Great Planes GPMA1185 User Manual

WARRANTY

Great Planes®Model Manufacturing Co. guarantees this kit to be free from defects in both material and workmanship at the date of purchase.This warranty does not cover

any component parts damaged by use or modification. In no case shall Great Planes’ liability exceed the original cost of the purchased kit. Fur ther, Great Planes
reserves the right to change or modify this warranty without notice.

In that Great Planes has no control over the final assembly or material used for final assembly, no liability shall be assumed nor accepted for any damage resulting from the
use by the user of the final user-assembled product.By the act of using the user-assembled product, the user accepts all resulting liability.

If the buyer is not prepared to accept the liability associated with the use of this product, the buyer is advised 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

3002 N. Apollo Dr. Suite 1

Champaign IL 61822

USA

Include a letter stating your name, return shipping address, as much contact information as possible (daytime telephone number, fax number, e-mail address), a
detailed description of the problem and a photocopy of the purchase receipt.Upon receipt of the package the problem will be evaluated as quickly as possible.

READ THROUGH THIS MANU AL BEFORE ST ARTING
CONSTRUCTION. IT CONTAINS IMPORTANT
WARNINGS AND INSTRUCTIONS CONCERNING
THE ASSEMBLY AND USE OF THIS MODEL.

GPMZ0206 for GPMA1185 V1.0© Copyright 2004

Champaign, Illinois

[phone], Ext 5

[e-mail]

INSTRUCTION MANUAL

Wingspan: 39-3/8 in [1000mm]
Wing Area: 555 sq in [35.8 dm2]
Weight: 24-30 oz [680-850 g]
Wing Loading: 6.22-7.78 oz/sq ft [19-23.7 g/dm

2

]

Length: 46-3/4 in [1188mm]
Radio: 4-channel with four micro servos
Recommended Motor: Kontronik Fun 400-36 with 4.2:1 gear box
Recommended Prop: APC 11x4.7SF

INTRODUCTION................................................................2

SAFETY PRECAUTIONS..................................................2

DECISIONS YOU MUST MAKE ........................................3

Radio Equipment ................................................................3

Speed Control ....................................................................3

Motor Recommendations...................................................3

Battery Recommendations.................................................4

Chargers.............................................................................4

ADDITIONAL ITEMS REQUIRED.....................................4

Adhesives and Building Supplies.......................................4

Optional Supplies and Tools...............................................4

IMPORTANT BUILDING NOTES.......................................4

KIT CONTENTS .................................................................5

ORDERING REPLACEMENT PARTS...............................5

BUILDING INSTRUCTIONS..............................................6

Install the Landing Gear.....................................................6

Install the Fuselage Servos ................................................6

Install the Receiver and Battery.........................................7

Install the Motor and ESC..................................................7

Install the Tail Surfaces ......................................................8

Connect the Control Linkages..........................................10

Install the Wing.................................................................11

GET THE MODEL READY TO FLY..................................12

Check the Control Directions ...........................................12

Set the Control Throws.....................................................13

Balance the Model (C.G.).................................................13

Balance the Model Laterally.............................................14

PREFLIGHT.....................................................................14

Identify Your Model...........................................................14

Charge the Transmitter Batteries......................................14

Balance Propellers...........................................................14

Ground Check..................................................................14

Range Check....................................................................14

MOTOR SAFETY PRECAUTIONS..................................15

AMA SAFETY CODE ......................................................15

CHECK LIST ....................................................................15

FLYING ..............................................................Back Cover

Takeoff...............................................................Back Cover

Flight..................................................................Back Cover

Landing..............................................................Back Cover

Thank you for purchasing the Great Planes Sukhoi SU-31 3D
Park Flyer ARF.The Sukhoi SU-31 is a profile model loosely
based on the full size Sukhoi SU-31, well known for its
aerobatic capabilities.

The Sukhoi SU-31 ARF is a slow flying, highly
maneuverable model that can be flown in a surprisingly
small area.Once you are thoroughly familiar with the model,
it could even be flown indoors in a large gymnasium.This is
one model with a very high fun:cost ratio.

For the latest technical updates or manual corrections to the
Great Planes Sukhoi SU-31 3D ARF visit the Great Planes
web site at www .greatplanes .com.Open the “Airplanes”link,
then select the Sukhoi SU-31 3D Park Flyer ARF. If there is
new technical information or changes to this model, a “tech
notice” box will appear in the upper left corner of the page.

Attention:The product you have purchased is
powered by a rechargeable battery. At the end
of its useful life, under various state and local
laws, it may be illegal to dispose of this battery

into the municipal waste system. Check with
your local solid waste officials for details in your area for
recycling options or proper disposal.The battery may contain

a chemical known to the state of California to cause cancer
and birth defects or other reproductive harm.

1. Your Sukhoi SU-31 ARF should not be considered a toy,
but rather a sophisticated, working model that functions very
much like a full-size airplane. Because of its performance
capabilities, the Sukhoi SU-31 ARF, if not assembled and
operated correctly, could possibly cause injury to yourself or
spectators and damage to property.

