GREAT PLANES Reactor ARF .61-.91 SPORT BIPLANE User manual

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
this kit immediately in new and unused condition to the place
of purchase.
To make a warranty claim send the defective part or item to Hobby
Services at the address below:
Hobby Services
3002 N. Apollo Dr., Suite 1
Champaign, IL 61822 USA
Include a letter stating your name, return shipping address, as
much contact information as possible (daytime telephone number,
fax number, e-mail address), a detailed description of the problem
and a photocopy of the purchase receipt. Upon receipt of the
package, the problem will be evaluated as quickly as possible.
READ THROUGH THIS MANUAL BEFORE STARTING CONSTRUCTION. IT CONTAINS IMPORTANT
INSTRUCTIONS AND WARNINGS CONCERNING THE ASSEMBLY AND USE OF THIS MODEL.
Champaign, Illinois
[phone], Ext 5
airsuppor[email protected]
WARRANTY
INSTRUCTION MANUAL
Entire Contents © Copyright 2008 GPMA1023Mnl1.0
Top Wingspan: 48 in [1220mm]
Bottom Wingspan: 48 in [1220mm]
Total Wing Area: 1145 sq in [73.9 dm2]
Weight: 7–7.5 lb [3170–3400 g]
Wing Loading: 14–15 oz/sq ft [43–46 g/dm2]
Length: 58.5 in [1485mm]
Radio: 4–5 ch.
Engine: .61 cu in [10cc] two-stroke,
.70–.91 cu in [11.5–15.0cc] four-stroke,
RimFire™.80 (50-55-500kV)
ARF .61-.91 SPORT BIPLANE
™

2
TABLE OF CONTENTS
INTRODUCTION ............................................................... 2
SAFETY PRECAUTIONS ................................................. 3
DECISIONS YOU MUST MAKE........................................ 3
Engine Recommendations......................................... 3
Motor/Battery/ESC Recommendations...................... 3
Radio/Servo Recommendations ................................ 4
ADDITIONAL ITEMS REQUIRED .................................... 6
Adhesives and Building Supplies............................... 6
Optional Supplies and Tools....................................... 6
Covering Tools ........................................................... 6
BUILDING NOTES ............................................................ 6
ORDERING REPLACEMENT PARTS .............................. 6
KIT INSPECTION.............................................................. 7
KIT CONTENTS................................................................ 7
PREPARATION ................................................................. 8
ASSEMBLE THE FUSELAGE .......................................... 8
Test-Mount the Elevator and Rudder Servos ............. 8
Mount the Horizontal Stabilizer (Stab) ....................... 9
Hinge the Elevators and Rudder .............................. 11
Hook up the Elevator and Rudder............................ 12
Mount the Main Landing Gear ................................. 14
Mount the Motor....................................................... 14
Mount the Engine..................................................... 16
Install the Fuel Tank ................................................. 17
Hook up the Throttle................................................. 18
Mount the Cowl ........................................................ 18
ASSEMBLE THE WINGS................................................ 22
Mount the Aileron Servos......................................... 22
Mount the Wings ...................................................... 23
Mark the Balance Point (C.G.) ................................. 26
FINAL ASSEMBLY ......................................................... 27
Mount the Canopy.................................................... 27
Final Radio Installation............................................. 27
GET THE MODEL READY TO FLY ................................. 28
Apply the Decals ...................................................... 28
LiPo Battery Precautions ......................................... 28
Check the Control Directions ................................... 29
Set the Control Throws ............................................ 29
Assemble the Balance Stand................................... 31
Balance the Model (C.G.)......................................... 31
Balance the Model Laterally..................................... 32
PREFLIGHT .................................................................... 32
Identify Your Model................................................... 32
Charge the Batteries ................................................ 32
Balance Propellers................................................... 32
Ground Check.......................................................... 33
Range Check ........................................................... 33
ENGINE SAFETY PRECAUTIONS................................. 33
AMA SAFETY CODE (EXCERPTS)..................................... 33
CHECK LIST................................................................... 34
FLYING............................................................................ 34
Takeoff ..................................................................... 34
Flight ....................................................................... 35
Landing .................................................................... 35
INTRODUCTION
Thank you for purchasing the Great Planes Reactor .60
biplane. The Reactor brings “new blood” into the hobby by
combining the stable, predictable flight characteristics of
models from the “old days,” with the light weight, style and
maneuverability contemporary modelers demand. In spite
of the Reactor’s aggressive appearance, the Reactor still
handles amazingly well at low speeds and is an absolute
“hoot” to bring in nice and slow for a landing.
There are several options and configurations for assembling
your Reactor .60 biplane, so please read through the manual
to decide on how your model will be completed.
For the latest technical updates or manual corrections to
the Reactor .60 biplane, visit the Great Planes web site at
www.greatplanes.com. Open the “Airplanes” link, then
select the Reactor .60 biplane 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
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 fly 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:
www.modelaircraft.org
IMPORTANT!!! Two of the most important things you can do
to preserve the radio controlled aircraft hobby are to avoid
flying near full-scale aircraft and avoid flying near or over
groups of people.

