.
The main thing to remember when flying a sailplane is not to over control. If the model does get out of control, and you
have sufficient altitude, a glider is so stable that you can usually just let go of the sticks momentarily and the model will
right itself. Many models have crashed because a beginner continued to send the wrong input. On landing, when the
sailplane is about two feet from the ground, make sure the wings are level and start slowly feeding in some up elevator to
slow the model and establish a gentle descent. The model should settle onto the ground in a slightly nose high attitude.
Thermal Soaring
Thermal soaring is by far the most popular type of
R/C soaring. It is not uncommon to see two or
more sailplanes riding the same thermal, all of
them circling for altitude and staying in the
thermal. A thermal is a rising column of hot air - air
that has been overheated by the sun radiating off
dark areas of ground such as roads, plowed fields,
buildings, etc. Thermals can be found year around
and just about anytime of the day. However, the
most active time for thermals is during the spring
and summer months with mid-morning to mid-
afternoon being the best time of day to find them.
Thermals are easy to detect on days when the
wind is light. Many times you can feel the
temperature difference when the warm thermal air
passes by you. Often a low fluffy cumulus cloud
indicates the location of a thermal. Also watch for
large birds (hawks, gulls, eagles, buzzards, etc.)
circling and maintaining their altitude without
flapping their wings. They are riding a thermal!
Thermals are normally small near the ground and
tend to increase in diameter the higher up they go.
To get into a thermal, we must first gain some
altitude. There are two commonly used methods
of launching a sailplane into the air.
HIGH-START:
A high-start is made up of surgical tubing and nylon cord. Its purpose is to "sling-shot" the glider into
the air like a large rubber band launched model. High-starts come in several different sizes to match the class of
the sailplane being flown - a two meter class or standard class hi-start is recommended for the RISER. The
standard class high-start usually consists of 100 feet of rubber surgical tubing and 350 feet of nylon cord (although
some brands may differ slightly). The surgical tubing is fastened to a stake pounded into the ground. The other end
of the tubing is then tied to the nylon cord, while the other end of the nylon cord has a small parachute attached to
it. The high-start is layed out on the ground directly into the wind. The parachute end of the high start is attached to
the sailplane's towhook. Start walking backwards with the model, stretching the high-start as you go. Go back until
the high-start has been stretched to a maximum of 800 feet.
With the sailplane pointed at the stake, raise the nose to approximately 30 degrees and level the wings. Firmly toss
the sailplane into the air. Feed in a small amount of up elevator after the launch and the sailplane will begin to climb
to the maximum height of the high start. If the sailplane veers to the left or right correct it with opposite rudder. DO
NOT OVER CONTROL! If it constantly veers from side to side and is hard to control, you are probably holding too
much up elevator. Back off a little to regain good directional control. As the sailplane reaches the top, the line
should drop off by itself. If it doesn't, feed in a little down elevator to allow the sailplane to dive slightly and the line
will fall off. Pull back on the elevator to level off so you can start trimming for the flattest glide.
WINCH:
A winch is a battery operated device that uses an electric motor to drive a large spool that reels in the long
towline. There is no rubber surgical tubing involved. As the line is reeled in, it pulls the sailplane up to altitude. The
speed of the winch is normally controlled by the glider pilot using a foot pedal as he flies the model with his hands.
Most competition oriented sailplane enthusiasts prefer a winch launch over a high-start simply because they can
control the speed that the line is reeled in and thus better control the speed and pull on their model. A practiced
winch operator can often get his sailplane to greater heights than with a high-start.