2. You must assemble the model according to the
instructions. Do not alter or modify the model, as doing
so may result in an unsafe or unfly able model.In a fe w cases
the instructions may differ slightly from the photos.In those
instances the written instructions should be considered
as correct.

3. You must take time to build straight, true and strong.

4. You must use an R/C radio system that is in first-class
condition. This model requires a micro receiver and
micro servos.

5. Y ou m ust correctly install all R/C and other components so
that the model operates correctly on the ground and in the air.

6. You must check the operation of the model before every
flight to insure that all equipment is operating and that the
model has remained structurally sound. Be sure to check
clevises or other connectors often and replace them if they
show any signs of wear or fatigue.

7. If you are not already an experienced R/C pilot, you
should fly the model only with the help of a competent,
experienced R/C pilot.

PRO TECT YOUR MODEL,Y OURSELF

& OTHERS...FOLLOW THESE

IMPORTANT SAFETY PRECAUTIONS

INTRODUCTION

TABLE OF CONTENTS

2

Remember:Take your time and follow directions to end
up with a well-built model that is straight and true.

If you’re an inexperienced modeler, we recommend that you
get assistance from an experienced, knowledgeable
modeler to help you with assembly and your first flights.
You’ll learn faster and avoid risking your model before y ou’re
truly ready to solo. Your local hobby shop has information
about flying clubs in your area whose membership includes
qualified instructors.

You can also contact the national Academy of Model
Aeronautics (AMA), which has more than 2,500 chartered
clubs across the country. Through any one of them,
instructor training programs and insured newcomer training
are available. Contact the AMA at the address or toll-free
phone number below:

Academy of Model Aeronautics

5151 East Memorial Drive

Muncie, IN 47302-9252

Tele. [phone]

Fax [phone]

Or via the Internet at:

http://www.modelaircraft.org

Please inspect all parts carefully before starting to
build. If any parts are missing, broken or defective, or if
you have any questions about building or flying this
airplane, please give us a call at [phone] or e-mail
us at [e-mail] and we’ll be
glad to help. If you are calling for replacement parts,
please reference the part numbers and have them ready
when calling.

This is a partial list of items required to finish the Sukhoi SU­31 ARF that must be purchased separately. For some of
these items there is more than one option which will require
a bit of decision making ahead of time. Order numbers (in
parentheses) are provided for your convenience.

The Sukhoi SU-31 ARF requires a four channel radio. If you
have a computer radio with mixing capability, and would like
to use the “flaperon”mix for the ailerons, you will need a five

(or more) channel radio. Four micro or mini servos are
required having a minimum of 15 oz-in torque.

The following are also required:

❏ (2) 12" [305mm] Ser vo extensions (rudder, elevator)
❏ (3) 6" [153mm] Servo extensions (ailerons , speed control)
❏ (1) “Y” connector
❏ (1) Screw-lock connector (GPMQ3870)

Suggested servos:

• (HCAM0090) Hobbico®CS-5, 16.7 oz-in torque

• (HCAM0100) Hobbico CS-15, 15 oz-in torque

• (FUTM0037) Futaba®S3103, 16.6 oz-in torque

• (FUTM0025) Futaba S3107, 16.6 oz-in torque

• (HRCM0981) HiTec®HS-55J, 15 oz-in torque

Suggested receivers:

• (GPML0044) Great Planes 4-channel FM, low band

• (GPML0045) Great Planes 4-channel FM, high band

• (FUTL0442) Futaba 4-channel FM, low band

• (FUTL0443) Futaba 4-channel FM, high band

Low band - channels 11-35
High band - channels 36-60

Receiver crystal:

• (FUTL62**) for GPM low band

• (FUTL63**) for GPM high band

• (FUTL62**) for FUT low band

• (FUTL63**) for FUT high band

** desired channel

Select a speed control suitable for the motor y ou will use.On
the prototypes we used the Kontronik Smile 30-6-12
(KONM3000) with the Kontronik motor.With the Mega motor
we used a Hacker F25-3ph.

There are several motor/gearbox/prop/battery combinations
that give good performance with the Sukhoi SU-31 ARF.
Many modelers do not realize that each component in this
combination is important. You can have a good
motor/gearbox/prop combination, but without the proper
battery, performance could be disappointing.

The Sukhoi SU-31 ARF will fly well on a variety of motors,
but for the best performance you should use a brushless
motor.While more expensive than normal ferrite motors, the
power, efficiency and light weight of brushless motors are
well worth the cost.

The motor we used extensively in testing the Sukhoi SU-31
ARF is the Kontronik Fun 400-36 with 4.2:1 gear box
(KONG2440) with an APC 11x4.7SF prop.

Motor

Speed Control

Radio Equipment

DECISIONS YOU MUST MAKE

Note: We, as the kit manufacturer, provide you with a top

quality kit and great instructions, but ultimately the quality and
flyability of your finished model depends on how you build it;
therefore, we cannot in any way guarantee the performance
of your completed model and no representations are
expressed or implied as to the performance or safety of your
completed model.

