THUNDER TIGER E-HAWK 2000 Assembly Instruction Manual page 15

THE FIRST FLIGHTS
You should always use the first few flights to get
accustomed to your new airplane and its flying
characteristics. Keep the model upwind and climb to
a good comfortable altitude to cut off the motor and
trim your E-Hawk for a glide. At altitude cut the motor
and start your glide. Have an experienced modeler
adjust the trims of the transmitter for you until the
plane will glide straight and level without any other
control input. Once the trims are set practice making
smooth turns in both directions while losing as little
altitude as possible. When the E-Hawk starts to get
too low for comfort turn the motor back on and climb
back up to altitude. Practice this climbing and gliding
until you are comfortable with the airplane.
Depending on the battery you use the E-Hawk will
make 2 to 3 good climbs up to a nice thermal
searching altitude from single battery charge. Once
the Auto Cut-off Device or ESC shuts off the power to
the motor you will need to set up for your landing.
Continue to make smooth gently turns while lining up
the E-Hawk with your landing strip. Once you are set
up to land keep the wings level and let the model
settle in for an nice gentle landing while adding up
elevator to keep the nose up slightly as the plane
slows down. Make several flights like this to really
familiarize yourself with the characteristics of your
model and to learn the glide and distance covering
abilities of the E-Hawk. Once you have mastered a
good "comfort level" you are ready to start searching
for thermals which will really increase your flight times.
THERMALS
Thermal soaring is one of the most interesting and
challenging types of flying there is. Believe it or not,
your E-Hawk is capable of flights thousands of feet
high, lasting for several hours, and covering dozens of
miles. The following paragraphs will help explain how
to take advantage of natures energy sources called
thermals.
"Thermal" is the term applied to columns of rising air.
This air is rising because it is warmer than the
surrounding air. A dust devil is simply a thermal which
ahs picked up some dust. Even a tornado is very
similar to a thermal, but of course much stronger.
Thermals occur when the sun, or other heat source,
heat the air in one location faster and/or warmer than
the surrounding air. Darker surfaces (plowed fields,
asphalt parking lots, etc.) absorb the sun's energy
faster than lighter colored and are generally good
thermal generators. This warmer air is lighter (less
dense) than the cooler air and thus rises. The rising
air naturally starts to rotate, much like water going
down a drain, and forms an inverted funnel shaped
column that usually gets larger with altitude. This
warmer air often contains water vapor which
condenses as it reaches the cooler air high above the
earth forming big puffy Cumulus clouds that
experienced sailplane flyers will watch to determine
where the thermals are forming. Thermals vary in
strength, but often contain air that is rising at speeds
over 1200 feet per minute. Some thermals are so
strong they can even rip a sailplane apart, especially
if the plane is flying fast when it passes through the
thermal.
THERMAL SOARING
It takes lots of practice and concentration to thermal
soar like the Hawks and Eagles. Since the pilot is not
sitting inside an model sailplane, he cannot feel the
thermal, he can only see his sailplanes reaction to the
thermal. Therefore, the majority of the time, unless
the pilot is paying careful attention to the plane, he
may not even realize that plane is near a thermal.
Since most thermals are relatively small, less than a
hundred feet in diameter near the ground, the
sailplane will rarely fly directly into the thermal and
start rising. More likely, it will fly near a thermal and
the wing closest to the thermal will rise turning the
plane away from the thermal. So as you can see, an
inexperienced pilot may bounce around between the
thermals with ever knowing that he is encountering
rising air.
In order to take advantage of thermals, you need to fly
smoothly with as few control inputs as possible.
Watch the sailplane carefully and it will tell you what
the air around it is doing.
When a sailplane does fly directly into a thermal it will
either start rising or stop sinking at its normal rate.
Either case is reason enough to explore further.
Continue flying straight ahead until you have
obviously passed through the area of strongest lift.
Now start circling in fairly tight, but smooth circles.
Because of the thermals inverted funnel shape, the
lower the planes altitude, the tighter the circles need
to be. As the plane gains altitude, the diameter of the
circles can be increased. If you see the plane falling
off on one side of the turn, move the circle over into
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