Page 6 - July 2013

6 - SEXY X2 MAGAZINE - JULY 2013
using materials such as fiberglass and carbon fiber are quickly
replacing aluminum. Composite materials allow aircraft design-
ers to create seamless and rivet-less structures with shapes that
produce less drag.
Wings
If you look at a glider next to a conventional powered plane,
you will notice a significant difference in the wings. While the
wings of both are similar, in general shape and function, those
on gliders are longer and narrower than those on conventional
aircraft. The slenderness of a wing is expressed as the aspect
ratio, which is calculated by dividing the square of the span of
the wing by the area of the wing.
Glider wings have very high aspect ratios -- their
span is very long compared to their width. This
is because drag created during the produc-
tion of lift (known as induced
drag) can
account for a signifi-
cant portion of the total
drag on a glider.
One way to increase
the efficiency of a wing is to
increase its aspect ratio. Glider
wings are very long and thin, which
makes them efficient. They produce less drag
for the amount of lift they generate.
The aspect ratio of a wing is the wingspan squared divided by
the area of the wing. The glider has a much larger aspect ratio
than a conventional plane.
Why not all planes have wings with high aspect ratios? There
are two reasons for this. The first is that not all aircraft are
designed for efficient flight. Military fighters, for example, are
designed with speed and maneuverability well ahead of effi-
ciency on the designer’s list of priorities. Another reason is that
there are limits to how long and skinny a wing can get before
In its simplest form, a glider is an unpowered aircraft,
an airplane without a motor. While many of the same de-
sign, aerodynamic and piloting factors that apply to powered
airplanes also apply to gliders, that lack of a motor changes a
lot about how gliders work. Gliders are amazing and graceful
machines, and are about as close as humans can get to soar-
ing like birds.
If you enjoy aviation sports, then you should check out
the paragliding article, video and images at Discov-
ery’s Fearless Planet to learn more.
From paper airplanes to the space shuttle during re-entry,
there are many types of gl­iders. In this article, we will
focus on the most common type of glider, often referred to
as a sailplane.
A glider has many of the same parts as an airplane:
Fuselage, wings, control surfaces, landing gear
However, there are significant differences in these
parts on a glider, so let us take a look at each.
Fuselage
Gliders are as small and light as pos- sible.
Since there is no large engine taking up space,
gliders are basically sized around the cargo they carry, usually
one or two people. The cockpit of a single-seat glider is small,
but it is large enough for most people to squeeze into. Instead
of sitting upright, pilots recline with their legs stretched out in
front of them. The frontal exposure of the pilot is reduced and
the cross-sectional area of the cockpit can be substantially
smaller.
Gliders, along with most other aircraft, are designed to have
skins that are as smooth as possible to allow the plane
to slip more easily through the air. Early glid-
ers were constructed from wood covered
with canvas. Later versions were
constructed from aluminum with
structural aluminum skins that were
much smoother. However, the rivets
and seams required by aluminum
skins produce additional drag, which
tends to decrease performance. In
many modern gliders, composite construction