3

An 8-cell (9.6 volt) 2000 mAh NiMH battery pack is
recommended (GPMP0352). This battery gives great
performance and fits well in the battery compartment.

The best type of charger for NiMH and NiCd batteries is a

peak

charger, because it charges the batteries until they are fully
charged, then automatically switches to trickle charge mode.
The Great Planes ElectriFly™Peak Charger (GPMM3000) is
suitable for NiMH and NiCd batteries as well as transmitter
battery packs.The Great Planes Triton™charger (GPMM3150)
is also suitable.

In addition to common household tools and hobby tools, this
is the “short list”of the most important items required to build
the Sukhoi SU-31 ARF.

Great Planes Pro™CA and Epoxy

glue are recommended.

❏ Pro 6-minute epoxy (GPMR6045)
❏ Pro 30-minute epoxy (GPMR6047)
❏ Hobby knife (HCAR0105)
❏ #11 blades (HCAR0211)
❏ Small T -pins (HCAR5100)
❏ Builder’s triangle (HCAR0480)
❏ Small Phillips and flat blade screwdrivers
❏ Pliers with wire cutter (HCAR0630)
❏ Great Planes Plan Protector (GPMR6167) or wax paper
❏ Sealing Iron (TOPR2100)
❏ Razor Saw

Here is a list of optional tools mentioned in the manual that
will help you build the Sukhoi SU-31 ARF.

❏ Great Planes CG Machine

™

(GPMR2400)

❏ Top Flite Precision Magnetic Prop Balancer

™

(TOPQ5700)

❏ Top Flite Hot Sock

™

iron cover (TOPR2175)

❏ Straightedge with scale (HCAR0475)
❏ Masking Tape (TOPR8018)

The fuselage and tail section of this model are built from
foam.Most CA glues will melt foam and should not be used.

Caution: During construction you will need to use paper
towels and alcohol to clean up any excess epoxy, but be
very careful doing so.The alcohol can dissolve the paint on
the fuselage and tail section, causing it to streak.

• When you see the term

test fit

in the instructions, it
means that you should first position the part on the
assembly without using any glue, then slightly modify or

custom fit

the part as necessar y for the best fit.

• Whenever the term

glue

is written you should rely upon
your experience to decide what type of glue to use.When a
specific type of adhesive works best for that step, the
instructions will make a recommendation.

• Whenever just

epoxy

is specified you may use

either

30­minute (or 45-minute) epoxy or6-minute epoxy. When 30­minute epoxy is specified it is highly recommended that you
use only 30-minute (or 45-minute) epoxy, because you will
need the working time and/or the additional strength.

• Photos and sketches are placed before the step they
refer to. Frequently you can study photos in following steps
to get another view of the same parts.

IMPORTANT BUILDING NOTES

Optional Items

Adhesives and Building Supplies

ADDITIONAL ITEMS REQUIRED

Charger

Battery

4

0" 1" 2" 3" 4" 5" 6" 7"

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Inch Scale

Metric Scale

To convert inches to millimeters, multiply inches by 25.4

5

Before starting to build, use the Kit Contents list to take an inventory of this kit to make sure it is complete and inspect
the parts to make sure they are of acceptable quality. If any parts are missing or are not of acceptable quality, or if you
need assistance with assembly, contact Great Planes Product Support. When reporting defective or missing parts, use
the part names exactly as they are written in the Kit Contents list on this page.

3002 N. Apollo Drive, Suite 1, Champaign, IL 61822

Telephone: [phone], Fax: [phone]

E-mail: [e-mail]

KIT CONTENTS

1 Wing
2 Ailerons (2)
3 Fuselage
4 Stab w/elevators
5 Rudder w/wood post
6 Vertical fin
7 Stab braces

8 Stab slot filler

9 Hook & loop mounting strips
10 Aileron hinge strips
11 Plastic tie-wraps
12 Landing gear wire
13 Wheels

Kit Contents (Photographed)

(2) Aileron pushrod
(2) Plastic wheel collars
Elevator pushrod
(4) Control horn

Rudder pushrod
Wire tail-skid
(4) Screw-lock connector, screw, retainer

Kit Contents (Not Photographed)

1

13

12

10

11

2

9

2

3

4

7

6

5

8

❏ 1. Mount the wheels to the landing gear wire, holding

them on with the short plastic tubes.

❏ 2. Insert the landing gear wire into the slot in the bottom of

the fuselage. This is easier to do if you squeeze the sides of
the wire together as you insert the wire into the fuselage.
Note: The landing gear is securely held in the slot by spring
tension, making it easy to remove if required.For a permanent
installation, put some epoxy into the slot.

❏3.Glue the tail skid wire to the bottom rear of the fuselage.

❏ 1. Install the rudder and elevator servosinto the fuselage

mount using the grommets, eyelets and screws provided
with your servos.Enlarge the mounting area as needed to fit
your servos.Note: Be sure to route the ser vo wires through
the hole in the fuselage and out the bottom.

