Great Planes GPMA1290 User Manual

Scale: 38%
Wingspan: 110.5 in [2805mm]
Fuselage Length: 103 in [2595mm]
Wing Area: 2279 sq in [147dm2]
Weight: 36–38 lb [16330–17235g]
Wing Loading: 36–38 oz/sq ft [111–117g/dm2]
Engine: 120 – 150cc Spark-Ignition Gas

INSTRUCTION MANUAL

WARRANTY

Great Planes® Model Manufacturing Co. guarantees this kit to

be free from defects in both material and workmanship at the date
of purchase. This warranty does not cover any component parts
damaged by use or modifi cation. 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 fi nal assembly or
material used for fi nal assembly, no liability shall be assumed nor
accepted for any damage resulting from the use by the user of
the fi nal user-assembled product. By the act of using the user­assembled 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.

Entire Contents © Copyright 2007

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]

GPMZ1290 for GPMA1290 V1.0

TABLE OF CONTENTS

INTRODUCTION

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

SAFETY PRECAUTIONS .................................................3

ITEMS REQUIRED FOR COMPLETION .......................... 3

Engine ........................................................................ 3

Servos ........................................................................ 3

Transmitter and Receiver ........................................... 3

Other Radio Gear ....................................................... 4

Hardware and Accessories ........................................ 4

Covering Tools ........................................................... 4

KIT INSPECTION .............................................................. 4

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

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

SHRINK THE COVERING ................................................. 6

ASSEMBLE THE WINGS .................................................. 6

Mount the Aileron Servos ........................................... 6

Hook Up the Ailerons ................................................. 7

ASSEMBLE THE HORIZONTAL STABS ..........................9

ASSEMBLE THE FUSELAGE ..........................................9

Mount the Landing Gear ............................................9

Attach the Rudder .................................................... 11

Install the Rudder Servos ......................................... 12

Hook up the Rudder ................................................. 13

Mount the Engine ..................................................... 14

Hook up the Throttle ................................................. 15

Assemble/Install the Fuel Tank ................................ 15

Finish Radio Installation ........................................... 17

Mount the Cowl ........................................................ 19

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

Apply the Decals ...................................................... 20

Set the Control Throws ............................................20

Balance the Model (C.G.).........................................21

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

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

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

Ground Check ..........................................................22

Range Check ........................................................... 22

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

AMA SAFETY CODE ...................................................... 23

CHECK LIST ................................................................... 24

FLYING ............................................................................ 24

3D FLYING ...................................................................... 27

Thank you for purchasing the Great Planes 38% Extra 330S
ARF. Thousands of R/C modelers have already enjoyed the
complete “package” that a Great Planes model delivers—
thoroughly illustrated, detailed, complete instruction manuals;
rugged, yet lightweight construction; complete hardware
packages; and superior fl ight characteristics. But many
serious IMAC/Freestyle 3D pilots have not yet been able to
enjoy these benefi ts—until now! This Great Planes 38% Extra
330S ARF features all the same, high-quality features of its
smaller brothers and sisters. We do realize that most pilots
who will be building this model already have experience with
high-performance, giant-scale airplanes. But there will still be
those who are new to a plane of this size and scope, so for
you, none of the details have been omitted. You’ll end up with
a model that is complete and properly fi nished, without having
to fi gure anything out by yourself.

For the latest technical updates or manual corrections to this
model visit the Great Planes web site at www.greatplanes.
com. Open the “R/C AIRPLANES” pull down tab across the top
of the page, then select “ARFs-GLOW.” Scroll down the page
and click on “38% Extra 330S ARF.” If there is new technical
information or changes an “Important! TECH NOTICE” box
will appear in the upper left corner of the page. Click on the
Tech Notice box to read the info.

Note: The stabilizer and wing incidences and engine thrust
angles have been factory-built into this model. However,
some technically-minded modelers may wish to check these
measurements anyway. To view this information visit the web
site at www.greatplanes.com and click on “Technical Data.”
Due to manufacturing tolerances which will have little or no
effect on the way your model will fl y, please expect slight
deviations between your model and the published values.

AMA

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

Tele: [phone]

Fax [phone]

Or via the Internet at:

IMPORTANT!!! Two of the most important things you can do
to preserve the radio controlled aircraft hobby are to avoid
fl ying near full-scale aircraft and avoid fl ying near or over
groups of people.

2

www.modelaircraft.org

PROTECT YOUR MODEL, YOURSELF

& OTHERS...FOLLOW THESE

IMPORTANT SAFETY PRECAUTIONS

ITEMS REQUIRED FOR COMPLETION

Engine

1. Your 38% Extra 330S ARF should not be considered a toy,
but rather a sophisticated, working model that functions very
much like a full-size airplane. Because of its performance
capabilities, the Extra, if not assembled and operated
correctly, could possibly cause injury to yourself or spectators
and damage to property.

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

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

4. You must use an R/C radio system that is in good condition,
a correctly sized engine, and other components as specifi ed
in this instruction manual. All components must be correctly
installed so that the model operates correctly on the ground
and in the air. You must check the operation of the model and
all components before every fl ight.

5. 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. If you’re not a member of a club, your local
hobby shop has information about clubs in your area whose
membership includes experienced pilots.

6. While this kit has been fl ight tested to exceed normal use,
if the plane will be used for extremely high stress fl ying, such
as racing, or 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.

The 38% Extra was designed for a 150cc engine—the
Desert Aircraft 150cc in specifi c—but the Extra’s size and
weight also make it suitable for any 150cc engine and other
engines down to 120cc. Instructions for installation and
throttle hookup feature the “DA,” so if using a different engine
use the instructions as a guide. The spinner is also drilled to
fi t the DA.

Servos

Following are the number of servos required and the minimum
torque ratings (at 6 Volts) for each:

❏ (4) Aileron servos with a minimum torque of 190 oz-in

each (such as Futaba® S9155 – FUTM0215)

❏ (3) Rudder servos with a minimum torque of 120 oz-in

each (such as Futaba S9155 – FUTM0215 or Futaba
S9350 – FUTM0235)

❏ (2) Elevator servos with a minimum torque of 300 oz-in

each (such as Futaba S9156 – FUTM0216 or Hobbico®
CS-170 – HCAM0316) If using Hobbico CS-170 servos,

one (1) servo horn set CS/TS35-59, 63-71 (HCAM1071)
must also be purchased separately for each servo.

❏ (1) Ball bearing, "medium-torque” throttle servo (such as

Futaba S9001 – FUTM0075)

❏ Receiver battery with a minimum capacity of 3000 mAh

(such as HydriMax™ Ultra 6.0 Volt 4200mAh NiMH –
HCAM6355)

❏ Ignition battery with a minimum capacity of 1000 mAh

(such as HydriMax Ultra 6.0 Volt 2000mAh NiMH –
HCAM6351)

7. WARNING: The cowl, wheel pants and landing gear fairings
included in this kit are made of fi berglass, the fi bers of which
may cause eye, skin and respiratory tract irritation. Never
blow into a part (wheel pant, cowl) to remove fi berglass dust,
as the dust will blow back into your eyes. Always wear safety
goggles, a particle mask and rubber gloves when grinding,
drilling and sanding fi berglass parts. Vacuum the parts and
the work area thoroughly after working with fi berglass parts.

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.

