Composite-ARF SPARK Instruction Manual page 37

Composite-ARF SPARK
techsupport@composite-arf.com
During take-off and landing both ailerons can be lowered 5 - 8mm, at the root, to act as 'flaper-
ons' if you wish.
Speed brake
The speedbrake should open at least 80 degrees, and 90 degrees is possible. We set it on a
slider on the Transmitter for easy adjustment - depending on the wind conditions.
You can also open the speedbrake about 20 degrees during take-off, which helps the plane to
rotate at slower speeds.
Flying the Spark
The CARF Spark is designed for powerful jet-flying with both electric and turbine propulsion. It
is not a "compromised EDF", where absolute light weight allows you to fly "low cost" with mini-
mum power, at the expense of rigidity and overall performance. It is a full blown Jet airplane, and
can be flown as such.
The structural integrity and aerodynamic design allows speeds up to 200 mph (320 km/h) with
both electric ducted fan and turbine. The control surfaces in size and deflection are well adjust-
ed to such flying, thus the Spark handles the different speeds very smoothly. At the slowest
speeds with high angles of attack it is still very controllable with the quite small control surfaces,
and at high speeds it does not feel "twitchy" at all. Despite its small size it's the smoothest flyer
you can imagine throughout the whole speed range - which is very wide.
The airfoil was developed by Robert Vess in the US for scale model race planes. Its minimum
drag at high loads made us choose this airfoil for the Spark. Large stab surfaces make the Spark
an uncritical flyer. The wings' geometry with the low drag tips accounts for the Spark's agility and
performance.
Aerobatic performance is unlimited. All kinds of rolling maneouvers are easy, vertical maneou-
vers are breathtaking due to the huge propulsion power we designed the Spark for. Even snaps
work great, but one must keep in mind that with such a small plane at such high speeds the snap
roll rate is unbelievable, therefore only the most experienced pilots should attempt snap rolls at
all - especially because it puts the highest possible stress on the airframe, if not done correctly.
Takeoffs and landings are easy, the plane tracks perfectly on the ground and slows down nicely
with the speedbrake. For slower take-off and landing speeds the ailerons can be lowered 5-8 mm
at the root. This increases the lift of the wing and slows the plane down, without making it criti-
cal. Also a 20% extended speed brake helps to rotate the plane during take-off at slower speeds.
With the speedbrake fully deployed, the plane still needs to be brought in with a quite high angle
of attack to slow it down for small flying fields. So, don't worry about slowing the plane down and
getting the nose up in the last turn, even before the final approach.
When we test flew the first prototypes we found the performance and agility that we hadn't even
dreamed of. You will love the flying characteristics of the Spark - that's our promise to you.
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