FINE-TUNING BALANCE POSITION (i.e. Center of Gravity)
►
It is well worth spending a little time verifying the proper balance and trim of your glider. Doing so will
ensure the Alula-TREK is a pure joy to fly and reacts predictably to the varying air currents experienced
while soaring. We find it easiest to fine-tune the CG position on the slope in light to moderate lift. This will
make it easy to climb quickly to altitude for the "dive test" described below.
To fine-tune the CG position for optimum performance, first climb to safe altitude, and verify glider is
trimmed for straight and level flight. Proceed to put glider into 45° dive. Allow glider to dive "hands-off"
and see which of the three scenarios holds true for your glider:
1.
Correct CG Position:
If properly balanced and trimmed for level flight, the Alula-TREK will remain in a
straight 45° hands-off dive. Additionally, a well-balanced and trimmed aircraft will fly hands-off in a
straight and level glide for a good while. If instead your glider noses up or down as speed increases, this
is a sign that your CG position is off; read on if this is the case.
2.
Nose-Heavy (too forward CG):
If the glider noses up as speed increases without any elevator input, the
aircraft is most likely nose-heavy.
Solution:
Remove a bit of nose-weight and add DOWN elevator trim
until the first scenario above is achieved.
3.
Tail-Heavy (too rearward CG):
If the glider increases steepness of dive at higher speed (i.e. "tucks
under"), then it is tail-heavy. A tail-heavy glider will be a chore to fly, constantly requiring elevator input
to maintain a smooth flight trajectory.
Solution:
Add nose-weight and UP elevator trim until the first
scenario above is achieved.
IMPORTANT NOTES
:
Make sure your transmitter's trim
steps are set to the absolute
minimum, since small flying wings
like the Alula-TREK are very
sensitive to trim adjustments. Note
that not all transmitters have
adjustable trim steps.
In order to achieve trimmed flight,
you will have to adjust elevator
trim slightly each time you add or
remove balance weight to the
nose of the glider.
19.
