Great Planes L-39 EP Ducted Fan ARF - GPMA1869 - Manual (Page 11)

11
GET THE MODEL READY TO FLY
Check the Control Directions
❏
1. Turn on the transmitter and receiver and center the trims.
❏
2. With the transmitter and receiver still on, check all the
control surfaces to see if they are centered. If necessary, adjust
the pushrod connectors on the control surface pushrods.
ELEVATORS MOVE UP RIGHT AILERON MOVES UP
LEFT AILERON MOVES DOWN
FULL THROTTLE
3-CHANNEL RADIO SETUP
(STANDARD MODE 2)
❏
3. Make certain that the control surfaces and the throttle
respond in the correct direction as shown in the diagram.
If any of the controls respond in the wrong direction, use
the servo reversing in the transmitter to reverse the servos
connected to those controls. Be certain the control surfaces
have remained centered. Adjust if necessary.
Set the Control Throws
Use a Great Planes AccuThrow ™ (or a ruler) to accurately
measure and set the control throw of each control surface
as indicated in the chart that follows. If your radio does not
have dual rates, we recommend setting the throws at the
low rate setting.
These are the recommended control surface throws:
High Rate Low Rate
ELEVATOR: 5/16" [8mm] up 1/8" [3.2mm] up
5/16" [8mm] down 1/8" [3.2mm] down
AILERONS: 3/16" [4.8mm] up 3/32" [2.4mm] up
3/16" [4.8mm] down 3/32" [2.4mm] down
NOTE: The throws are measured at the widest part of
the control surfaces.
IMPORTANT: The L-39 ARF has been extensively fl own
and tested to arrive at the throws at which it fl ies best. Flying
your model at these throws will provide you with the greatest
chance for successful fi rst fl ights. If, after you have become
accustomed to the way the L-39 fl ies, you would like to
change the throws to suit your taste, that is fi ne. However,
too much control throw could make the model diffi cult to
control, so remember, “more is not always better.”
Balance the Model (C.G.)
More than any other factor, the C.G. (balance point)
can have the greatest effect on how a model fl ies, and
may determine whether or not your fi rst fl ight will be
successful. If you value this model and wish to enjoy it for
many fl ights, DO NOT OVERLOOK THIS IMPORTANT
PROCEDURE. A model that is not properly balanced will
be unstable and possibly unfl yable.
At this stage the model should be in ready-to-fl y condition
with all of the systems in place including the receiver, ESC,
and battery pack.
❏
1. The C.G. is located 1-15/16" [49mm] back from
the leading edge of the wing at the fuselage (the seam
where the wing panels have been joined to the fuselage).
If you mark the C.G. position onto the top of the wing, be
very careful if using tape as it could damage the paint when
removed. Also, do not attempt to remove felt-tip pen marks
with alcohol. We suggest making small marks on the wing
beneath the ducted fan inlets.
This is where your model should balance for the fi rst
fl ights. Later, you may wish to experiment by shifting the
C.G. up to 3/16" [4.8mm] forward or 1/8" [3.2mm] back to
change the fl ying characteristics. Moving the C.G. forward
may improve the smoothness and stability, but the model
may be more diffi cult to slow for landing. Moving the C.G.
aft makes the model more maneuverable, but could also
cause it to become too diffi cult to control. In any case,
start at the recommended balance point and do not at
any time balance the model outside the specifi ed range.