Great Planes GPMA1208 User Manual

SPECIFICATIONS

Wingspan:

Length: 42.5 in [1080mm]

Wing Area:

52 in [1320mm]

2

550 in

[35.5 dm2]

INSTRUCTION MANUAL

Weight: 5– 5.75 lb

[2270– 2610 g]

Wing

Loading:

21– 24 oz /ft
[64–73 g/dm2]

Radio: Minimum four channel

Engine: .46-.55 cu in (7-9 cc) 2-stroke

2

or .70 (11.5 cc) 4-stroke

Electric: RimFire 32, 45 amp ESC

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.
Further, 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

READ THROUGH THIS MANUAL BEFORE STARTING CONSTRUCTION. IT CONTAINS IMPORTANT

INSTRUCTIONS AND WARNINGS CONCERNING THE ASSEMBLY AND USE OF THIS MODEL.

© 2014 Great Planes Model Mfg. A subsidiary of Hobbico,® Inc.

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.

Champaign, Illinois

[phone], Ext 5

[e-mail]

GPMA1208

TABLE OF CONTENTS

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

AMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

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

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

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

ESC (electronic speed control) . . . . . . . . . . . . . . . . . .3

Flight Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

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

Engine Recommendations. . . . . . . . . . . . . . . . . . . . . .3

Optional Pilot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

ADDITIONAL ITEMS REQUIRED. . . . . . . . . . . . . . . . . . .3

Required Hardware and Accessories . . . . . . . . . . . . .3

Optional Supplies and Tools . . . . . . . . . . . . . . . . . . . .3

KIT INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

ORDERING REPLACEMENT PARTS . . . . . . . . . . . . . . .3

KIT CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

IMPORTANT BUILDING NOTES . . . . . . . . . . . . . . . . . . . 5

ASSEMBLE THE WING . . . . . . . . . . . . . . . . . . . . . . . . . .5

ASSEMBLE THE FUSELAGE . . . . . . . . . . . . . . . . . . . . 11

ELECTRIC MOTOR INSTALLATION . . . . . . . . . . . . . . . 14

ENGINE INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 16

COMPLETE THE RADIO INSTALLATION . . . . . . . . . . .18

INSTALL THE COWL . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

FINISH THE MODEL . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Install a Pilot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Apply The Decals. . . . . . . . . . . . . . . . . . . . . . . . . . . .20

GET THE MODEL READY TO FLY. . . . . . . . . . . . . . . . .20

Install and Connect the Motor Battery . . . . . . . . . . . .20

Check the Control Directions. . . . . . . . . . . . . . . . . . .20

Set the Control Throws . . . . . . . . . . . . . . . . . . . . . . .21

Balance the Model (C.G.) . . . . . . . . . . . . . . . . . . . . .22

Balance the Model Laterally . . . . . . . . . . . . . . . . . . .22

PREFLIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Identify Your Model . . . . . . . . . . . . . . . . . . . . . . . . . .22

Charge the Batteries . . . . . . . . . . . . . . . . . . . . . . . . .22

Balance Propellers. . . . . . . . . . . . . . . . . . . . . . . . . . .23

Ground Check and Range Check . . . . . . . . . . . . . . .23

ENGINE SAFETY PRECAUTIONS. . . . . . . . . . . . . . . . .23

AMA SAFETY CODE (excerpts) . . . . . . . . . . . . . . . . . .24

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Radio Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

CHECKLIST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

FLYING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Fuel Mixture Adjustments . . . . . . . . . . . . . . . . . . . . .25

Takeoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

INTRODUCTION

The Sport Fighter Mustang is a great fl ying sport model. For

the latest technical updates or manual corrections visit the
Great Planes web site at www.greatplanes.com. Open the

“Airplanes” link, then select the Sport Fighter Mustang 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.

AMA

Academy of Model Aeronautics: If you are not already a
member of the AMA, please join! The AMA is the governing

body of model aviation and membership provides liability
insurance coverage, protects modelers’ rights and interests

and is required to fl y at most R/C sites.

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

very much like a full-size airplane. If not assembled and
operate d corre c tly, it c o uld poss ibly cause injur y to yoursel f
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 unfl yable model

3. You must u se an R /C radio system that is in good co ndition,

a correctly sized engine, and other components as specifi ed
in this instruction manual.

4. If you are not an experienced pilot or have not fl own this

type of model before, we recommend that you get the
assistance of an experienced pilot in your R/C club for
your fi rst fl ights.

5. While this kit has been fl ight tested to exceed normal use,

if an engine larger than one in the recommended range is
used, the modeler is responsible for taking steps to reinforce
the high stress points and/or substituting hardware more
suitable for the increased stress.

6. WARNING: The cowl included in this kit is made of

fi berglass, the fi bers of which may cause eye, skin and
respiratory tract irritation. Never blow into a part to remove
fi berglass dust, as the dust will blow back into your eyes.

