Global Hobby AK-18 Instructions Manual Download Page 22

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4) The switch should be mounted on the fuse-

lage side, opposite the muffler, close enough to the
receiver so the lead will reach. Use the faceplate of
the switch itself to locate and mark the switch cutout
and mounting holes.

5) Cut out the switch hole using a modeling

knife. Use a 5/64” drill bit and drill out the two mount-
ing holes through the fuselage side.

6) Secure the switch in place using the two ma-

chine screws provided with the radio system.

7) Mount the optional Cirrus On-Board Battery

Indicator and the optional Ernst charge jack to the
fuselage side. Plug the battery indicator into an empty
slot in the receiver and secure the charge lead firmly
into the charge jack.

INSTALLING THE SWITCH

1) It is critical that your airplane be balanced

correctly. Improper balance will cause your plane to
lose control and crash. The center of gravity is lo-
cated 3-1/8” back from the leading edge of the wing,
at the fuselage sides. This location is recommended
for initial test flying and trimming. There is a 3/8”
margin forward and aft, but it is not recommended
that the center of gravity be located any further back
than 3-1/2”. Balance the Yak-18 upside down with
the fuel tank empty.

2) Mount the wing to the fuselage. Using a

couple of pieces of masking tape, place them on the
top side of the wing 3-1/8” back from the leading edge,
at the fuselage sides.

3) Turn the airplane upside down. Place your

fingers on the masking tape and carefully lift the plane.

4) If the nose of the plane falls, the plane is nose

heavy. To correct this first move the battery pack fur-
ther back in the fuselage. If this is not possible or does
not correct it, stick small amounts of lead weight on
the fuselage sides under the horizontal stabilizer. If
the tail of the plane falls, the plane is tail heavy. To
correct this, move the battery and receiver forward or
if this is not possible, stick weight onto the firewall or
use a brass heavy hub spinner hub, similar to those
offered by Harry Higley. When balanced correctly,
the airplane should sit level or slightly nose down when
you lift it up with your fingers.

BALANCING

Once you have flown and trimmed the Yak-18
the balance point can be moved forward or aft

up to 3/8” to change the flight performance. Moving
the balance point back will cause the airplane to be
more responsive, but less stable. Moving the balance
point forward will cause the airplane to be more stable,
but less responsive. Do not fly the Yak-18 beyond
the recommended balance range or an uncontrol-
lable crash could result!

By moving the position of the clevis at the con-
trol horn toward the outermost hole, you will

decrease the amount of throw of that control surface.
Moving the clevis toward the control surface will in-
crease the amount of throw.

CONTROL THROWS

1) We highly recommend setting up the Yak-18

using the control throws listed below. We have listed
control throws for both initial test flying/sport flying
and aerobatic flying.

2) Turn on the radio system. With the trim tabs

on the transmitter in neutral, center the control sur-
faces by making adjustments to the clevises. The
servo arms should be centered also.

3) When the elevator, rudder and aileron con-

trol surfaces are centered, use a ruler and check the
amount of the control throw in each surface. The
control throws should be measured at the widest
point of each surface!

FLIGHT PREPARATION

1) Check the operation and direction of the

elevator, rudder, steering, ailerons and throttle.

A) Plug in your radio system per the

manufacturer's instructions and turn everything on.

INITIAL FLYING/SPORT FLYING

Ailerons:

5/16” up

5/16” down

Elevator:

5/16” up

5/16” down