Hobbico Extra 300S Assembly Instructions Manual

Entire Contents © Copyright, 1996

HCAZ3078 V 1.0

™

ASSEMBLY INSTRUCTIONS

Take a moment now to
match the box contents
with the items listed
below. Following the
Extra 300S assembly
instructions will be
quite easy if you
identify and organize
the parts before you
begin. You may also
want to review the
glossary of special
modeling terms that
starts on page 33 of
this manual. Words in
your instructions that
appear in bold italic
type are explained in
this section.

Replacement Parts Available

HCAA3621...Wing Kit HCAA3625 ....Wheel Pants Set

HCAA3622...Fuselage Kit HCAA3626 ....Canopy

HCAA3623...Cowl Set HCAA3627 ....Spinner

HCAA3624...Fin Set HCAA3628 ....Landing Gear Set

2

Landing Gear

Part # Quantity

15 Main landing gear .....................2

5 Tail gear wire.............................1

4 Tail wheel ..................................1

14 Main wheels..............................2

13 Wheel pants..............................4

48 4 x 18mm bolts..........................2

49 3 x 10mm sheet metal screws..2

50 Axles .........................................2

51 3mm nuts ..................................6

Wing Assembly

Part # Quantity

6 Wing fairing..............................................1

7 Right wing panel......................................1

8 Left wing panel.........................................1

28 *Clevises..................................................2

39 Fiberglass tape........................................1

40 4mm washers ..........................................2

41 4 x 35mm bolt..........................................2

42 4mm O-ring..............................................2

43 Plywood front plate..................................1

44 Plywood rear plate...................................1

45 Servo tray supports..................................2

46 Servo tray ................................................1

47 *Aileron control horns ..............................2

51

40

42

43

44

47

46

45

39

49

48
50

You’re about to build in just days what took aviation

pioneers years—a powered machine that flies. Specially
created for you and other experienced radio control
modelers, Hobbico’s Extra 300S offers nearly all the
excitement of piloting a real airplane...and develops skills
that will take you anywhere you want in your hobby.

41

*Parts marked with an asterisk are found on the plastic parts tree.

Know Your Model’s Parts

Tail Assembly

Part # Quantity

1 Stabilizer and elevator...................1

16 Rudder and fin ..............................1

28 *Clevises.......................................5

29 *Control horns...............................2

30 Pushrods.......................................2

31 2mm x 18 mm machine screws....4

48 Elevator splitter plate ....................1

30

28

48

31

29

28

Engine Mounting Parts

Part # Quantity

11 Engine mount ....................................2

32 4 x 18mm bolts..................................4

33 4mm washers....................................4

34 4 x 25mm bolts..................................4

35 4mm lock washers.............................4

36 4mm nuts ...........................................4

37 Pushrod tube.....................................1

38 Pushrod wire......................................1

Fuse Parts

Part # Quantity

2 Canopy ..............................................1

3 Aft tail cover.......................................1

9 Cowl top.............................................1

10 Cowl bottom.......................................1

12 Spinner ..............................................1

17 Servo tray..........................................1

18 Servo tray former...............................1

27 Fuselage............................................1

Fuel Tank & Parts

Part # Quantity

19 Fuel tank ............................................1

20 Rubber tank stopper ..........................1

21 Fuel pick-up weight (clunk)................1

22 Plastic stopper compression disks

(one large and one small)..................2

23 Aluminum fuel tubing

(one short and one long)....................2

24 3 x 18mm screw.................................1

25 Silicone fuel line.................................1

26 Foam tank collar ................................1

3

18

17

23

21

25

24

20

22

38

26

6

7

19

17

18

11

12

9

27

14

14

15

13

16

8

10

1

2

* Engine mounting parts may differ from those shown in the photo.

3

5

4

Nylon
Hardware

35

33

34

Parts shown smaller than actual size (out of proportion).

37

32

36

Getting Ready for Flight

Your Hobbico Extra 300S is ready for takeoff in as little as 20 hours. Your hobby
dealer or flying instructor (see next page) can help you decide what accessories
you’ll need for flight. Most are one-time only purchases—and your instructor will
probably allow you to use his field box until you can outfit your own with a glow
plug starter, fuel pump and “chicken stick" or electric starter. You will need to
provide your own fuel. Use glow fuel with a 10-15% nitro blend to keep your
engine performing at its peak...and your Extra 300S will have the power to make
you an accomplished pilot!