3
PROTECT YOUR MODEL, YOURSELF
& OTHERS...FOLLOW THESE
IMPORTANT SAFETY PRECAUTIONS
1. Your Reactor .60 Bipe 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 Reactor, 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 unflyable 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 specified
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 flight.
5. If you are not an experienced pilot or have not flown
this type of model before, we recommend that you get the
assistance of an experienced pilot in your R/C club for
your first flights. 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 flight tested to exceed normal use,
if the plane will be used for extremely high stress flying, 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.
7. WARNING: The cowl, wheel pants and center wing brace
included in this kit are made of fiberglass, the fibers of which
may cause eye, skin and respiratory tract irritation. Never
blow into a part (wheel pant, cowl) to remove fiberglass 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 fiberglass parts. Vacuum the parts and
the work area thoroughly after working with fiberglass parts.
We, as the kit manufacturer, provide you with a top quality,
thoroughly tested kit and instructions, but ultimately the
quality and flyability of your finished model depends
on how you build it; therefore, we cannot in any way
guarantee the performance of your completed model,
and no representations are expressed or implied as to
the performance or safety of your completed model.
Remember:Take your time and follow the instructions to
end up with a well-built model that is straight and true.
DECISIONS YOU MUST MAKE
Engine Recommendations
The recommended engine sizes for the Reactor .60 biplane
are specified on the cover of this instruction manual. If you
haven’t yet decided whether to go 2-stroke or 4-stroke, one
big advantage of most 4-strokes (such as the O.S. Max .91
illustrated in this manual) is that the muffler can be positioned
to aim messy exhaust out the bottom of the fuselage keeping
most of the plane pretty clean. If mounting a 2-stroke inverted
(positioning the muffler on the side of the fuselage), much of
the exhaust tends to get deposited on the side of the fuselage
unless preventative measures are taken.
If using the O.S. Max .91 and you wish to configure the muffler
as shown in the manual (see page 20), an O.S. “Exhaust
Header Pipe (IN)” will also be required (OSMG2624).
3’ [900mm] standard silicone fuel tubing (GPMQ4131) will
also be required for glow engine installation.
A #29 (.135" [3.4mm]) drill and an 8/32 tap will be required
for drilling and tapping holes in the motor mount. A Great
Planes 8-32 tap & drill set (GPMR8103) or a Great Planes
10 piece tap & drill set (GPMR8108) are suitable.
Motor/Battery/ESC Recommendations
If electric power is your preference, rest assured that an
extensive part of testing and development of the Reactor .60
biplane was done with electric power. With the recommended
power plant, the Reactor was a thrill to fly and able to perform
all the same “3D” maneuvers it did when powered with glow.
If not certain whether to go glow or electric, consider some
of the advantages of electric, which are: absence of oily
exhaust residue and the constant cleaning that goes with it;
“instant on” from never having to start the engine; and most
important to some people, silence. Of course, there are
other variables that may offset some of these advantages
such as the expense of LiPo batteries and all the charging
paraphernalia, charging time, and shorter flight times. (Using
the batteries and motor recommended, average flight times
for the Reactor were approximately 8 minutes.)

Following are the items illustrated in the instruction
manual for equipping your Reactor .60 biplane with an
electric motor:
POWER SYSTEM
❏Great Planes ElectriFly™RimFire™.80 (50-55-500kV)
electric motor (GPMG4740)
❏Great Planes ElectriFly Brushless Motor Mount for large
motors (GPMG1260)
❏Great Planes ElectriFly Silver Series 60A Brushless ESC
(GPMM1850)
❏(4) 3mm x 10mm socket-head cap screws (DUBQ3227)
❏(4) 3mm or #4 flat washers (DUBQ3307)
❏(4) 3mm or #4 lock washers (DUBQ3285)
❏APC 15 x 8E propeller (APCQ4013)
❏APC 15 x 6E propeller (APCQ1505)
BATTERY
A 3200mAh “6S” (6-cell, 22.2V) 20C LiPo (Lithium Polymer)
battery is recommended.However, 6S batteries are not readily
available, so two 3S (3-cell, 11.1V) batteries connected in
series (via a Y-connector) are required to make one flight
pack. This means two batteries will be required for the each
“flight pack” desired. Also note the “20C” requirement which
means that the batteries must be able to deliver current at a
rate that is at least 20 times its rated capacity. This enables
the motor to draw enough current to suitably fly the plane.
The required battery adapter to convert two 3S packs into a 6S
pack is the Great Planes U.S. Deans®2 to 1 Series adapter.
❏Great Planes ElectriFly™3200mAh 11.1V (3S), 20C LiPo
battery (GPMP0623)
❏Great Planes U.S. Deans 2 to 1 Series adapter
(GPMM3143)
❏Great Planes adhesive-backed Velcro®(for mounting the
batteries) is also required (GPMQ4480)
BATTERY CHARGING SETUP
A battery charger suitable for charging LiPo batteries is also
required. The Great Planes PolyCharge4 DC LiPo charger
can charge up to four 3S LiPo batteries simultaneously.
The PolyCharge4 is powered by a 12V source such as an
automobile battery. But if charging from a 110V wall outlet is
preferred, a 110V-powered 12V power supply (for powering
the battery charger) will be required.
Another critically important component of the motor battery
charging system is a cell balancer. LiPo battery technology is
so powerful that each, individual cell within the battery pack
should be charged equally—or balanced.Otherwise, capacity,
power and the overall battery life will be diminished. (1) Great
Planes ElectriFly Equinox LiPo Cell Balancer for each battery
to be charged simultaneously is recommended.
Finally, propeller selection has a noticeable effect on how the
Reactor performs. During flight testing we learned that an
APC 15 x 8E propeller was the best all-around propeller for
performance and sport flying, but if flying mostly 3D maneuvers
(specifically hovering), an APC 15 x 6E is recommended.
Here are the part/order numbers for all of the charging
items suggested:
❏Great Planes PolyCharge4™DC LiPo charger
(GPMM3015)
❏Hobbico 12V Power Supply (HCAP0250)
❏Great Planes ElectriFly Equinox™LiPo Cell Balancer
(GPMM3160)
IMPORTANT: Before experimenting with different battery
combinations and connecting multiple battery packs with
adapter plugs, read the Battery Precautions on page 28.
Radio/Servo Recommendations
SERVO OPTIONS
With the exception of the throttle servo, the rest of the servos
used to fly the Reactor .60 biplane require a minimum
torque rating of 50 oz.-in. [3.6 kg-cm], although the S3102
micro servos used for the ailerons should not be used for
the elevators or rudder. The cutouts in the fuselage for the
two elevator servos and the one rudder servo are sized for
sub-standard size servos (such as Futaba S9650s, optimum
for light weight and flight precision and illustrated in these
instructions). However, standard size servos (such as
S9001s) may also be used simply by enlarging the openings
with the included plywood template.
Because each elevator is operated by a separate servo, a
radio capable of servo mixing or a servo reverser (such as
the Futaba SR-10 Dual Servo Reverser, FUTM4150) will
be required. However, because the elevator servos are
“mirrored” on opposite sides of the fuselage (with the
exception of one servo positioned ahead of the other so they
do not interfere with each other in the narrow fuselage), a
“computer” radio capable of separately adjusting the servo’s
endpoints is not required.
The mounting blocks for the four aileron servos fit almost
any size servo from the S3102 mini servos (also optimum
for light weight and flight precision and illustrated in these
instructions) to standard-size servos (such as S9001s for
sport flying).
4

