Multiplex alpha 21 Instrucciones De Montaje página 16

As the range increases your assistant should operate one
transmitter function constantly while you watch the model's
control surfaces. The servos not being moved should remain
motionless up to a range of about 80 m, and the moving
servo should follow the stick deflections immediately and
smoothly.
This test can only be carried out successfully if the radio
band is not suffering interference, and if no other RC
transmitters are switched on - even on different channels!
Note that in high mountain areas extreme field strengths
and excessive range of other transmitters makes such
checking procedures worthless.
If you are not sure the system is working correctly, please
don't risk a flight - even if you are dying to fly the new glider
and your mates are egging you on. Check first that your
channel really is vacant. If so, and if the problem persists,
pack up your entire RC system (complete with batteries,
switch harness and servos) and send it back to the equipment
manufacturer for checking.
Faults don't cure themselves!
The first flight
The first flight can be carried out in any of several ways - at
the slope from a hand-launch, at a flat field using a bungee
system or winch. If you have fitted an electric power system
the model has to be hand-launched.
For the first flight ask an experienced modeller to launch for
you, so that you have both hands on the sticks right from
the outset.
Adjust the trims as necessary once the model is at a safe
altitude: straight and level flight at cruise speed is the first
aim. The next step is to fly turns alternately to left and right
to check the model's turning characteristics, the
harmonisation (balance) between ailerons, elevator and
rudder, and the aileron differential. Be sure also to lower the
landing flaps (or raise the ailerons) so that you have a chance
to see the resultant change in pitch trim.
If you still have plenty of height you should check the Centre
of Gravity right at this early stage. The procedure for CG
testing described here is a method of fine-tuning the
model's balance. It can only work when air movements are
slight, and when the initial CG position is approximately
correct. It is bound to fail if the model is way out of balance
and/or there is a strong wind. In windy conditions it is
difficult to set up the model for normal cruise speed, as it is
hard to judge the model's speed relative to the surrounding
air.
Now - assuming that you have plenty of height in hand -
apply full down-elevator briefly to place the model in a
vertical dive. Immediately centre the stick and watch the
model carefully. If it recovers to normal flight in a broad,
gentle curving arc (30 - 40 m) by itself, without ballooning
up above the horizontal, then the CG is correct.
If the model bounces up again immediately and climbs
strongly, the CG is too far forward. If possible move the flight
battery slightly further aft to move the CG back. If not,
remove a little lead ballast (about 30 g) from the nose, apply
slight down-trim, and repeat the test.
If the model shows no tendency to recover by itself - the dive
may even become steeper - the CG is too far aft. Immediately
recover the model with gentle up-elevator. If possible move
the flight battery slightly further towards the nose to move
the CG forward. Add a little lead (min. 20 g, max. 40 g) to the
fuselage nose, fix it securely, and apply a little up-trim.
Repeat the test.
16
Safety
Safety is the First Commandment when flying any model
aircraft. Third party insurance should be considered a basic
essential. If you join a model club suitable cover will usually
be available through the organisation. It is your personal
responsibility to ensure that your insurance is adequate.
Make it your job to keep your models and your radio control
system in perfect order at all times. Check the correct
charging procedure for the NC batteries used in your RC set.
Make use of all sensible safety systems and precautions
which are advised for your system. An excellent source of
practical accessories is the MULTIPLEX main catalogue, as
our products are designed and manufactured exclusively by
practising modellers for other practising modellers.
Always fly with a responsible attitude. You may think that
flying low over other people's heads is proof of your
piloting skill; others know better. The real expert does not
need to prove himself in such childish ways. Let other pilots
know that this is what you think too. Always fly in such a way
that you do not endanger yourself or others. Bear in mind
that even the best RC system in the world is subject to
outside interference. No matter how many years of accident-
free flying you have under your belt, you have no idea what
will happen in the next minute.
The fascination of it all
Model flying is, and always has been, a fascinating hobby,
and a thoroughly enjoyable way of spending your leisure
hours. Take your time to get to know your new alpha21 / 27
really well. Plan to spend many hours in the open air, where
you will learn to appreciate the model's outstanding
performance and its docile handling. You can join us in
enjoying one of the few types of sport which combine high
technology, manual dexterity, and sophisticated personal
skills. You can fly alone or with friends, and at the same time
you can enjoy the pleasures of nature - treats which have
become rare in today's world.
We - the MULTIPLEX team - wish you many hours of pleasure
in building and flying your new model. Happy landings!
MULTIPLEX Modelltechnik GmbH
Model Development Dept.