Great Planes P-51 Mustang GP/EP ARF - GPMA1205 - Manual (Page 21)

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for the 2 oz. [57g] weight). If spinner weight is not practical or
is not enough, use Great Planes (GPMQ4485) “stick-on” lead.
A good place to add stick-on nose weight is to the fi rewall
(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 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 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.
Balance the Model Laterally
❏
1. With the wing 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 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 24 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 and receiver batteries 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 and receiver 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.
Balance Propellers
Carefully balance your propeller and spare propellers before
you fl y. An unbalanced prop can be the single most signifi cant
cause of vibration that can damage your model. Not only
will engine mounting screws and bolts loosen, possibly with
disastrous effect, but vibration may also damage your radio
receiver and battery. Vibration can also cause your fuel to
foam, which will, in turn, cause your engine to run hot or quit.
We use a Top Flite Precision Magnetic Prop Balancer
(TOPQ5700) in the workshop and keep a Great Planes
Fingertip Prop Balancer (GPMQ5000) in our fl ight box.
Ground Check
If the engine is new, follow the engine manufacturer’s
instructions to break-in the engine.
After break-in, confi rm
that the engine idles reliably, transitions smoothly and rapidly
to full power and maintains full power—indefi nitely. After you
run the engine on the model, inspect the model closely to
make sure all screws remained tight, the hinges are secure,
the prop is secure and all pushrods and connectors are secure.
Range Check
Ground check the operational range of your radio before the
fi rst fl ight of the day. With the transmitter antenna collapsed
and the receiver and transmitter on, you should be able to walk
at least 100 feet away from the model and still have control (if
using a 2.4GHz radio system, refer to the radio manual for the
range checking procedure). Have an assistant stand by your
model and, while you work the controls, tell you what the control
surfaces are doing. Repeat this test
with the engine running
at various speeds with an assistant holding the model, using
hand signals to show you what is happening. If the control
surfaces do not respond correctly,
do not fl y! Find and correct
the problem fi rst. Look for loose servo connections or broken
wires, corroded wires on old servo connectors, poor solder
joints in your battery pack or a defective cell, or a damaged
receiver crystal from a previous crash.