5
Here is some technical data for the suggested servos to
assist you in making a decision:
WeightTorque (@ 4.8V)
Speed
(sec./60° @ 4.8V)
S9001
(FUTM0075)
54 oz-in
[3.9 kg-cm]
1.7 oz
[48g]
.22 sec.
S3102*
(FUTM0034)
51 oz-in
[3.7 kg-cm]
.7 oz
[21g]
.25 sec.
*
S9650
(FUTM0260)
50 oz-in
[3.6 kg-cm]
.9 oz
[26g]
.14 sec.
Ailerons only
SERVO ARMS
If planning to do much 3D flying with Reactor .60 biplane,
extended servo arms will be required to achieve the necessary
3D throws. Otherwise, the standard servo arms that came
with your servos are suitable. For 3D flight, an extended
servo arm such as a Great Planes large-scale 1-1/2" [38mm]
single-sided servo arm (GPMM1105) is recommended for
the rudder servo and a Great Planes large-scale 1" [25mm]
single-sided servo arm (GPMM1100) is recommended for
each elevator servo. Standard servo arms are suitable for
the ailerons.
RECEIVER BATTERY
A minimum 1,000mAh receiver battery such as Futaba NR4F
1500mAh 4.8V battery (FUTM1285) is required to power the
radio system.
ELEVATOR/RUDDER SERVO WIRE EXTENSIONS
If using Futaba servos for the elevators and rudder, Futaba
400mm (16") servo extensions may be used, but they
are just long enough to reach the receiver. These are the
extensions illustrated in the instruction manual. If for some
reason you will be mounting your receiver farther forward,
or if you prefer more economical servo extensions, Hobbico
24" [610mm] servo extensions are also suitable. If using
digital servos, remember to use servo extensions suitable
for digital servos.
These are the order numbers for the elevator and
rudder servo extensions for digital servos:
❏(3) Futaba 400mm (16") AEC-15 servo extensions for
digital servos (FUTM4145)
OR
❏(3) Hobbico Pro 24" [610mm] heavy-duty servo extensions
for digital Futaba servos (HCAM2721)
These are the order numbers for the elevator and
rudder servo extensions for standard servos:
❏(3) Futaba 400mm (16") AEC-11 servo extensions for
standard servos (FUTM3955)
OR
❏(3) Hobbico Command™24" [610mm] servo extensions
for standard Futaba servos (HCAM2200)
AILERON SERVO WIRE EXTENSIONS:
Same as for the elevator and rudder servos, if using digital
servos, be certain to use compatible servo extensions.
These are the order numbers for the aileron servo
extensions for digital servos:
❏(4) Hobbico Pro 6" [300mm] servo extensions for digital
Futaba servos (HCAM2701)
❏(1) Hobbico Pro 12" [600mm] servo extension for digital
Futaba servos (HCAM2711)
❏(3) Futaba AEC-16 dual servo connectors for digital
servos (FUTM4135)
These are the order numbers for the aileron servo
extensions for standard servos:
❏(4) Hobbico Command 6" [300mm] servo extensions for
standard Futaba servos (HCAM2000)
❏(1) Hobbico Command 12" [600mm] servo extension for
standard Futaba servos (HCAM2100)
❏(3) Futaba AEC-13 dual servo connector for standard
servos (FUTM4130)
If Y-harnesses are preferred inside each wing (instead
of two 6" [300mm] servo extensions and one dual
servo connector), these are the order numbers for
Y-harnesses for digital servos:
❏(2) Hobbico Pro Y-harnesses for digital Futaba servos
(HCAM2751)
❏(1) Hobbico Pro 12" [600mm] servo extension for digital
Futaba servos (HCAM2711)
❏(1) Futaba AEC-16 dual servo connector for digital servos
(FUTM4135)
These are the Y-harnesses and extensions for
standard servos:
❏(2) Hobbico Command Y-harnesses for standard Futaba
servos (HCAM2500)
❏(1) Hobbico Command 12" [600mm] servo extension for
standard Futaba servos (HCAM2100)
❏(1) Futaba AEC-13 dual servo connector for standard
servos (FUTM4130)

