Reely HCP80 3D RtF Notice D'emploi page 87

If the adjustment areas of the nod and roll trimming are not quite adequate for an optimum correction, you
adjust control of the main rotor blades mechanically. For further information, refer to the following chapter
11 „Fine-tuning the model helicopter".
Pitch trim:
Adjust the pitch value to the middle value (higher signal sound) with the trim button for pitch trimming (see figure 1,
item 16). The helicopter should then hover at a consistent height if the control stick for the pitch function is in its middle
position. If required, you can correct the control stick position where the helicopter is in hover flight with the trim button.
Caution, important!
If you push the trim button up repeatedly until the upper end position of the pitch trimming is reached, the
rotors of the helicopter may already start up if the flight battery is connected, even though the control stick
for the pitch function is still in the bottom position.
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