Other Items You’ll Need:

Glues

Choose 6-minute and 30-minute epoxy, such as Great Planes
Pro

TM

Epoxy, which has been formulated especially for R/C
model building. Pro Epoxies offer a strong bond and a variety
of curing times suited for every step of assembly. You’ll also
need a thin instant-setting CA (cyanoacrylate), a thicker CA+,
plus rubbing alcohol for easy epoxy cleanup.

Model Engine

Power your Extra 300S with any high-quality,
.60-size model engine. The O.S. .60 FP, or
SuperTigre S-61K are fine engines for this plane.
Look for features such as easy break-in, easy
starting, efficient carburetion and low maintenance.
Check the manufacturer’s recommendations for
propellers to use with your engine.

Radio Equipment

To let you send the commands that control your Extra
300S’s “flight path,” you’ll need a 4-channel aircraft radio
system with four standard servos. Many 4-channel
radios include just three servos. You may need to
purchase the fourth separately. The servos and radio
receiver will be mounted on-board your model and need
to be cushioned from jolts and vibration. One-half inch
thick foam rubber sheets (HCAQ1050) are available for
this purpose

.

Hardware

Tools and accessories required for
assembly include a hobby knife; small and
large Phillips screwdrivers; needle nose
pliers; drill with 1/16", 1/8", 3/32" 3/16",
5/32" and 17/64" bits; ruler; #64 rubber
bands; 1 foot of medium fuel tubing;
petroleum jelly; and 400-grit sandpaper.

Other General Items Required

Epoxy Brushes (GPMR8062) Mixing Sticks (GPMR8055) Clothespins Foam Rubber (HCAQ1050)
T-Pins (HCAR5150) Masking Tape String Felt-Tip Pen
Sanding Block Adjustable Wrench Paper Towels Builders Triangle Set (HCAR0480)
Plastic Wrap or Wax Paper Round Toothpicks Bondo Filler Wire Cutter
70% Isopropyl Alcohol Small Hobby Clamps Razor Saw Thread Locking Compound

4

T

he best way to begin flying your
Extra 300S is with an experienced
R/C pilot or flying instructor at your
side. You’ll learn faster, and avoid
risking your model before you’re
truly ready to solo.

Where do you find an instructor?
Ask at your local hobby shop.
They’ll have information about
flying clubs in your area whose
membership includes qualified
instructors. You should also join the
Academy of Model Aeronautics

(AMA), a 165,000 member-strong
national organization with more
than 2,300 chartered clubs across
the country. Through any one of
them, instructor training programs
are available. Contact the AMA at
the address or phone number

below:

Academy of Model Aeronautics

5151 East Memorial Drive

Muncie, IN 47302

Office: [phone]

Toll Free: [phone]

Fax: [phone]

Find a Flying Instructor

WARNING! This is not a Toy! Please follow these safety precautions:

90-Day Limited Warranty

If you, as the original owner of this model, discover defects in parts or

workmanship within 90 days of purchase, Hobbico will repair or replace it –

at
the option of our authorized U.S. repair facility, Hobby Services – without
charge. Our liability does not include cost of shipping to us. However, Hobby
Services will pay shipping expenses to return your model to you.

You must provide proof of purchase, such as your original purchase invoice

or receipt, for your model’s warranty to be honored.

This warranty does not apply to damage or defects caused by misuse or
improper assembly, service or shipment. Modifications, alterations or repair
by anyone other than Hobby Services voids this warranty. We are sorry, but
we cannot be responsible for crash damage and/or resulting loss of kits,
engines, accessories, etc.

Repair Service

Your Extra 300S must be returned directly to Hobby Services for warranty
work. The address is:
Hobby Services, Attn: Service Department, 1610 Interstate Drive,
Champaign, IL 61821-1067 Phone: [phone].

Please follow the instructions below when returning your model. This will
help our experienced technicians to repair and return it as quickly
as possible.

1. ALWAYS return your entire system, including airplane and radio.

2. Disconnect the receiver battery switch harness and make sure that the

transmitter is turned off. Disconnect all batteries and drain all fuel.

3. Include a list of all items returned and a THOROUGH, written explanation

of the problem and service needed. If you expect the repair to be covered
under warranty, also include your proof of purchase.

