Hangar 9 Sukhoi SU-31 Instruction Manual

INSTRUCTION MANUAL

1/3-Scale Unlimited Aerobatic ARF

Specifications

Wingspan: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 in (2463.8 mm)

Length: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88.7 in (2253 mm)

Wing Area: . . . . . . . . . . . . . . . . . . . . . . . . . . . 1810 sq in (116.7 sq dm)

Weight: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.5–25.5 lb (10.2–11.6 kg)

Recommended Engines: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60–80cc

WE GET PEOPLE FLYING

TM

®

• Superior controllability and aerobatic flight characteristics

• Lightweight construction

• Designed by veteran TOC competitor Mike McConville

• 90% built 1/3-scale ARF

• Plug-in wings for easy transport and field assembly

3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Additional Required Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Other Items Needed (not included in the kit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Tools and Adhesives Needed (not included in the kit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Additional Items Needed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Contents of Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Section 1. Installing the Wing to the Fuselage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Section 2. Installing the Aileron Servos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Section 3. Installing the Aileron Control Horns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Section 4. Hinging and Sealing the Aileron Control Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Section 5. Installing the Aileron Linkages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Section 6. Installing the Rudder and Elevator Servos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Section 7. Installing the Elevator, Control Horns, and Linkages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Section 8. Installing the Rudder, Control Horns, and Linkages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Section 9. Attaching the Tail Wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Section 10. Installing the Landing Gear and Wheelpants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Section 11. Installing the Receiver, Battery, and Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Section 12. Mounting the Engine and Cowl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Section 13. Hatch Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Section 14. Balancing the Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Section 15. Radio Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Section 16. Control Throws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Section 17. Preflight at the Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Section 18. Setup and Flight Information by Mike McConville . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

AMA Safety Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table of Contents

4

Thank you for purchasing the Hangar 9

®

33% Sukhoi Su-31.
Because size and weight create a higher degree for potential danger,
an added measure of care and responsibility is needed for both
building and flying giant scale models. If this is your first giant
scale aerobatic aircraft, it’s important that you carefully follow the
instructions, especially those regarding hinging and the section
on flying. Like all giant scale aerobatic aircraft, the 1/3-Scale
Sukhoi Su-31 requires powerful, heavy-duty servos. Servos
greatly affect the flight performance, feel, and response of the
model. To get the most out of your Su-31, it’s important to use
accurate, powerful servos with a minimum of 80 oz in of torque
for elevator and rudder and 60 oz in of torque for each of the
four aileron servos. In the prototype models, we used JR 8101
and JR 8231 servos with excellent results. A less powerful servo
can lead to a crash.

The 1/3-Scale Sukhoi Su-31 does not include hardware. Many
experienced giant scale pilots have specific hardware preferences
and can individually choose the components they prefer.

Hangar 9 offers an optional Hardware Package (HAN1220-JR,
HAN1221-FUT) that includes the hardware that our staff regularly
uses and recommends.

Throughout the manual, the above hardware will be used during
the assembly process. If using another type/brand of hardware,
it’s your responsibility to be sure that it’s strong enough for this
application and properly installed.

If you encounter difficulty in any construction sequence, please
contact one of our technicians. We can provide assistance
concerning the construction of your 1/3-Scale Sukhoi. You can
contact us at:

Horizon Hobby, Inc.
4105 Fieldstone Road
Champaign, IL 61822
[phone]
www.horizonhobby.com

Introduction

Warning

An R/C aircraft is not a toy! If misused, it can cause serious
bodily harm and damage to property. Fly only in open areas,
preferably AMA (Academy of Model Aeronautics) approved

flying sites, following all instructions included with your radio
and engine.

5

Additional Required Equipment

Radio Equipment with Computer Radio

1000mAh receiver battery pack or larger
Servos with 80 oz in of torque minimum (elevator and rudder) (JR8101, 4721, 2721, or 8411 or equivalent) (4)
Servos with 60 oz in of torque (aileron) (4)
Servo for throttle (standard) (1)
Y-Harness (JRP133) (2)
24" Servo Extension (JRPA102) (6)
18" Servo Extension (JRPA099) (1)
12" Servo Extension (JRPA098) (2)

Radio Equipment (Non-Computer Radio)

1400mAh receiver battery pack or larger
Servos with 80 oz in of torque minimum (elevator and rudder) (JR8101, 4721, 2721, or 8411 or equivalent) (4)
Servos with 60 oz in of torque (aileron) (4)
Servo for throttle (JR537) (1)
Y-Harnesses (JRP133) (3)
24" Servo Extension (JRPA102) (2)
18" Servo Extension (JRPA099) (5)
6" Servo Extension (JRPA095) (2)

Note: Requires one reversed servo for elevator

Recommended JR Systems:

JR XP662
JR X-378
JR XP8103
JR PCM10X

Engine Requirements

Recommended Engines:

62–80cc Gasoline Engine

Recommended Gasoline Engines:

Zenoah®G-62 Gasoline Engine
Zenoah GT-80 Gasoline Engine

JR XP8103

JR PCM10X

JR X-378JR XP662

Zenoah GT-80
(ZENE80T)

Zenoah G62
(ZENE62A)

6

Tools and Adhesives Needed (not included in the kit)

Additional Items Needed

Tools

• Drill

• Drill Bits: 1/16", 1/8", 5/32", 3/8", 5/16"

• Phillips screwdriver (medium)

• Straight screwdriver (small)

• Needle-nose pliers

• Hobby knife with #11 blade

• Mixing stick

• Straight edge

• Saw

• Soldering iron and solder

• Measuring device (e.g., 12" or longer ruler, 36" ruler, tape measure)

• Scissors

• Moto-tool with cut-off wheel

• 8-32 Tap and Drill Bit (DUB363)

• Sealing iron

• Glue syringe or toothpick

• Hex Wrench: 5/32" and 1/8"

• Adjustable wrench

• Countersink

Adhesives

• Thick CA (cyanoacrylate) glue

• CA remover/debonder

• 30-minute epoxy

• 6-minute epoxy

• Silicon glue

• 4

1

/4" Spinner (Tru-turn TRU4252MZ)

• Spinner Adapter Kit (TRU0127)

• Propeller (refer to recommendations listed in

your engine’s operating instructions)

• 2' gas compatible tubing

• Cup engine mount B+B 6202 (G-62 only)

• Sandpaper (coarse)

• Radio packing foam

• Antenna tube

• Canopy glue

• Threadlock

• Electrical tape

• Masking tape

• 1/8" light plywood

• 1/4"-20x1

1

/2" socket head screws (G-62 only) (4)

• 1/3-scale pilot

• Cable ties (small)

• Paper towels

• Rubbing alcohol

• Felt-tipped pen/pencil

• Instrumental Panel (HAN190)

Other Items Needed (not included in the kit)

Zenoah®Gas Start Kit (ZEN20002) Includes:

• Kill Switch (ZEN20000)

• Oil (2-cycle) (ZEN20001)

• Fuel Filler (HAN115)

• Fuel Filter (HAN143)

• Mixing Cup (HAN3101)

• Gas Stopper (DUB400)

• 3' Fuel Line (DUB799)

• Line Keeper (DUB677)

7

Replacement Parts

Fuselage (HAN1276)
Right Wing Panel with Aileron (HAN1277)
Left Wing Panel with Aileron (HAN1278)
Right Horizontal Stabilizer and Elevator (HAN1279)
Left Horizontal Stabilizer and Elevator (HAN1280)
Rudder (HAN1281)
Wing Tube (HAN1256)

P

Stabilizer Tubes (2)(HAN1257)
Canopy (HAN1282)

R Canopy Hatch (HAN1283)

Fiberglass Painted Cowl (HAN1284)
Landing Gear (HAN1285)
Wheelpants (HAN1286)

HAN1220—JR
HAN1221—Futaba

3

1

/2" Pro-Lite wheels (HAN308)
41/2" 4-40 Threaded Pro-Links (HAN3556) (4)
5" 4-40 Thread Pro-Links (HAN3557) (4)
32 oz Fuel Tank (DUB690)

Tail Wheel Assembly with Hardware (OHI130)
4-40 Ball Links (DLR87) (9)
8-32 Swivel Control Horns (DLR01B) (8)
3/16" Main Axles (DUB249)
Super Hinge Points (ROB309) (24)
4-40 3-D Arm (11/4" long) JR Version (HAN3578) (2)
4-40 HD Arm (1" long) JR Version (HAN3574) (6)

B

E

Contents of Kit

H

A

F

G

E
F
G

C

D

B

J

K

L

M

I

A

C
D

H

I
J
K
L

M

a

b

c

d

e

k

a
b

c

d

e

f
g

h

i

j

k

j

h

f

g

Included in the optional Hangar 9®1/3-Scale Hardware Package

i

8

Parts Needed

• Left wing panel w/aileron attached (taped in place)

• Right wing panel w/aileron attached (taped in place)

• Fuselage

• Wing Tube

• 1/4" x 20 bolt with washer (2)

Tools and Adhesives Needed

• Hobby knife w/#11 blade

• Thick CA

Step 1. Locate the wing tube and be sure it does not have any
“burrs” on the ends. Also check the tube socket openings in the
fuselage for covering and/or any debris. If you need to remove
any covering or debris from around the inside of the tube socket
openings, use a hobby knife with a sharp #11 blade and carefully
clear the socket openings

Step 2. Be sure the alignment tubes located on the root rib
of each wing panel are securely glued in before installing the
wings. If the tubes are not secure, remove them and apply thick
CA (small amount) into the tube socket and reinstall

Step 3. Insert the wing tube into a wing panel and slide the
wing in place on the fuselage. Reach inside the fuselage and
hold the wing alignment tube blocks while inserting the wing
half. Make sure the wing panel alignment tubes slide into the
holes in the fuselage.

