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At this stage the model should be in ready-to-fly condition
with all of the systems in place including the motors, landing
gear, complete radio system, and 8-cell battery.

1. Use a felt-tip pen or 1/8"-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 2-7/16" [62mm] 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), 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

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, nose weight may
be easily added by using Great Planes (GPMQ4485) “stick
on” lead. A good place to add stick-on nose weight is to the
inside of the nose section of the fuselage. Begin by placing
incrementally increasing amounts of weight on the bottom of
the fuse over the nose 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
and glued permanently inside the fuselage.

Note: Do not rely upon the adhesive on the back of the lead
weight to permanently hold it in place. 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 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 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 the back cover and place it in your model.

Follow the battery charging instructions that came with your
radio control system to charge the batteries. You should
always charge your transmitter 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

This is where your model should balance for the first
flights. Later, you may wish to experiment by shifting the
C.G. up to 2-5/16" [59mm] forward or 2-3/4" [70mm] 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.)

17

Summary of Contents for Douglas DC-3

Page 1: ...sed to return this kit immediately in new and unused condition to the place of purchase To make a warranty claim send the defective part or item to Hobby Services at the address below Hobby Services 3...

Page 2: ...ts Information about R C clubs and instructors is provided later in this manual For the latest technical updates or manual corrections to the DC 3 EP ARF visit the Great Planes web site at www greatpl...

Page 3: ...w modelaircraft org This is a partial list of items required to finish the DC 3 EP ARF that may require planning or decision making before starting to build Order numbers in parentheses are provided f...

Page 4: ...pplicator tips GPMR6033 Curved tip canopy scissors for trimming plastic HCAR0667 When you see the term test fit in the instructions it means that you should first position the part on the assembly wit...

Page 5: ...h 15 1 8 3 2mm Ply Servo Tray 16 51 5mm Main Wheels 2 17 1 8 3 2mm Ply Mid Former Servo Tray 18 1 8 3 2mm Ply Aft Former Servo Tray 19 1 8 3 2mm Ply Wing Joiners 4 20 Fiberglass Nose Hatch Strips 4 21...

Page 6: ...s If you need assistance locating a dealer to purchase parts visit www greatplanes com and click on Where to Buy If this kit is missing parts contact Product Support Replacement Parts List Order Numbe...

Page 7: ...e wing wire outlets 2 gear openings 2 wing bolt holes 2 servo openings 2 on left and right panels not pictured 4 There are two strings inside the wing center section that have the ends taped to each r...

Page 8: ...with the center section Be careful not to get any epoxy on the strings 9 Wipe away excess epoxy that squeezes out from between the joint with paper towels saturated with alcohol Use masking tape on t...

Page 9: ...s a good quality carpet tape 2 Assemble the propeller shaft extension propeller and the propeller adapter as shown in the above photo Place the rubber propeller adapter into the propeller and press it...

Page 10: ...the screws then screw them into place Remove the screws and harden the holes with a few drops of thin CA After the CA hardens reinstall the servo and screws 4 Mount the nylon control horn on the aile...

Page 11: ...attery tray does not cause the fuselage sides to flex outwards as it is inserted into place Sand the sides of the tray if necessary If the sides flex outwards the battery hatch will not fit properly I...

Page 12: ...lue them into place Also glue the outer tubes at the exit points at the rear of the fuselage 4 Assemble the elevator and rudder servos as shown in the above photo using the grommets brass eyelets and...

Page 13: ...ends are the same distance Mark the stab at the leading and trailing edges with a fine tip marking pen Remove the stab from the fuselage Do not glue the stab into place yet 4 The two elevator halves...

Page 14: ...glue on the stab or on the fuselage When you have the elevators in place with no gaps between the stab and elevators place six drops of thin CA on both sides of each hinge and let it cure Do not use a...

Page 15: ...elage using two 2 5mm x 9 5mm flanged Phillips head screws as shown in the photo above Drill 1 16 1 6mm pilot holes for the screws Harden the holes with thin CA 7 Mount the 25mm tail wheel with a 2mm...

Page 16: ...mained centered Adjust if necessary Use a Great Planes AccuThrow or a ruler to accurately measure and set the control throw of each control surface as indicated in the chart that follows If your radio...

Page 17: ...u 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 B...

Page 18: ...hot Do not touch them during or right after operation The electric motors and battery used in your DC 3 EP ARF are very powerful and the spinning propellers have a lot of momentum therefore if you to...

Page 19: ...ROG takeoffs are only possible from a smooth surface If you are flying from a grass field the DC 3 EP can be safely and easily hand launched Do not attempt to do so by yourself Have an assistant laun...

Page 20: ...el stalls This model does not slow rapidly on final approach so a low dragged in approach may be needed Always land into the wind Due to the small wheel size the model may start to nose over Gradually...

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