14
Balance the Model (C.G.)
At this stage the model should be in ready-to-fl y condition
with all of the systems in place including the motor, landing
gear, covering, 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 bottom of the wing on both sides of the
fuselage. The C.G. is located 3-5/8" [92mm] back from the
LE of the wing.
❏
2. With the wing attached to the fuselage, all parts of the
model installed (ready to fl y) and a motor battery on board,
place the model on a Great Planes C.G. Machine, or lift it 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, use Great Planes (GPMQ4485)
“stick-on” lead. A good place to add stick-on nose weight
is to the fi rewall. Begin by placing incrementally increasing
amounts of weight on the fuse over the fi rewall 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 under the stab at the fuse. Note:
Do not rely upon the adhesive on the back of the lead weight
to permanently hold it in place. Over time, the adhesive may
soften and cause the weight to fall off. Use thin CA, RTV
silicone or epoxy to permanently hold the weight in place.
❏
4. IMPORTANT: If you found it necessary to add any weight,
recheck the C.G. after the weight has been installed.
Balance the Model Laterally
❏
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 fi n. 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.
PREFLIGHT
Identify Your Model
No matter if you fl y at an AMA sanctioned R/C club site or if
you fl y 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 fl ying sites
and AMA sanctioned fl ying events. Fill out the identifi cation
tag on page 18 and place it on or inside your model.
Charge the Batteries
Follow the battery charging instructions that came with your
radio control system to charge the batteries. You should always
charge your transmitter the night before you go fl ying, and at
other times as recommended by the radio manufacturer.
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 fl ying with
batteries that are only partially charged.