Note: The fit may be tight; use caution when inserting
the wing panels onto the wing tube and fuselage.

Step 4. Carefully slide the other wing panel onto the wing tube
that projects from the other side of the fuselage. Reach inside the
fuselage and hold the wing alignment tube blocks while inserting
the wing half.

Note: The tight fit of the wing tube into the wing panels
is intentional, and it will loosen with use.

Step 5. Locate the holes for the 1/4" x 20 wing bolts on the
root rib of the wing. The fuselage has a hole in the same spot as
the holes on the wing panel. To secure the wing to the fuselage
thread the wing bolts from the inside of the fuselage as shown.

Step 6. Remove the wing panels before proceeding with the
section titled “Installing the Aileron Servos.”

Section 1: Installing the Wing to the Fuselage

9

Parts Needed

• Left and right wing panels

• Servos w/mounting hardware (60 oz in minimum torque) (4)

• 6" Servo Extension (JRPA095) (2)

• 24" Servo Extension (JRPA102) (2)

• Y-Harness (JRPA133) (3 for non-computer radios) (2)

• 1" Servo Arms (HAN3574-JR or HAN3575-Futaba) (4)

Tools and Adhesives Needed

• Phillips screwdriver

• Drill

• Drill Bit: 1/16"

• Electrical tape

• Threadlock

Note: The ailerons require a minimum of 60 oz in of
servo torque. In the example used for this manual we
installed JR 8411 digital servos for the ultimate in
precision control. We have test flown the Sukhoi with
JR8101 and JR8231 servos with great results.

MatchBox Option: To simplify the installation of the aileron
servos, you may want to use the new JR MatchBox™servo
matching/power system (JRPA900). Two MatchBoxes would
be used in this application—one for each wing. The MatchBox
allows easy adjustment of the servo’s center and endpoints,
making aileron setup a snap. You can also use a seperate battery
to run the Matchbox, reducing the load on the flight battery
powering the receiver.

FAST FACTS: It is common to use two servos per aileron on
many larger models. This setup requires some special attention
to assure that the servos do not fight each other. If this is not
done correctly, battery consumption will be greatly increased,
and in the case of a high torque digital servo, the servos may be
damaged. When setting up the ailerons with two servos, there
are some special steps that need to be taken.

Step 1. Select two sets of servos and Hangar 9®1" arms that
have the same neutral. All servos will have a slightly different
neutral. If you are using Hangar 9 metal arms, they don’t all orient
the same, (i.e., the splines are not oriented the same relative to
the arm). First choose one servo and arm, plug it into the aileron
channel on your receiver through the Y-connection, and set to
EXACT NEUTRAL, (i.e., servo arm is perpendicular to the servo
centerline). Next, start plugging in your other servos one by one
and installing the arms until you find one that is as close as you
can get to the EXACT SAME NEUTRAL as the other servo.
Repeat this process to find a second pair of servos.

Note: The arms need to face outward toward the
wing tips as shown Step 4. Be sure to use a drop of
threadlock to secure the servo arm screws if using
metal-geared servos.

Step 2. Install the servo hardware (grommets and eyelets)
included with the servo.

Step 3. Plug a 6" and 24" extension into each of the sets of
matched aileron servos. Tie a knot at the connector as shown,
then wrap with electrical tape to prevent the servo connectors
from pulling apart.

Step 4. Insert the servo with the 6" extension into the aileron
cutout on the bottom of the wing closest to the wing root, as
shown below. Be sure the output shaft is oriented toward the
trailing edge of the wing with the servo arm pointing towards
the wing tip. Insert the second servo with the 24" extension into
the servo cutout located closest to the wing tip. Allow the servo
leads to exit the root of the wing.

Section 2: Installing the Aileron Servos

10

Note: A computer radio using flapperon mixing is recommended.
In this case, each wings servos plug into a Y-harness and
then the Y-harnesses are plugged directly into the receiver
using the aileron and appropriate auxiliary channel used for
flapperon mixing (see your radio’s instructions).

Note: If a non-computer radio is used, three Y-harnesses
are required. Plug one Y-harness into the aileron port of
your receiver. Plug each wings servos into a Y-harness and
then plug those into the Y-harness connected to the receiver.

Step 5. With the servos in position, mark the four locations for
the mounting screws. Remove the servo and drill a 1/16" pilot
hole in the servo rails. Secure the servos to the wing using the
screws provided with the servos.

11

Parts Needed

• Left and Right wings w/ailerons

• Control Horns (DLR01B) (4)

• Robart Super Hinge Points (ROB309) (2)

Tools and Adhesives Needed

• 12" or longer ruler

• Drill

• Drill Bits: 1/16", 5/32"

• 8-32 tap

• #8 countersink

• 30-minute epoxy

• Felt-tipped pen

• Rubbing alcohol

• Paper towels

Step 1. Temporarily install the aileron to the wing panel using
2 Robart Super Hinge Points. Do not glue them in at this time.

Step 2. Center the aileron servos. Use a strait edge at 90 degrees
to the hinge line and aligned with the outer hole on the servo
arm to mark the aileron at the top of the bevel.

Step 3. Measure 1/4" rearward from the marks above 90 degees
to the hinge line and make another mark using a pen. This is the
position for the control horn. Remove the aileron from the wing
and also the hinge points.

Step 4. The hole for the control horn is drilled at 90 degrees to
the centerline of the aileron as shown in the illustration below.
Drill strait through the aileron using the bit included with the
8–32 tap or a 1/8" drill bit.

Note: Hardwood blocks (hard point) are located below
the sheeting; you will be drilling through this block.

Section 3: Installing the Aileron Control Horns

90°

12

Step 5. Carefully counter sink the holes on the top of the
aileron with a #8 counter sink. Use an 8-32 tap to tap the holes
in the aileron.

Step 6. Mix a small amount of 30-minute epoxy and lightly
coat the inside of the tapped holes and the 8-32 x 2" screws.
From the top of the aileron, install the 8-32 x 2" screw into the
tapped holes and securely tighten. Wipe away any excess epoxy
with rubbing alcohol and a paper towel.

Step 7. Screw the A-nuts in place as shown. Allow the epoxy to
fully cure.

Step 8. Repeat Steps 1 through 7 for the opposite aileron.

13

Parts Needed

• Wings with ailerons

• Robart Super Hinge Points (ROB309) (12)

• UltraCote strips (2)

Tools and Adhesives Needed

• Sealing iron

• Hobby knife with #11 blade

• Ruler: 36"

• Glue Syringe (DLR910) (or toothpick)

• Sandpaper (coarse)

• Felt-tipped pen

• Zap Hinge glue or 30-minute epoxy

• Rubbing alcohol

• Paper towels

FAST FACTS: Properly hinging the control surfaces on giant
scale models is vitally important! Poorly installed hinges affect
the model’s precision and control response and can also be
dangerous. Each and every hinge needs to be securely bonded
in place in both the flying surface and the control surface. The
hinge pivot points need to be exactly parallel to each other and
precisely located on the center of the hinge line. We regularly
use Robart Super Hinge Points in all giant scale aircraft. They
are easy to install, very strong, and offer smooth friction-free
control. The Hangar 9 1/3-Scale Sukhoi control surfaces are
predrilled to use Robart Super Hinge Points (ROB309).

Step 1. Lightly sand each end of the hinge point using coarse
sandpaper. This will improve the bond of the epoxy to the hinge.

Step 2. Mix 1 ounce of 30-minute epoxy. Using a glue syringe
or toothpick, place a sufficient amount of 30-minute epoxy into
one of the hinge pockets on the wing’s trailing edge. Install one
of the hinge points until the hinge point center is flush with the
trailing edge of the wing. Some epoxy should ooze out of the
pocket as the hinge is installed. If not, remove the hinge and
apply more epoxy. Wipe away excess epoxy with rubbing alcohol.
Recheck that the center of the hinge point is flush and parallel
with the trailing edge. Continue installing hinges in the trailing
edge of the wings. The ailerons will be installed after the epoxy
is fully cured.