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

Transmitter and Receiver

A minimum of 5 or 6 channels will be required. All three rudder
servos may be connected to one channel in the receiver via
a servo synchronizer. The aileron servos in one wing should
be connected to one channel and the aileron servos in the
other wing should be connected to another channel. The two
channels for ailerons should be mixed electronically via mixing
in the transmitter. The elevator servos may be connected to
separate channels in the receiver and mixed electronically
through the transmitter, or they can both be connected to a
single channel in the receiver. If using one channel for the
elevators, a servo reverser will also be required to get one
servo to respond in the opposite direction.

3

Other Radio Gear

Hardware and Accessories

The following servo extensions were used on the model in
the instruction manual:

Note: If using digital servos, be certain to use servo
extensions suitable for use with digital servos. The servo
extensions listed below are suitable for both analog and
digital servos.

❏ (2) 6" [150mm] heavy-duty dual servo extension (coming

from the receiver inside the fuselage for ailerons –
FUTM4134 for Futaba)

❏ (2) 6" [150mm] Pro HD servo extensions (1-throttle servo,

1-servo synchronizer for rudder servos – HCAM2701 for
Futaba)

❏ (2) 12" [305mm] Pro HD servo extensions (for inboard

aileron servos – HCAM2711 for Futaba)

❏ (2) 36" [915mm] Pro HD servo extensions (for outboard

aileron servos -- HCAM726 for Futaba)

❏ A servo synchronizer for the three rudder servos is also

required (Such as MSA-10 used for Futaba servos –
FUTM4155)

If connecting the elevator servos to separate channels in
the receiver (and using the mixing in the transmitter) the
following servo extensions will also be required:

❏ (2) 6" [150mm] Pro HD servo extensions (HCAM2701

for Futaba)

❏ (2) 12" [305mm] Pro HD servo extensions (HCAM2711

for Futaba)

❏ (2) 36" [915mm] Pro HD servo extensions (HCAM2726

for Futaba)

In addition to typical hobby tools, following is the rest of the
hardware and accessories used to fi nish the Extra 330S
ARF:

™

❏ Pro

30-minute epoxy (GPMR6047)

❏ 1 oz. [30g] Medium Pro CA+ (GPMR6008)
❏ CA applicator tips (HCAR3780)
❏ Threadlocker thread locking cement (GPMR6060)
❏ (2 pkgs) 3' Du-Bro 1/8" Tygon fuel tubing (DUBQ0493)
❏ 1/4" [6.5mm] R/C foam rubber (HCAQ1000)
❏ 1/8" single-sided foam tape (GPMQ4424)
❏ Silver solder w/fl ux (GPMR8070)

Covering Tools

A Top Flite® or 21st Century® model airplane covering iron with
a protective covering sock may be necessary for tightening
any covering on the model that may have loosened or formed
wrinkles between the time of production and your purchase.
The 21st Century iron is preferred as it has a longer cord and
a rounded, contoured shoe. A trim iron is not as much of a
necessity, but would still be very handy for sealing the edges
down inside servo openings and other small areas.

❏ 21st Century sealing iron (COVR2700)
❏ 21st Century iron cover (COVR2702)
❏ 21st Century trim seal iron (COVR2750)

❏ Top Flite MonoKote
❏ Top Flite Hot Sock
❏ Top Flite MonoKote trim seal iron (TOPR2200)

®

sealing iron (TOPR2100)

™

iron cover (TOPR2175)

If connecting the elevator servos to the same channel in
the receiver, a servo reverser and (2) 36" [915mm] servo
extensions will be required:

❏ (1) servo reverser (such as Futaba SR-10 – FUTM4150)
❏ (2) 36" [915mm] Pro HD servo extension (HCAM2726 for

Futaba)

These switches and charge receptacles were also used:

❏ (2) Heavy-duty on/off switches (1-ignition battery, 1-

radio system such as Hobbico HD switch for Futaba J
(HCAM2761)

❏ (2) Ernst Charge Receptacles (ERNM3001 for Futaba)

KIT INSPECTION

Before starting to build, 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

Champaign, IL 61822

Telephone: [phone], ext. 5

Fax: [phone]

E-mail: [e-mail]

4

KIT CONTENTS

1

8

6

9

5

1. Fuselage

2. Wing w/Ailerons

3. Stabilizer w/Elevators

4. Rudder

5. Wheel Pants

10

7

6. Landing Gear

7. Wheels

8. Spinner

9. Fuel Tank

10. Landing Gear Fairings

ORDERING REPLACEMENT PARTS

Replacement parts for the Great Planes 38% Extra 330S ARF are
available using the order numbers in the Replacement Parts List that
follows. The fastest, most economical service can be provided by
your hobby dealer or mail-order company.

To locate a hobby dealer, visit the Great Planes web site at www.
greatplanes.com. Choose “Where to Buy” at the bottom of the
menu on the left side of the page. Follow the instructions provided
on the page 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 and payments by personal check to:

Hobby Services

3002 N. Apollo Drive, Suite 1

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 telephone at [phone], or by
e-mail at [e-mail].

3

12

13

11

2

4

11. Wing Tube

12. Stab Tubes

13. Tail Gear

Replacement Parts List
Order Number Description How to Purchase

Missing pieces ...........Contact Product Support

Instruction manual .....Contact Product Support

Full-size plans ............................... Not available

Contact your hobby supplier for the following parts:

GPMA3190 ......... Wing Set

GPMA3191 ......... Fuselage w/Canopy

GPMA3192 ......... Horizontal Stabilizer

GPMA3193 ......... Rudder

GPMA3194 ......... Hatch w/Canopy

GPMA3195 ......... Cowl

GPMA3196 ......... Wheelpants

GPMA3197 ......... Carbon Fiber Landing Gear

GPMA3198 ......... Wing Tube

GPMA3199 ......... Stab Joiners

GPMA3200 ......... Spinner

GPMA3201 ......... Canopy Only

GPMA3202 ......... Tail Gear Set

GPMQ3728 ......... Deluxe 6-32 Pull-Pull Set

GPMA3203 ......... 8-32 Rudder Torque Rod Mount

GPMM1107 ........ Single-Sided 1.5" Servo Arm Set

GPMM1167 ........ Double-Sided 3" Servo Arm Set

GPMA3204 ......... Rudder Servo Tray

GPMQ3760 ......... Turnbuckle Pushrod 3.5" x 6-32

GPMQ3754 ......... Turnbuckle Pushrod 2.125" x 6-32

GPMA3206 ......... Decals

GPMA3207 ......... Pilot

5

5

SHRINK THE COVERING

p

❏ 2. Also cut the covering from the holes in the top and

bottom of the ailerons for the threaded torque rods.

Torque Rod Nut

Torque Rod Washer

Torque Rod Washer

❏ 1. Where necessary, use a covering iron (set to

approximately 250°F [120°C] with a covering sock to go
over any parts of the model where the covering requires
tightening. Over sheeted areas, press down on the iron to
bond the covering to the wood. If the covering expands or
bubbles, use less heat. Note: Naptha (lighter fl uid) can be
used to remove any adhesive left from the masking tape that
may have been used to hold any of the parts together.

❏ 2. Make sure the elevators and ailerons are securely

hinged by pulling hard on each control surface.

ASSEMBLE THE WINGS

Mount the Aileron Servos

Servo opening in wing.

Cut the covering 1/8" [3mm]
inside the edges of the
opening. Slit the covering u
to the corners.

[75mm]

(Ailerons and Elevators)

75mm Threaded Torque Rod

3"

❏ 3. Use a cordless drill with a Phillips bit and a 5/16" [or

8mm] wrench or pliers to hold the plastic torque rod nut
and mount two 3" [75mm] threaded torque rods into each
aileron with a torque rod washer on both sides.

