Ground Effect
ATTENTION!
Up to a height of about 30 cm, the model is in the area of in
ß
uence of the air turbulence caused by its own
rotors.
On one hand, this “ground effect” facilitates the lift off of the helicopter since
the air pressed downwards by the rotors of the helicopter helps lift the aircraft
from the ground.
But in the immediate area this effect is reversed, since the air
ß
owing away
laterally from the helicopter creates an underpressure and the model is
actually sucked back down towards the ground. This can lead to an ungentle
landing.
For this reason the
ß
ight behaviour of the model at low heights is rather un-
stable. If the restless
ß
ight behaviour causes dif
Þ
culties for you, increase the
ß
ying height by degrees.
The helicopter is no longer in the area of in
ß
uence of the air turbulence from its own rotors as of a
ß
ying height of
about 2 m and the
ß
ight situation is more stable.
Begin with simple
ß
ying formations:
- Train your command of the model, allow it to ascend and descend, hover and move for-
wards and backward in the air as well as execute turns.
- When you feel secure, stand laterally to the model and practice control from this angle of
view or
- allow the model to
ß
y toward you and control it in the opposite direction
- Avoid jerky load variation. since otherwise the upper and lower rotor could touch and cause
the model to crash.
- Always
ß
y the model in front of you or allow it to circle above you.
If you allow the model to
ß
y behind your back, you could lose your orientation and thereby
the control over the helicopter.
-
Never attempt to catch the model in mid
ß
ight!
Corrective action
The rotor blades of the two principal rotors have the largest in
ß
uence on the
ß
ight characteristics of the helicopter.
Very often one can attain a major improvement of
ß
ight behaviour simply by exchanging one or more rotor blades. There is
an especially serious difference between balanced and non-balanced rotor blades. If the model does not show a balanced
ß
ight behaviour, then at
Þ
rst the balancing state of the rotor blades should be inspected and corrected and if necessary the
respective blade should be replaced.
The
track running
of the rotor blades also has an influence on the flight behaviour apart from the balancing state. Both
rotor blades of a rotor rotation travel exactly in one plane if their track running is correct. If this is not the case, vibrations
arise which adversely affect the flight behaviour.
To check the track running, mark a blade tip with colour and observe the corresponding rotor rotation from the side.
If the marked and the unmarked blade apparently “overlap”, then the track
running is correct (1).
Otherwise you will see both points at different heights (2).
(1)
(2)
12 CARSON Apache 2CH 507001
WWW.CARSON-MODELSPORT.COM
