the forming of aluminum parts. If you
live in a country where birch plywood is inexpensive, it will probably
prove more practical than aluminum. Fabric(!) over a wooden frame is
a valid method, assuming the trailer can be stored in a secure area.
Finally, if your funds are limited you may have to consider a steel
frame welded from conduit and covered with corrugated roofing panels.

I will include a couple of drawings of a typical glider trailer but a
big part of this project is to encourage input at the local level. We
can also expect to have the real glider folks point us toward some
photos of the real thing.

-R.S.Hoover