❏ 1. Cut the covering 1/8" [3mm] inside the edges of both

aileron servo openings in the bottom of both wings. Slit the
covering up to the corners and use a trim iron to seal the
covering down inside.

❏ 4. Use epoxy to glue two 10 x 30mm hardwood wing

dowels into the root end of each wing.

666

Hook Up the Ailerons

❏ 5. Connect a 12" [305mm] servo extension (HCAM2711

for Futaba) to one of the aileron servos and 36" [915mm]
servo extension (HCAM2726 for Futaba) to the other aileron
servo. Secure each connection with 1-1/2" [38mm] pieces
of heat shrink tubing cut from one of the 3" [75mm] pieces
included with this kit.

Use 7/64" [2.8mm]

(or 1/8" [3.2mm]) drill

Enlarge the

holes indicated

Futaba Servo Wheel

Drill holes in

the mold marks.

Bottom of Hobbico

Servo Wheel

❏ 1. If using Futaba servos, drill out the holes in the servo

wheel with a 7/64" [2.8mm] (or 1/8" [3.2mm]) drill. If using
different servos, use one of the aluminum servo arms that
came with this kit as a template for drilling the holes. All the
servo wheels used for the control surfaces in this model
require drilling, so if you have all your servo wheels handy
you could drill them all now, or just drill them as needed.

Note: The servo wheels that come with the CS/TS35-59, 63­71 Hobbico Servo Horn set (HCAM1071) have mold marks
in the bottom that happen to align with the holes in the
aluminum servo arms. Double-check to make sure the mold
marks align with the holes in one of the servo arms. Then,
drill 1/16" [1.6mm] pilot holes at the marks. Enlarge the pilot
holes with a 7/64" [2.8mm] (or 1/8" [3.2mm]) drill.

❏ 6. Tie the string in one of the wings to the servo wires as

shown. Then, pull them through the tube in the wing.

❏ 7. Place the aileron servos in the servo openings of one

of the wings. Drill 1/16" [1.6mm] holes for the servo mounting
screws. Temporarily mount the servos with the screws that
came with them. Note: For some JR (or other brand) servos,
the servo mounts may require slight trimming to accommodate
the servos and larger holes may have to be drilled for larger
servo mounting screws.

❏ 8. IMPORTANT: Remove the servo mounting screws

and set the servos aside (without pulling the servo leads
out of the wing). Add a few drops of thin CA to each screw
hole to harden the “threads.” Allow the CA to harden. Then,
remount the servos.

Whenever screws are mounted into wood you must harden
the holes with CA after installing, and then removing the
screws. The complete process will not be written out
every time this is necessary. Instead, you will simply be
reminded to “harden the screw holes with thin CA.”

❏ 9. Mount the aileron servos in the other wing the same

way—don’t forget to harden the screw holes with thin CA!

Your radio system will be required for the next step,
so gather your transmitter, receiver, battery and
on/off switch.

❏ 2. Connect one of the aileron servos to your receiver and

turn the system on. Center the trim and position the servo
wheel on the servo so that when the top servo arm will be
mounted to the wheel it will be perpendicular to the servo.

7

Scratch a small arrow

h

onto the servo wheel
so you will know whic
way is forward.

❏ 3. Once the correct orientation of the servo wheel has

been determined, use a hobby knife to scratch an arrow on
the wheel so you will know how to mount the arm later.

Threaded Retainer Disc

Lock Pin

Pin Clevis

Single-Sided

Top Servo Arm

3mm Spacer

Servo Wheel

Single-Sided

Bottom Servo Arm

4-40 x 7/16" [10mm]

Flat-Head Phillips Screws

(USE THREADLOCKER)

4-40 Nut

1mm Standoff

Ball Link Ball

1mm Standoff

Servo Arm Assembly

❏ 4. Assemble one of the servo arm assemblies with the

parts shown—it’s easiest to fi rst mount the ball link and
1mm standoffs to the servo arms and temporarily secure
with the 4-40 nut, then join the servo wheel and spacer.

IMPORTANT: Threadlocker must be used on the threads of
all fi ve screws.

❏ 6. Thread one of the reverse-thread pin clevises onto

the reverse-threaded end of a 2-1/2" [64mm] turnbuckle
pushrod. Thread the turnbuckle pushrod to the ball link on
the servo arm and connect the pin clevis to the torque rod
horn with the lock pin.

❏ 7. Turn on your radio and adjust the turnbuckle pushrod

so the aileron will be neutral when the servo is centered. The
turnbuckle should be threaded equally into both the ball link
and the pin clevis.

❏ 8. Connect the outboard aileron to your receiver. With the

radio on, connect the outboard servo to the outboard torque
rod arm using the same hardware as the inboard servo.

Adjust the torque rod horns up or

down to equalize the pressure from

the pushrods when the servos are

at the extremes of their throw.

Pin Clevis

2-1/2" [64mm]

Turnbuckle Pushrod

❏ 5. Gather all the pin clevises included with this kit. Note

that only two have a “normal” thread and the rest have a
reverse thread. Test-thread each pin clevis onto the “normal”
threaded end of one of the 2-1/2" [64mm] turnbuckle
pushrods until you fi nd the two that fi t. Mark those as “N” and
set them aside.

❏ 9. With the radio on and both servos still connected to the

receiver, adjust the position of the torque rod horns on the
torque rods so the servos will not be “fi ghting” each other
and will be applying the same pressure on the horns when
the servos are at the extremes of their throw.

❏ 10. Hook up the aileron on the other wing the same way.

8

Cotter Pin

Pin Washer

❏ 11. While you have your wings on your workbench and

the servos operating, you could go ahead and set the control
throws as indicated on page 21 now, or wait until the model
has been completed. Once the aileron throws have been set,
fasten the lock pins to the clevises and control horns with a
pin washer followed by a cotter pin. Bend the cotter pins
over so they won’t come out. Secure all the servo wheels
to the servos with the screws that came with them. Note: If
your servos have metal output shafts, use threadlocker on
the threads of the servo arm screws.

except the turnbuckle pushrods are 3-1/2" [90mm] in length.
Also remember to harden the screw holes for the servo
mounting screws.

❏ 3. Wet the mounting tabs on the ends of both stab halves

with thin CA. Allow the CA to penetrate into the wood
and harden.

❏ 4. When ready to set the throws or check the C.G. and

you need to mount the stab halves to the fuselage, use the
carbon fi ber stabilizer tubes and two 4-40 x 1/2" [13mm]
SHCS, #4 lock washers and #4 fl at washers in each stab.
When mounting the stabs for fl ying, use threadlocker on
the threads of the screws.

❏ 12. Use CA or rubber cement to glue the black, foam

rubber strips to the end of both wings.

ASSEMBLE THE HORIZONTAL STABS

❏ 1. Install a 3" [75mm] torque rod in both elevators with

the torque rod washers and torque rod nuts. Also cut the
covering from the elevator servo openings in the horizontal
stabilizers (stabs).

❏ 2. Mount the elevator servos and hook up the elevators—

all the hardware is the same as was used for the ailerons

ASSEMBLE THE FUSELAGE

Mount the Landing Gear

First the tail gear…

❏ 1. Temporarily remove the tail wheel bracket from the tail

gear wire with a 1.5mm Allen wrench. File a fl at spot in the wire
for the set screw in the bottom collar. Reassemble the tail gear
with a drop of threadlocker on the threads of the set screws.

