At this stage the model should be close to ready-to-fly
condition with all of the systems in place including the motor,
landing gear, motor battery, and the radio system.
❏
1. Use a felt-tip pen or 1/8" [3mm]-wide tape to accurately
mark the C.G. on the top of the wing on both sides of the
fuselage. The C.G. is located 2-3/16" [56mm] back from the
leading edge of the wing.
❏
2. With the wing attached to the fuselage, all parts of the
model installed (ready to fly) and the motor battery installed,
place the model upside-down on a Great Planes CG Machine,
or lift it upside down at the balance point you marked.
❏
3. If the tail drops, the model is “tail heavy” and the motor
battery 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 motor battery and/or receiver must be
shifted aft or weight must be added to the tail to balance. If
possible, move the motor battery and receiver forward or aft
to minimize or eliminate any additional ballast required. If
additional weight is required, use Great Planes [GPMQ4485]
“stick on” lead. A good place to add stick-on nose weight is to
the firewall (don’t attach weight to the cowl-it is not intended
to support weight). Begin by placing incrementally increasing
amounts of weight on the bottom of the fuse over the firewall
until the model balances. Once you have determined the
amount of weight required, it can be permanently attached. If
required, tail weight may be added by cutting open the bottom
of the fuse and gluing it permanently inside.
If moving the motor battery forward or aft will balance the
plane without adding additional weight, mark the battery tray
or the fuselage inside where the aft end of the battery
should be placed. This will allow you to position the battery
correctly before each flight.
❏
4. IMPORTANT: If you found it necessary to add any
weight, recheck the C.G. after the weight has been installed.
❏
1. With the wing level lift the model by the prop 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 page 23 and place it on or inside your model.
Follow the battery charging instructions that came with your
radio control system to charge the transmitter. You should
always charge your transmitter the night before you go flying
and at other times as recommended by the radio manufacturer.
Charge the Batteries
Identify Your Model
PREFLIGHT
Balance the Model Laterally
2-3/16" [56mm]
This is where your model should balance for the first
flights. Later, you may wish to experiment by shifting the
C.G. up to 3/16" [5mm] forward or 3/16" [5mm] 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.
More than any other factor, the C.G. (balance point) can
have the greatest effect on how a model flies and may
determine whether or not your first flight will be
successful. If you value this model and wish to enjoy it for
many flights, DO NOT OVERLOOK THIS IMPORTANT
PROCEDURE. A model that is not properly balanced will
be unstable and possibly unflyable.
Balance the Model (C.G.)
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