6
ADDITIONAL ITEMS REQUIRED
Adhesives and Building Supplies
❏1/4" [6mm] R/C foam rubber (HCAQ1000)
❏1/2 oz. [15g] Thin Pro™CA (GPMR6001)
❏1/2 oz. [15g] Medium Pro CA+ (GPMR6007)
❏Pro 30-minute epoxy (GPMR6047)
❏Threadlocker thread locking cement (GPMR6060)
❏Silver solder w/flux (STAR2000)
❏Great Planes .050" Ballwrench for screws in aileron servo
hatches (GPMR8000)
❏#1 Hobby knife (HCAR0105)
❏#11 blades (5-pack, HCAR0211)
❏Drill bits: 1/16" [1.6mm], 3/32" [2.4mm], 1/8" [3.2mm],
❏Small metal file
Optional Supplies and Tools
❏Great Planes 1/5-Scale Sport pilot:
GPMQ9015 Red, GPMQ9016 Blue,
GPMQ9017 Yellow, GPMQ9018 Unpainted
❏Robart Super Stand II (ROBP1402)
❏8mm prop reamer (for propellers and included spinner –
GPMQ5007)
❏Tap handle (GPMR8120)
❏Stick-on segmented lead weights (GPMQ4485)
❏2 oz. [57g] spray CA activator (GPMR6035)
❏R/C-56 canopy glue (JOZR5007)
❏CA applicator tips (HCAR3780)
❏CA debonder (GPMR6039)
❏Epoxy brushes (6, GPMR8060)
❏Mixing sticks (50, GPMR8055)
❏Mixing cups (GPMR8056)
❏Dead Center™Engine Mount Hole Locator (GPMR8130)
❏Denatured alcohol (for epoxy clean up)
❏Kevlar thread (for horizontal stabilizer alignment)
❏Panel Line Pen (TOPQ2510)
❏Rotary tool such as Dremel
❏Hobby Heat™micro torch (HCAR0755)
Covering Tools
The 21st Century covering iron and protective cover sock
are recommended for tightening the covering or removing
any wrinkles.
❏21st Century®sealing iron (COVR2700)
❏21st Century iron cover (COVR2702)
BUILDING NOTES
•The Reactor .60 biplane ARF is factory-covered with
Top Flite®MonoKote®film. Should repairs ever be required,
MonoKote can be patched with additional MonoKote
purchased separately. MonoKote is packaged in six-foot rolls,
but some hobby shops also sell it by the foot. If only a small
piece of MonoKote is needed for a minor patch, perhaps a
fellow modeler would give you some. MonoKote is applied
with a model airplane covering iron, but in an emergency a
regular iron could be used. A roll of MonoKote includes full
instructions for application. Following are the colors used on
this model and order numbers for six foot rolls.
White: TOPQ0204
Orange: TOPQ0202
Metallic Blue: TOPQ0402
Aluminum: TOPQ0205
•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 fly, please expect slight
deviations between your model and the published values.
ORDERING REPLACEMENT PARTS
Replacement parts for the Great Planes Reactor .60
bipe 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” and 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 e-mail at productsupport@greatplanes.
com, or by telephone at [phone].

7
REPLACEMENT PARTS LIST
GPMA3340..... Fuselage
GPMA3341..... Top Wing
GPMA3342..... Bottom Wing
GPMA3343..... Horizontal Stabilizer
GPMA3344..... Rudder
GPMA3345..... Cowl
GPMA3346..... Landing Gear
GPMA3347..... Wheelpants
GPMA3348..... Canopy
GPMA3349..... Struts
GPMA3350..... Decals
GPMA3351..... Battery Hatch
GPMA3352..... Fuel Tank
NOTE: Full-size plans are not available.You can download a
copy of this manual at www.greatplanes.com.
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
Champaign, IL 61822
Telephone: [phone], ext. 5
Fax: [phone]
E-mail: [email protected]
KIT CONTENTS
1. Cowl
2. Fuselage
3. Canopy
4. Tailwheel Assembly
5. Rudder
6. Horizontal Stab
7. Wing Brace
8. Fuel Tank
9. Main Landing Gear
10. Wheel Pants
11. Main Wheels
12. Spinner
13. Wing Struts
14. Bottom Wing
15. Top Wing
12
3
4
5
6
8
7
10
10 11
9
9
12
13
13
14
15