Note: Be sure that the hinge pivot pins are parallel
and flush to the trailing edge. It’s important to
frequently mix afresh batch of 30-minute epoxy in
order to achieve good glue joint penetration. If you
notice the epoxy becoming thicker, mix a new batch.

Step 3. Allow the epoxy to fully cure for at least six hours.
When cured, work each hinge throughout its full motion several
times using your hands. This will break free any epoxy that may
have found its way into the hinge joint. Move the hinge through
its full travel until no resistance is left. This may take as many as
40 or 50 times.

Section 4: Hinging and Sealing the Aileron

Control Surfaces

14

Step 4. Mix 1 ounce of 30-minute epoxy. Using a syringe or
toothpick, place a sufficient amount of epoxy in each of the hinge
pockets in one aileron half.

Step 5. Carefully insert the aileron on the wing, making sure
the hinges are inserted into their respective hinge pockets. Press
the aileron and wing together such that less than 1/64" hinge
line gap exists between the aileron and wing. The bevels should
virtually touch. Using a paper towel and rubbing alcohol, wipe
away any visible epoxy around the hinges.

Step 6. Double-check the hinge gap and secure the aileron
using masking tape. Allow the epoxy to fully cure for at least
six hours. Repeat Steps 1 through 6 for the other wing half.

Step 7. When the epoxy has fully cured, move each control
surface throughout its travel range several times to break away
any epoxy in the hinge. Be sure to deflect the surface fully.

FAST FACTS: Sealing the Hinge Gaps It’s vital that the
aileron and elevator hinge lines be sealed airtight to prevent flutter.
Sealing the hinge line has several advantages. A sealed hinge line
gives a greater control response for a given control deflection.
It also offers more precise, consistent control responses and
makes trimming easier.

Caution: Sealing the aileron and elevator hinge line is
mandatory. Failure to do so may cause control surface
flutter, resulting in a crash.

Step 8. Locate two pieces of Midnight Blue UltraCote

®

(included)
for sealing the ailerons to approximately 3" x 36". Fold both
pieces of UltraCote down the center with the adhesive side
to the outside, making a sharp crease at the fold.

Step 6 photo

15

Step 9. Using a ruler, measure 1/2" from the folded crease and
mark the pieces with a pen.

Step 10. Using a sharp hobby knife with a #11 blade and
straight edge, carefully cut through both layers of UltraCote

®

covering at the 1/2" point marked in the previous step. Cut
both pieces.

Step 11. Mark and cut both folded coverings to an overall
length of 333/4". These pieces will be inserted and ironed down
into the hinge bevel on the bottom of the ailerons.

Step 12. Remove the backing from one piece of the UltraCote.
Place the folded crease side to the center of the hinge line on the
bottom of one wing half. Deflect the aileron full up and using a
straight edge as shown, hold one side of the covering in place
while ironing down the opposite side with a sealing iron. We
recommend setting the iron temperature to 320° for this operation.

Step 13. Place the straight edge over the hinge line covering
that you just ironed down in the previous step. With the edge
of the straight edge placed firmly at the bottom of the hinge line
as shown, iron down this side of the covering, making sure the
aileron is fully deflected.

Step 14. Repeat Steps 12 and 13 for the other aileron gap seal.

16

Parts Needed

• Left and right wing assembly

• 4

1

/2" 4-40 Pro-Links (HAN3556) (4)

• 4-40 Ball Links (DLR87) (4)

• Control horn parts left over from Section 3

Tools and Adhesives neede

• Screwdriver (small)

• Threadlocker

• Pro-Link Wrench (HAN3558)

Step 1. Screw a Clevis onto the inboard screw horn until the
bottom of the clevis is 5/8" from the aileron.

Step 2. Install a 4-40 ball link five to six turns onto a 41/2" long
4-40 Pro-Link. Screw the opposite end of the linkage five to six
turns into the clevis that is to attach to the swivel control horn
that was installed in the previous step. Attach the linkage to the
swivel horn on the inboard servo only with the bolt supplied.
Adjust the linkage length until the hole in the ball link aligns
with the outer hole in the servo arm when the aileron is neutral
and the servo arm is centered.

Note: Hangar 9®Titanium Pro-Links feature right-hand
threads on one end and left-hand threads on the other,
allowing for easy, accurate adjustment without
disconnecting the linkages. Consistently putting the
right-hand threads toward the servo arms on all servos
will prevent you from getting confused as to which way
to turn the Pro-Link to lengthen or shorten the linkage.
Hangar 9 also offers a Pro-Link Wrench (HAN3558) to
make adjustments easier.

Step 3. Using the 4-40 screws and nuts included in the control
horn package (don’t substitute a standard screw), attach the ball
link to the outer hole in the arm from the bottom side as shown on
both servos. The sequence is screw, ball link, servo arm, and nut.
Don’t forget to use threadlock. The tapered standoff is not used.

Note: Do not attach the outboard linkage to the control
horn at this time.

Section 5: Installing the Aileron Linkages

17

Step 4. Temporarily plug the servos into the receiver and set
the programming to get the aileron functioning correctly. Center
the control surface with the trailing edge of the wing.

Step 5. Install the clevis on the outboard control horn screw.
Screw on the clevis until the bottom of the clevis is the same
distance from the aileron hinge line as the inboard clevis, not the
bottom surface of aileron.

Step 6. Deflect the ailerons stick to full right. Hold it there (the
easiest way is to have your transmitter set to PCM: hold and
then turn off the transmitter). Hold the clevis on the outboard
servo up to the horn and note how the holes align. Turn the
transmitter on and hold full left aileron and again note how the
holes align. The holes have to line up nearly perfectly. If they
don’t line up perfectly, adjust the horn length (distance out from
the aileron) in or out a few turns and recheck. Repeat this
process until it is nearly perfect at full deflection in both stick
directions and at neutral.

Step 7. Attach the swivel clevis to the horn with the supplied screw.

18

Parts Needed

• Fuselage

• Servos w/mounting hardware (a minimum of 80 oz in of torque) (4)

• 1" Heavy-Duty Servo Arms (2)

(HAN3574-JR or HAN3575-Futaba)

• 11/4" Heavy-Duty Servo Arms (2)
(HAN3578-JR or HAN 3579-Futaba)

If using a computer radio:

• 24" Servo extensions (JRPA102) (4)

If using a non-computer radio:

• Y-Harnesses (JRPA133) (2)

• 18" Servo Extensions (JRPA099) (4)

Note: If using a non-computer radio, one of the servos
used for elevator must be a reversed-direction servo.
See the “Radio Setup” section for more details.

Tools and Adhesives Needed

• Phillips screwdriver

• Screwdriver (small)

FAST FACTS: The rudder and elevators require a minimum of
80 oz in of servo torque. Using servos with less torque could
cause a crash. In the prototype 1/3-Scale Sukhoi Su-31, we used
JR8101 and JR8411 servos with excellent results.

Step 1. Locate and center the two elevator servos and install 1"
heavy-duty servo arms. Center the two rudder servos and install
11/4" heavy-duty servo arms onto the rudder servos.

Note: If using a non-computer radio, one of the elevator
servos must be a reversed servo.

Computer Radio

Step 2. If using a 7-channel or greater computer radio with

mixing (highly recommended), install four 24" servo extensions,
one on each servo. Tie a knot at each connector and tape to prevent
inadvertent disconnection.

Non-Computer Radio

Step 2a. If using a non-computer radio, install four 18" servo

extensions, one on each servo. Tape and tie a knot at each
connector to prevent inadvertent disconnection. Install one side
only of the two Y-harnesses to two of the servos, also tying
knots to prevent disconnection. The other two servos will be
hooked up to the Y-harness when installed in the airplane. One
elevator servo will need to be a reversed-direction servo.

Step 3. Install the servo hardware (grommets and eyelets) on
the rudder and elevator servos. Install the elevator servos in the
fuselage tail section with the output shaft forward. The rudder
servos are installed with the output shaft to the rear as shown in
the photo below (elevator in the upper opening and rudder in the
lower opening). Mark the locations for the mounting screw holes.

Note: If using a non-computer radio, install one of the
servos with the Y-harness attached in the top opening
(elevator) and the other servo with the Y-harness
attached in the bottom opening (rudder). Install the
other servos in the opposite side of the fuselage being
sure to connect the servo to the other open connector of
the respective Y-harnesses. Don’t forget to knot and
tape the connectors.

Step 4. Mark the locations for the servo mounting screws and
drill pilot holes at the marks using a 1/16" drill bit.

Step 5. Secure the servos in place with the screws provided
with your servos.

