User's Manual

179
Detail program description - Control adjust
value on this line so that a glow motor is held at a safe
idle during the auto-rotation phase without the clutch
engaging; electric drive systems should be set safely to
"Off".
Note:
You may wish to make use of the "Motor Stop" option
on the "Base setup model" menu as an alternative
"Emergency STOP" function.
Tail rotor AR
In normal fl ight, the tail rotor is set so that it
compensates for motor torque while the model is
hovering. It therefore generates some a certain amount
of thrust even in its normal position. The level of thrust is
then varied by the tail rotor control system, and also by
the various mixers which provide all manner of torque
compensation, while the tail rotor trim is also used to
compensate for varying weather conditions, fl uctuations
in system rotational speed and other infl uences.
For auto-rotation, however, the main rotor is not driven
by the motor, but by the "windmill" principle. Since this,
in turn, does not generate any torque for which the tail
rotor must compensate, all corresponding mixers are
switched off automatically.
Since the absence of torque in auto-rotation also means
the above-mentioned thrust is superfl uous, however, a
different tail rotor confi guration is also required:
Cut the motor and place the helicopter on the ground in
a level attitude. With the transmitter and receiving system
switched on, select the fl ight phase "Auto-rotation" and
then fold the tail rotor blades down. Now change the
value on the "Tail rotor" line until the tail rotor blade angle
of attack is zero degrees. Viewed from the tail, the tail
rotor blades should be parallel to one another.
Depending on the friction and running resistance of the
gearbox, the fuselage may still yaw slightly, however. This
relatively slight torque must then be corrected if necessary
by adjusting the tail rotor blade pitch angle. This value
will always be a fi gure between zero degrees and a pitch
angle opposed to the pitch angle in normal fl ight.