18
The ring is engaged on the towhook, the towline un
your assistant (launcher) takes the free end and walks up
until the line is taut. The model should be held under g
tension before it is released. T
(over his shoulder), adjusting his pace to maintain a steady
rate of climb. Take care not to overstress the model during the
launch; this is a particular danger in any wind above moder
strength.
Bungee launching
This is the easiest method of launchi
no assistant is needed, and launc
are easily achieved. From this altitude quite long fl
can be achieved, and the
to contact a thermal, although your chances of this vary ac-
cording to the prevailing
Thermal flying
Making the best use of flat field thermals is not
easy, and calls for considerable skill and experie
rising air are harder to detect and recognis
because they tend to occur at higher altitude
de, where it is often possible to find
cruising along the edge of the
it. A thermal at a flat field which occurs directly overhead is
very hard to recognise,
highly skilled pilot. For this reason it is always best to go
thermal seeking off to one side of
You will recognise thermal contact by the glider’s behaviour.
Good thermals are obvious because the model
strongly, but weak thermals take a practised
and you will need a lot of skill to make use of them.
little practice you will be able to recog
for thermals in the local landscape. The ground warms up in
the sun’s heat, but heat absorption varies
type of terrain and the angle of the sun’s rays. The air over
the warmer ground becomes warm
warm air flows along close to the ground, driven by the bree-
ze. Strong winds usually prev
struction - a shrub or tree, a fence, the edge of
a passing car, even your o
- may cause this w
gine a drop of water on the c
lessly, and initially staying stuck to the ceiling. If it strikes an
obstruction it will fall on your
thought of as the opposite of the drop of
The most obvious thermal triggers
snow fields on mountain slopes. T
is cooled, and flows downhill; at the edge of the snow field,
part-way down the valley, the cool air meets warm air flowing
gently uphill, and pushes it up and a
knife. The result is an extremely po
bubble. Your task is to locate the rising warm air
your model in it. You will need to control the glider constantl
to keep it centred, as you can
in the core of the thermal. Once again, this technique does
demand some skill.
To avoid losing sight of the machine be sure to leave the
thermal in good time. Remember that a glid
to see under a cloud than against a clear bl
to lose height in a hurry, do bear the following in mind:
The structural strength of the Cularis is very great for this
class of model, but it
the model forcibly, please don’t e
pensation from us (alas, we speak from experience).
Flying at the slope
Ridge soaring is an extremely attractive form of model fl
Soaring for hours on end in slope lift,
outside aid for launching, must
ling experiences. But to “milk” a thermal to the limits of vision,
bring it down again in a continuous series of aerobatic ma-
noeuvres, and then repeat the whole show - that must surely
be the last word in model flying.
But take care - there are dangers for your model lurking at the
slope. Firstly, in most cases landing is much more difficult
than at a flat field site. It is usually
of the hill where the air is turbulent; this calls for concentration
and a high-speed appr
on. A landing on the slope face, i.e. right in the slope
even more difficult. Here the trick is to approach slightly
downwind, up the slope, and flare
just before touch-down.
Aero-to
An ideal combination for learning to aero-tow, and for actual
aero-towing, is a Magister and a Cularis. You
brushless power set, # 33 2632, for the Magister.
For the tow you require a 20 m length of brai
1.5 mm Ø. Tie a loop of nylon line (0.5 mm Ø) to the glider
end of the cable; this acts as a “weak link”, in
should go badly
A loop in the other end of the towline should be connect
the aero-tow coupling of the Magister. Assemble the
connect them as described, and set them up directl
wind, the glider behind the tug. Ch
sting on top of the Magister’s tailpla
forward until the towline is taut, and only
pilot apply full-throttle. Both aeroplanes accelerate: the tug
stays on the ground initially, while the glider lifts off, but the
glider pilot keeps his model flying low above the gr
rectly in the wake of the tug; the tug can no
The two models should be kept
through turns. Avoid flying directl
first few attempts at aero-towing, as it is difficult to detect the
models’ attitudes from this angle. T
transmitter control which opens the tow release mechanism.
Electric flying
With the electric version you
nomy and independence. You can fl
carry out about eight climbs to a se
(around 150 m) from a single battery ch
can also keep the electric power system as a “lifebelt”, i.e. you
only use the motor to “keep afloat”, and avoid la
landing at the bottom of the slope when the lift fails.
Flight performance
What is meant by a glider’s performance?
The two most important parameters are sink
glide angle. Sinking speed is a measur
lost per second relative to the surroundi
speed is primarily d
relative to wing area). Here the Cularis offers a re
lent performance - much better than conve
its wing loading is so low (only around 27 g / dm²). T
ans that only slight thermal ass
rising) to cause the model to gain hei
the main factor in determining the model’s airspeed
lower the loading, the slower the model. Lo
that the model can be turned extremel
advantageous when thermal flyi
very small when close to the ground.