4. Include your full return address and a phone number where you can be

reached during the day.

If your model is past the 90-day warranty period or is excluded from
warranty coverage, you can still receive repair service through Hobby
Services at a nominal cost. Repair charges and postage may be prepaid or
billed COD. Additional postage charges will be applied for non-warranty
returns. All repairs shipped outside the United States must be prepaid in
U.S. funds only.

All pictures, descriptions and specifications found in this instruction manual
and on the product package are subject to change without notice. Hobbico
maintains no responsibility for inadvertent errors.

Before you fly:

1. Make sure that no other fliers are using your radio
frequency.

2.Your radio transmitter must be the FIRST thing you
turn ON, and the LAST thing you turn OFF.

3.Double check all control surfaces.

4. Make sure that the transmitter & receiver batteries
are fully charged.

Fuel storage and care:

1.Do not smoke near your engine or fuel.

2.Store all engine fuel in a safe, cool, dry place, away
from children and pets. Model fuel will evaporate, so
make sure that you always store it with the
cap secure.

When starting and running your engine:

1.Always wear safety glasses.

2.Make certain that your glow plug clip is securely
attached to the glow plug and cannot pop off,
possibly falling into the spinning propeller.

3. Use a “chicken stick” or electric starter to start the
engine – NOT your fingers.

4.Make sure that the wires from your starter and glow
plug clip cannot become tangled with the spinning
propeller.

5. Do not stand at the side of the propeller when you
start or run the engine. Even at idle speed, the
spinning propeller will be nearly invisible.

6. If any engine adjustments are necessary, approach
the engine only from behind the spinning propeller.

5

JOIN THE AMA

6

General Inspection

❏ Remove the fuselage, wing panels, rudder assembly

and stabilizer assembly from their bags. Inspect all
items closely to check for any damage. If any damage
is found, contact the the place your Extra was
purchased, or Hobby Services to obtain replacement for
your damaged items. Also check for any covering that
may have came loose. If any is found, it can be
reattached using Medium CA glue.

Prepare the Wing Panels:

❏ Mark the ailerons using masking tape, then remove

them from the wing panels and set them aside. This
marking process is done to insure the proper ailerons
can be returned to its respective panel when the
ailerons are reattached.

Test Fit the Wing Panels:

❏ The wing panels in the Extra 300S are joined

upside down. The top of the wing must be flat on your

work surface to obtain the proper dihedral angle. Test fit
the panels together to make sure there is no gap
between the panels. If any gap exists, use a flat sanding
block or similar tool to sand the wing roots to achieve
a perfect fit between the panels.

Join the Wing Panels:

❏ After putting down a piece of plastic to protect your

work surface, mix up 3/4 oz.of 30-minute epoxy and
liberally coat the root of each panel. Securely tape the
panels together, making sure that the leading edges of
the wing are lined up with each other. The rear of the
wing can be held in alignment using clamps and mixing
sticks. Clean up any excess epoxy that may remain
using a paper towel and 70% Isopropyl Alcohol. Use
books or some other form of weight to hold the wing
panels flat against the work surface while the epoxy dries.

Flat Building Surface

Bottom of the Wing

Wing Assembly

Prepare the Servo Box Plates:

❏ Locate the 2-3/8" x 1-3/8" x 1/16" plywood front

plate and the 2-3/8" x 1-1/4" x 1/16" plywood rear
plate. Also locate the two 2-1/8" x 7/16" x 1/16" servo
tray supports. Draw a line on both the front and rear

plywood plates, 7/16" from the top. Using Medium CA,
glue the servo tray supports into position.

Note: Before mixing any epoxy, perform a trial run of
this step to make sure that all parts fit securely. The
servo tray in this step will hold the front and rear plates
in position while the epoxy dries.

Construct the Aileron Servo Box:

❏ Coat the entire inside of the servo box using

30-minute epoxy. Install the front and rear plates with
the servo tray supports towards the top of the wing.
Apply a small amount of epoxy to the servo tray
supports and install the aileron servo tray.