❏ 2. Connect a 12" [305mm] servo extension wire to the

rudder and elevator servos.Use tape or shrink tubing to hold
the connections securely together.Route these wires in the
channel already cut in the bottom of the fuselage.This must
be done neatly so that the filler strip can be installed in the
next step.

❏ 3. Using foam safe CA, install the 3/16" x 1/4" x 12-3/4"

[4.8 x 6.4 x 324mm] foam filler strip in the channel to cover
the servo wires and hold them in place.

Install the Fuselage Servos

Install the Landing Gear

BUILDING INSTRUCTIONS

6

❏ 1.Plug the elevator and rudder servos into the receiver .Y ou

will also probably need a 6" [152mm] servo extension wire for
the speed control. Install the receiver in the receiver
compartment with a short piece of the supplied hook and loop
mounting tape.The photo shows a Futaba R114F four channel
receiver .Note in the photo how the wires are routed.When the
wing is installed, the aileron servo wire will come down the
opening in the fuselage at the upper left of the photo.

❏ 2. Extend the receiver antenna to its full length and

route it to the tail skid. Use clear tape to hold it to the side of
the fuselage.

❏ 3. Install the hook and loop mounting tape for the battery

in the battery compartment. We used four short pieces of
hook material. On the battery, we mounted one long piece of
loop material. This allows the batter y to be moved within the
battery compar tment to help balance the model.

INSTALLING A KONTRONIK MOTOR

❏ 1. Trim the foam

fuselage as needed
to accommodate the
motor and wires from
the motor.

❏ 2. Drill a 3rd hold to for a zip tie.

❏ 3. Install the motor using the supplied nylon tie straps.

Note: The tie straps may not hold the motor tight enough to
prevent it from twisting slightly at full power with the prop
installed. If this happens, put a small drop of CA on the rear
of the motor where it touches the fuselage.

INSTALLING A MEGA CAN 16/15/3 BRUSHLESS MOTOR

❏ 1.Install your motor on the model with the included nylon

tie-wraps. The motor should be positioned just behind the

Install the Motor

Install the Receiver and Battery

7

hardwood strip at the front of the fuselage.The motor shown
is a MEGA Can 16/15/3 brushless.Note: The tie-wraps may
not hold the motor tightly enough to prevent it from twisting
slightly at full power with the prop installed. If this happens,
put a small drop of CA on the rear of the motor where it
touches the fuselage.

❏2.T rim the f oam fuselage as needed for wires from the motor

❏ 1.The Electronic Speed Control (ESC) can be held to the

fuselage with a short piece of the included hook and loop
tape.The speed control shown is a Kontronik Smile 30-6-12.

❏ 2. Mount the ESC switch to the side of the fuselage with

6-minute epoxy. Do not use CA as it could get into the switch.

❏ 3. Route the receiver connector wire from the ESC into the

battery compar tment and then to the extension wire from the
receiver .Fasten the wire to the top of the battery compartment
with some tape.

❏ 1. On a flat surface, glue the 1/8" x 3/16" x 11-7/8" [3.2 x

4.8 x 302mm] hardwood elevator joiner in place with
6-minute epoxy. Make sure the elevators are aligned with
each other.Note: Use some plan protector or wax paper on
your building surface.

❏ 2. Using a fine tip marking pen, measure and mark the

centerline on the top of the horizontal stab. At the leading
edge, put a mark 5/16" [8mm] on each side of the centerline.
Note: The top of the horizontal stab has the clear cellophane
tape hinge applied to it.

Install the Tail Surfaces

Install the ESC

8

❏ 3. On a flat surface, use 6-minute epoxy to glue the

vertical fin to the balsa post already taped to the rudder.

❏ 4. Temporarily insert the wing into place in the fuselage,

aligning the two center ribs with the fuselage sides.Insert the
horizontal stab into the slot in the rear of the fuselage and
align it with the sides of the fuselage.Check the alignment of
the stab with the wing, making sure it is parallel with the wing.
Also check that the stab and wing are perpendicular to the
fuselage side. Make any needed adjustments to the slots in
the fuselage for the stab and wing.Note: If the wing and stab
are not parallel, it is easier to adjust the wing by twisting it
slightly in its slot.

❏ 5. Glue the stab into place with 6-minute epoxy, using as

little epoxy as possible.

❏ 6. Remove the wing. Glue in the small foam filler strip

in the rear of the fuselage behind the stab.

❏ 7. Prepare the reinforcing foam braces for the stab

bottom. Referring to the above three photos and the photo
for the next step, trim the short end and long side at an
angle. Note that the angle on the second brace is trimmed
the opposite way, making the braces a mirror of each other.

Caution: Do not use alcohol to clean up any excess epoxy
as it could remove and/or streak the paint on the fuselage.
Wipe up any excess epoxy only with paper towels.

Caution: Be careful that the elevator joiner does not catch on
the rear of the fuselage when you insert the horizontal stab.