9

❏ 2. Using the nylon straps as a guide, drill 3/32" [2.4mm]

holes for the mounting screws. Mount the tail gear in the
fuselage with the straps and four #4 x 1/2" [12mm] screws—
don’t forget to harden the holes with thin CA.

Now the main gear…

90°

❏ 6. Fit both wings to the fuselage with the wing tube. Use a

fi ne point felt-tip pen to mark the outline of the wings directly
onto both fairings.

❏ 7. Slide the wings part way off the fuselage and remove

the fairings. Use a rotary tool with a sanding drum to trim the
fairings to the lines you marked. Test fi t and trim the fairings
as necessary for a good fi t. CAUTION: Always wear safety
goggles, a particle mask and rubber gloves when grinding,
drilling and sanding fi berglass parts—wearing a long-sleeve
shirt and working outdoors is also a good idea. Vacuum
the parts and the work area thoroughly after working with
fi berglass parts.

❏ 3. Add a few drops of threadlocker to four 8-32 x 1-1/4"

[32mm] SHCS (socket-head cap screws) and mount the
main landing gear to the fuselage with the screws and four
#8 lock washers and fl at washers. Note: The edge of the
landing gear that’s 90° goes forward.

❏ 4. Mount the landing gear cover to the bottom of the

fuselage with two 1/4-20 x 2" [50mm] nylon bolts.

❏ 5. Slip the fi berglass landing gear fairings over the main gear

all the way to the fuselage. Note: There is right and a left.

❏ 8. Use large beads of RTV silicone rubber to securely, but

not permanently, glue the fairings to the landing gear. This
way, the fairings may be removed if ever necessary.

10

NOW THE WHEELS…

S

e

Refer to the illustration while mounting the wheels.

Flat Spot

#8 Flat Washer

6-32 x 1/4" [6.4mm]

SHCS (Both Collars)

Attach the Rudder

Use the Middle Hol

3/16" [4.8mm]
Wheel Collars

6-32 x 3/4"

[19mm] SHC

Torque Rod Horn

(For Rudder)

❏ 1. Assemble two rudder torque rod assemblies using

the hardware shown. Note: Install the torque rod in the
middle hole of threaded torque rod horns.

❏ 9. Use a rotary tool with a cutoff wheel to grind a fl at spot

about 1/16" [1.5mm] from the end of both 3/16" x 2" [4.8 x
50mm] bolt-on axles. For perfection, use a small metal fi le to
“square-up” the fl at spots.

❏ 10. Mount each axle to the gear with a 5/16-24 lock nut.

Use a 1/2" and 7/16" wrench to tighten the axles and nuts.

❏ 11. Mount the wheels to the axles with the hardware

shown—be certain to use threadlocker.

❏ 12. Mount the wheel pants to the gear with 6-32 x

3/4" [19mm] SHCS and #6 lock washers (and a drop of
threadlocker on the threads). If necessary, reposition the
wheels on the axles so they do not rub on the pants.

❏ 2. Use coarse sandpaper to roughen the aluminum rudder

torque rod mount so glue will adhere. Use epoxy to securely

glue the rudder torque rod mount, centered, into the rudder.

❏ 3. Mount the torque rod assemblies to the torque rod

mount in the rudder—be sure to use threadlocker on the
threads. Use two 12mm wrenches to tighten both aluminum
torque rod nuts simultaneously.

11

❏ 4. Mount the aluminum tail wheel arm where shown by

s

drilling 1/16" [1.6mm] holes for the three #2 x 3/8" [10mm]
mounting screws—don’t forget to harden the “threads” in the
holes with thin CA.

❏ 5. Test fi t the rudder to the fuselage with all fi ve hinges.

Make sure the hinges fi t and align—each hinge should be
exactly halfway in both parts and there should be a small
hinge gap—just enough to see light through or to slip a piece
of paper through. Make any adjustments necessary for a
good fi t.

Install the Rudder Servos

❏ 1. Use coarse sandpaper to roughen the bottom of the

aluminum rudder servo tray so glue will adhere. Glue the plywood
rudder servo tray doubler to the bottom of the tray with medium
CA or epoxy. Glue six 1/4" x 1-1/2" [6 x 38mm] plywood strips
across the bottom of the doubler for the servo screws.

Tiller Post

4 x 25mm SHCS

Tiller Arm

Ball Bearing

❏ 6. Take out all the hinges. Add a few drops of plastic-

compatible oil to the pivot point of each hinge using care not
to get any oil on the rest of the hinge.

4-40 x 1/4" [6.4mm]

SHCS w/#4 Lock Washer

4mm Lock Nut

❏ 2. Mount the rudder servos in the tray. Harden the the

holes with CA. Mount the tiller arm using the hardware
shown—be certain to use threadlocker on the threads of the
4-40 screws. Tighten the 4mm bolt in the tiller arm until there
is no more free play, but the arm still rotates freely.

Cut

❏ 7. Use 30-minute epoxy to permanently join the rudder

to the fuselage with all the hinges—use a piece of wire to
thoroughly coat the inside of each hinge hole and the hinges
before inserting them. Do not use 5-minute or 15-minute epoxy
for hinging—otherwise, you may run out of working time!

N

Reverse Thread

orm

al Thread

❏ 3. Cut the “normal” threaded end off two dual-ended

ball links.

❏ 4. Assemble two rudder pushrod assemblies using

the hardware shown in the Rudder Pushrod Assembly
illustration on page 26.

12

Refer to the following photo to fi nish

mounting the rudder servos.

90°

❏ 8. Connect the rudder pushrods to the aft rudder servo

using the synchronizer again. Don’t forget to use threadlocker
on the threads of all the screws.

❏ 9. Finally, connect the last ball links on the end of the

rudder pushrods to the tiller arm with two 4-40 x 1/2" [12mm]
Phillips screws and 4-40 lock nuts.

❏ 10. Secure the servo arm assemblies to the servos with the

servo wheel screws that came with the servos—if the screws
go into metal output shafts be certain to use threadlocker on
the threads.

Hook Up the Rudder

❏ 5. Same as was done for the aileron and elevator servo

wheels, drill the holes in the three rudder servo wheels
with a 7/64" [2.8mm] (or 1/8" [3.2mm]) drill and mount the
double-sided servo arms to the servo wheels. Place the arm
assemblies on the servos and use a servo synchronizer to
center all the servo arms.

1mm Standoff

1mm Standoff

Double-Sided

Servo Arms

❏ 6. Connect only the front of both rudder pushrods to the

front rudder servo arm using the same hardware that was
used to connect the aileron and elevator pushrods (that is
two 1mm brass standoffs, a 4-40 x 7/16" [11mm] fl at-head
Phillips screw and a 4-40 nut with threadlocker).

❏ 1. Center the rudder servo tray assembly on the mounting

rails in the fuselage. Drill 3/32" [2.4mm] holes in the rails for the
mounting screws. Mount the tray with four #4 x 1/2" [13mm]
screws. Don’t forget to harden the screw holes with thin CA.

❏ 2. Cut the braided rudder cable into two equal-lengths.

Make the aft end of both rudder cables from the hardware
shown (the “normal-thread” pin clevises are used here).

Shrink Tubing

]

22" [560m

m

❏ 7. Connect the pushrods to the middle rudder servo arm

using the servo synchronizer to align the holes in the arm with
the ball link balls in the pushrod. Using the servo synchronizer,
also make sure the servo arms are synchronized at the ends
of their throw.

❏ 3. Cut the included 1/8" [3.2mm] diameter heat shrink

tubing into two equal lengths. Slide one tube over each cable
until the middle of each one is 22" [560mm] from the end of
the pin clevis. Shrink the tubing over the cables and glue it
into position with thin CA.