Section 6: Installing the Rudder and Elevator Servos

19

Parts Needed

• Right and left stabilizers w/elevators

• Tail tubes (2)

• 4-40 x 1/2" screws (2)

• #4 washer

• #4 split washers (2)

• UltraCote®strip (1)

• Robart Hinge Points (ROB309)

• Control horns (DLR01B) (2)

• 4-40 Ball Links (DLR87) (2)

• 5" 4-40 Pro-Links (HAN3557) (2)

Tools and Adhesives Needed

• Sealing iron

• Hobby knife with #11 blade

• Drill

• Drill Bit: 1/8"

• 8-32 Tap and Drill Bit (DUB363)

• Glue Syringe (DLR910) (or toothpick)

• Zap Hinge glue or 30-minute epoxy

• Rubbing alcohol

• Paper towels

• Ruler

• Hex Wrench: 3/32"

Note: The technique for installing the control horns in the
elevators is similar to the aileron control horn installation.

Step 1. To properly locate the position of the control horn on
the bottom of the elevator, measure inward 11/8" from the root
and rearward 1/4" from the top of the bevel. Mark this position
on both elevators.

Step 2. The hole for the control horn is drilled at 90 degrees to
the centerline of the elevator as shown in the illustration below.
Drill strait through the elevators using the bit included with the
8-32 tap or a 1/8" drill bit.

Note: Hardwood blocks (hard point) are located below
the sheeting; you will be drilling through this block.

Step 3. Carefully counter sink the holes on the top of the elevators
with a #8 counter sink. Use an 8-32 tap to tap the holes in the aileron.

Section 7: Installing the Elevator,

Control Horns, and Linkages

90°

1

/8"

1

1

/4"

20

Step 4. Mix a small amount of 30-minute epoxy and lightly
coat the inside of the tapped holes and the 8-32 x 2" screws.
From the top of the elevator, install the 8-32 x 2" screw into the
tapped holes and securely tighten. Wipe away any excess epoxy
with rubbing alcohol and a paper towel.

Step 5. Screw the A-nuts in place as shown. Allow the epoxy to
fully cure.

Step 6. The two inboard hinges of each elevator where they
insert into the horizontal stabilizer must be trimmed 1/2" to allow
clearance for the long stabilizer tube. Glue the elevator hinges in
place using the same techniques used to hinge the ailerons.
After hinging the elevator, use the same techniques to seal the
elevator hinge gaps. Use the provided 3" x 36" Midnight Blue
UltraCote

®

strip cut in half for the bottom of the elevators.

Note: You may need to drill out the inboard hinge
location in the elevators with a 5/32" drill bit to allow
the hinge to seat correctly.

Note: Since the holes in the long stabilizer tube are
not drilled or tapped, you will have to make sure this
is done so the stabilizers can be securely attached to
the fuselage. Check the tube opening sockets on both
sides of the fuselage and remove any covering or
debris with a sharp #11 blade.

Step 7. Locate the holes in each of the stabilizer’s top surface.
The holes have been drilled for the 4-40 x 1/2" cap screws
washers and split washers. These screws are used to secure each
stabilizer to the fuselage. The longer of the two tail tubes will
require holes to be drilled in each end for the 4-40 cap screws.

21

Step 8. Insert the shorter of the tail tubes into the forward hole
in the rear of the fuselage. Insert the longer of the tail tubes into
the rear hole in one of the stabilizers halves then into the rear
hole of the fuselage and slide it onto the smaller tube in the
fuselage until it touches the side of the fuselage. This may fit
tightly; use caution not to damage the stabilizer half.

Step 9. Install the other stabilizer half onto the tubes on the
other side of the fuselage. Carefully slide the stabilizer onto the
tubes until it contacts the side of the fuselage. When both stabilizer
halves are touching the fuselage sides, make a mark through the
hole for the 4-40 cap screw onto the tail tube located near the
trailing edge of the stabilizers. We suggest using a 1/16" drill bit
to make the mark. If you use a larger drill bit, use caution not to
round out the hole.

Step 10. Remove the stabilizers and drill and tap the long tail
tube. Reinstall the stabilizers and thread the 4-40 cap screws and
split washers into place, securing the stabilizers to the fuselage.

Caution: Check the security of the screws before each flight.

Step 11. Install the molded swivel clevis onto the control horn

screws until the bottom of the clevis is 5/8" from the elevator.

Step 12. Screw a 4-40 ball link five to six turns onto a 5" long
4-40 Pro-Link. Screw the opposite end of the linkage into the swivel
control horn on the elevator. Adjust the linkage length until the
hole in the ball link lines up with the outer hole in the servo arm
when the elevator is neutral and the servo arm is centered.

Step 13. Using the 4-40 screws and nuts included in the control
horn package, attach the ball link to the outer hole in the arm.
The correct sequence is 4-40 screw, ball link, servo arm, and
4-40 nut. Do not use the beveled standoff. Be sure to use
threadlock on the 4-40 screw and nut.

Step 14. Repeat Steps 11 through 13 for the oppsite elevator half.

22

Section 8: Installing the Rudder, Control Horns,

and Linkages

Parts Needed

• Rudder

• Fuselage

• Control Horn (DLRO1B) (2)

• 4-40 Ball Links (DLR87) (2)

• 5" 4-40 Pro-Links (HAN3557) (2)

Tools and Adhesives Needed

• 8-32 Tap and Drill Bit (DUB363)

• Drill

• Drill Bit: 1/8"

• Phillips screwdriver

• Straight screwdriver

• 30-minute epoxy

• Rubbing alcohol

• Paper towels

• Ruler

Step 1. Mark the position for the rudder control horn with a
felt-tipped pen. The correct location is 3/4" up from the bottom
of the rudder and 1/4" rearward from the edge of the rudder bevel.

Step 2. Using the drill bit supplied with your 8-32 tap or a
1/8" drill bit, carefully drill a hole through the rudder perpendicular
(90°) to the rudder centerline at the marked position. Be especially
careful when penetrating through the backside of the rudder.

Step 3. Using an 8-32 tap, thread the hole you just drilled in
the rudder.

Step 4. Mix a small amount of 30-minute epoxy and lightly
coat the center of the threaded portion of the 4" long 8-32 bolt
included with the swivel control horn package. Thread the bolt
into the tapped hole in the rudder until 1" of thread is exposed
on the opposite side.

Step 5. Using a Moto-tool and a cut-off wheel, cut the bolt on
the side with the head so that 1" of thread is exposed.

23

Step 6. Thread an A-nut (included with swivel clevis) onto each
side of the threaded rod and securely tighten against the rudder.

Step 7. Screw a molded swivel clevis onto each side of the
8-32 threaded rod so that it is tight against the A-nut.

Step 8. Hinge the rudder using the same techniques as with the
aileron and elevator.

Note: You may need to drill out the bottom hinge location

in the rudder using a 5/32" drill bit to allow the
hinge to seat correctly.

Step 9. Screw a 4-40 ball link five to six turns onto a 5" long
4-40 Pro-Link. Screw the opposite end of the linkage into the
swivel control horn that was installed in Step 7. Adjust the length
until the hole in the ball link lines up with the outer hole in the
servo arm when the rudder is in neutral and the arm is centered.

Step 10. Using the 4-40 screws and nuts included in the swivel
control horn package, attach the ball link to the outer hole in the
arm. The correct sequence is 4-40 screw, ball link, servo arm,
and 4-40 nut. Don’t use the beveled standoff. Be sure to use
threadlock on the 4-40 screws.

Step 11. Repeat Steps 9 and 10 for the other rudder servo linkage.

24

Parts Needed

• Fuselage assembly

• Ohio Superstar Large Tail Wheel Assembly (#OHI130)

• #6 x 3/4" button head screws (DUB351) (not included) (2)

Tools and Adhesives Needed

• Hex Wrench: 2mm

• Drill

• Drill Bit: 7/64"

• Felt-tipped pen

Step 1. Assemble the tail wheel per the instructions included
with the tail wheel assembly. The nylon control horns included
with the tail wheel assembly are not used.

Step 2. Position the tail wheel in place as shown, centering on
the rear of the fuselage. Using a felt-tipped pen, mark the position
for the mounting screws through the tail wheel bracket.

Step 3. Drill 7/64" pilot holes at the previously marked positions.

Step 4. Using two #6 x 3/4" sheet metal screws, secure the

tail wheel bracket in place. Note that the hardwood plate is
positioned in the rear of the fuselage, allowing these screws
to be firmly tightened.

Hint: Remove the #6 x 3/4" screws and wick thin CA
into the holes to strengthen the threads. When dry,
reinstall the screws.

Step 5. Using the provided spring, hook up the tiller arm to the
rudder per the instructions included with the tail wheel assembly.