9

❏ 8.Glue a brace to the bottom of the stab, one on each side

of the fuselage.The narrow end faces the front of the model.

❏ 9. Glue the vertical fin and balsa rudder post to the model

with 6-minute epoxy. Be sure the vertical fin is perpendicular
to the stab.

The smaller micro and mini servos this model requires
usually do not include the long servo arms needed for
high rate throws on this model. Depending on the servo
you are mounting the extended servo arm on it my be
necessary to sand the face of the servo arm flat to make
a good gluing surface.

❏ 1. Attach the ser vo arm extender to the servo arm with

the servo screw. With the radio on position the servo arm
extender in the correct position. Glue the extender to the
servo arm with thin CA.

❏ 2. Temporarily install the servo arm and screw-lock

connector on the elevator servo. Do not install a push-on
retainer ring on the screw-lock connector. Insert the short
elevator pushrod in the hole in the screw-lock connector and
sight down the pushrod to determine where the elevator
control horn should be mounted. Cut a slot in the elevator
for the control horn and glue it into place with 6-minute epoxy.

Caution: In the following steps you will be using screw­lock connectors to connect the pushrods from the control
horns to the servo arms. Before installing the Push-On
Retainer Ring on the screw-lock connector, you should
first turn on your radio system and check which hole the
screw-lock connector should be installed in to get the
desired control throw. Once the push-on retainer ring has
been installed, it can’t be removed without damaging it.

Connect the Control Linkages

10

❏ 3. Remove the servo arm from the servo. Insert the

elevator pushrod into the elevator control horn. Re-install
the servo arm and screw-lock connector on the servo. Do
not install a push-on retainer ring on the screw-lock
connector.Use your radio system and determine which hole
in the servo arm will give the desired control throw.

❏ 4. Install the push-on retainer ring onto the screw-lock

connector. Secure the pushrod to the screw-lock connector
with the 2mm x 5mm screw. Cut off the excess pushrod,
leaving about 5mm protruding.

❏ 5. In the same manner, install the long rudder pushrod.

Before proceeding, iron the covering on the wing so that
it is firmly glued to the center ribs and the servo openings.

❏ 1. Cut a 9/16" [14mm] wide strip of covering material from

the center of the top and bottom of the wing.Use the two center
ribs as a guide to mark the wing prior to cutting the covering.Be
careful not to cut into the wood under the covering.

❏ 2. Cut the covering from over the servo bays on the wing.

❏❏3.Hinge the right aileron to the wing with the included

9/16" x 20-1/2" [14mm x 520mm] hinge material. Attach the
hinge material to the trailing edge of the wing first, then
carefully place the aileron in position. Tr y to leave a slight
gap of about 1/32" [0.8mm] between the wing and aileron.
Once the aileron is in the proper position, press the hinge
material firmly onto the wing and aileron. Note: It is fairly
easy to reposition the aileron if the hinge material has not
been firmly pressed into place.

When you install the aileron servos in the following steps you
will need to install a short servo extension wire or a Y-harness.
If you have a computer radio and intend to program the
ailerons as “flaperons”, you will need to install a 6" [152mm]
extension wire on each servo and plug each aileron servo
into a separate channel on a five (or more) channel receiver.
Otherwise, a Y-harness can be used on a four channel
receiver. The installation shown in the photos used Futaba
S3107 servos and a Futaba “dual extension cord”
(or Y-harness) (FUTM4130). This resulted in a very neat
installation with little excess wire, but did require some careful
planning to get the servo wires plugged into the extension
cord. A standard Y-harness could also be used, but there
would be a considerable amount of excess wire to deal with.

Install the Wing

11

Hinge Material

❏❏4. Connect a ser vo extension wire or “Y” harness to

the right aileron servo. Install the right aileron ser vo in its
mount using the grommets, eyelets and screws provided
with your servo.Enlarge the mounting area as needed to fit
your servo. Note: Be sure to route the servo wire through
the hole in the wing and out the bottom of the wing.

❏❏5.Using the same technique you did with the elevator ,

install the aileron control linkage.

In the following step you will glue the wing into place on the
fuselage. Normally, you would use a string or tape measure
to align the wing with the fuselage.This will not work with this
model as the foam fuselage easily flexes, making alignment
using that technique difficult. This is one case where the
TLAR method (That Looks About Right) works best. The
center ribs of the wing also help in its alignment. Sight the
model from above, making sure the wing is not cocked
sideways. Sight the model from the rear to make sure the
wing is parallel with the stab (see page 9, step 4).

❏ 6. Insert the wing into the fuselage and glue it into place.

It is best to use 30-minute epoxy as it allows time to adjust
the wing, but if you use 6-minute epo xy, practice aligning the
wing before gluing it into place. Be careful not to use any
excess epoxy as cleanup can be difficult. Note: To spread

the epoxy, slide the wing about 1/2" [12.7mm] so that it is
slightly off center. Spread some epoxy on the wood of the
exposed wing rib, on the top and bottom of the rib. Then,
slide the wing so that it is 1/2" [12.7mm] off center in the
other direction and spread some epoxy on the other
exposed rib.If you are careful not to use an excess amount
of epoxy, there will not be much to clean up.It does not take
a lot of epoxy to hold the wing securely in place.