13

❏ 4. Guide the cables through the slots in the fuselage and

temporarily connect the pin clevises to the horns on the rudder.

❏ 5. Use masking tape to temporarily hold the front of the

balance tab on the rudder centered to the vertical stab.

Refer to this photo for steps 6 & 7.

❏ 6. Mount a ball link with a threaded cable coupler to the

outer holes in both ends of the tiller arm with 4-40 x 1/2"
[12mm] Phillips screws, a 1mm standoff under each ball link
and 4-40 lock nuts.

❏ 7. Cross the rudder cables once inside the fuselage—the

cable on the right side of the rudder should go to the left
side of the tiller arm and vice-versa. Slide a brass swage
over each cable. With the rudder servos connected to the
receiver and the radio on, loop one of the cables through one
of the threaded cable couplers on the tiller arm. Permanently
connect the cable to the cable coupler with the swage. Cut
off any excess wire.

❏ 8. Connect the other cable to the cable coupler on the

other side of the tiller arm the same way.

❏ 9. Remove the masking tape that was holding the rudder

centered. If necessary, adjust the tension in one or both
cables by removing the locking pin on the rudder and turning
one of the threaded inserts in or out. CAUTION: If, in the
future, the cables ever require tightening or loosening, always
disconnect one end of the cable you will be tightening
before turning the threaded couplers. This way, you will not
be twisting the cable (which could otherwise untwist). Never

twist the cables when tightening them.

❏ 10. Connect the tail wheel to the tail wheel arm on the

bottom of the rudder with the springs and spring hooks. Use
an .050" allen wrench to lock the spring hooks into the tail
gear arm with 4-40 set screws and a drop of threadlocker on
the threads. Center the tail wheel to the rudder by adjusting
the position of the spring hooks in the arm.

Mount the Engine

Instructions are provided for mounting the Desert
Aircraft 150cc engine. If using a different engine, use
the instructions as a guide. The centerlines on the
fi rewall note where the centerline of your engine should
be mounted so the spinner will align with the cowl.

❏ 1. If mounting the DA 150, drill 1/8" [3.2mm] pilot holes

through the four crossmarks in the fi rewall for the engine
mounting bolts. If using a different engine, use the template
that came with your engine or take measurements from your
engine to mark the location of the engine mounting bolts,
and then drill the pilot holes.

❏ 2. Enlarge the pilot holes in the fi rewall with a 19/64"

[7.5mm] (or 9/32" [7mm]) drill.

❏ 3. Use a 3/16" Allen wrench to draw the blind nuts into the

back of the fi rewall with one of the included 1/4-20 x 2-1/2"
[60mm] SHCS and included aluminum engine spacers.

❏ 4. Temporarily mount the engine to the fi rewall with the

spacers and the 1/4-20 x 2-1/2" [60mm] SHCS and 1/4"
[6.4mm] lock washers. (During assembly, you will probably end
up removing and remounting the engine a couple of times, so
no need to fully tighten the mounting bolts at this time.)

The ignition battery and ignition module will be mounted later.

14

Hook Up the Throttle

t

Refer to these photos of the completed throttle servo

installation while hooking up the throttle.

❏ 3. Drill a 3/16" [4.8mm] hole through the fi rewall for the

throttle pushrod guide tube.

❏ 4. Cut the throttle pushrod and the guide tube to the

correct length and make the throttle pushrod from the parts
shown—silver solder is recommended for soldering the
threaded coupler to the pushrod.

❏ 5. Connect the throttle pushrod to the servo and engine

and securely glue the throttle servo mount in the fuselage.

Throttle Servo Mount Guide Tube Suppor

Assemble/Install the Fuel Tank

❏ 1. Glue together the plywood throttle servo mount using

the parts shown. Mount the throttle servo in the mount.
Harden the screw holes with thin CA.

❏ 2. Place the mount with the servo in the fuselage where

shown so it will align—as closely as possible—with the
carburetor arm on the engine.

❏ 1. Assemble the stopper assembly with the fuel tubes as

shown—the easiest way is to fi rst solder a fuel line barb onto
one end of all three tubes. Insert the tubes into the stopper
with the metal plates, and then solder a barb onto the other

1515

end of the two short tubes. The tubing is pretty hard, so use a

g

block of wood with a 5/32" [4mm] hole drilled in it to bend the
vent tube. Connect the pickup and fueling/de-fueling lines
(not included) to the short tubes and connect the clunks to
the lines.

Fuel Tank Rin

Fuel Tank Neck

❏ 2. Press the fuel tank ring over the neck of the tank.

Then, insert the stopper assembly into the tank and tighten
the screw.

Fuel Line Mounts

❏ 5. Drill holes for the fuel lines where necessary and

connect the lines. The included plywood fuel line mounts
may be used to mount the fueling/de fueling and the vent
lines so they come out the bottom of the fuselage.

❏ 3. Center the plywood fuel tank tray over the mounting

rails in the fuselage. Use the holes in the tray as a template
to drill 3/32" [2.4mm] holes through the rails. Temporarily
mount the tray with four #4 x 1/2" [13mm] screws and
#4 washers. As always, don’t forget to remove the screws
and tray and harden the holes with thin CA.

While we’re still working “under the cowl,” go ahead and
mount the ignition module…

Ignition Wire Guides

❏ 4. Securely mount the fuel tank to the tray with the included

hook and loop strips and a 4" x 7" [100 x 180mm] sheet of
1/4" [6.4mm] R/C foam rubber (not included) under the tank.
Remount the fuel tank tray in the fuselage with the screws.

❏ 6. Mount the ignition module where preferred. There are

slots in the bottom of the “engine box” for hook and loop or

16

nylon tie straps (not included). In addition to hook and loop or

o

s

tie straps, use adhesive foam mounting tape to cushion the
module and to keep it from shifting. Plywood ignition wire
guides are also provided for routing the spark plug wires, or
you could also use J’Tec clamp loks (not included).

Glue the plywood strips

to the bottom so Velcro

can wrap around.

Mount the Ignition Battery

Mount for Futaba

On/Off Switch

Mount for Ernst

On/Off Switch

Mount for Hobbic

On/Off Switch

❏ 8. Connect the battery to a heavy-duty on/off switch and an

external charge receptacle. Secure the connections with heat
shrink tubing and mount the switch and charge receptacle to
the pre cut switch holes in the front of the fuselage for the
type of switch you are using.

Finish the Radio Installation

Pre-Cut Receiver Tray

Blank Receiver Tray

Receiver Tray

Mount Doubler

❏ 7. Glue the plywood strips to one side of the plywood

ignition battery mount. Mount the ignition battery to the
mount with R/C foam and a strap made from the included hook
and loop. Securely glue the battery mount into position.

❏ 1. Glue together whichever of the two plywood receiver

trays you will be using—the one photographed has slots cut

in it for hook and loop straps or nylon tie wraps (not included)
for mounting the receiver and servo synchronizer. If you will be
mounting your receiver and servo synchronizer differently, or if
you will be using different or additional equipment, you could
use the blank receiver tray and fashion it the way you like.

17

Refer to this photo while fi nishing

r

the rest of the radio installation.

❏ 2. Glue the plywood receiver tray mount doublers to the

bottom of the side stringers—the hole in each doubler aligns
with each hole in the side stringer.

