Great Planes Yak-55 EP 3D ARF - GPMA1190 - Manual (Page 13)

fuselage. The C.G. is located 3 " [76.2mm] back from the
leading edge of the wing.
❏
2. With all parts of the model installed, including the
battery (ready to fly) lift it upside-down on your fingertips at
the balance point you marked.
❏
3. If the tail drops, the model is “tail heavy” and the
battery pack and/or receiver must be shifted forward or
weight must be added to the nose to balance. If the nose
drops, the model is “nose heavy” and the battery pack
and/or receiver must be shifted aft or weight must be added
to the tail to balance. If possible, relocate the battery pack
and receiver to minimize or eliminate any additional ballast
required. If additional weight is required, begin by placing
incrementally increasing amounts of weight on the bottom of
the fuse until the model balances. Once you have
determined the amount of weight required, it can be
permanently attached.
❏
4. IMPORTANT: If you found it necessary to add any
weight, recheck the C.G. after the weight has been
permanently installed.
❏
1. With the wing level, have an assistant help you lift the
model by the motor propeller shaft and the bottom of the
fuse under the TE of the fin. Do this several times.
❏
2. If one wing always drops when you lift the model, it means
that side is heavy. Balance the airplane by adding weight to the
other wing tip. An airplane that has been laterally balanced will
track better in loops and other maneuvers.
No matter if you fly at an AMA sanctioned R/C club site or if
you fly somewhere on your own, you should always have
your name, address, telephone number and AMA number
on or inside your model. It is required at all AMA R/C club
flying sites and AMA sanctioned flying events. Fill out the
identification tag on the decal sheet and place it on or inside
your model.
Follow the battery charging instructions that came with your
radio control system to charge the batteries. You should
always charge your transmitter batteries the night before
you go flying, and at other times as recommended by the
radio manufacturer.
Charge the flight battery using a charger designed for
Lithium-Polymer batteries. Charging with any other type of
charger is very dangerous, and may cause the batteries to
combust violently.
Carefully balance your propeller and spare propellers before
you fly. An unbalanced prop can be the single most
significant cause of vibration that can damage your model
and may also damage your radio receiver and battery.
We use a Top Flite Precision Magnetic Prop Balancer ™
(TOPQ5700) in the workshop and keep a Great Planes
Fingertip Prop Balancer
™ (GPMQ5000) in our flight box.
Ground check the operational range of your radio before the
first flight of the day. With the transmitter antenna collapsed
and the receiver and transmitter on, you should be able to
Range Check
Balance the Propellers
CAUTION: Unless the instructions that came with your
radio system state differently, the initial charge on new
transmitter batteries should be done for 15 hours using
the slow-charger that came with the radio system. This
will “condition” the batteries so that the next charge may
be done using the fast-charger of your choice. If the initial
charge is done with a fast-charger the batteries may not
reach their full capacity and you may be flying with
batteries that are only partially charged.
Charge the Batteries
Identify Your model
PREFLIGHT
Balance the Model Laterally
This is where your model should balance for the first
flights. Later, you may wish to experiment by shifting the
C.G. up to 1/2
" [13mm] forward or 1/2 " [13mm] back to
change the flying characteristics. Moving the C.G. forward
may improve the smoothness and stability, but the model
may then require more speed for takeoff and make it
more difficult to slow for landing. Moving the C.G. aft
makes the model more maneuverable, but could also
cause it to become too difficult to control. In any case,
start at the recommended balance point and do not at
any time balance the model outside the specified range.
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