SAFETY PRECAUTIONS

Protect Your Model, Yourself & Others…

Follow These Important Safety Precautions

1. Your Sport Fighter Mustang should not be considered a toy,

but rather a sophisticated, working model that functions

We, as the kit manufacturer, provide you with a top quality,
thoroughly tested kit and instructions, but ultimately the
quality and fl yability of your fi nished 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.

2

DECISIONS YOU MUST MAKE

ADDITIONAL ITEMS REQUIRED

This is a partial list of items required to fi nish the Sport Fighter

Mustang that may require planning or decision making before
st ar ting to buil d. Orde r numbers are provided in parentheses.

Motor Battery Recommendations

The Sport Fighter P-51 ARF comes with a mounting box for

the Great Planes RimFire brushless outrunner motor. This
motor has been tested with this plane and works well.

❍ Great Planes RimFire .32 (42-50-800) Brushless

Outrunner Motor [GPMG4700]

ESC (electronic speed control)

A brushless ESC (electronic speed control) is required for
the recommended motor set-up. We recommend using the:

❍ Great Planes Silver Series SS-45A Brushless ESC

[GPMM1840]

Flight Battery

We recommend the FlightPower FP 30 LiPo 4S 3800mAh

14.8V 30C with an APC 13" x 8E propeller.

❍ Great Planes ElectriFly LiPo 4S 2200mAh 14.8V

30C [GPMP0862]

❍ FlightPower FP 30 LiPo 4S 3800mAh 14.8V 30C

(FPWP3384)

❍ APC 13" x 8E Propeller (APCQ3080)

Radio Equipment

Required Hardware and Accessories

This is the list of hardware and ac cessories required to fi nish

the Sport Fighter Mustang. Order numbers are provided in
parentheses.

❍ Three 6" [150mm] servo extensions

(TACM2090 for Futaba)

❍ 6" Y-harness (FUTM4135)
❍ R/C foam rubber (1/4" [6mm] - HCAQ1000
❍ 1/2 oz. [15g] Thin Pro CA (GPMR6001)
❍ 1/2 oz. [15g] Medium Pro CA+ (GPMR6007)
❍ Pro 30-minute epoxy (GPMR6047)
❍ Drill bits: 1/16" [1.6mm], 5/64" [2mm],

1/8" [3mm], 7/64" [2.8mm].

❍ 6-32 tap and drill set (GPMR8102)
❍ Tap handle (GPMR8120
❍ #1 Hobby knife (HCAR0105)
❍ #11 blades (5-pack, HCAR0211)
❍ Threadlocker thread locking cement (GPMR6060)
❍ Masking tape
❍ Fine line marker

Optional Supplies and Tools

Here is a list of optional tools mentioned in the manual that
will help you build the Sport Fighter Mustang.

❍ 2 oz. [57g] spray CA activator (GPMR6035)
❍ Epoxy brushes (6, GPMR8060)
❍ Mixing sticks (50, GPMR8055)
❍ Mixing cups (GPMR8056)
❍ Rotary tool such as Dremel
❍ Denatured alcohol (for epoxy clean up)

The Sport Fighter Mustang requires a minimum of four

channels. The airplane requires the use of fi ve servos for
the glow engine installation, or four servos and an ESC for
the electric motor installation.

A servo with a minimum 54oz-in of torque is required on all
of the control surfaces. A lower torque servo is acceptable
as the throttle servo. We used th e Fu taba 9001 (FUTM0 075 )
throughout our testing. Additionally, three 6" [150mm] servo
extensions (TACM2090 for Futaba) are required for the aileron
servos and one 6" Y-harness (FUTM4135 for Futaba).

Engine Recommendations

The recommended engine size range for the Sport Fighter

Mustang is 2-stroke .46-.55 cu in (7-9 cc) OR 4-stroke .70
(11.5 cc). If an engine in the upper end of the size range

is used, remember that this is a semi-scale model that is
intende d to fl y at scale-like s peeds, s o throt tle man agement

should be practiced.

Optional Pilot

❍ Great Planes 1/5 scale pilot (GPMQ9115)

KIT INSPECTION

Before starting to build, 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 Product Support. When reporting defective
or missing parts, use the part names exactly as they are
written in the Kit Contents list.

Great Planes Product Support

3002 N Apollo Drive, Suite 1 Ph: [phone], ext. 5
Champaign, IL 61822 Fax: [phone]

E-mail: [e-mail]

ORDERING REPLACEMENT PARTS

Replacement parts for the Great Planes Sport Fighter Mustang
ARF are available using the order numbers in the Replacement
Parts List that follows. The fastest, most economical service
can be provided by your ho b by dealer or mail- order company.

To locate a hobby dealer, visit the Great Planes web site at

www.greatplanes.com. Select “Where to Buy” in the menu

3

across the top of the page and follow the instructions provided
to locate a U.S., Canadian or International dealer.

Parts may also be ordered directly from Hobby Services by
calling [phone], or via facsimile at [phone], but
full retail prices and shipping and handling charges will apply.
Illinois and Nevada residents will also be charged sales tax.
If ordering via fax, include a Visa® or MasterCard® number
and expiration date for payment.