8
PREPARATION
❏1. Use a covering iron with a cover sock to tighten the
covering or remove any wrinkles found on parts of the model.
Note: When moving the iron over trim pieces that are sharply
pointed, be certain to move the iron away from the point, not
toward it.
❏2. Lay three or four
paper towels over each
other and cut the stack
into small squares. These
smallpaper towelsquares,
dampened with denatured
alcohol, will come in
handy for epoxy cleanup
and other general cleanup
throughout assembly.
ASSEMBLE THE FUSELAGE
Test-Mount the Elevator
and Rudder Servos
It will be easier to cut the covering from the servo mounts and
drill the servo mounting screws now, before the horizontal
stabilizer is glued into position.
❏1. If using Futaba S9650 servos, cut the side-mount tabs
from each servo using a razor saw—don’t try to simply score
the tabs with a knife thinking they can be broken off—this will
probably damage the case. Use a small file or sandpaper to
sand the cut corners smooth and even.
LEFT ELEVATOR
SERVO OPENING
RIGHT ELEVATOR
SERVO OPENING
RUDDER
SERVO OPENING

9
❏2. Test fit the servos in the servo openings in the fuselage.
If using standard-size servos that don’t fit in the openings,
use a fine-point felt-tip pen and the plywood servo cutout
template as a guide to mark larger openings. Cut the
enlarged openings along the lines you marked.
❏3. Using the screw holes in the servos as a guide, drill
1/16" [1.6mm] holes through the fuselage for mounting all
three servos.
❏4.Temporarily mount the servos with the mounting screws
that came with the servos. Remove the screws and add a
few small drops of thin CA to each hole. This important
procedure will harden the “threads” cut by the screws to keep
your servos securely mounted.
Mount the Horizontal Stabilizer (Stab)
❏1.Use 30-minute epoxy to glue both 6 x 25mm bottom wing
dowels into the bottom wing with 1/4" [6mm] protruding.
❏2. If you haven’t yet done so, make sure the wrinkles have
been removed from the covering on the horizontal stabilizer
(stab) and around the stab openings on both sides of the
fuselage. (This will be a little more difficult to do after the stab
is glued in.)
❏3. Temporarily bolt the bottom wing to the fuselage with
the 1/4-20 x 2" [51mm] nylon wing bolts.
Before using glue, make a “trial run” of mounting the
stab by performing steps 3 through 7.
AA'
A = A'
❏4. Slide the stab into the fuselage. Center the trailing edge
(TE) in the fuselage by taking accurate measurements on
both sides.

10
❏5. Once the trailing edge is centered, stick pins into the
trailing edge tightly against both sides of the fuselage. This
will keep the trailing edge centered while centering the
leading edge in the next step.
❏6. Push another pin through the top of the fuselage at the
small mark indicating centerline on the firewall. Tie a small
loop in one end of an approximately 50" [1.25m] piece of
non-elastic string such as K&S Kevlar line or Kevlar fishing
line. Loop the string over the pin.
B
B' B = B'
❏7. Fold a piece of masking tape over the other end of the
string end and mark a line on it. Pull the string to the tip of
one side of the stab. Slide the tape along the string until the
line on the tape aligns with the tip. Swing the string over to
the same spot on the other side of the stab. If the mark on
the tape doesn’t align, rotate the stab and slide the tape until
both sides are the same and the stab is aligned.
One more alignment procedure to go before gluing…
❏8. Standing about 6’ [2m] behind the model, view the
alignment of the stab and wing. If the stab is not parallel with
the wing, place incrementally increasing amounts of weight
on the stab until you can get it parallel with the wing.
The next few steps may get messy, so make sure you
have your denatured alcohol and plenty of paper towel
squares ready.
❏9. Now that you’ve practiced the stab alignment procedure,
remove the stab from the fuselage. Liberally apply 30-minute
epoxy all the way around the exposed balsa on the right side
of the stab up to the covering.

11
❏10. Slide the stab into position, then partially out the other
side, exposing the uncovered balsa on the other side of the
stab. Apply more epoxy around the top and bottom of the
stab, then slide it back into place. Use your finger or a piece
of balsa or cardstock to thoroughly work epoxy back into the
joint all the way around the top and bottom on both sides.
Reinsert the pins into the trailing edge next to the fuselage.
Use your paper towel squares to wipe away excess epoxy
and use the pin and string and any weight that may have
been necessary to align the stab with the wing. Do not disturb
the model until the epoxy has hardened.
Hinge the Elevators and Rudders
1" [25mm]
CA HINGE 1" [25mm]
❏1. Cut ten 1" x 1" [25 x 25mm] CA hinges from the included
CA hinge strip. Snip off the corners so they go in easier.
❏2. Stick a pin through the middle of three hinges. Without
glue, fit the hinges into the hinge slots in one side of the stab.
(The T-pins will keep the hinges centered.)
❏3. Join the matching elevator to the stab and take out the
T-pins. Make sure there is a small hinge gap—just enough to
see light through or to slip a piece of paper through.
❏4. Add eight to ten drops of thin CA to the top and bottom
of each hinge allowing a few seconds between drops for the
CA to soak in so it doesn’t run into the hinge gap.
❏5. Hinge the other elevator the same way, but don’t hinge
the rudder yet.
❏6.Without using any glue, test fit the tail wheel assembly into
the fuselage, then join the rudder with four hinges with pins.
Make any adjustments necessary so everything fits well.
❏7. Use coarse sandpaper to roughen the “arm” portion of
the tail gear wire (where it goes into the rudder) so glue will
adhere. Add a drop of oil to both ends of the tail gear bearing
so glue will not get in.