❏ 3. Mount the receiver tray to the side stringers with four

#4 x 1/2" [13mm] screws and #4 washers—don’t forget to
remove the screws and the tray, apply a few drops of thin CA
in the screw holes and allow to harden. Remount the tray.

straps (not included) or the included hook and loop strap
material to mount the Rx battery to one of the sub fuselage
sides on either side of the fuselage as shown. Note the foam
wing tape (not included) used to keep the tie straps from
slipping. Secure the connections between the battery and
on/off switch and the switch and charge receptacle with heat
shrink tubing. Remount the fuel tank tray.

❏ 8. Refer to the illustration on page 26 for the elevator servo

extensions. Make up the extensions for the way you will be
hooking up your servos.

❏ 4. Mount your receiver and servo synchronizer to the

receiver tray using straps from the included hook and loop
or nylon tie wraps (not included) and foam cushioning to
protect them from vibration. Guide the receiver antenna
down through the antenna tube in the fuselage.

❏ 5. Connect the aileron servo extensions, the throttle servo

and rudder servo synchronizer to the receiver. As shown in
the photo, the dual servo extensions used were glued to the
receiver tray.

❏ 6. Same as the on/off switch and charge receptacle were

mounted for the ignition battery, mount the on/off switch for
the receiver—the switch mounting holes are just ahead of
the receiver tray.

❏ 9. Pull the extensions down through the tube in the

fuselage and connect the elevator servos to the receiver.

Servo Wire Guide Servo Wire Hange

❏ 10. After all the radio extensions, batteries, switches, etc.

have been installed, use the provided plywood servo wire
guides and servo wire hangers (or more J’Tec clamp loks)

to suspend or guide any servo wires out of the way that could
interfere with the rudder servos or anything else.

❏ 11. Test fi t the canopy hatch with six 4-40 x 1/2" [13mm]

Phillips screws and #4 fl at washers. When ready to fl y the
model and mounting the canopy hatch at the fi eld, use
threadlocker on all the screws.

❏ 7. Temporarily unscrew the fuel tank tray from the

mounting rails and move the tank forward. Use nylon tie

18

Mount the Cowl

❏ 1. Use manilla folder material or thin cardstock to make

templates for the bottom two cowl mounting screws. Tape
the templates to the fuselage with the hole in the templates
centered over the cowl mounting screws.

❏ 6. Use coarse sandpaper to roughen the inside of the cowl

over each screw hole. Use medium CA to glue the 1/32" [.8mm]
plywood cowl reinforcements centered over each hole.

1-1/4" [32mm]

Diameter

❏ 2. Remove the screws. With the muffl ers off the engine,

tape the cowl into position. Mark the holes in the screw
templates directly onto the cowl.

❏ 3. Remove the cowl and drill 1/8" [3.2mm] holes through

the cowl where you made the marks for the screws.

6-3/8" [162mm]

DA 150 Exhaust Pipe Template

(From Manilla Folder)

❏ 7. If using the DA 150cc engine, use the dimensions

in the illustration to make a template for the exhaust pipe
cutout from thin cardstock or manila folder material. If using
a different engine, make a template from measurements
taken from your engine.

❏ 4. Reposition the templates over the screw holes in the

next two blocks. Mount the cowl with the bottom two 4-40 x
1-1/4" [32mm] SHCS and nylon washers. Mark the holes in
the templates onto the cowl.

❏ 5. Remove the cowl, drill the next two holes, and repeat

until all seven cowl screw holes have been drilled.

❏ 8. Temporarily mount the muffl ers to the engine. Tape the

template to the bottom of the fuselage over the exhaust pipes.

19

❏ 9. Remove the muffl ers. Mount the cowl to the fuselage.

Use a fi ne-point felt-tip pen to mark the holes for the exhaust
pipe cutouts directly onto the cowl.

❏ 10. Remove the cowl. Use a rotary tool with cutting bits

to rough-cut the exhaust pipe holes in the cowl. CAUTION:
Always wear safety goggles, a particle mask and rubber
gloves when grinding, drilling and sanding fi berglass parts—
wearing a long-sleeve shirt and working outdoors is also a
good idea. Vacuum the parts and the work area thoroughly
after working with fi berglass parts.

and mark the cowl as necessary until you can get it to fi t
over the pipes. Also make a generous cutout for cooling air
fl ow. Smooth the edges of all the holes you have cut with
400-grit sandpaper.

GET THE MODEL READY TO FLY

Apply the Decals

1. Use paper towels and window cleaner to wipe oily
fi ngerprints and dust from the model. Cut out the decals.

2. “Float” the decals into position by dipping them in a solution
of liquid dish soap and warm water—just a few drops of soap
per gallon of water.

3. Use a piece of soft balsa or something similar to squeegee
the water from under the decals.

Set the Control Throws

Perform the following procedures to measure and set the
control throws according to the measurements on page

21. The illustrations depict measuring elevator throw, but
the procedure is the same for measuring the ailerons and
rudder. Note: The throws are measured at the widest part
of each control surface.

❏ 11. Remount the muffl ers. Fit the cowl to the fuselage

noting where the cowl must be trimmed to neatly fi t over
the exhaust pipes with plenty of clearance. Continue to cut

❏ 1. Use a small box or something similar to prop up the

fuselage until the wings and horizontal stab are level.

❏ 2. With the surface centered, take the initial reading at the

widest part of the surface you are measuring.

20

(Move the ruler forward)

❏ 3. Defl ect the control surface and move your ruler

forward so it will be contacting the trailing edge. Read the
measurement to get the throw.

These are the recommended control surface throws:

HIGH RATES

IMPORTANT: The 38% Great Planes Extra 330S ARF
has been extensively fl ight tested to arrive at the throws
at which it fl ies best. Flying your model at these throws will
provide you with the greatest chance for successful fi rst
fl ights. If, after you have become accustomed to the way
the Extra 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 diffi cult to control, so remember,
“more is not always better.”

Note: We have also found that approximately 5% up elevator­to-rudder mixing will improve mild down-pitch coupling that
occurs during rudder inputs.

Inches Millimeters Degrees
ELEVATOR: 1-3/4" up 45mm up 16° up

1-3/4" down 45mm down 16° down

RUDDER: 7" right 180mm right 29° right
7" left 180mm left 29° left

AILERONS: 2" up 50mm up 20° up
2" down 50mm down 20° down

LOW RATES

Inches Millimeters Degrees
ELEVATOR: 1" up 25mm up 9° up

1" down 25mm down 9° down

RUDDER: 5" right 130mm right 22° right
5" left 130mm left 22° left

AILERONS: 1-3/8" up 35mm up 14° up
1-3/8" down 35mm down 14° down

3D RATES

Inches Millimeters Degrees
ELEVATOR: 4-3/4" up 120mm up 42° up

4-3/4" down 120mm down 42° down

Balance the Model (C.G.)

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

At this stage the model should be in ready-to-fl y condition
with all of the systems in place including the engine, propeller
and spinner and the complete radio system.

RUDDER: 8" right 200mm right 32° right
8" left 200mm left 32° left

AILERONS: 3-1/2" up 90mm up 40° up
3-1/2" down 90mm down 40° down

❏ 1. Assemble the plywood C.G. cradles as shown.

❏ 2. Bolt the wings to the fuselage with the wing tube.

21

❏ 3. Using an assistant, lift the model with the C.G. cradles

under the tips of the wings with screwdrivers in the middle
holes that are marked 5.75".

For initial flights, the plane should balance

5-3/4" [146mm] from the leading edge of

the wing measured at the WING TIPS.