Mail parts orders Hobby Services
and payments by 3002 N Apollo Drive, Suite 1
personal check to: Champaign IL 61822

Be certain to specify the order number exactly as listed in the
Replacement Parts List. Payment by credit card or personal
check only; no C.O.D.

If additional assistance is required for any reason contact
Product Support by e-mail at productsupport@greatplanes.
com, or by telephone at [phone].

KIT CONTENTS

REPLACEMENT PARTS LIST

Order No. Description

GPMA5365
GPMA5366
GPMA5367
GPMA5368
GPMA5369
GPMA5370
GPMA5371
GPMA5372
GPMA5373
GPMA5374

Wing
Fuse
Tail Surface Set
Cowl
Spinner
Landing Gear Set
Gear Covers
Canopy/Hatch
Decals
EP Motor Mount

11

Kit Contents

1. Spinner

2. Cowl

3. Fuselage

4. Motor Mount

2

1

4

12 13 14

5

5. Fuel Tank

6. Wing Joiner

7. Canopy

8. Wing

9. Landing Gear Doors

10. Landing Gear Wires

3

7

6

8

15

11. Electric Motor Box

12. Forward Fairing

10

9

16 16

16. Main Wheels

17. Tail Wheel

10

17

13. Air Scoop

14. Stab & Elevators

15. Fin, Rudder, & Tail Wheel
Assembly

4

IMPORTANT BUILDING NOTES

● Throughout the manual you will be told to drill holes into

the wood and insert the screws. In all cases you should
insert the screw and then remove the screw. Apply a drop of
thin CA glue to harden the threads. After the glue hardens
re-install the screws.

● When installing nuts on screws and bolts be sure to apply

a drop of thread locker to each one.

● Whenever the term glue is written you should rely upon

your experience to decide what type of glue to use. When
a specifi c type of adhesive works best for that step, the
instructions will make a recommendation.

● The canopy/hatch is pre-installed on the fuselage. To

remove it, slide the canopy forward and lift it from the rear.

3. Install servo arm and hardware. Tie string to the

❏ ❏

servo lead.

ASSEMBLE THE WING

1. Tighten the covering.

❏

4. The end of the string is taped to the root rib of the

❏ ❏

wing. Pull servo lead through the wing.

2. Remove the end of the string from the wing. Do not

❏ ❏

pull the string completely out of the wing.

❏ ❏

5

5. Pull the servo lead through the hole in the wing.

6. Remove the string and then tape the lead to the wing.

❏ ❏

7. Drill four 1/16" [1.6mm] holes through the servo

❏ ❏

mounting holes, into the plywood plate.

10. Glue pin into the right wing root rib.

❏

11. Using 30 minute epoxy, glue two wing joiners together.

❏

Allow it to harden.

12. Apply 30 minute epoxy to both sides of the wing joiner.

❏

8. Mount the servo with four servo screws. Install the

❏ ❏

servo arm so it points toward wingtip.

9. Repeat steps 2 - 7 for the other wing.

❏

13. Apply epoxy inside the joiner pocket and all along the

❏

ro ot rib (includ ing the tab) of both wings. Inser t the joiner and
assemble the wings.

6

14. Tape the wings together and allow the glue to harden.

Hinge Line Hinge Line

CORRECT INCORRECT

FasLink

2-56 (.074") Pushrod Wire

Servo Horn

1/16"

❏

control horn with two 1/16" x 3/8" [2x10mm] screws. Drill a
5/64 [2mm] hole in the outer hole of the servo arm. Install the
clevis to the outer hole of the control horn. Center the aileron
and the servo. Make a mark on the wire where it aligns with
the servo arm outer hole. Bend the wire on the mark. Secure
the wire to the servo arm with a Faslink and then cut off the
excess length of wire.

15. Install a Y-harness to the two aileron servo leads.

❏

Secure the leads with shrink tube or tape.

16. Assemble the pushrod components as shown. Place

❏

the control horn on the aileron in line with the servo arm. Drill a

1/16" [1.6mm] hole though the surface of the aileron. DO NOT

DRILL THROUGH THE TOP OF THE AILERON! Secure the

17. Repeat this for the other aileron servo.

❏

18. Temporarily mount the wing to the fuselage with two

❏

10-24 x 2" [51mm] nylon bolts.

7

19. Place the forward fairing onto the wing and trace the

❏

location onto the wing with a felt tip marker. Do the same with
the air scoop. Using a “Sharp” hobby knife cut the covering

1/16" [1.6 mm] inside of the lines you have drawn. DO NOT

CUT THROUGH THE BALSA WING SKIN!

20. Apply glue to the edges of the fairing. Tape it in place

❏

on the wing.

8

21. Remove the wing bolts from the wing. Insert them into

❏

the holes in the air scoop. Apply glue to the edges of the air
scoop.

23. Assemble the landing gear as shown.

❏

22. Place the air scoop onto the wing, tighten the bolts

❏

to the fuselage and tape the front of the air scoop in place.
Allow the glue to dry.

24. Install the landing gear into the slots in the bottom of

❏

the wing. The landing gear should be angled forward.