Reinforcing the Wing Center Section:

❏ Lightly sand the center section of the wing to

remove any excess epoxy and smooth the center
section for the application of the Fiberglass Cloth.
Starting on the bottom of the wing, cut a piece of the
2-3/4" fiberglass so that it is 1/16" shorter than the chord
of the wing. Mix up 3/4oz. of 30-Minute epoxy. Using an
epoxy brush, apply a coat of epoxy to the wing center
section. Lay the fiberglass cloth down, and gently
squeegee the cloth so the epoxy comes through the
cloth. Use the squeegee to help spread the epoxy over
the cloth. Clean up any excess epoxy that may have
gotten onto the covering of the wing using a paper towel
and 70% Isopropyl Alcohol.

❏ After the epoxy has fully cured, repeat this process

for the top of the wing. Fiberglass the area in front of the
servo box separately from the rearward area. Trim any
fiberglass that may protrude from the wing edges using
a hobby knife.

Attach the Wing Front Former:

❏ Lightly sand the front of the wing to remove any

excess epoxy and to even up the front of the wing.
Attach the wing front former using 30-Minute epoxy.
The wing front former is properly aligned when the top
edge of the former is even with the top edge of the wing.
Use masking tape to hold the former in position until the
epoxy has fully cured.

7

8

Install Wing Alignment Dowels:

❏ Using a 17/64" drill bit, drill two holes into the front of

the wing using the wing front former as a guide. Drill
these holes 1-3/4" deep. Af ter test fitting the dowels into
the holes, glue the wing dowels into place. Make sure
to leave 1/2" of the dowel exposed to fit into the fuselage.

Install Aileron Tray Doublers:

❏ Cut two mixing sticks to fit into the openings of the

servo box as shown. Glue them into position using
Medium

CA.

Install Servo Tray Doublers:

❏ Using Medium CA, glue two mixing sticks to the

servo tray as shown. Do not let the sticks overlap into
the openings for the servo or the sides of the servo tray .

❏ Using Medium CA, install the servo tray and servo

tray former into position. Note that the doublers are on

the underside of the servo tray.

Locate the Wing Bolt Mount:

❏ Locate the three wing bolt plates – they should be

numbered. If the numbering can’t be read, use the
photo to distinguish the differences between the plates
and number them accordingly.

Fuse Assembly

Laminate the Wing Bolt Mounts:

❏ Apply 30-minute epoxy to one side of each the #1

and #3 wing bolt mounts. S tack the mount s in numerical
order – 1, 2, 3. Align the holes in the mounts and use
either clamps or clothespins to hold the mounts together
and in alignment until the epoxy has cured.

Install the Blind Nuts:

❏ Clean up the holes in the wing bolt mounts using a

3/16" drill bit. Install the blind nuts into mount plate #3
by gently tapping them into place using a hammer.
Apply a small amount of Medium CA to the blind nuts to
hold them into position. Be careful not to get any CAinto
the threaded area of the nuts.

Note: Perform the next two steps with the same
batch of epoxy.

Install the Wing Bolt Mount:

❏ Test fit the wing bolt mount into the fuselage, with the

blind nut on the inside of the fuselage. Light sanding

may be required to achieve a snug fit of the mount.
Once a good fit has been achieved, glue it into position
using 30-minute epoxy.

Install the Tail Mounting Block:

❏ With the excess epoxy, glue the tail mounting block

into position at the rear of the fuselage.

Fitting the Wing to the Fuselage:

❏ Clean up the holes for the wing dowels in the

fuselage using a 17/64" drill bit.

Attach the Wing to the Fuselage

9

❏ Test fit the wing into position. The wing may need

slight sanding to fit around the fuselage. If so, remove
only a small amount of material at a time until the wing
fits into position. Make sure to apply a thin coat of Thin
CA to the exposed wood so that fuel won’t damage the
wood over time.

Aligning the Wing:

❏ Place a T-pin in the center of the tail mounting block

at the rear of the fuselage. Tie a piece of string to the
pin. Pull the string to the wing tip and put a piece of
masking tape on the line at the wing tip. Put an arrow on
the tape, then slide the tape so that it points at the tip of
the wing. Swing the line over to the opposite tip and see
if the arrow aligns with the other tip. If not, adjust the
position of the wing in the fuselage. Slide the tape to
indicate the new wing position, and swing the line back

to the opposite tip. Continue this process until the arrow
lines up with each tip. Make a mark from the wing to the
fuselage to indicate the proper alignment.