Section 9: Attaching the Tail Wheel

25

Parts Needed

• Fuselage

• Aluminum landing gear

• Wheelpants (2)

• 4-40 x 1/2" socket head screws (2)

• 4-40 blind nuts (2)

• #4 washers (2)

• 10-32 x 1" landing gear mounting screws (4)

• 10-32 lock nuts (4)

• #10 split washers (4)

• 31/2" Wheels (HAN308) (2)

• 3 /16" x 2" Axles (DUB24) (2)

• 3 /16" Wheel Collars (DUB141) (4)

Tools and Adhesives Needed

• Drill

• Drill Bit: 1/8"

• Hex Wrenches: 5/32" and 1/8"

• Adjustable wrench

• Felt-tipped pen

• Threadlock

Step 1.

Install the axles in the landing gear as shown and secure

in place using an adjustable wrench.

Note: A plywood mounting plate is glued in place
inside the wheelpant for mounting it to the landing gear.

Step 2. Place a wheel centered in the wheelpant and mark the
edge of the wheelpant at the axle hole. Mark the position on both
wheelpants with a felt-tipped pen, being sure to mark the same
side that the plywood plate is installed.

Step 3.Place the wheelpant on a flat surface and using a square
draw a line approximately 1

1

/2" long at the centered mark made
in the previous step. Make a mark 3/4" up from the bottom of the
wheelpant. This will be the axle location.

Section 10: Installing the Landing Gear

and Wheelpants

26

Step 4. Make a 1/2" hole at the marked position on the wheelpants.
It may be easier to drill a smaller hole first, then progressively
increasing to a larger bit size finishing up with a Moto-tool.

Step 5. Fit the wheelpants over the axle and align the small
hole with the 1

1

/2" line made in Step 3. With the wheelpants
properly aligned, mark the location of the mounting holes through
the landing gear on the wheelpants using a felt-tipped pen.

Step 6. Remove the wheelpants and carefully drill a 9/64" hole
through the wheelpants at the mark made in the previous step.

Step 7. Install the 4-40 blind nut from inside the wheelpants.
Later we will fully seat the blind nut into the plywood when
installing the wheelpants onto the landing gear.

Step 8. Install the following items onto the axle: wheelpant,
3/16" collar, wheel, and then another 3/16" collar. It will be
necessary to fit the parts inside the wheelpant and slide them
onto the axle.

27

Step 9. Secure the wheelpants in place using 4-40 x 1/2"
screws with washer and split washer through the landing gear
and into the blind nut in the wheelpants. Use threadlock and
securely tighten the screws to properly seat the blind nuts.

Step 10. Center the wheels in the wheelpants and tighten the
collars against the wheels so that they are held in place. Use
threadlock on the wheel collar set screws.

Step 11. Remove the landing gear hatch and mount the landing
gear to the fuselage using four 10-32 x 1" bolts and locking nuts.

Step 12. Reinstall the landing gear hatch.

28

Parts Needed

• Fuselage assembly

• 1400mAh or larger battery pack

• Receiver

• Receiver switch

• 1/8" light plywood

• Radio mounting foam (thick gyro tape also works well)

• Cup hooks

• Rubber bands #64

Tools and Adhesives Needed

• Hobby knife w/#11 blade

• 6-minute epoxy

Step 1. Remove the hatch to allow access to the interior of
the fuselage. Using the included templates on the back cover
of the manual cut out the battery tray and receiver tray from
1/8" light plywood.

Step 2. If using the Zenoah®GT-80, it will be necessary to
mount the battery pack just aft of the wing tube. The lighter
Zenoah G-62 requires the battery be mounted in the nose.
Using 6-minute epoxy, attach the battery tray to the fuselage.
(Our model uses the battery location for the GT-80.)

Step 3. Securely attach the battery to the battery tray. Be sure
to place RC foam under the battery to isolate vibration.

Step 4. Using 6-minute epoxy, fasten the receiver mount in
place just aft of the rear anti rotation blocks as shown below.

Step 5. Use an antenna tube and route the antenna back through
the fuselage. Secure the antenna tube with 6-minute epoxy and
1/8" light plywood. Secure the receiver to the tray and be sure to
use RC foam to isolate the receiver from vibration.

Section 11: Installing the Receiver, Battery,

and Fuel Tank

29

Step 6. Mount the receiver switch in a convenient location in
the side of the fuselage.

Step 7. Assemble the tank per the instructions included with the
tank. Mount the gas tank just ahead of the wing tube close to the
center of gravity. Be sure to use a gas-compatible stopper and
tubing. Place foam on the floor of the tank compartment. Secure
the tank in place by wrapping rubber bands or Velcro

®

straps
around the tank and tank floor. Cup hooks can be used to hook
the rubber bands to the tank floor.

30

Fast Fact: The Hangar 9

®

1/3-Scale Sukhoi Su-31 was
designed around the Zenoah GT-80 gasoline engine. We at
Hangar 9 understand that you may be tempted to use one of the
many 100cc gas engines currently available in the hobby indus­try. The use of 100cc engines require careful throttle manage­ment during all realms of flight, any misuse of power settings
could cause catastrophic airframe failure resulting in damage to
property or serious bodily injury to yourself or others. The use of
engines larger than 80cc will void any warranty claims you may
have. The prototype Sukhois were flown using the Zenoah GT-80
and other 80cc gasoline engines and were found to have more
than enough power to perform the IMAC Unlimited sequence as
well as 3-D flight maneuvers.

Parts Needed

• Fuselage assembly

• Engine

• Engine-mounting adapter plate (G-62 only)

• 1/4"-20 x 1/2" socket head cap screws w/split washers

(GT-80) (4)

• 1/4"-20 x 11/2" socket head screws w/split washers (G-62) (4)

• Cup engine mount (B+B6202) (G-62 only)

• Fiberglass cowl w/included mounting hardware

• 2' of Gas-Compatible Fuel Tubing (DUB800)

• Throttle servo

• 18" Servo Extension (JRPA009)

• 4-40 x 6" threaded (choke) rod

• 1/8" plywood

• Fuel Filler (HAN115)

• Kill Switch (ZEN20000)

• 6" 4-40 Rod Threaded (DUB802)

• 4-40 Solder Link (DUB604)

• 4-40 Ball Links (ROC87) (2)

Tools and Adhesives Needed

• Moto-tool w/cut-off wheel and drum sander

• Drill

• Drill Bit: 5/16"

• Hobby knife w/#11 blade

• Phillips screwdriver

• Scissors

• 6-minute epoxy

• Masking tape

• Soldering iron and silver solder

Using a GT-80

Step 1. Fit the engine to the firewall using four 1/4"-20 x 1/2"

socket head screws, split washers, and blind nuts provided.

Step 2. The GT-80 throttle servo is position as shown in the top
of the engine box. Cut the opening for the throttle servo in the
top of the engine box. The servo is located 11/2" from the left
side and centered in the top of the engine box. Mount the servo
using the hardware supplied with the servo.

Step 3. Make up the throttle linkage using a 4-40 rod, ball link,
and solder clevis. Carefully tap the throttle arm of the carburetor
with a 4-40 tap and connect the ball link to the throttle. Use the
solder clevis at the servo arm. Bend the linkage as shown to
keep the clevis level throughout the servo movement.

Section 12: Mounting the Engine and Cowl

31

Step 4. Use a 4-40 rod with a ball link to attach to the engines
choke lever. Attach the ball link to the choke lever using a 4-40
screw, stand off, and nut.

Using a G-62

Step 1. Remove the metal engine mount (if attached) from the

G-62. Attach the B+B Cup mount to the engine. Attach the cup
mount to the adapter plate using the hardware supplied with the
cup mount.

Step 2. Install the adaptor plate and engine to the firewall
using 1/4-20 x 1

1

/2" socket head cap screws (not included),

split washers, and blind nuts.

Step 3. Mount the throttle servo on the bottom of the engine
box 1/2" from the right side as shown in the photo. Mount the
servo using the hardware included with the servo.

Step 4. Using a 4-40 threaded rod and two ball links, make up
the throttle pushrod to the appropriate length. Securely install a
ball link in place and attach the 4-40 ball link to the pushrod and
the servo arm.

32

Step 5. Run the fuel lines from the pick up in the tank to the
carburetor and run the vent line out the bottom of the firewall.
We recommend using a fuel filler and a kill switch mounted on
the fuselage for convenient fueling and safety.

Step 6. Using a Moto-tool with a cut-off wheel and drum
sander cut air outlets in the bottom of the cowl as shown. It may
also be necessary to cut out an area for the mufflers to exit
depending on the mufflers and engine you use.

Step 7. Temporarily install the canopy hatch and trial fit the
Sukhoi cowl in place. Mark the location of the four mounting
screws and use a 1/8" drill bit to drill the holes for the 4-40 x

3

/4"

socket head screws.

Step 8. Mount the cowl and install the propeller and spinner.

