Balancing
The Centre of Gravity should be within the range 70 to 90 mm aft of the wing root
leading edge; if necessary, adjust the position of the receiver battery until this is the
case. Check the CG by supporting the model under the wing roots on two fingertips;
it should then balance level.
Test-flying
For test-flying please wait for a day with flat calm conditions, or no more than a very
gentle breeze. A grassy meadow with a gentle slope facing directly into wind is ideal.
Assemble the model completely, ready to fly, and check that the control surfaces are
at neutral.
Give the model a hand-glide by pushing it forward directly into any breeze, with
the wings level and the nose inclined slightly down. Trot forward for a few
steps to gain sufficient launch speed. On no account throw the model upward as if
it were a javelin. If you do, the model will climb briefly, then stall and return to earth
very abruptly, usually suffering damage in the process. If necessary, the model
should be trimmed for straight flight by applying very slight rudder correction. Fine
trimming is carried out by adjusting the trim sliders located below and adjacent to the
transmitter sticks. If you have set the CG to the forward end of the range (70 to 80
mm) you will need to trim the elevator up by about 1 mm.
Start by flying the model with small control deflections. Keep the machine flying in
straight lines as far as possible, and keep all turns broad and flat initially. Important:
the procedure for turning the model is to apply rudder for a moment to initiate
the turn, then neutralise the stick again. If you hold the rudder over for too
long, or with too great a deflection, the turn will tighten up and degenerate into
a spiral dive. Land the model exactly into wind with the motor stopped, and reduce
its airspeed just before touch-down by applying gentle up-elevator. Always land
directly into wind!
If you have access to a smooth take-off strip, you can allow the Elektro-UHU to take
off from the ground, just like a full-size aeroplane. Once again you must take off
exactly into wind. The rudder is used to keep the model on course on the ground.
There will be a tendency for the model to tip forward on the take-off run, but you can
prevent this by applying full up-elevator while it is gathering speed. The Elektro-UHU
takes off after a ground-roll of about three metres.
All of us at GRAUPNER Modellbau wish you many fine flights with your new model,
the >Elektro-UHU<.