Prepare the Wing Bolt Plate:

❏ Using the embossed line on the wing bolt plate as a

reference, lightly score the plate. Be careful not to cut
the plate too deep, as the scoring of the plate is simply
to allow it to bend to match the dihedral of the wing.

Install the Wing Bolt Plate:

❏ Lightly sand the fiberglass at the trailing edge of the

wing to make sure that the wing bolt plate will rest on a
flat surface. Draw a line 1/8" from the trailing edge of the
wing. Align the wing bolt plate so the rear edge lines up
on this line. With the wing aligned on the fuselage, align
the wing bolt plate so it is centered between the fuse
sides. Mark the position of the plate and remove the

10

wing. Trim away any covering that may be beneath the
wing bolt plate so that is resting on either wood or
fiberglass. Using 30-minute epoxy, glue the wing bolt
plate into position on the wing. Use clothespins or
masking tape to hold the plate in position until the epoxy
has cured.

Drilling for the Wing Bolts:

❏ Using the holes in the wing bolt plate as a guide, drill

two 3/16" holes through the wing. Make sure that the
drill remains perpendicular to the wing bolt plate in
all directions.

Install the Wing Bolts:

❏ Slide a M4 washer onto a M4 x 35 wing bolt. Pass

the bolt through the hole just drilled from the bottom of
the wing. Place a M4 O-ring onto the bolt so it won’t fall
out of the wing during transport.

Install the Rear Wing Former:

❏ Use one of the empty plastic bags and place it

between the wing and the fuselage at the rear. Position
the rear wing former so there is a 1/16" gap between
the former and fuselage. Glue the former into position
using Medium CA. Using leftover plywood found in the
kit, make two former reinforcements to prevent the
former from moving. Glue these into position on top of
the wing bolt plate using Medium CA.

Rear Wing Former

11

Trimming the Wing Fairing:

❏ Use a hobby knife or polycarbonate scissors to trim

out the wing fairing. Trim only the sides at this time.

Fitting the Wing Fairing:

❏ Align the rear scribe line to the trailing edge of the

wing. Temporarily tape the wing fairing into position.
Turn the wing over and check to make sure that the
wing bolts can be easily accessed through the holes in
the fairing. If not, adjust the position slightly until access
can be made. Mark the positions of the rear wing former
and front wing former. Remove the fairing and trim it
along the lines just drawn. Save the excess plastic for
use in a later step.

Install the Wing Fairing:

❏ Glue the wing fairing into position using Medium CA.

Center the Stabilizer:

❏ Remove the plastic tail piece and cut the tail post

using a razor saw. Carefully mark the centerline of the
stabilizer. Slide the stabilizer into position so that it is
centered in the opening. Use the T-pin and string
alignment technique to properly align the stabilizer in
the fuselage. Mark the stabilizer so that it can be
returned to proper alignment for the following step.

Stabilizer and Vertical Fin Installation

12

Horizontal Stabilizer Alignment:

❏ With the wing bolted on, slide the stabilizer into

position, centering it using the marks made in the
previous step. Check to make sure that the stabilizer is
parallel to the wing. If not, sand the stabilizer opening in
the fuselage. Continue checking and sanding until the
horizontal alignment is correct. Once you are satisfied
with the alignment, mix up some 30-minute epoxy and
glue the stabilizer into position. Clean up any excess
epoxy using a paper towel and 70% isopropyl alcohol.

Install the Vertical Fin:

❏ Test fit the vertical fin into position. Using a builders

triangle, check that the vertical fin is perpendicular to the
stabilizer. If the fin is not perpendicular, lightly sand the
opening in the fuselage until proper alignment of the fin
can be achieved. Use a generous amount of 30-minute
epoxy to make sure that the area in the fuselage where
the fin fits is well coated. Slide the fin into position and
use masking tape to hold the fin while the epoxy cures.

Trim the Aft Fuselage Cover:

❏ Use a hobby knife or polycarbonate scissors to trim

out the aft fuselage cover along the scribed lines. Test
fit the cover into position. Sand a slight radius on the tail
mounting block to allow the aft fuselage cover to fit
tightly against the block. Adjust the fit of the cover so
that is rests in the recessed areas of the fuselage. Once
satisfied with the fit of the cover, glue it in place using
Medium CA.