9

25. Lay two plastic landing gear straps over each landing

❏

gear wire. Drill four 5/64" [2 mm] holes in each wing half.
Secure the landing gear straps to each wing half with four

1/8" x 3/8" [3 mm x 10mm] screws.

26. Install the landing gear fairings.

❏

10

ASSEMBLE THE FUSELAGE

1. Cut away the block at the rear of the fuselage.

❏

2. Test fi t (do not glue) the stabilizer into the slot in the

❏

rear of the fuselage.

3. Test fi t (do not glue) the fi n into the slot in the fuselage

❏

and stabilizer.

5. Apply glue to the top, center of the stab and the stab

❏

opening in the fuselage. Insert the stab into the opening in
the fuselage. Wipe away excess glue.

4. Look at the stab. It should be aligned with the wing. Sand

❏

the stab saddle as needed to make the stab align with the wing.

11

6. Apply glue to the sides and the bottom of the fi n. Install

❏

it into the fuselage and stab opening. Tape the fi n in place

while the glue dries.

7. Secure the tail wheel bracket with two 1/16" x 3/8"

❏

[2mm x 10mm] screws.

8. Install the control horns on the rudder and elevator.

❏

12

9. Install the tail wheel, securing it with the wheel collar

❏

and set screw.

11. As you did with the ailerons, drill 1/16" [1.6mm] holes

❏

for mou nting each ser vo. S ecure each ser vo with four ser vo
screws. Drill a 5/64" [2mm] hole in the outer hole of the
servo arm. Center servos, rudder, and elevator, then make
a mark on the wire where it aligns with the servo arm outer
hole. Bend the wire on the mark. Secure the wire to the servo
arm with a Faslink and then cut off the excess length of wire.

Note: If you are installing a glow engine continue with step

12. If you will be using electric power skip ahead to page 14.

12. If you are installing a glow engine, install the throttle

❏

servo the same as you did the elevator and rudder servos.

10. Install a clevis and clevis keeper onto two 20" [508mm]

❏

pushrod wires. Insert the wires into the holes in each side
of the fuselage. Attach the clevis to the outer hole of each
control horn. Slide the clevis keeper over the clevis.

13. As you did with the other servos, drill 1/16" [1.6mm]

❏

holes for mounting each servo. Secure the servos with four
servo screws. Drill a 5/64" [2mm] hole in the outer hole of the
servo arm. You will complete the throttle servo installation
during the engine installation. Skip ahead to the ENGINE

INSTALLATION on page 16.

13

ELECTRIC MOTOR INSTALLATION

4. Mount the

❏

motor box to the
front of the fuselage.

1. Locate the motor box components. Glue the two parts

❏

shown together.

2. Tap the 6-32 blind nuts

❏

into the holes in each corner
of the fi rewall.

5. Mount the

❏

motor to the motor
box with the
remaining 6-32
hardware.

3. Glue the motor box

❏

together. Glue triangle stock

into each joint before gluing
the bottom of the motor box

in place.

6. Remove the opening in the fi rewall.

❏

14

7. Install a 6" [152mm] servo extension on the ESC speed

❏

control. Secur e the c o nnection with t a pe or h eat shrink tubing.

8. Install one half of the provided Velcro® to the back of

❏

the ESC and the other inside the fuselage. Cut the Velcro as
needed to fi t properly.

10. Install your battery, securing it with the included Velcro

❏

strap. Cut the Velcro to fi t your battery.

9. Install the ESC inside of the fuselage. Plug the motor

❏

wires into the ESC and the servo lead into the receiver
following the instructions with the ESC.

11. For proper cooling, with a sharp hobby knife remove

❏

the covering from the pre-cut holes in the rear of the fuselage.

Note: This completes the motor installation. Move ahead to
page 18 to complete the assembly of the airplane.

15

ENGINE INSTALLATION

1. Cut the tabs from the motor mount. Slide the motor

❏

mount together. Locate the four 6-32 x 1" [25mm], #6 fl at
washers and #6 lock washers. Install the mount to the fi rewall
as shown. The engine will be mounted inverted.

4. Tap each of the four holes with a 6-32 tap.

❏

2. Place the engine onto the engine mount, spacing it 4-1/8"

❏

[105mm] from the fi rewall. Mark the location of mounting holes
for the engine onto the motor mount.

3. Drill four 7/64"

❏

[2.8mm] holes on each
of the marks, drilling
through the engine
mount.

5. Mount the engine with four 6-32 x 3/4" [19mm] screws,

❏

#6 fl at washer and #6 lock washers.

6. Locate the 11-1/2" plastic pushrod tube.

❏

16

7. Insert it in the hole in the fi re wall (You may need to cut

❏

away a small portion of the triangle stock on the back side
of the fi rewall to allow the tube to pass through the fi rewall)

and through the hole in the former. Apply a drop of glue to
the tube where it passes through the fi rewall and the former

in the fuselage.

9. Slide the brass

❏

screw lock connector
over the end of the
wire. Insert the brass
pin into the lower hole
of the carburetor arm,
se c uring it with a nylo n
retainer. Rotate the
throttle arm forward,
and then insert and
tighten the set screw
against the pushrod
wire. Make a slight
be nd in th e wire so the
wire moves freely. Cut
off the excess wire.