33

Parts Needed

• Hatch

• Canopy

• 4-40 screws w/split washers and #4 washers (4)

• Decal for instrument panel

• 1/3-scale pilot

Tools and Adhesives Needed

• Hex Wrench: 3/32"

• Phillips screwdriver

• Formula 560-canopy glue

• Masking tape

Step 1. The Sukhoi canopy comes painted from the factory
and is attached with six screws. Remove the screws holding
the canopy to the hatch.

Step 2. Cut out the instrument panel decal from the decal sheet
and install it to the dash area of the hatch.

Step 3. Install a 1/3-scale pilot figure to the canopy hatch using
Shoe Goo or a similar adhesive that will remain flexible. Let the
glue dry before securing the canopy in place.

Step 4. Secure the canopy to the hatch using Formula 560 canopy
glue and the screws provided. Hold the edges of the canopy in
place with masking tape until the glue has dried (overnight).

Step 5. Mount the completed hatch. Use 4-40 screws with
#4 split washers to fasten the hatch in place.

Step 6. Apply the included decals as per the box top.

Section 13: Hatch Assembly

34

A 7-channel or greater computer radio is highly recommended
for the Hangar 9 1/3-Scale Sukhoi SU-31. This allows the
following features:

• Mixing the right aileron to the left aileron
(flapperon mix)

• Electronically adjustable aileron differential

• Mixing the right elevator to the left elevator

(dual elevator mixing)

• Independent travel and trim adjustments of
each elevator half

• Mixing the right rudder servo to the left rudder servo

• Rudder to elevator mixing to correct rudder to

elevator coupling

• Rudder to aileron mixing to correct rudder to
aileron coupling

When using a 7-channel or greater computer radio, each servo
is plugged into its own separate channel. Consult your radio
manual for specific details on hookup and programming. If using
a 6-channel radio with flapperon mix, the aileron servos are each
plugged into their own channels. The right aileron servo plug
into the aileron socket in the receiver, while the left aileron servo

plug into channel 6. With flapperon activated in the programming,
this allows for independent travel adjustment of each aileron in
each direction and electronic aileron differential. Consult your
manual for more programming details. With a 6-channel computer
radio, it will be necessary to Y-harness the two rudder and elevator
servos; a reversed elevator servo is needed to achieve the correct
control direction or a reversed servo can be used here. Special
attention must be taken with the rudder servos so that they don’t
fight each other throughout the rudder travel. This is caused by
non-symmetrical pushrod geometry right to left. It may be
necessary to rotate the arm on the servo one or two splines
(most of the time toward the rear) and readjust the linkage
length in order to prevent binding.

Using a non-computer radio will require that the aileron, elevator,
and rudder be Y-harnessed. Be sure to use a reversed servo for
one of the elevator servos. Again, special attention must be taken
with the rudder servos so that they don’t fight each other
throughout the rudder travel. This is caused by non-symmetrical
pushrod geometry right to left. It may be necessary to rotate the
arm on the servo one or two splines (most of the time toward the
rear) and readjust the linkage length in order to prevent binding.
If you’ve ever thought about purchasing a computer radio, now
is a good time to do it!

Section 14: Balancing the Model

Section 15: Radio Setup

Correctly balancing an aerobatic model is critical to its performance
and flight characteristics. The recommended Center of Gravity
(CG) for the Hangar 9®1/3-Scale Sukhoi Su-31 is at the center
of the wing tube opening at the fuselage sides. There is a range of

1

/2" forward and 1/2" rearward from the center of the wing tube. It
may be necessary to move batteries and radio equipment to
achieve the correct balance on your Sukhoi. Do this first before
adding any weight to the aircraft.

35

Recommended Control Throws

Standard Rate 3-D Rate

Aileron 20 degrees up 35 degrees up

20 degrees down 35 degrees down

Elevator 12 degrees up 38 to 40 degrees up

14 degrees down 38 to 40 degrees down

Rudder 28 degrees left-right 40 degrees left-right

Section 16: Control Throws

Range Test Your Radio

Step 1. Before each flying session, be sure to range check your

radio by turning on your transmitter with the antenna collapsed.
Turn on the receiver in your airplane. With your airplane on the
ground and the engine running, you should be able to walk 30
paces (approximately 100 feet) away from your airplane and still
have complete control of all functions. If not, don’t attempt to fly!
Have your radio equipment checked out by the manufacturer.

R

Step 2. Double-check that all controls (aileron, elevator, rudder,

and throttle) move in the correct direction.

Step 3. Be sure that your batteries are fully charged, per the
instructions included with your radio.

Section 17: Preflight at the Field

36

Our new 1/3-Scale Sukhoi will blow away almost any pilot wanting
to fly aerobatics. When designing this model, I incorporated
design features and enhancements that I used in several
Tournament of Champions and IMAC competitions. Does this
mean the Sukhoi is only for the serious competitor? Absolutely
not! What this does mean is that the Sukhoi is fine-tuned and
tweaked to excel in both precision aerobatics and wild freestyle
type 3-D, so doing any aerobatics will be easier than it has ever
been. I’ve found the Eppler 169 airfoil used on this Sukhoi to
make the low-speed flight exceptionally good.

Preflight

Before getting to the really fun stuff, flying, I’d like to reiterate
some very important steps that were covered in the assembly
instructions. For those of you who are veterans of large models,
this is old news. But to you new comers to the world of large
models, this is very important information. While many smaller
models are very tolerant of improper control linkage setups and
flying techniques, large models are not. Don’t let that scare you
away from large models; they are truly one of the best flying
experiences in RC that money can buy. However, please pay
particular attention to the following areas:

Seal the aileron and elevator hinge gaps.

This should be considered part of finishing the model and is as
important as installing the fuel tank or battery pack. On large
aerobatic models, this is absolutely necessary. Failure to do this
may very well cause control surface flutter, and on a large model,
this will most likely cause a crash. Putting safety and model
preservation to the side, there are several other reasons to do
this on an aerobatic model. It will increase the effectiveness of
the control surfaces, and the model will track more true and
precise. Hinge gaps sealed? CHECK!

Maintain the proper mechanical advantage on all con­trol surface linkages.

Same as unsealed hinge gaps, this is often the cause of flutter.
Please follow the control horn and servo arm lengths recommended
in this manual. Shorter arms on the servo or longer control
horns on the elevator and ailerons are fine, but do not try to go
the other way to increase throw. It will cause flutter on the
Sukhoi. The recommended linkage setups are more than adequate
to achieve full 3-D throws. That’s straight off of the prototypes.
Linkages are set? CHECK!

Never attempt to make full throttle dives!

Large models perform much more like full-size aircraft than
small models. If the airframe goes too fast, such as in a high
throttle dive, it may fail. The Sukhoi should be flown like a full­scale Sukhoi. Throttle management is absolutely necessary. If the
nose is down, the throttle comes back. CHECK!

The Prototype Model Setup

All of the recommended settings in this manual are a result of
the flight-testing on the prototype Sukhois. There are no secrets.
If you follow the instructions and these tips, your Sukhoi will be
set up just like mine.

Although a computer radio is not mandatory, it is preferable in
this model. I use exponential on all controls to soften the feel
around neutral. This makes it easier to fly smooth in precision
maneuvers and also makes it less likely to over-control in 3-D
mode. I use the following expo values: Elevator +38% Low Rate,
+70% 3-D Rate. Aileron +40% Low Rate, +55% 3-D Rate.
Rudder +25% Low Rate, +50% 3-D Rate. Note that + expo
values soften the neutral with JR radios. Other brand systems
may require "-" (negative) expo values to soften the neutral.

I have flown Sukhois equipped with JR 8101, JR8231 and
JR 8411 digital servos. While all are excellent choices for the
Sukhoi, I personally prefer the feel with the digital 8411 servos;
with these servos, the model feels slightly more responsive. I
use a 6V Ni-Cd battery pack for maximum speed and torque
from the servos.

The prototype Sukhois were tested on my favorite power plant,
the Zenoah GT-80. I use a Bolly 24 x 10 propeller, which the
GT-80 turns at approximately 7000 rpm, and a preshaped and
balanced Bolly 24 x 10 at 7700 rpm. Both work well, but I feel
the preshaped prop has the edge in hovering maneuvers. This
combination has proven to be totally unlimited and allows
anything imaginable from torque rolls just a few inches off the
ground to multiple vertical snaps. I found that adequate engine
cooling is very important with the GT-80 and strongly recommend
cutting the cowl bottom hole to the size recommended in the
instructions. When this was done, the performance difference
was dramatic. If you aren’t getting this kind of performance,
take a look at the cowl and how well the GT-80 is being cooled.

Performance Tip: Drill eight 5/16" diameter holes through the
internal baffle plate in the GT-80 mufflers. I drilled seven through
the intake opening and one up through the exhaust stack. Just be
sure to flush out all of the metal shavings from the mufflers. This
little 10-minute trick will add 300 rpm to the top end.