5-3/4" [146mm]

to balance and, if necessary, add lead ballast to the tail. If,
when lifting the model with the C.G. cradles, the nose pivots
upward, the model is tail-heavy. If possible, shift and remount
internal components forward to get it to balance and, if
necessary, add lead ballast to the nose.

❏ 5. IMPORTANT: Recheck the C.G. after any adjustments

have been made.

Balance the Model Laterally

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

model by the engine propeller shaft and the bottom of the
fuselage under the trailing edge of the horizontal stabilizer.
Do this several times.

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

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

balanced will track better in loops and other maneuvers.

5-3/4" [146mm]

5-3/4" [146mm] (from the leading edge of the wing at the
tips) is the ideal, beginning balance point for your fi rst
fl ights. Balanced here, it has been proven that the model
will be aerobatic, but won’t get you into trouble or react
unexpectedly (provided the control throws are also set
to the high and low rates on page 21). The model could
be fl own balanced at or between the forward (5.0") or
aft (6.5") holes, but for the fi rst few fl ights try to get it to
balance at the recommended 5.75" marks.

❏ 4. If, when lifting the model with the C.G. cradles, the

nose pivots downward, the model is nose-heavy. If possible,
shift and remount internal components aft to get the model

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.

Ground Check

If the engine is new, follow the engine manufacturer’s
instructions to break it in. After break-in, confi rm that the

engine idles reliably, transitions smoothly and rapidly to full
power and maintains full power—indefi nitely. After you run
the engine on the model, inspect the model closely to make
sure all screws remained tight, the hinges are secure, the
prop is secure and all pushrods and connectors are secure.

Range Check

Follow the manufacturer’s instructions that came with your
radio to ground check the operational range of your radio
before the fi rst fl ight of the day—both with the engine off and
with the engine running at various speeds with an assistant
holding the model. If the control surfaces do not respond
correctly, do not fl y! Find and correct the problem fi rst.

22

ENGINE SAFETY PRECAUTIONS

AMA SAFETY CODE (EXCERPTS)

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,
sparks or fl ames, 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.

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

• Always use an assistant or a secure retention device to
anchor the plane while starting the engine and operating it
on the ground.

• Always shut off the engine and turn off the ignition battery
switch before making engine adjustments.

• 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.

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 demonstrations 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 operate models with pyrotechnics (any device
that explodes, burns, or propels a projectile of any kind).

Radio Control

• 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.

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 qualifi ed fl ier, 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 ying site except 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.

23

CHECK LIST

FLYING

During the last few moments of preparation your mind may
be elsewhere, anticipating the excitement of the fi rst fl ight.
Or you may be staying up late at night trying to fi nish your
model for the next day. Because of this, you may be more
likely to forget or overlook something that could cause a
crash. Review this check list to make sure you haven’t
missed anything and the model is truly ready to fl y.

❏ 1. Make sure you have “C.G.’d” the model per the manual.

❏ 2. Confi rm that all controls operate in the correct direction

and the throws are set up according to the manual.

❏ 3. Be certain the batteries, receiver and all other radio

components are securely mounted.

❏ 4. Make sure your receiver battery, ignition battery and

transmitter batteries are fully charged. It would also
be a good idea to cycle new batteries and note their
discharge capacity to make sure they are at or close to
their rated capacity.

❏ 5. Extend the receiver antenna down through the antenna

tube in the fuselage.

CAUTION: Because of the power of the engine and the
size of the propeller and the injury that they could infl ict,
extraordinary care must be taken during operation of this
model—both on the ground and in the air! While the Great
Planes 38% Extra 330S has been tested to withstand the
stresses of 3D fl ight, you still must exercise common
sense and proper throttle management. This is a high­performance, aerobatic “thoroughbred,” not an over-built
sport model for the undisciplined fl yer. “Hack” maneuvers
such as high-speed dives with sudden pullouts and the
like are to be avoided and the throttle must be reduced
during descending components of all maneuvers (such as
on the downside of loops or during down lines). Failure

to practice common sense and exercise restraint
could result in high-speed control surface fl utter or
structural failure. If these general, safe, common-sense

fl ying practices are not in your nature, one way to keep
them in mind would be to fl y the plane as though you are
actually in the cockpit. If you are not capable of fl ying
this model with proper control, set it aside and learn on
something smaller.

❏ 6. Make sure all the servo arms/wheels are secured to

the servos with the screws. Any servo arm/wheel
mounting screws that go into metal output shafts
should have threadlocker.

❏ 7. Make sure any other screws that go into metal

are threadlocked.

❏ 8. Strongly pull on each control surface to make sure all

the hinges are securely glued in place.

❏ 9. Make sure holes for wood screws are reinforced with thin

CA where appropriate (servo mounting screws, etc.).

❏ 10. Make sure servo extensions or other wires do not

interfere with other systems (servo arms, pull/pull
rudder cables, etc.).

❏ 11. Make sure the fuel lines are connected and are

not kinked.

❏ 12. Balance your propeller and spare propellers.

❏ 13. Tighten the propeller bolts/nut and spinner.

Mount the Wings and

Fasten the Canopy Hatch

Mount the wings to the fuselage with the wing tube and four
1/4-20 nylon wing mounting bolts. Don’t forget to connect the
aileron servos to the extensions coming from the receiver.
Then, mount the canopy hatch with the 4-40 x 1/2" [13mm]
Phillips screws, #4 fl at washers and threadlocker on all the
screws. Important: Check the four nylon wing mounting
bolts frequently to make certain they remain tight.

Start the Engine

Always use an assistant or a secure retention device to hold
the plane while starting the engine. Adjust the carburetor so
the engine idles smoothly and transitions rapidly and without
hesitation to full-throttle. Be certain you can stop the engine
from the radio by shutting off the throttle.

Takeoff

❏ 14. Place your name, address, AMA number and telephone

number on or inside your model.

❏ 15. Range check your radio when you get to the

fl ying fi eld.

Whenever fl ying—and especially during the fi rst fl ight—it’s
always a good idea to have a “spotter” with you to keep an
eye on other R/C traffi c so you can taxi, takeoff, fl y and land
without getting too close to another model. Before taking off,
perform a few practice runs at low speeds on the runway to
see if the tail wheel needs adjusting. If necessary, adjust the
spring hooks so the model rolls straight.

24

Double-check the control directions before every fl ight. And
for the fi rst fl ight, takeoff on low rates. Remember to takeoff
into the wind, point the model straight down the runway, hold
a bit of up elevator to keep the tail down, and then gradually
advance the throttle. Do not use full-throttle for takeoff until
you have become familiar with the engine power. As the
model gains speed decrease up elevator, allowing the tail
to come off the ground. Be ready to apply right rudder to
counteract engine torque. When the plane has reached fl ying
speed gently apply up elevator, being ready on the ailerons
and rudder to keep the wings level and the nose pointed
straight-ahead. Establish a gentle climb and make your fi rst
turn away from the pits.

CAUTION: 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 land as
soon as safely possible. Identify 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; worn or loose-fi tting
control linkages; Worn servos or excessive free play in
servo gears; Insecure servo mounting; and one of the most
prevalent causes of fl utter; Flying at excessive speeds.

Landing

When ready to land, make a few “test passes” at reduced
throttle settings learning how the model glides and the rate
it bleeds off air speed. To initiate a landing approach, lower
the throttle while on the downwind leg and allow the nose
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 overshoot, smoothly advance the throttle
(always ready to apply right rudder to counteract torque) and
climb out to make another attempt. When you’re ready to
make your landing fl are and the model is a foot or so off the
deck, continue to gradually increase up elevator until it gently
touches down. Once the model is on the runway and has lost
fl ying speed, switch to high elevator and rudder rates so the
model will be easier to taxi. If necessary, hold up elevator to
hold the tail on the ground.

