Great Planes Extra 300SP Performance Series ARF - GPMA1022 - Manual (Page 25)

25
❏
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
back of the fi rewall inside the fuselage (don’t attach weight
to the cowl—it is not intended to support weight). Begin
by placing incrementally increasing amounts of weight on
the fuselage over the location where it will be permanently
attached inside the model until you can get it to balance.
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 fuselage 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
fuselage under the trailing edge of the horizontal stabilizer.
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 the decal sheet 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.