Basic HTML Version
JULY 2013 -
SEXY X2
MAGAZINE -
7
SAILPLANES
Flying feeling like a bird
Landing Gear
Another way to reduce the size of an airplane is to reduce
the size of the landing gear. The landing gear on a glider
typically consists of a single wheel mounted just below the
cockpit.
Getting off the Ground
Three basic forces act on gliders: lift, gravity and drag (air-
planes have a fourth force: thrust):
Lift is the all-important force, created by the wings and counter-
acting the weight, which allows an aircraft to stay aloft. In the
case of a glider, the lift is enhanced through the use of highly
efficient wings.
Drag is the force that tends to slow a plane down. Drag reduc-
tion is critical on a glider, even more so than on a convention-
al airplane. In motorized aircraft, a pilot can simply increase
the thrust (using the engines) to overcome drag. Since there is
no engine on a glider, the drag must be minimized wherever
possible or the plane will not remain in the air for long.
Weight can be made to work for or against a glider. A lighter
overall weight, for example, may allow the glider to stay
aloft longer or travel further. A heavier weight, on the
other hand, can be an advantage if greater speed is
the objective. Many gliders contain ballast tanks that
pilots can fill with water before takeoff. The added
weight of the water allows greater speeds while in
the air. If the pilot wished to reduce his weight, he can
dump the tanks while in the air to lighten the plane.
Without an engine, a glider’s first problem is getting off
the ground and up to altitude. The most common
launching method is an aero-tow. A conventional
powered plane tows the glider up into the
sky using a long rope. The glider
pilot controls a quick-release
mechanism
located
in the glider’s nose and
releases the rope at the desired altitude.
Right after release, the glider and the tow plane turn in
it is no longer able to carry the required
loads.
Control Surfaces
Gliders use the same control
surfaces
(movable sections of the
wing and tail)
that are found on conven-
tional planes to
control the direction
of flight. The ailerons
and elevator are
controlled using a single
control stick
between the pilot’s legs. The
rud-
der, as in conventional aircraft, is
controlled using foot pedals.
Mouse-over the control names to see where
they are located on the glider.
Ailerons:
Ailerons are the movable sections cut into the trailing
edges of the wing. These are used as the primary directional
control and they accomplish this by controlling the roll of the
plane (tilting the wing tips up and down). Ailerons operate
in opposite directions on each side of the plane. If the pilot
wants to roll the plane to the right, he moves the control
stick to the right. This causes the left aileron to deflect
down (creating more lift on this side) and the right
aileron to deflect up (creating less lift on this
side). The difference in lift between the two
sides causes the plane to rotate about its long
axis.
Elevator (horizontal stabilizer):
The elevator is the movable horizontal wing-like struc-
ture on the tail.
It
is used to
control
the pitch
of the plane,
allowing the pilot
to point the nose of the plane up
or down as required.
Rudder (vertical stabilizer):
The rudder is the vertical wing-
like structure
on the tail. It is used to control the yaw of the aircraft by allow-
ing the pilot to point the nose of the plane left or right.