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THE WING
The wing is built up of a composite sandwich. The 25% chord flap and
the tapered aileron are connected to each other and work as a flaperon. The
spar forward ribs, carry a tubular fuel tank made of fiberglass. The wingtip
is made of a skin of fiberglass.
WING SKIN
The wing skin comprises an upper and lower shell built up of two fiberglass
weaves with a 4 mm Airex foam core in between. The section FWD of the wing
spar has furthermore a carbon fiber weave between the outer FG weave and the
foam core. This has its fibers in 45 deg. for increased torsion stiffness.
WING SPARS
The wing spar is located at 35% cord and is built up of carbon fiber. The
spar caps mainly consist of unidirectional CF tapes with their thickness
adapted to the bending moment curve. At 75% C a C-channel FG spar is located.
This also serves as flaperon channel. The spar web has doublers where the
wing strut and fuselage attachments are located.
AIRFOIL
The chosen airfoil is NACA 643-418. The main reason for this relatively thick
airfoil (18%) is to save weight. With a smooth and even wing
skin, a rather extensive laminar airflow can be achieved which may compensate
for the slightly increased
frontal area and profile drag. The wing chord is 1,000 mm.
FLAPERON
Is divided in an inner part with constant chord and an outer part that tapers
toward its outer end to a chord 50% of its inner end. This outer part’s upper
surface remains in the same plane and the tapering thus creates a twist. The
end result is an aerodynamic twist of 1.39 deg. of the whole wing. The wing
tip chord thereby becomes 900 mm and since the wing panel has a constant
section, the airfoil thickness increases to 20% at the wing tip.
Both flaperon parts are built up of PVC foam ribs
wrapped in a skin of carbon fiber composite.
There is a carbon fiber spar at 17% flaperon chord. Both the skin and the
spar is made of a 100 gr/sq.M carbon fiber weave with epoxy matrix. For
increased torsional stiffness, the fiber direction is 45 deg. to the length
of the flaperon. Each part has two hinges with ball bearings. To allow the
flaperon to move freely also when the wing bends, the connection between the
two parts is stiff in torsion but not in bending.
A lead strip in the nlaperon nose, provides 100% static balancing.
A torsion rod attached to the inner end of the flaperon achieves the flaperon
movement. The end of the rod extends into the fuselage and by a lever
connects directly to the aileron push rod from the joysticks. This oives thm
shortest possible linkage meaning less friction, high stiffness and minimum
play.

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