10. Install a Velcro strip through the slots along the side

❏

of the front of the fuselage where the fuel tank mounts.

8. Install a nylon clevis and clevis keeper onto the threaded

❏

end of the 2-56 x 19-1/2" [500mm] wire. Insert the end of the
wire into the tube, sliding it forward towards the engine. Install
the clevis into the outer hole of the servo arm. Slide the clevis
keeper over the clevis. Rotate the servo arm toward the front
of the fuselage.

11. From the bottom of the fuselage insert the pre-assembled

❏

fuel tank, turning it on its side, into the front of the fuselage.

The neck of the tank will align with the hole in the fi rewall.

12. Pull the fuel lines

❏

from the tank through
the hole. The blue
line attaches to the
carburetor, the clear line
will attach to the muffl er
and the green line with
the fuel plug is the fi ll
line. Secure the tank
with the Velcro.

17

COMPLETE THE RADIO INSTALLATION

1. Insert Velcro strips into the slots to secure the battery

❏

from the bottom of the tray and the receiver on the top of
the tray.

2. Cut holes in the fuselage for the switch and charge jack.

❏

3. Following the instructions with your radio, plug the servos

❏

into the receiver and install a 6" [152mm] servo extension in
the receiver for the aileron servo.

18

INSTALL THE COWL

1. Install the canopy top onto the fuselage.

❏

4. Position the cowl on the fuselage so that the drive

❏

washer extends in front of the cowl approximately 1/8" [3mm].
From the marks on the tape measure forward 1-1/2" [38mm].
Drill a 1/16" [1.6mm] hole through the cowl and the plywood
mounting tab. Secure the cowl with a 3/32" x 3/8" [2.5 x

10mm] washer head screw. Double check the position of the

cowl and do the same for another of the mounting holes. Do
this for all four mounting holes.

2. Slide the cowl over the engine, making marks where

❏

you need to cut clearances for the cowl. Cut clearance in the
cowl for the muffl er, needle valve, muffl er bolt access, etc. as
needed for your engine.

3. With the cowl cut outs completed, place 2-1/2" [64mm]

❏

pieces of tape to the plywood mounting tabs extending back
towards the fuselage. Mark the location for the mounting hole,
centered on the “tab” and then draw a line back from the mark

1-1/2" [38mm]. Do this for all four pieces of tape.

5. Install the muffl er onto the engine. Access holes for

❏

the bolts need to be provided on the left side of the cowl to
mount the muffl er.

19

6. Install the spinner and propeller onto the engine.

❏

FINISH THE MODEL

Install a Pilot

Apply The Decals

1. If you wish to install a pilot, cut away the bottom of the

❏

canopy and install a pilot of your choice. Replace the portion
you cut from the bottom of the canopy using glue. We installed
the Great Planes 1/5 scale pilot (GPMQ9115).

1. Apply the decals using these photos and the box photos

❏

to determine the proper location.

GET THE MODEL READY TO FLY

EP VERSION

Install and Connect the Motor Battery

Before you can power the radio system and set up the controls,
the motor battery will need to be charged. Charge the battery
following the instructions with your battery and charger.

Check the Control Directions

1. Turn on the transmitter and receiver and center the trims.

❏

If necessary, remove 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 clevises on the pushrods to center the control surfaces.

20

FULL

THROTTLE

RUDDER

MOVES

RIGHT

ELEVATOR

MOVES DOWN

RIGHT AILERON

MOVES UP
LEFT AILERON
MOVES DOWN

4-CHANNEL RADIO SET UP

(STANDARD MODE 2)

Measure the high rate elevator throw fi rst…

2. Hold a ruler vertically on your workbench against the

❏

widest part (front to back) of the trailing edge of the elevator.
Note the measurement on the ruler.

3. Make certain that the control surfaces and the throttle

❏

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 necessary.

Set the Control Throws

To ensure a successful fi rst fl ight, set up your Sport Fighter
Mustang according to the control throws specifi ed in this
manual. The throws have been determined through actual
fl ight testing and accurate record-keeping allowing the
model to perform in the manner in which it was intended.
If, after you have become accustomed to the way the Sport
Fighter Mustang fl ies, you would like to change the throws
to suit your taste, that is fi ne. However, too much control
throw could make the model too responsive and diffi cult to
control, so remember, “more is not always better.”

1. Use a box or something similar to prop up the bottom of

❏

the fuselage so the horizontal stabilizer and wing will be level.

3. Move the elevator up with your transmitter and move

❏

the ruler forward so it will remain contacting the trailing edge.

The distance the elevator moves up from center is the “up”

elevator throw. Measure the down elevator throw the same way.

These are the recommended control surface throws:

NOTE: The throws are measured at the widest part of the

elevators, rudder and ailerons.