12
❏8. Use a small metal ruler or straightedge to work
30-minute epoxy down into the slot in the fuselage for the tail
gear bearing. Apply epoxy to the bearing, then fit it into the
slot. Wipe away excess epoxy.
❏9. Apply epoxy in the hole in the rudder for the tail gear
wire and apply epoxy to the arm. Make sure the rudder
hinges are in place, then join the rudder to the fuselage with
the hinges. Wipe away any excess epoxy.
❏10. Remove the pins from the hinges and permanently
join the rudder to the fuselage by gluing in the hinges with
thin CA.
Hook Up the Elevator and Rudder
❏1.Connect your servo extensions to the rudder and elevator
servos. Secure the connectors with 1-1/2" [38mm] pieces of
heat shrink tubing cut from the 3" [76mm] tubing supplied.
Use a heat gun or a hobby torch to shrink the tubing.
Refer to these photos while hooking up the elevator and
rudder servos.
❏2. Mount the elevator and rudder servos in the fuselage
using the screws that came with them.

13
We’re going to instruct you to center the servos and
adjust the pushrods now, but this could be done later
during final setup if you prefer.
❏3. Temporarily connect the servos to your receiver with a
battery and a switch so you can move the servos with your
transmitter. Turn on your transmitter and make sure the trims
are centered and turn on the receiver.
90˚ 90˚
NO
NO
YES
CUT OFF THE
UNUSED ARMS
GREAT PLANES
LARGE-SCALE ARM
❏4. Mount your servo arms to the servos—if using the
recommended Great Planes large-scale servo arms,
position the square plastic inserts so the servo arms will be
90-degrees to the servo. If using the standard servo arms that
came with your servos, find the arm that will be 90-degrees
to the servo and cut off the remaining unused arms.
❏5. Read the following Expert Tip about how to solder
pushrods, then make the pushrods and connect the rudder
and elevator with the pushrods and control horns as shown
in the photos. IMPORTANT: Be certain you are soldering the
solder clevises onto the non-threaded end of the pushrods
and threading the threaded clevises onto the threaded end
of the pushrods. Sometimes modelers mistake unthreaded
clevises for threaded clevises. Note: Make sure the horns
are-mounted over the hardwood plates built into each control
surface and are positioned as thown in the sketch at step 6.
And drill 1/16" [1.6mm] holes for the #2 x 1/2" [12.7mm] Phillips
horn mounting screws. Don’t forget the important procedure
of installing, then removing the screws and hardening the
holes with thin CA.
HOW TO SOLDER
❏A. Use denatured alcohol or other solvent to thoroughly
clean the pushrod. Roughen the end of the pushrod with
coarse sandpaper where it is to be soldered.
❏B. Apply a few drops of soldering flux to the end of
the pushrod, then use a soldering iron or a torch to heat
it. “Tin” the heated area with silver solder (Stay Brite,
STAR2000) by applying the solder to the end.The heat of
the pushrod should melt the solder—not the flame of the
torch or soldering iron—thus allowing the solder to flow.
The end of the wire should be coated with solder all the
way around.
❏C. Place the clevis on the end of the pushrod. Add
another drop of flux, then heat and add solder. The same
as before, the heat of the parts being soldered should
melt the solder, thus allowing it to flow. Allow the joint to
cool naturally without disturbing. Avoid excess blobs, but
make certain the joint is thoroughly soldered. The solder
should be shiny, not rough. If necessary, reheat the joint
and allow to cool.
❏D. Immediately after the solder has solidified, but while
it is still hot, use a cloth to quickly wipe off the flux before
it hardens. Important: After the joint cools, coat with oil
to prevent rust. Note: Do not use the acid flux that comes
with silver solder for electrical soldering.
This is what a properly soldered clevis looks like—shiny
solder with good flow, no blobs, flux removed.
“JAM” NUT
SILICONE RETAINER
❏6. After all the pushrods have been made and the elevator
and rudder connected, tighten the 4-40 “jam” nuts to
the threaded clevises and install silicone retainers on all
the clevises.