❏ 7. After the epoxy cures, return to step 3 and install the

left aileron, servo and control linkage.

For safety, remove the propeller from the motor. Move the
throttle stick to the off position (towards you.)

❏ 1. Connect a charged batter y to the speed control. Tur n

on the transmitter, then follow the instructions that came with
your speed control to turn on the receiver .Center the trims on
the transmitter.If necessary , remo v e the servo arms from the
servos and reposition them so they are centered. Reinstall
the screws that hold on the servo arms.

❏ 2. With the transmitter and receiver still on, check all the

control surfaces to see if they are centered. If necessary,
adjust the Screw-lock connectors on the pushrods to center
the control surfaces.

❏ 3. Make certain that the control surfaces and motor

respond in the correct direction as shown in the diagram. If
any of the controls respond in the wrong direction, use the
servo reversing in the transmitter to reverse the servos
connected to those controls. Be certain the control surfaces
have remained centered.Adjust if necessar y.

Warning: Whenever the model is not being flown or setup,
the battery should be disconnected.

Check the Control Directions

GET THE MODEL READY TO FLY

Caution:You will need to use paper towels and alcohol to

clean up any excess epoxy, but be very careful doing so.
The alcohol can dissolve the paint on the fuselage,
causing it to streak. Use a dr y paper towel to clean the
fuselage. Use another paper towel, lightly dampened in
alcohol, to clean the wing. Be careful not to touch the
damp paper towel to the fuselage.

12

4-CHANNEL RADIO SETUP

(STANDARD MODE 2)

4-CHANNEL

TRANSMITTER

ELEVATOR MOVES UP

4-CHANNEL

TRANSMITTER

RIGHT AILERON MOVES UP

LEFT AILERON MOVES DOWN

RUDDER MOVES RIGHT

FULL THROTTLE

4-CHANNEL

TRANSMITTER

4-CHANNEL

TRANSMITTER

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 does not have
dual rates, we recommend setting the throws at the low rate
setting. NOTE: The throws are measured at the widest part
of the elevators, rudder and ailerons.

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

❏ 1. Use a felt-tip pen or 1/8"-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 4-1/4" [108mm] back from

the leading edge of the wing.

❏ 2.Place the model on a Great Planes CG Machine, or lift

it at the balance point you marked.

❏ 3. If the tail drops, the model is “tail heavy”and the battery

pack 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 must be shifted aft or weight must be
added to the tail to balance. If possible, relocate the battery
pack 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 just
behind the motor. Begin by placing incrementally increasing
amounts of weight on the top of the fuse above the motor 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 a slot in the bottom of the
fuse and gluing it permanently inside.

❏ 4. IMPORTANT: If you found it necessary to add any

weight, recheck the C.G.after the weight has been installed.

This is where your model should balance for the first
flights. Later, you may wish to experiment by shifting the
C.G. up to 5/16" [8mm] forward or 5/16" [8mm] back to
change the flying characteristics. 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.)

IMPORTANT: The Sukhoi SU-31 3D Park Flyer ARF has

been extensively flown and tested to arrive at the throws
at which it flies best.Flying your model at these throws will
provide you with the greatest chance for successful first
flights. If, after you have become accustomed to the way
the Sukhoi SU-31 ARF flies, you would like to change the
throws to suit your taste, that is fine. However, too much
control throw could make the model difficult to control, so
remember, “more is not always better.”

These are the recommended control surface throws:

High Rate Low Rate

ELEVATOR: 2-3/4" [70mm] up 1-1/4" [32mm] up

2-3/4" [70mm] down 1-1/4" [32mm] down

AILERONS: 1-1/2" [38mm] up 3/4" [19mm] up

1-1/2" [38mm] down 3/4" [19mm] down

RUDDER: 4" [102mm] right 3" [76mm] right

4" [102mm] left 3" [76mm] left

Set the Control Throws

13

❏ 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 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 of this man ual and place
it on your model.

Follow the instructions that came with your radio to charge
the batteries the evening before you plan to fly. You should
always charge the transmitter batteries before flying and at
other times as recommended by the radio manufacturer.

Carefully balance your propeller and spare propellers before
you fly. An unbalanced prop can be the single most
significant cause of vibration that can damage your model.
Not only will motor mounting screws and bolts loosen,
possibly with disastrous effect, but vibration may also
damage your radio receiver and battery.

We use a Top Flite Precision Magnetic Prop Balancer

™

(TOPQ5700) in the workshop and keep a Great Planes
Fingertip Prop Balancer (GPMQ5000) in our flight box.