These are the recommended control surface throws:

LOW HIGH

DownUp Up Down

ELEVATOR

AILERON

RUDDER

1/2 "

[13 mm]

13°

3/16"

[5mm]

9°

3/4"

[19 mm]

14°

1/2 "

[13 mm]

13°

DownUp Up Down

3/16"

[5mm]

9°

LeftRight LeftRight

3/4"

[19 mm]

14°

3/4"

[19mm]

19°

5/16"

[8mm]

14°

3/4"

1"

[19mm]

[25mm]

37°

19°

3/4"

[19mm]

5/16"

[8mm]

[25mm]

19°

14°

1"

19°

21

Balance the Model (C.G.)

More than any other factor, the C.G. (center of gravity/
balance point) can have the greatest effect on how a model
fl ies and could determine whether or not your fi rst fl ight will
be successful. If you value your model and wish to enjoy it
for many fl ights, DO N OT OVERLOOK THIS IMPO RTANT
PROCEDURE. A model that is not properly balanced may
be unstable and possibly unfl yable.

At this stage the model should be in ready-to-fl y condition
with all of the components in place including the complete
radio system, engine, muffl er, propeller, spinner and pilot. If
you’ve built the electric version, install the motor battery. If
you’ve built the glow version the fuel tank should be empty.

1. If using a Great Planes C.G. Machine, set the rulers to

❏

3-1/2" [89mm]. If not using a C.G. Machine, use a fi ne-point
felt tip pen to mark lines on the top of wing on both sides of
the fuselage 3-1/2" [89mm] back from the leading edge. Apply
narrow (1/16" [2mm]) strips of tape over the lines so you will

be able to feel them when lifting the model with your fi ngers.

If possible, move the battery pack and/or receiver aft. If the
receiver and/or battery cannot be moved, or if additional
weight is still required, nose weight may be easily added
by using “spinner weight” (GPMQ4645 for the 1 oz. [28g]
weight, or GPMQ4646 for the 2 oz. [57g] weight). If spinner
weight is not practical or is not enough, or if tail weight is
required, use Great Planes “stick-on” lead (GPMQ4485). To
fi nd out how much weight is required, place incrementally
increasing amounts of weight on the bottom of the fuselage
over the location where it would be mounted inside until the
model balances. A good place to add stick-on nose weight
is to the fi rewall. Do not attach weight to the cowl—this will
cause the mounting screws to open up the holes in the cowl.
Once you have determined the amount of weight required,
it can be permanently attached. If required, tail weight may
be added by cutting open the bottom of the fuse and gluing
it permanently inside.

Note: If mounting weight where it may be exposed to fuel
or exhaust, do not rely upon the adhesive on the back to
permanently hold it in place. Over time, fuel and exhaust
residue may soften the adhesive and cause the weight to fall
of f. In stead, perm anentl y attac h the we ight with glue or scr ews.

This is where your model should balance for the fi rst
fl ights. Later, you may experiment by shifting the C.G. 1/4"
[6mm] forward or 1/4" [6mm] back to change the fl ying
characteristics. Moving the C.G. forward will improve the
smoothness and stability, but the model will then be less
aerobatic (which may be fi ne for less-experienced pilots).
Moving the C.G. aft makes the model more maneuverable
and aerobatic for experienced pilots. In any case, start at
the recommended balance point and do not at any time
balance the model outside the specifi ed range.

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

❏

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

Balance the Model Laterally

1. With the wing level, have an assistant help you lift the

❏

model by the engine propeller shaft and the bottom of the
fuse under the TE of the fi n. Do this several times.

2. If one wing always drops when you lift the model, it means

❏

that side is heavy. Balance the airplane by adding weight
to the other wing tip. An airplane that has been laterally

balanced will track better in loops and other maneuvers.

PREFLIGHT

Identify Your Model

No matter if you fl y at an AMA sanctioned R/C club site or
if you fl y somewhere on your own, you should always have
your name, address, telephone number and AMA number
on or inside your model. It is required at all AMA R/C club
fl ying sites and AMA sanctioned fl ying events. Fill out the
identifi cation tag on the decal sheet and place it on or inside
your model.

2. With the wing attached to the fuselage, all parts of the

❏

model installed (ready to fl y) and an empty fuel tank, or LiPo

batteries in place, place the model upside-down on a Great

Planes CG Machine, or lift it upside-down at the balance

point you marked.

3. If the tail drops, the model is “tail heavy.” If possible,

❏

move the battery pack and/or receiver forward to get the
model to balance. If the nose drops, the model is “nose heavy.”

Charge the Batteries

Follow the battery charging instructions that came with your
radio control system to charge the batteries. You should
always charge your transmitter and receiver batteries the night
before you go fl ying, and at other times as recommended by
the radio manufacturer.

22

CAUTION : Unless the instructions that came with your
radio system state differently, the initial charge on new
transmitter and receiver batteries should be done for 15
hours using the slow-charger that came with the radio
system. This will “condition” the batteries so that the next
charge may be done using the fast-charger of your choice.
If the initial charge is done with a fast-charger the batteries
may not reach their full capacity and you may be fl ying with
batteries that are only partially charged.