Section 18: Setup and Flight Information by

Mike McConville

Computer Radio Enhancements

A computer radio will allow you to do quite a bit of fine-tuning of
the feel of the Sukhoi, which will make aerobatics even easier.
Below are the programming enhancements I normally use to trim
out an aerobatic model.

• Rudder-to-Elevator and Rudder-to-Aileron Mixing

This mix is used to dial out unwanted pitch or roll caused
by the rudder. The Sukhoi has very little coupling, but
dialing it out will make knife-edge maneuvers easier. Use
a preprogrammed mix if your radio has this feature, or if
not, use a P-mix feature. Assign rudder as the master
channel and elevator as the slave. Set the mixing values
so when the rudder is deflected all the way in either direc­tion on high rate, the elevator moves up 1/4". Fine-tune
this as part of your flight trimming process.

• Spoileron Mixing

This can be achieved by using either a preprogrammed
elevator to flap mix or a P-mix. Assign elevator as the
master channel and flap as the slave. Set the mix values
so that when full up, 3-D elevator is given, both ailerons
also go up 35-degrees. This mix helps stabilize the
model in some 3-D maneuvers, such as the Elevator
and Harrier.

• Throttle Curve

This is normally a preprogrammed function. It can also be
achieved in radios that do not have this premix but do have
curve type P-mixing by mixing throttle as the master and
slave channels. Then adjust the curve to get the desired
throttle servo response. This is particularly useful to get an
engine to “act” linear throughout the entire throttle stick
movement. I also use this at times to make the throttle
response less sensitive in the rpm ranges used for hovering
the model. This makes altitude control easier and smoother
when doing torque rolls.

Rates and Expos: When andWhere to
Use Them

I always use expo to soften the feel of the model. On high 3-D
rates, I use quite a bit. The goal on 3-D rates is to get the model
to feel the same around neutral as it does on low rates. I use
low-rate settings for all flying except for 3-D aerobatics. For
precision flying or general sport hot-dogging, the low rate
throws are perfect, even for snap rolls. The only exception is
rudder rates. I go to 3-D rate when doing stall turns and rolling
circles, since the more rudder the better for these. When doing
3-D aerobatics, I normally flip to 3-D rates just before the
maneuver. As soon as the maneuver is done, I flip back down to
low rate to avoid over-controlling the model.

Let’s Get Down To It

When flying aerobatics with a larger model, you will find that it

will do everything just like a smaller model....only better and

easier. There are just a few exceptions to how things are done.
Throttle management is a must. You have to throttle back to idle
when the nose is pointed down.

Snap Rolls

Just like the need to be throttle managed like a full-scale airplane,
larger aerobatic airplanes need to be snapped like a full scale.
Let’s back up to how we all learned to do a snap roll. If it’s an
inside (positive) snap, we pull the sticks into the corner, i.e. full
up, full aileron, and full rudder in the same direction as aileron.
When we want to stop snapping, we release the controls. For
smaller models, this technique not only works but also is normally
the only way to get the model to snap. In a full-scale aerobatic
plane, as well as with large models, snaps are different,
particularly on the new breed of aerobatic birds like the Sukhoi,
which have large control surfaces.

Unloading Snaps

To start a snap roll, the same method as with a smaller model is
used. Pull full up, full rudder, and aileron in the same direction.
But soon as the sticks reach the corners, neutralize the elevator
while keeping the rudder and ailerons at full deflection. When
you do this correctly, the Sukhoi will not get “deep” into snaps.
This allows it to keep more airspeed as it exits the snap, so it
stops snapping where you what it to and flies out with more air
speed. You’ll also find that it will be easier to exit a snap heading
the same direction you were when you entered the snap. It’ll take
a little practice to get the hang of “flying” the snaps, but I’ll bet
you’ll see a big improvement in the quality of your flying.

37

38

Sukhoi at Its Best

3-D maneuvers (in simplest terms) are maneuvers performed by
an airplane that are not usually done in a normal airplane flight
path. What can be done with a 3-D plane is to make it fly like no
other. For example, hovering in the air nose high at a 45-degree
descent, floating along in level flight, hanging on the prop, or
tumble tail-over-nose in a rapid flipping motion. When you
sprinkle these maneuvers together with other loops, rolls, snaps,
and spins, it seems like the aerobatic options are endless. To fly
3-D, you must have a plane that’s capable. What’s capable?

Well, it starts with having outlandish pitch control from having
huge elevators. The same applies, but not to the same extent,
with rudder and ailerons. When it comes to 3-D aerobatics, our
Sukhoi lives up to the Sukhoi reputation and then some.

The Maneuvers

Let’s cover the seven 3-D maneuvers where the Sukhoi really excels.

• The Blender

What it is: The Blender or Panic maneuver is a vertical

diving roll that virtually stops its descent as it instanta­neously enters into a flat spin.

Setup: Follow the 3-D setup as described in the manual.
Be sure to use Expo. Setting the CG toward the aft location
will help, but I have had great results even at the forward
CG location. This is a wing tester and can be extremely
violent but will always generate gasps of excitement.
Done correctly, the Sukhoi can handle the challenge.

How to do it: Start from about 400-500 feet straight and
level, chop throttle, and push the nose straight down. As
soon as the model is diving straight down at low throttle,
add full left aileron. Let the model compete two or three
rolls and then quickly transition the sticks to an inverted
snap roll position (left aileron, right rudder, down elevator)
all at the same time. As soon as the Sukhoi enters a spin,
quickly neutralize the ailerons while holding full right
rudder and down elevator. If you do it right, the airplane
will instantly transition from a left roll to a flat spin in the
same direction, and the decent will all but stop.

Tip: Add full throttle just after the spin goes flat. That’ll
keep fuel going to the engine, make the rotation speed
high, and help stop the vertical decent.

Recovery: Simply release rudder and hold just a little
down elevator. The model will stop rotating and begin to
fly out. As it gains airspeed, roll back to upright. Since
you’re in 3-D mode, make sure you don’t do anything
abrupt, or you’ll stall again.

The Blender

39

• The Elevator

What it is: The plane drops vertically while in a nose

high attitude. Depending on the head wind conditions, the
model will drop anywhere from about a 45° angle in calm
conditions to vertical or even a little backwards in more
windy conditions. Throttle is used to determine rate of
descent and the nose high attitude of the model.

Setup: Same as the Blender, except flip the switch to
turn on the spoilerons. This will help to keep the Sukhoi
from teetering back and forth.

How to do it: At near stall airspeed up high, slowly feed
in up elevator until you have the full 3-D rate up in it.
With low throttle, the Sukhoi will fall like a rock. To guide
it around, use the rudder, not ailerons. Just keep the wings
level. Add power to change the attitude of your Sukhoi.

Trickiest part: Aside from steering it with the rudder,
you’ll quickly see that this maneuver is a matter of jug­gling the throttle and rudder to get the plane to go where
you want it to go.

Recovery: Basic recovering-add full power, flip to normal
rate elevator, and fly out.

Advanced recovery: Take the elevator all the way to the
ground, adding some power before it touches down to
slow the decent and transition into a Harrier and land.

OR

Add power to get the nose to rise to vertical and transition
into a Torque Roll. Elevator down from a hundred feet
down to 20 feet (or less) and power up into a torque roll.
Ooh!!

Worst way to mess up: Let your direction control
(rudder) get away from you after starting too low—you
could snap it right into the ground. Ouch!

• The Harrier

What it is: It is very slow forward flight in a very nose

high (about 45°) attitude.

Setup: Same as the Elevator, and the raised ailerons help
in this maneuver even more.

How to do it: Start by entering an Elevator maneuver.
Let the Sukhoi drop a small amount, then slowly add
power until the vertical decent stops and the model
begins to fly forward with the nose very high, all the while
your holding full up elevator (on 3-D rate). Juggle the
power to control the attitude and forward speed of the
model. In a head wind, you may also have to juggle the
elevator some to keep the model from pitching up to a
vertical attitude. Use the rudder to steer the model around
in the Harrier attitude. Try to use the ailerons very little,
as they will cause the model to wobble side to side.

Trickiest part: Keeping up with the model if it begins
to wobble.

Recovery: Simply add full power and reduce elevator to
transition into normal forward flight.

Advanced recovery: After you get the hang of flying
around in the Harrier, juggle the throttle to slowly lose
altitude and do a Harrier landing. The model will land on
the rear of the rudder first, and then add a little power so
it doesn’t smack the landing gear too hard.

The Harrier

40

• The Waterfall

What it is: This maneuver is a continuous tail-over-nose

descending flip. It is not a loop, but the aircraft actually
flops around its canopy.

Setup: Again, this is the critical component is having the
3-D elevator. The aft CG helps this the most.