Before you fly y ou should perf orm one last ov erall inspection
to make sure the model is truly ready to fly and that you
haven’t overlooked anything. If you are not thoroughly
familiar with the operation of R/C models, ask an
experienced modeler to perform the inspection. Check to
see that you have the r adio installed correctly and that all the
controls are connected properly. The motor must also be
checked by confirming that the prop is rotating in the correct
direction and the motor sounds like it is reaching full power.
Make certain all control surfaces (elevators, rudder,
ailerons) are secure, the pushrods are connected, the
controls respond in the correct direction, radio components
are securely mounted and the C.G. is correct.

Ground check the operational range of your r adio before the
first flight 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. 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 motor 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 fly! Find and
correct the problem first.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.

Get help from an experienced pilot when learning to operate
motors.

Use safety glasses when starting or running motors.
Do not run the motor in an area of loose gravel or sand;the

propeller may throw such material in your face or eyes.
Keep your f ace and body as well as all spectators a wa y from the

plane of rotation of the propeller as you start and run the motor.
Keep these items away from the prop: loose clothing, shirt

sleeves, ties, scarfs, long hair or loose objects such as
pencils or screwdrivers that may fall out of shirt or jacket
pockets into the prop.

Failure to follow these safety precautions may result
in severe injury to yourself and others.

MOTOR SAFETY PRECAUTIONS

Range Check

Ground Check

Balance Propellers

Charge the Transmitter Batteries

Identify Y our Model

PREFLIGHT

Balance the Model Laterally

14

The motor gets hot! Do not touch it during or right
after operation.

The electric motor and battery used in your Sukhoi SU-31
ARF are very powerful and the spinning propeller has a
lot of momentum; therefore, if you touch the propeller
while it is spinning it may inflict severe injury. Respect
the motor and propeller for the damage it is capable of
and take whatever precautions are necessary to avoid
injury. Always disconnect and remove the battery until
you are ready to fly again and always make sure the
switches are turned off before connecting the battery.

Read and abide by the following Academy of Model
Aeronautics Official Safety Code:

1. I will not fly my model aircraft in sanctioned events, air
shows, or model flying demonstrations until it has been
proven to be airworthy by having been previously
successfully flight tested.

2. I will not fly my model aircraft higher than approximately
400 feet within 3 miles of an airport without notifying the
airpor t operator. I will give right of way to and avoid flying in
the proximity of full scale aircraft. Where necessary an
observer shall be used to supervise flying to avoid having
models fly in the proximity of full scale aircraft.

3. Where established, I will abide by the saf ety rules for the
flying site I use and I will not willfully and deliberately fly my
models in a careless, reckless and/or dangerous manner.

7. I will not fly my model unless it is identified with my
name and address or AMA number, on or in the model.

9. I will not operate models with pyrotechnics (any device
that explodes, burns, or propels a projectile of any kind).

1. I will have completed a successful radio equipment
ground check before the first flight of a ne w or repaired model.

2. I will not fly my model aircraft in the presence of
spectators until I become a qualified flier, unless assisted b y
an experienced helper.

3. I will perform my initial turn after takeoff away from the
pit or spectator areas and I will not thereafter fly over pit or
spectator areas, unless beyond my control.

4. I will operate my model using only radio control frequencies
currently allowed by the Federal Communications Commission.

❏ 1. Check the C.G. according to the measurements

provided in the manual.

❏ 2. Be certain the battery and receiver are securely

mounted in the fuse.

❏ 3. Extend your receiver antenna and make sure it has a

strain relief to keep tension off the solder joint inside
the receiver.

❏ 4. Balance your model laterally as explained in

the instructions.

❏ 5. Use threadlocking compound to secure critical fasteners

such as the screw-lock pushrod connectors, etc.

❏ 6. Add a drop of oil to the axles so the wheels will turn freely.
❏ 7. Make sure all hinges are secure.
❏ 8. Reinforce holes for wood screws with thin CA where

appropriate (servo mounting screws).

❏ 9. Confirm that all controls operate in the correct direction

and the throws are set up according to the manual.

❏10. Make sure that all servo arms are secured to the

servos with the screws included with your radio.

❏11.Secure connections between servo wires and

Y-connectors or servo extensions with vinyl tape, heat
shrink tubing or special clips suitable for that purpose.

❏12. Make sure any servo extension cords you may have

used do not interfere with other systems (servo arms,
pushrods, etc.).

❏13. Balance your propeller (and spare propellers).
❏14.Tighten the propeller nut.
❏15.Place your name, address, AMA number and

telephone number on or inside your model.

❏16. Cycle your battery pack (if necessary) and make sure

it is fully charged.

❏17. If you wish to photograph your model, do so before

your first flight.

❏18.Range check your radio when you get to the flying field.

The Sukhoi SU-31 ARF is a great-flying model that flies
smoothly and predictably. The Sukhoi SU-31 ARF does not,
however, possess the self-recovery characteristics of a primary
R/C trainer and should be flown only by e xperienced R/C pilots.
If you are an inexperienced modeler we strongly urge you to
seek the assistance of a competent, experienced R/C pilot to
check your model f or airworthiness AND to teach you how to fly.

