Great Planes Fokker Dr-1 60 ARF - GPMA1380 - Manual (Page 27)

At this stage the model should be in ready-to-fly condition
with all of the systems in place including the engine, landing
gear, covering and paint and the radio system.
❏
1. Use a Top Flite Panel Line Pen or 1/8" wide tape to
accurately mark the C.G. on the bottom of the mid wing on
both sides of the fuselage. The C.G. is located 2-5/8"
[67mm] back from the leading edge of the mid wing.
❏
2. With the wings attached to the fuselage, all parts of the
model installed (ready to fly) and an empty fuel tank, lift the
model 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
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 top 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. Note: Do
not rely upon the adhesive on the back of the lead weight to
permanently hold it in place. Over time, fuel and exhaust
residue may soften the adhesive and cause the weight to fall
off. Use #2 sheet metal screws, 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.
❏
1. With the wings level, have an assistant help you lift the
model by the engine 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 page 35 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 and receiver batteries 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
2-5/8" [67mm]
This is where your model should balance for your first flights.
Later, you may wish to experiment by shifting the C.G. up to
3/4" [19mm] forward or 5/8" [16mm] back to change the flying
characteristics. Moving the C.G. forward may improve the
smoothness and stability, but it 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 for you to control. In any
case, start at the location we recommend and do not at any
time balance your model outside the recommended range.
2-5/8" [67mm]
Middle Wing
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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