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d) Checking the Centre of Gravity Position
Let your model climb to a safe height and then switch off the motor. Fly at a 90°-angle to your view and push the model
down against the wind at an angle of approx. 30°. If the model has picked up speed, move the control lever for the
elevator back to the middle position and observe the flying behaviour of your model.
If the model catches itself on its own in a flat angle, the
centre of gravity is set correctly (see figure 13, curve A).
If the model catches itself quickly and flies upwards in a
curve, the centre of gravity is too far towards the front. The
model is too heavy in front (see figure 13, curve B).
If the model continues to fly on straight and the pilot has to
catch it by remote control command, the centre of gravity
is too far towards the rear. The model is too heavy in the
tail (see figure 13, curve C).
e) Checking the Slow-Flight Characteristics
Let your model climb to a safe height again and then switch off the motor. Slowly increase the elevator deflection in
order to reduce your model's flying speed. Now observe the speed at which the model starts to react inaccurately to
control commands and when it starts to tip.
If the centre of gravity is correct, the model will tip down with the fuselage tip and can be fully controlled again after
losing a few metres of altitude.
If your model tips over its wing, check whether one wing half is heavier than the other after landing (balancing around
the longitudinal axis) and if the centre of gravity is set correctly.
f) The First Touch-Down
Like the start, landing should always be performed against the wind. When approaching for touch-down, ensure that
you have enough speed and reduce speed only when you are near the ground by continually pulling the elevator.
Caution, important!
Check the motor, flight controller and flight battery temperatures at once after the first flight.
Then you may re-adjust the rudder, elevator and aileron linkages so that the model flies straight and the trim levers on
the transmitter are in centre position again.
Figure 13