Installing the Tail Cover:

❏ Test fit the tail cover into position so that is tight

against the bottom of the stabilizer. Mark and trim the
excess material that is below the aft fuselage cover.
Glue the tail cover into position using Medium CA.

13

Prepare the Tail Gear:

❏ Pass the pre-bent tail gear wire through the tail gear

bushing. Measure 3/4" from the end of the wire and

make a 90° bend in the wire so that it passes back over
the lower portion of the tail gear wire.

Mounting the Tail Gear Assembly:

❏ Position the tail gear assembly so that the wire is

tight against the tail cover. Mark the positions for the
screws and drill them using a 1/16" drill bit. Attach the
assembly using three M2.6 x 10 wood screws.

Locate the Elevator Hinges:

❏ Measure and mark the positions for the elevator

hinges as shown in the photo.

Preparing the Elevator for Hinges:

❏ Using a 1/8" drill bit, drill a hole 5/8" deep at the

locations marked. Use a hobby knife to cut a 1/8" deep
slot 1/4" above and below the hole to allow free movement
of the hinge. Test fit the hinges into the elevators.

Mounting Control Surfaces

14

Prepare the Stabilizer for Hinges:

❏ Using the same measurements from the elevators,

mark the positions for the hinges on the stabilizer.
Double check that the positions are correct by holding
the elevator to the stabilizer and matching the hinge
positions. Adjust the positions if necessary. Drill and slot
the stabilizer for the hinges.

Glue the hinges into position:

❏ Test fit the elevators to the stabilizer with the hinges

installed. Move the elevators up and down to make sure
that the elevators move freely without any binding.
Once satisfied with the fit of the hinge, glue it in place
using the following technique: Mix up 1/4 oz. of 30-minute
epoxy. Using a round toothpick, force some epoxy into
the drilled holes in the stabilizer. Apply some epoxy to
one side of the hinges, and position them into the
stabilizer . Apply some more epoxy to the exposed hinge.
Force epoxy into the holes in the elevators using

the
blunt end of a cut-off toothpick and slide the elevators
into position. Push the elevators so that there is a gap
of only 1/32" or less between the elevators and the
stabilizer. Clean up any excess epoxy using a paper
towel and 70% isopropyl alcohol. Allow the epoxy to
cure before continuing onto the next step.

Locate the Rudder Hinges:

❏ Measure and mark the positions for the rudder

hinges as shown in the photo.

Prepare the Rudder:

❏ Using the same method as for the elevators, drill and

slot the rudder for hinges. Do not slot the bottom hole.
Using a hobby knife, cut a groove from the bottom hole
that extends to the bottom of the rudder. Trim the lower
plastic slightly. This is to provide a channel for the tail
gear wire to pass when the rudder is installed.

Installing the Rudder:

❏ Roughen the tail gear wire where it will be inserted

into the rudder with 80-grit sandpaper. Insert a small
piece of plastic cut from an empty parts bag between
the tail gear wire and the tail cover to prevent the
accidental gluing of the wire to the cover. Use the same
technique of gluing the hinges on the elevator to glue
the rudder hinges. Make sure the tail gear wire is
securely glued into the rudder with epoxy.

15

Preparing the Aileron:

❏ Measure in 1-1/4" in from the end of the aileron. Drill

a 5/32" hole that is 1" deep at this location for the aileron
torque rod.

Installing the Ailerons:

❏ Since the holes are pre-drilled for the aileron hinges,

all that is needed is to cut the slots. Roughen the torque
rod using 80-grit sandpaper. Tape some scrap plastic

under the aileron torque rod to prevent gluing the rod
to the wing. Apply some petroleum jelly to the aileron
torque rod and work it up into the aileron torque rod
tube to prevent the epoxy from gluing the torque rod
assembly together. Test fit the aileron into position to
make sure it does not bind against the center of the
wing during operation. Glue the ailerons into position
using the same hinge gluing method.

❏ Now would probably be the best time to fuelproof the

engine and fuel tank comp artments. Use your favorite
method for this process. We recommend using 30-minute
epoxy thinned with isopropyl alcohol, then just brush the
mixture onto the surface you want to fuelproof. Be
careful not to get any epoxy into the blind nuts that are
already installed in the firewall.