ENGINE SAFETY PRECAUTIONS

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

● Keep all engine fuel in a safe place, away from high heat,

sp arks or fl ame s, as fuel is very fl ammable. Do not smoke
near the engine or fuel; and remember that engine exhaust

gives off a great deal of deadly carbon monoxide. Therefore
do not run the engine in a closed room or garage.

Balance Propellers

Carefully balance your propeller and spare propellers before
you fl y. An unbalanced pr op can b e the single mo st sign ifi cant
cause of vibration that can damage your model. Not only
will engine mounting screws and bolts loosen, possibly with

disastrous effect, but vibration may also damage your radio
receiver and battery. Vibration can also cause your fuel to
foam, which will, in turn, cause your engine to run hot or quit.

We use a Top Flite Precision Magnetic Prop Balancer
(TOPQ5700) in the workshop and keep a Great Planes
Fingertip Prop Balancer (GPMQ5000) in our fl ight box.

● Get help from an experienced pilot when learning to operate

engines.

● Use safety glasses when starting or running engines.

● Do not run the engine in an area of loose gravel or sand;

the propeller may throw such material in your face or eyes.

● Keep your face and body as well as all spectators away

from the plane of rotation of the propeller as you start
and run the engine.

● 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.

● Use a “chicken stick” or electric starter to start the engine.

Do not use your fi ngers to fl ip the propeller. Make certain
the glow plug clip or connector is secure so that it will not

pop off or otherwise get into the running propeller.

● Make all engine adjustments from behind the rotating

propeller.

● The engine gets hot! Do not touch it during or right after

operation. Make sure fuel lines are in good condition so
fuel will not leak onto a hot engine, causing a fi re.

Ground Check and Range Check

Run the engine for a few minutes to make sure it idles reliably,
transitions smoothly and maintains full power indefi nitely.
Afterward, shut the engine off and inspect the model closely,
making sure all fasteners, pushrods and connections have
remained tight and the hinges are secure. Always ground
check the operational range of your radio before the fi rst fl ight
of the day following the manufacturer’s instructions that came
with yo ur rad io. T his sho uld be d one onc e with t he engine off
and once with the engine running at various speeds. If the
control surfaces do not respond correctly, do not fl y! Find and
correct the problem fi rst. Look for loose servo connections
or broken wires, corroded wires on old servo connectors,

poor solder joints in your battery pack or a defective cell, or

a damaged receiver crystal from a previous crash.

● To stop a glow engine, cut off the fuel supply by closing

off the fuel line or following the engine manufacturer’s
recommendations. Do not use hands, fi ngers or any other
body part to try to stop the engine. To stop a gasoline
powered engine an on/off switch should be connected to
the engine coil. Do not throw anything into the propeller
of a running engine.

23

AMA SAFETY CODE (excerpts)

CHECKLIST

Read and abide by the following excerpts from the Academy
of Model Aeronautics Safety Code. For the complete Safety
Code refer to Model Aviation magazine, the AMA web site or
the Code that came with your AMA license.

General

1) I will not fl y my model aircraft in sanctioned events, air shows,
or model fl ying demonstrati ons until it has been proven to be
airworthy by having been previously, successfully fl ight tested.

2) I will not fl y my model aircraft higher than approximately
400 feet within 3 miles of an airport without notifying the
airport operator. I will give right-of-way and avoid fl ying in the

proximity of full-scale aircraft. Where necessary, an observer

shall be utilized to supervise fl ying to avoid having models fl y

in the proximity of full-scale aircraft.

3) Where established, I will abide by the safety rules for the
fl ying site I use, and I will not willfully and deliberately fl y my
models in a careless, reckless and/or dangerous manner.

5) I will not fl y my model unless it is identifi ed with my name
and address or AMA number, on or in the model. Note: This

does not apply to models while being fl own indoors.

7) I will not o p erate model s with pyrotechnic s (any device that
explodes, burns, or propels a projectile of any kind).

Radio Control

1) I will have completed a successful radio equipment ground
check before the fi rst fl ight of a new or repaired model.

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

3) At all fl ying sites a straight or curved line(s) must be
established in front of which all fl ying takes place with the
other side for spectators. Only personnel involved with fl ying
the aircraft are allowed at or in the front of the fl ight line.
Intentional fl ying behind the fl ight line is prohibited.

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

5) I will not knowingly operate my model within three miles

of any pre-existing fl yin g site exc e pt in accordance with
the frequency sharing agreement listed [in the complete

AMA Safety Code].

9) Under no circumstances may a pilot or other person touch
a powered model in fl ight; nor should any part of the model

other than the landing gear, intentionally touch the ground,

except while landing.

During t he last few moments of prepar ation your mind may
be elsewhere anticipating the excitement of the fi rst fl ight.
Because of this, you may be more likely to overlook certain
checks and procedures that should be performed before the
model is fl own. To help avoid this, a check list 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!).

1. Fuelproof all areas exposed to fuel or exhaust residue

❏

such as the cowl mounting blocks, wing saddle area, etc.

2. Check the C.G. according to the measurements provided

❏

in the manual.