One fi nal note about fl ying. 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
altitude or airspeed. Every maneuver should be calculated
and 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.

Flight

When the plane has become airborne, have your assistant
keep an eye on other traffi c and remind you to throttle back
if necessary—do not use full throttle until you have become
familiar with the model and it has been trimmed! Once at
cruise, the fi rst thing you should do is reach a safe altitude
and trim the model for “hands-off,” straight-and-level fl ight.
Then you may test different control throw rates one at a time.
While still at a safe altitude, slow the model to see how it
reacts. Take it easy with your 38% Extra for the fi rst few fl ights,
gradually getting acquainted with it as you gain confi dence.
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. Mind your fuel
level, but use this fi rst fl ight to become familiar with your
model before landing.

Have a ball!

But always stay in control and fl y in a safe manner.

GOOD LUCK AND GREAT FLYING!

25

RUDDER PUSHROD ASSEMBLY

55mm

Regular Ball Link (x2) Dual-Ended Ball Link (x6)

Turnbuckle Pushrod (x6)

90mm 90mm 90mm

(Reverse Thread)

Brass Ball

Link Ball (x8)Cut-Off Ball Link (x2)

Cut-Off Ball Link

ELEVATOR SERVO EXTENSIONS

Make the servo extensions this way if connecting

the elevator servos to separate channels.

Make the servo extension this way if connecting

the elevator servos to the same channel.

26

3D FLYING

Because of the power to weight ratio on 3D planes,
straight and level fl ight should be at a reduced throttle
and full power should only be used when the airplane
is “loaded” during a maneuver. Learn to manage the

throttle and experiment while in the maneuver. The power
needed will depend on the maneuver being performed. C.G.
also plays a large role in the 3D capability of models as well.
Experiment, but keep in mind that being tail heavy is not
always the best way to go.

Propeller thrust and thrust vectoring need to be considered
for 3D aerobatics. A large diameter prop with a low pitch
will provide a lot of pull for the aircraft but will not offer
enough air moving across the tail surfaces (thrust vectoring)
for 3D. Due to the large number of factors involved, some
experimentation will be necessary to fi nd the right propeller
pitch and diameter for your model.

Higher RPM engines such as a .46 two-stroke require a
low pitch propeller and lower RPM motors such as a 1.60
will require a higher pitch propeller. If you feel that the
effectiveness of the tail surfaces is not enough, try a smaller
propeller with a higher pitch.

UPRIGHT FLAT SPINS

Pull the nose up slightly and slowly decrease power. As the
model slows down to a few mph, slowly add in full left rudder
and power. Next, start adding in up elevator as needed to
keep the model fl at in the spin. Most airplanes will require
some aileron as well to keep the wings level. This is one of the
maneuvers to experiment on; try different C.G. positions and
different amounts of throw and power to see how fl at the spin
will go. It is possible to maintain altitude in the fl at spin and in
some cases it is also possible to climb during the spin.

INVERTED FLAT SPINS

This is the same as the up-right fl at spin except most planes
like to spin in the opposite direction, for example: right rudder
and down elevator.

THE WALL

Fly straight across the fi eld at a moderate speed and simply
pull full up until vertical. Adjust the power as necessary to
maintain a hover.

KNIFE EDGE TUMBLE

Another thing to remember is that maximum control throw is
not necessary for all 3D maneuvers. Occasionally, too much
throw can place the model too far into a stall causing the
model to become uncontrollable. Practice your maneuvers
at a higher altitude while you become accustomed to your
particular plane’s stall characteristics.

WATERFALLS

With the model pointing straight up (almost in a hover), push
full down elevator and full throttle. As the model rotates and
begins to point downwards, reduce the throttle (to keep the
model from being pulled downwards). As the model fl attens
out, add power back in to pull the model around. A lot of
models will require a little bit of rudder correction (usually
right rudder) during this maneuver. Some planes will require
aileron correction to keep the wings level.

This is an impressive looking maneuver that really isn’t as
diffi cult as it looks. (Before learning this maneuver you must
be able to confi dently Snap and Tumble your plane and stop
the aircraft exactly, without over rotating.) Fly the model
Knife Edge from the right at a moderate airspeed, using
just enough rudder to maintain Knife Edge, not climbing or
diving. Perform one full right negative Tumble by maintaining
your rudder setting while applying full throttle, full down
elevator, and full right aileron, releasing in time to end again
fl ying Knife Edge to the right. Note that you may need to use
some positive elevator and/or left aileron to stop the Tumble
at exactly Knife Edge. This maneuver is easier to the right
because torque helps stop the Tumble and it can be done at
varied airspeeds with proper throttle and rudder modulation.

VERTICAL HOVER

Fly a straight pass across the fi eld at 75ft high and 100ft out
and pull the model vertical. Roll the model until the top of it is
facing you and slowly begin to reduce power. As the model
begins to slow down to 10mph or so, slowly add a little bit of
power back in. You will have to adjust the throttle as needed,
but make your adjustments smooth. Some right aileron may
be needed to keep the model from torque rolling. Use the
rudder and elevator to keep the nose pointing straight up. Be
patient as this maneuver will take a while to learn.

27

TORQUE ROLL

This is the same as the vertical hover but without the use of
right aileron to keep the model from rolling. If needed, you
can use a little left aileron to speed the roll up. As the model
rotates around, the controls will appear to be reversed to you
but only the orientation of the model has changed.

HARRIER

The harrier is nothing more than a high angle of attack fl ying
stall. Check the stall characteristics of your plane before
proceeding with this maneuver. Bring your plane across the
fi eld at 75 ft high and 100 ft out away from yourself. Slowly
pull back on the elevator while reducing throttle. The nose of
the plane should come up. Depending on the plane/setup,
you may have to make constant aileron (wing walking) and
rudder corrections for this maneuver. As the nose of the plane
comes up, start adding in a little bit of power to help maintain
airspeed. The rudder is now used to turn the model. This
maneuver will take some practice as there are a lot of small
corrections made to keep most planes in the maneuver.

This is one maneuver where less control is needed. Too
much elevator and the model goes into an uncontrollable
stall. The C.G. of the plane will have a large effect on the
stability of the model during this maneuver. Some planes
perform better with more elevator defl ection and a farther
forward C.G. while other planes prefer a further aft C.G. and
less elevator defl ection. Elevator to fl ap mixing can be used
on airplanes with marginal wing area, and some planes won’t
stall so elevator to spolieron mixing will be needed.

ROLLING HARRIER

Once you get comfortable with the up-right harrier, it’s time
to work rolls into the mix. From an up-right harrier, add in left
aileron and change from up elevator to down elevator when
inverted. If you are comfortable with four point rolls and slow
rolls, inputting rudder on the knife edges can improve the
maneuver considerably. To turn the model, simply input the
elevator or rudder a little sooner or later in the rotation. It’s all
a matter of timing.

PINWHEEL

Climb vertically and bring the model to a vertical hover, but do
not stop long enough to let the torque pull the model around
(climbing or sliding slightly will not be noticeable to spectators
but will keep air fl owing over the ailerons and provide you roll
authority to stop the torque). When the model is hanging,
rock the plane left with rudder, then apply full throttle and
full right rudder and hold both, completing 3/4s of a VERY
tight Knife Edge Loop and fl ying out Knife Edge. When done
correctly, the plane pivots around the wingtip in a very small
area. This maneuver can be done either direction.