Note: If you intend on performing high “G” maneuvers
with your Extra 300S, it is suggested that you create a
fillet of 30-minute epoxy behind the firewall to help
increase the dispersion of loads from the engine to the
fuse sides.

Install the Engine Mount:

❏ Using four M4 x 18 bolts and four M4 washers,

temporarily attach the engine mount to the firewall. Do
not tighten the bolts at this time.

Positioning the Engine:

❏ Position the engine between the engine mounts.

Slide the mounts together to fit against the engine.
Adjust the distance of the drive washer from the firewall
so that it is 4 3/4" away from the firewall.

Mounting the Engine

16

Marking the Engine Mount:

❏ After checking the distance of the drive washer from

the firewall, and that the engine is perpendicular to the
firewall, mark the positions for the engine bolts using a
1/16" drill bit. Remove the engine and mount from the
firewall and drill a hole at the positions marked using a
5/32" drill bit.

Attach the Engine to the Mount:

❏ Using four each of the M4 x 28 bolts, M4 washers,

M4 lock washers and M4 nuts, attach the engine to

the engine mount as shown in the photo. The washers

will be on the top of the engine mounting flange and
the lock washers on the bottom of the engine mount.
Temporarily tighten the bolts at this time.

Install the Engine:

❏ Reattach the engine mount to the firewall. Tighten up

the mount to the firewall, then the engine to the mount.
Note: If you are installing a four-stroke engine, the

throttle pushrod location will have to be changed. This
location will vary depending on the manufacturer of your
particular engine. It would be advisable to relocate the
pushrod at this time.

17

Install the Muffler (Two-Stroke):

❏ Open the access panels in both the firewall and

fuselage bottom if you are planning on using the
standard muffler. Install the muffler as shown, routing
the exhaust through the access holes to the bottom of
the fuselage as shown. You may need to enlarge the
holes depending on your muffler configuration.

Assemble the Fuel Tank Plug:

❏ Push one long and one short aluminum tube

through the rubber stopper (the third aluminum tube
will not be used). Place the two metal disks over the
tubes. The larger disk will go in the front of the stopper,
or to the outside. Insert the M3 x 15 screw from the
front and thread it into the rear disk. Do not tighten the
screw at this time.

Bend the Vent Tube:

❏ Bend the longer tube (pressure tube) up as shown so

that it will come within 1/16" of touching the top of the
tank when installed. Use your fingers to bend the tube,
being careful not to kink it closed.

Install the Clunk:

❏ Locate the clunk (metal fuel pick-up weight) and the

fuel tubing. Att ach the fuel tubing to the aluminum tube

that is not bent. Attach the clunk to the opposite end of
the fuel tubing.

Install the Stopper Assembly:

❏ The stopper assembly can now be inserted into the

fuel tank. The pressure tube should be adjusted so the
tube is pointed straight up, resting 1/16" from the top of
the tank. Position the stopper so that the tubes are
positioned side-to-side. Make sure the clunk can move
freely in the tank. If not, remove the stopper and shorten
the fuel tube slightly and reinstall the stopper. After

Assemble and Install the Fuel Tank

18

making sure the stopper is fully seated and the clunk
moves freely, tighten the screw to secure the stopper
into position. Do not overtighten the screw, as this may
strip the threads or possibly damage the tank or stopper .

Install the Foam Tank Collar:

❏ Locate the foam tank collar and slide it into position.

It should rest against the fuel tank when installed.

Install the Fuel Tank:

❏ Slide the fuel tank into position. Secure its location by

gluing a mixing stick at the rear of the fuel tank as
shown. Make sure to glue the stick low as shown, as a
higher position may interfere with the installation of
the wing.

Attach the Fuel Tubing:

❏ Cut two 8" pieces of 3/32" fuel tubing. Attach these to

the vent and fill tubes on the fuel tank. Attach the other
ends to their proper positions on the engine. (On the
four-stroke, leave the pressure line free for the time
being). Trim the fuel lines if they are too long or have
kinks or sharp bends that may cause fuel flow problems.

Locate the Landing Gear Blind Nuts:

❏ Locate the position of the landing gear blind nuts by

gently

pressing

the covering. They should be located 1"

Install the Landing Gear

19

in front of the wing saddle. Trim the covering using a
hobby knife to expose the blind nuts.