FLYING

During the last few moments of preparation your mind
may be elsewhere anticipating the excitement of the first
flight. Because of this, you may be more likely to overlook
certain checks and procedures that should be performed
before the model is flown.To help avoid this, a checklist is
provided to make sure these important areas are not
overlooked. Many are covered in the instruction manual,
so where appropriate, refer to the manual for complete
instructions. Be sure to check the items off as they are
completed (that’s why it’s called a

check list

!).

CHECK LIST

Radio Control

General

AMA SAFETY CODE (

EXCERPT

)

15

Remember to takeoff into the wind.When you’re ready, point
the model straight down the runway, hold a bit of up elevator
to keep the tail on the ground, then gradually advance the
throttle. As the model gains speed decrease up elevator
allowing the tail to come off the ground. One of the most
important things to remember with a tail dragger is to always
be ready to apply right rudder to counteract motor torque.
Gain adequate speed before gently applying up elevator,
lifting the model into the air.Be smooth on the elevator stic k,
allowing the model to establish a gentle climb to a safe
altitude before turning into the traffic pattern.

OK, ok - this is a highly aerobatic model. After the first flight,
a takeoff run of a few feet with a vertical climb might be in
order.But please, don’t do this on the first flight.Get used to
the control throws first.

For reassurance and to keep an eye on other traffic, it is a
good idea to have an assistant on the flight line with you.Tell
him to remind you to throttle back once the plane gets to a
comfortable altitude.While full throttle is usually desirable for
takeoff, most models fly more smoothly at reduced speeds.

Take it easy with the Sukhoi SU-31 ARF for the first flight,
gradually getting acquainted with it as you gain confidence.
Adjust the trims to maintain straight and level flight. After
flying around for a while and while still at a safe altitude with
plenty of battery life, practice slow flight and execute

practice landing approaches by reducing the throttle to see
how the model handles at slower speeds.Add power to see
how she climbs as well. Continue to fly around, executing
various maneuvers and making mental notes (or having
your assistant write them down) of what trim or C.G.
changes may be required to fine tune the model so it flies
the way you like. Mind your battery charge, but use this first
flight to become familiar with your model before landing.

To initiate a landing approach, lower the throttle while on the
downwind leg.Allow the nose of the model to pitch downward to
gradually bleed off altitude. Continue to lose altitude, but
maintain airspeed by keeping the nose down as you turn onto
the crosswind leg. Make your final turn toward the runway (into
the wind) keeping the nose down to maintain airspeed and
control. Level the attitude when the model reaches the runway
threshold, modulating the throttle as necessary to maintain your
glide path and airspeed.If you are going to overshoot, smoothly
advance the throttle (always ready on the right rudder to
counteract torque) and climb out to make another attempt.
When you’re ready to make your landing flare and the model is
a foot or so off the deck, smoothly increase up elevator until it
gently touches down.Once the model is on the runway and has
lost flying speed, hold up elevator to place the tail on the ground.

One final note about flying your model. Have a goal or flight
plan in mind for every flight. This can be learning a new
maneuver(s), improving a maneuver(s) you already know, or
learning how the model behaves in certain conditions (such as
on high or low rates). This is not necessar ily to improve your
skills (

though it is never a bad idea!

), but more importantly so
you do not surprise yourself by impulsively attempting a
maneuver and suddenly finding that you’ve run out of time,
altitude or airspeed.Every maneuver should be deliberate, not
impulsive.For e xample, if y ou’re going to do a loop, check your
altitude, mind the wind direction (anticipating rudder
corrections that will be required to maintain heading),
remember to throttle back at the top and make certain you are
on the desired rates (high/low rates). A flight plan greatly
reduces the chances of crashing your model just because of
poor planning and impulsive moves. Remember to think.

Have a ball!

But always stay in control and fly in a safe manner.

GOOD LUCK AND GREAT FLYING!

Landing

Flight

Takeoff

CAUTION (THIS APPLIES TO ALL R/C AIRPLANES): If,

while flying, you notice an alarming or unusual sound
such as a low-pitched “buzz,” this may indicate control
surface

flutter

.Flutter occurs when a control surface (such
as an aileron or elevator) or a flying surface (such as a
wing or stab) rapidly vibrates up and down (thus causing
the noise). In extreme cases, if not detected immediately,
flutter can actually cause the control surface to detach or
the flying surface to fail, thus causing loss of control
followed by an impending crash. The best thing to do
when flutter is detected is to slow the model immediately
by reducing power, then land as soon as safely possible.
Identify which surface fluttered (so the problem may be
resolved) by checking all the servo grommets for
deterioration or signs of vibration. Make certain all
pushrod linkages are secure and free of play. If it fluttered
once, under similar circumstances it will probably flutter
again unless the problem is fixed.Some things which can
cause flutter are; Excessive hinge gap; Not mounting
control horns solidly; Poor fit of clevis pin in horn; Side­play of wire pushrods caused by large bends; Excessive
free play in servo gears; Insecure servo mounting; and
one of the most prevalent causes of flutter;Flying an over­powered model at excessive speeds.