14
Mount the Main Landing Gear
❏1. Use a 1/2" wrench and a 7/32" wrench (or crescent
wrenches) to fasten a 5/32" x 1-1/4" [4mm x 32mm] bolt-on
axle to each fiberglass main landing gear leg with a 5/16"-24
lock nut.
❏2. Use a small metal file or a rotary tool with a reinforced
cutoff wheel to grind a flat spot 1/8" [3.2mm] from the end of
both axles.
5/32" [4mm] WHEEL COLLAR
AND 6-32 SET SCREW
❏3. Mount the wheels to the axles with 5/32" [4mm] wheel
collars and 6-32 set screws (and a drop of threadlocker)—
before tightening the set screws, test fit the pant to the gear
to get the wheel centered. Mount the pants to each gear with
4-40 x 1/2" [12.7mm] Phillips screws, #4 lock washers and
flat washers (and threadlocker).
❏4. Mount the main landing gear to the fuselage with six
4-40 x 3/4" [19mm] SHCS and #4 lock washers and flat
washers—use a drop or two of threadlocker on the threads
of the screws.
Mount the Motor
If mounting a glow engine,
skip to Mount the Engine on page 16.
Refer to this photo for steps 1 and 2.
❏1. Mount your motor to the motor mount (not included) with
three 3 x 10mm SHCS, 3mm lock washers and flat washers
(not included)—and don’t forget to use threadlocker on the
threads. Mount the motor mount to the firewall with four 8-32
x 1/2" [12.7mm] SHCS and #8 lock washers.
❏2. Move the front plate of the mount as far back as it will
go, add some threadlocker to the screw, then tighten the
eight 6-32 screws that hold the plates together. Using the
back plate of the spinner as a reference for measurement,
this should set the front of the propeller adapter on the motor
5-5/8" [143mm] from the firewall.

15
2" [51mm] OVERLAP
5-1/2" [140mm]
“LOOP” SIDE
BATTERY
MOUNT
PLATE
7" [178mm]
“HOOK” SIDE
❏3. Prepare the plywood battery mounting plate by
determining exactly how you will be mounting your battery
pack—if using the batteries recommended, you can do it as
illustrated, or use this as a guide for mounting the batteries
your own way. Cut strips of the softer, “loop” side of a
1" x 6" [25.4 x 152mm] Great PlanesVelcro strip (GPMQ4480,
not included) and stick them to the bottom of your batteries.
Stick strips of the rougher, “hook” side to the mounting plate.
Make a battery strap from the included hook-and-loop strap
by cutting a 5-1/2" [140mm] piece of the loop side and a
7" [178mm] piece of the hook side. Test fit the battery to the
plate with the strap. Suggestion: Hold the two battery packs
together with a few small strips of Velcro or double-sided
foam tape.
❏4. Test fit the battery and the mounting plate in the
fuselage—note that the tabs in the front of the mounting plate
key into the notches in the back of the firewall and that the
sides of the mounting plate are locked into the former near the
rear. (For clarity in the photo on the top, the battery strap has
been removed so you can see how the battery plate fits.)
❏5. Once satisfied with the mounting method and battery
placement, remove the battery and mounting plate. Glue the
strap to the bottom of the battery mounting plate (so it cannot
fall out when the batteries are removed), and securely glue
the battery mounting plate into position.
ESC CUTOUT
(REMOVE)
❏6. Remove the ESC cutout in the firewall by carefully
cutting across the tabs around the edges with a hobby knife.

16
❏7. Glue together the plywood ESC mount and glue the
plywood screw doublers to the bottom of the mount. Mount
the ESC to the mount with three #4 x 1/2" [12.7mm] screws
and #4 flat washers.
❏8. Securely glue the ESC mount to the firewall. Connect
the motor wires to the motor.
IMPORTANT: Before connecting your batteries to power
up the motor in the following step, be certain NOT to have
a propeller mounted to the motor and read the Battery
Precautions on page 28.
❏9. Temporarily connect your receiver, on/off switch,
receiver battery and motor batteries so you can power the
motor to make sure it is hooked up correctly.Turn on the radio
and use the throttle stick on your transmitter to make sure
the motor turns in the correct direction (counter-clockwise
when viewed from the front). If the motor does not turn the
correct direction, switch any two motor and ESC wires with
each other to reverse the direction. Use nylon tie wraps or
electrical tape to secure all the wires and make certain they
will not rub on the motor or motor shaft.
Mount the Engine
(A 4-stroke is shown in the photos, but the procedure for
a 2-stroke is the same.)
❏1. Temporarily mount the included Great Planes .60-1.20
adjustable motor mount to the firewall with four 8-32 x 1"
[25.4mm] SHCS and #8 flat washers and lock washers, but
don’t tighten the bolts all the way yet.
❏2. Place your engine on the mount and adjust the spacing
to fit the engine. Now tighten the bolts. Use a small clamp to
hold the engine to the mount so the front of the drive washer
(or the back plate of your spinner) will be 5-5/8" [143mm]
from the firewall.
❏3. Use a Great Planes Dead-Center Hole Locator or
another method to mark the locations of the engine mounting
bolts onto the engine mount.
❏4. For perfection, if you have access to a drill press,
remove the mount halves and drill #29 (.135" [3.4mm]) holes
at the marks. If a drill press is not available, the holes may be
drilled while the mount is fastened to the firewall.
❏5. Use an 8-32 tap to cut threads into the holes—this is
easily and quickly done holding the mount halves in your
hand with your tap chucked in a hand drill at low speed.