How to do it: Start relatively high. At low throttle,
gradually pull the nose up until its near vertical. Just
before it stalls, add full down and, at the same time, add
full power. You have to continuously “fly” the rudder and
ailerons to keep the model flipping over in a straight line.
To do consecutive Waterfalls, continue to hold full down
and to “fly” rudder and ailerons and chop the throttle as
the nose comes back up to vertical, then add full power
as it flips straight down.

Trickiest part: No doubt here, it’s flying the rudder and
aileron correctly. You have to fly the rudder and ailerons
and make constant corrections. The amount you add will
vary. If you do not do this, the model will fall off into a
knife edge spin

Recovery: Just neutralize the elevator and the Sukhoi
will quit flipping, but expect some over-rotation, so
practice high until you get the feel of it. Fly out straight
and level or stop the rotation while pointed vertical and
go into a Torque Roll.

Worst way to mess up: Take it down too low, over­control your elevator on recovery, and snap into the ground.
To avoid this, simply change rates on your elevator to
normal travel.

• The Torque Roll

What it is: The Sukhoi “hovers” vertically in place,

rotating left around its roll axis.

Setup: Full 3-D throws in elevator and rudder are a
must. An aft CG helps a little. Also gyros provide the best
aid to stabilize the aircraft. They won’t do the maneuver
for you but they’ll help. I found them a fantastic tool in
learning to torque roll, kind of like training wheels. A few
years ago gyros made a big difference for me, now I don’t
use them anymore. You’ll need to use the Zenoah®GT-80
or an engine that will give you unlimited vertical before
you try this one.

How to do it: Fly low along the ground at low throttle
and gently add power with up elevator to bring the model
into a vertical position. Add throttle to keep the nose
pointed up and make corrections with rudder and elevator
to keep things straight. If the model hovers but won’t start
rolling left, quickly blip the throttle up and down. The
torque change will usually get it going.

Trickiest part: Recognizing your correction when the
model’s belly is toward you.

Tip: Think push the rudder toward the low wing when
the belly is toward you. You have to be fast with throttle
corrections. Add bursts of power, along with rudder/
elevator corrections. If you simply hold full throttle,
you’ll climb out of the maneuver.

Recovery: Fly out at full throttle.

Worst way to mess up: Have an unreliable engine.

Torque rolls are tough on engines because there’s only
prop-induced airflow over the cylinders. I’d really recommend
putting the baffling in the cowl if you are running a twin
cylinder engine and plan on doing torque rolls.

The Waterfall

The Torque Roll

41

• The Parachute

What it is: The Parachute is a vertical dive that instantly

decelerates in its descent as it instantaneously corners
into an Elevator.

Setup: Same as the Elevator, and the raised ailerons help
in this maneuver too.

How to do it: Start from about 400-500 feet straight and
level, chop throttle, and push the nose straight down. As
soon as the model is diving straight down at low throttle,
add full up elevator. If you do it right, the Sukhoi will
instantly transition from a vertical dive to an Elevator.

Tip: Add a little throttle just after transition to an Elevator.
That’ll keep fuel going to the engine and keep it from
quitting.

Recovery: Simply add full power and reduce elevator to
transition into normal forward flight.

Advanced recovery: Juggle the throttle to slowly lose
altitude and do a Harrier landing. The model will land on
the rear of the rudder first, then add a little power so it
doesn’t smack the landing gear too hard.

Worst way to mess up: To build up too much speed.
This maneuver has huge “WOW” factor, but just like a
Blender, too much speed and it over stresses the wing.
Watch the speed.

• The Wall

What it is: The Wall is a Parachute turned on end. The

model starts in normal level flight and suddenly corners
nose up 90°, as if it hit a wall.

Setup: Same as the Elevator, and the raised ailerons help
in this maneuver too.

How to do it: Start from about 100 feet straight and
level, chop throttle, and as the model begins to slow down,
quickly pull full up elevator. When the Sukhoi corners to
vertical, add full power and release the up elevator.

Tip: Start a low speed and add power at the same time
that you begin to pull full up elevator.

Recovery: Simply release the elevator, go to full throttle,
and fly out upward.

Advanced recovery: Juggle the throttle to sustain a
hover and transition into a torque roll.

Worst way to mess up: Don’t get the throttle in quickly
enough and the model falls backward.

• Great Combo

This has become one of my favorites to do with the
Sukhoi. Takeoff normally, but as soon as the Sukhoi is
airborne, chop the throttle and do the Wall, then transition
into a torque roll over the runway. Practice all of this stuff
up high before you try that. I hope you enjoy your Sukhoi
as much as I do!

Happy Landings!

Mike McConville

The Wall

The Parachute

42

AMA National Model Aircraft Safety Code

Effective
January 1, 2001

Model flying must be in accordance with this code in order for
AMA Liability Protection to apply.

General

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

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

3. Where established, I will abide by the safety 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.

4. At all flying sites a straight or curved line(s) must be
established, in front of which all flying takes place and the
other side designated for spectators. Only personnel
involved with flying the aircraft are allowed in front of
the flight line. Flying over the spectator side of the line is
prohibited, unless beyond the control of the pilot(s). In any
case, the maximum permissible takeoff weight of the models
with fuel is 55 pounds.

5. At air shows or model flying demonstrations, a single
straight line must be established, one side of which is for
flying and the other side designated for spectators. Only
those persons accredited by the contest director or other
appropriate officials as necessary for flight operations or
having duties or functions relating to the conduct of the
show or demonstration are to be permitted on the flying
side of the line. The only exceptions which may be permitted
to the single straight line requirements, under special
circumstances involving consideration of site conditions
and model size, weight, speed, and power, must be jointly
approved by the AMA President and the Executive Director.

6. Under all circumstances, if my model weights over 20
pounds, I will fly it in accordance with paragraph 5 of this
section of the AMA Safety Code.

7. I will not fly my model unless it is identified with my name
and address or AMA number on or in the model. (This does
not apply to models while being flown indoors.)

8. I will not operate models with metal-bladed propellers or
with gaseous boosts, in which gases other than air enter
their internal combustion engine(s); nor will I operate models
with extremely hazardous fuels, such as those containing
tetranitromethane or hydrazine.

9. I will not operate models with pyrotechnics (any device
that explodes, burns, or propels a projectile of any kind)
including, but not limited to, rockets, explosive bombs
dropped from models, smoke bombs, all explosive gases
(such as hydrogen-filled balloons), or ground-mounted
devices launching a projectile. The only exceptions permitted
are rockets flown in accordance with the National Model
Rocketry Safety Code or those permanently attached (as per
JATO use); also those items authorized for Air Show Team
use as defined by AST Advisory Committee (document
available from AMA HQ). Models using rocket motors as a

primary means of propulsion are limited to a maximum
weight of 3.3 pounds and a G series motor. (A model aircraft
is defined as an aircraft with or without an engine, not able
to carry a human being.)

10. I will not operate any turbo jet engine (axial or centrifugal
flow) unless I have obtained a special waiver for such
specific operations from the AMA President and Executive
Director, and I will abide by any restriction(s) imposed for
such operation by them. (This does not apply to ducted fan
models using piston engines or electric motors.)

11. I will not consume alcoholic beverages prior to nor during
participation in any model operations.

Radio Control

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

2. I will not fly my model aircraft near spectators until I become
a qualified flier, unless assisted by 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 by control.

4. I will operate my model using only radio control frequencies
currently allowed by the Federal Communications Commission.
(Only properly licensed amateurs are authorized to operate
equipment on Amateur Band frequencies.)

5. I will not knowingly operate an R/C system within 3 miles
of a pre-existing model club flying site without a frequency­sharing agreement with that club.

6. Models flown in air-to-air combat are limited to maximum
total engine displacement of .30 cubic inches and a maximum
dry weight prior to flying of 4 pounds.

7. An RC racing event, whether or not an AMA Rule Book
event, is one in which model aircraft compete in flight over
a prescribed course with the objective of finishing the
course faster to determine the winner.

AMA National Model Aircraft Safety Code
Organized RC Racing Event

A. In every organized racing event in which contestants,

callers,and officials are on the course:

1. All officials, callers and contestants must properly

wear helmets which are OSHA, DOT, ANSI, SNELL, or
NOCSAE approved or comparable standard while on
the race course.

2. All officials must be off the course except for the

starter and his/her assistant.

3. “On the course” is defined as any area beyond the

pilot/staging area where actual flying takes place. B. I
will not fly my model aircraft in any organized racing
event which does not comply with paragraph A above
or which allowsmodels over 20 pounds unless that
competition event is AMA sanctioned.

Note: Refer to AMA Headquarters for Free Flight, Control Line,
boat, car, and rocket safety codes.
ACADEMY OF MODEL AERONAUTICS,
5161 EAST MEMORIAL DRIVE
MUNCIE, INDIANA 47302-9252

43

Battery Tray

Receiver Tray

© Copyright 2002, Horizon Hobby, Inc.

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