3. Be certain the battery and receiver are securely mounted

❏

in the fuse. Simply stuffi ng them into place with foam rubber
is not suffi cient.

4. Balance your model laterally as explained in the

❏

instructions.

5. Use threadlocking compound to secure critical fasteners

❏

such as the set screws that hold the wheel axles to the struts,
screws that hold the carburetor arm (if applicable), 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 securely glued in place.

❏

8. Reinforce holes for wo o d screws wit h thin CA wh ere

❏

appropriate (servo mounting screws, cowl mounting
screws, etc.).

9. Confi rm that all controls operate in the correct direction

❏

and the throws are set up according to the manual.

10. Make sure there are silicone retainers on all the clevises

❏

and 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, and the connection between

your battery pack and the on/off switch 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. Secure the pressure tap (if used) to the muffl er with

❏

high temp RTV silicone, thread locking compound or J.B. Weld.

14. Make sure the fuel lines are connected and are not

❏

kinked.

24

15. Balance your propeller (and spare propellers).

❏

16. Tighten the propeller nut and spinner.

❏

17. Place your name, address, AMA number and telephone

❏

number on or inside your model.

18. Cycle your receiver battery pack (if necessary) and

❏

make sure it is fully charged.

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

❏

your fi rst fl ight.

20. Range check your radio when you get to the fl ying fi eld.

❏

FLYING

The Sport Fighter Mustang is a great-fl ying model that fl ies

smoothly and predictably. It does not, however, possess the
self-recovery characteristics of a primary R/C trainer and
should be fl own only by experienced R/C pilots.

Fuel Mixture Adjustments

A fully cowled engine may run at a higher temperature than
an un-cowled engine. For this reason, the fuel mixture should

be richened so the engine runs at about 200 rpm below peak

speed. By running the engine slightly rich, you will help prevent

dead-stick landings caused by overheating.

CAUTION : (THIS APPLIES TO ALL R/C AIRPLANES): If,
while fl ying, you notice an alarming or unusual sound such
as a low-pitched “buzz,” this may indicate control surface
fl utter. Flutter occurs when a control surface (such as an
aileron or elevator) or a fl ying surface (such as a wing or
stab) rapidly vibrates up and down (thus causing the noise).
In extreme cases, if not detected immediately, fl utter can
actually cause the control surface to detach or the fl ying
surface to fail, thus causing loss of control followed by
an impending crash. The best thing to do when fl utter is
detected is to slow the model immediately by reducing
power, then la nd as s oon as s afel y possi ble. Identif y which
surface fl uttered (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 fl uttered once, under similar circumstances
it will probably fl utter again unless the problem is fi xed.
Some things which can cause fl utter are; Excessive hinge
gap; Not mounting control horns solidly; Poor fi t of clevis
pin in horn; Side-play of wire pushrods caused by large
bends; Excessive free play in servo gears ; Insecure servo
mounting; and one of the most prevalent causes of fl utter;
Flying an over-powered model at excessive speeds.

Takeoff

Before you get ready to takeoff, see how the model handles
on the ground by doing a few practice runs at low speeds
on the runway. Hold “up” elevator to keep the tail wheel on
the ground. If necessary, adjust the tail wheel so the model
will roll straight down the runway. If you need to calm your
nerves before the maiden fl ight, shut the engine down and
bring the model back into the pits. Top off the fuel, then check
all fasteners and control linkages for peace of mind.

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 to maintain tail wheel steering,
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 engine torque. Gain as much speed as your runway
and fl ying site will practically allow before gently applying up
elevator, lifting the model into the air. At this moment it is likely
that you will need to apply more right rudder to counteract
engine torque. Be smooth on the elevator stick, allowing the
model to establish a gentle climb to a safe altitude before
turning into the traffi c pattern.

Flight

For reassurance and to keep an eye on other traffi c, it is a
go o d idea to have an assi stant on the fl ight 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 fl y more smoothly at reduced speeds.

Take it easy with the Sport Fighter Mustang for the fi rst

few fl ights, gradually getting acquainted with it as you gain
confi dence. Adjust the trims to maintain straight and level
fl ight. After fl ying around for a while, and while still at a safe
altitude with plenty of fuel, practice slow fl ight 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 fl y 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 fi ne tune the model so it fl ies the way you like.
Mi nd your fue l level, but use this fi rst fl ig ht to become familiar
with your model before landing.

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 fi nal 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

25

overshoot, smoothly advance the throttle (always ready on
the right rudder to counteract torque) and climb out to make
an other attempt. When you’re ready to make your land ing fl are
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 fl ying speed, hold up elevator
to place the tail on the ground, regaining tail wheel control.

One fi nal note about fl ying your model. Have a goal or fl ight

plan in mind for every fl ight. 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 necessarily 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 fi nding that you’ve run
out of time, altitude or airspeed. Every maneuver should be
deliberate, not impulsive. For example, if you’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 fl ight 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 fl y in a safe manner.

GOOD LUCK AND GREAT FLYING!

26

27

© 2014 Great Planes Model Mfg. A subsidiary of Hobbico,® Inc.

GPMA1208