17
O.S. .61FX
O.S. FS91 II,
O.S. FS81
O.S. FS91 II PUMP
❏6. Before-mounting the engine, drill 3/16" [4.8mm] holes
through the firewall at the crossmarks that align with the
carburetor arm on your throttle as indicated in the sketch. If
using a different engine, you may have to mark and drill the
hole in a different location.
❏7. Bolt the engine to the engine mount with for 8-32 x 1"
[25.4mm] SHCS and #8 lock washers.
Install the Fuel Tank
❏1. Assemble the stopper with the aluminum tubes, fuel
lines and clunks as shown. Bend the long tube so it will be
at the top of the tank and cut the fuel lines so the clunks
cannot contact the back of the tank—otherwise they could get
stuck. Note that one of the lines will be used for fueling and
defueling and the other line will be the pickup line that goes
to the carburetor. The bent tube will be connected to the vent/
pressure line that will go to the pressure tap on the muffler.
❏2. Write “BOTTOM” on either of the two narrower surfaces
of the tank so you will know which way to install it after
installing the stopper assembly. Insert the stopper so the
vent tube will be at the top of the tank, then tighten the screw
to squish the stopper and seal the tank. Shake the tank to
make sure the fuel lines are not too long and the clunks are
able to flop around. If necessary, remove the stopper and
shorten the lines.
❏3. Glue both plywood fuel tank rings to the back of the
firewall centered on the opening.
FUEL TANK HOLDER
HOOK RUBBER
BANDS HERE
❏4. Install the fuel tank and hold it in place with a couple of
rubber bands hooked around the former where shown in the
sketch. Test-fit, then glue the plywood fuel tank holder into
position at the back of the tank as shown.

18
Hook Up the Throttle
Refer to these photos and sketches while hooking up
the throttle.
GUIDE TUBE SUPPORTS
SCREW-LOCK
PUSHROD
CONNECTOR 4-40 x 1/8" [3.2mm] SHCS
(USE THREADLOCKER)
2-56 PUSHROD
NYLON
RETAINER ❏1. Glue in the plywood throttle servo tray and hook up
the throttle using the 36" [914mm] pushrod cut to length with
a gray, plastic guide tube. Use a clevis on the carburetor end
and a screw-lock connector on the servo end as shown. Use
the plywood guide tube supports to anchor the throttle
guide tube as necessary.
❏2. Once you have the fuel tank mounted and the throttle
hooked up, place the fuselage hatch in the hatch opening in
the bottom of the fuselage. Optional: The back of the fuel
tank hatch and the “retaining lip” in the fuselage for the hatch
have been fuelproofed, but if you would like to completely
seal off the area, cut the hatch seal template from page
35 and use spray adhesive to mount it to the backing on a
sheet of orange or clear MonoKote (not included). Cut out the
MonoKote, then remove the backing and iron the MonoKote
over the hatch for a fuelproof seal.
Mount the Cowl
On models such as the Reactor where portions of the engine
and/or muffler protrude from the cowl, cutting holes for the
engine and muffler can be a “catch-22” situation. You can’t
know exactly where to cut holes for the engine and muffler
until the cowl is mounted, but the cowl can’t be mounted until
these holes are cut. In some cases templates may be used,
but on models where the cutouts are over contoured, parts
of the cowl templates may not work well. So on models like
this, the best way is to “cut and fit” as illustrated:

19
❏1. Take an estimated measurement of where the engine
head will protrude from the cowl. In this case the front of the
cutout will be approximately 4-1/2" [115mm] from the back
of the cowl.
❏2. According to the measurement, mark the location on
the cowl.
❏3. Using a powered rotary tool with a small cutting bit,
make the first cut in the cowl much smaller and slightly
farther aft than you know will be required, but good enough
for a starting point. Try fitting the cowl over the engine and
mark where the cut needs to be enlarged. In the photo, the
cowl isn’t very close to fitting, but it’s a start.
❏4. Continue to fit, mark and cut the cowl as necessary until
you can get it at least partially into position. As you proceed,
try to keep the cutout as small as possible. Later, once the
cowl has been mounted to the fuselage, the cutout will be
trimmed to perfection.
❏5. Once you can get the cowl to fit onto the fuselage over
the engine, set the cowl aside. Use a fine-point felt-tip pen
to draw a line on both sides of the fuselage aligned with the
front of the firewall. Mark two points on both sides of the
fuselage 1/8" [3.2mm] aft of the lines for the cowl mounting
screw holes.

20
❏6. Make four templates with holes from thin cardstock to be
used for marking the screw holes once the cowl is in position.
Tape the templates to the fuselage with the holes in the
templates aligned over the marks made in the previous step.
❏7. Fit the cowl into position.Temporarily fit the spinner onto
the engine so the cowl can be accurately aligned with it.
❏8. Centering the cowl on the spinner with a 1/8" [3.2mm]
space in between, use a fine point felt-tip pen to mark each
screw hole in the template onto the cowl.
❏9. Remove the cowl. Drill 3/32" [2.4mm] holes through the
cowl at each mark.
❏10. Remove the cardstock templates. Reposition the cowl
and spinner. Holding the cowl in position, use the holes in the
cowl as a guide for drilling four 3/32" [2.4mm] holes into the
fuselage for the mounting screws.
❏11. Enlarge the holes in the cowl only with a 1/8" [3.2mm]
drill. Test mount the cowl with four #4 x 1/2" [12.7mm] screws
and #4 washers. Make any adjustments necessary for a
good fit. If necessary, the holes may be slightly elongated or
enlarged to realign the cowl for perfecting the fit.
❏12. Once satisfied with the fit of the cowl, glue the four
thin plywood cowl reinforcements to the inside of the cowl
centered over each hole. Don’t forget to harden the screw
holes in the fuselage with thin CA.