Attach the Landing Gear:

❏ Attach the landing gear to the fuselage using two

M4 x 18 bolts. Use a small amount of thread locking

compound on the bolts to prevent them from vibrating
loose during flight.

Trimming the Wheel Pants:

❏ Using a hobby knife or Polycarbonate scissors, trim

the wheel pants along the scribed lines. Before cutting
the opening for the wheel, you can use a T-bar sander
to even up the cut to provide for a cleaner seam
between the two pant halves.

Joining the Wheel Pant Halves:

❏ Using Medium CA, glue the two wheel pant halves

together. Do not use any accelerator on the wheel
pants, as it will damage the plastic.

Filling your Pants:

❏ Fill the seam on the wheel pants using either

Squadron

®

White Putty or Bondo®. The Bondo will have
a faster cure time and is easily sanded, but must be
purchased in larger quantities. The Squadron White
Putty works well, but requires a longer curing time. It
may also take a few applications, as this filler shrinks as
it dries. You may also want to apply thin coats of the
Squadron White Putty to help in speeding up the cure
time, as thinner coats will dry faster than thicker ones.

Painting the Wheel Pants:

❏ After the filler has cured, sand it down so there is a

smooth, unnoticeable seam using 400-grit sandpaper.
Sand the entire wheel pant using the same sandpaper.
Wash the wheel pant with a mild soap to remove any
dust or oil and mask the wheel pant so it can be painted
to match the box. Use a good fuelproof paint for the
painting process. It is suggested to paint the wheel
pants at the same time as the cowling.

Preparing the Wheel Pants

20

Install the Tail Wheel:

❏ Slide the tail wheel onto the tail wheel wire. Secure

the wheel by using two M2 nuts, locking them together
so they won’t loosen and fall off.

Locating the Axle Position:

❏ Mark the position for the axle on the wheel pant. This

location should be centered with the opening, and 1/4"
from the bottom of the pant. Drill the location with a

5/32" drill bit. Glue the supplied plywood disc slightly
above the hole using Medium CA. Make sure to make
both a right and left wheel pant.

Installing the Axle:

❏ Install the axle, bushing, M3 washer and M3 nut as

shown in the photo. The bushing is on the recessed
side of the wheel. Only thread the nut so it is flush with
the end of the axle as shown.

Install the Wheel into the Pant:

❏ Pull the axle so the bushing is tight against the wheel.

Place the wheel assembly into the wheel pant as shown
in the photo. Slowly turn the axle, pressing the nut
against the inside of the wheel pant. This is done to
tighten the nut. Once you can’t turn the axle, there

Installing the Wheels

21

should be enough of the axle exposed on the outside of
the pant to continue tightening. Do not tighten the nut
too much, as the wheel will need to rotate freely on
the axle.

Temporarily attach the Wheel Pants:

❏ Using one M3 nut, attach the wheel pant assembly to

the landing gear. The nut only needs to be snug at
this time.

Positioning the Wheel Pants:

❏ Position the wheel pants as shown in the photo.

Securing the Wheel Pants:

❏ Drill a 1/16" hole through the open hole in the landing

gear. It should drill into the plywood disc that was glued

in earlier. Harden the plywood using a drop of Thin CA.
Install an M3 x 10 sheet metal screw. Tighten the M3
nut, making sure the wheels rotate freely. Install a
second M3 nut at this time, to “jam” the first nut into
position and to prevent it from loosening.

Trimming the Cowling:

❏ Using a hobby knife or polycarbonate scissors, trim

out the upper and lower cowl halves as shown.
Measure

1/4" inside the raised area for the spinner ring
and trim out the area for the shaft on the engine. Use a
T-bar to even up the edges of the cowl.

Gluing the cowl halves together:

❏ Glue the upper and lower cowl halves together using

Medium CA. Remember not to use any accelerator. Cut
the air openings in the front as shown in the photo.
Make sure to round the corners of the air openings. If
not, the cowl may crack at the corners.

Preparing the Cowling

22

Locating the Engine position:

❏ Use a thin piece of cardboard to make a template for

the cutout in the cowl for the engine. Cut the opening to
match the shape of the head on your particular engine.
Tape the template to the fuselage side to indicate the
position of the head.

Marking the Engine Location on the Cowl:

❏ Place the backplate of your spinner on the engine

and measure the distance between the firewall and the
backplate (it should be 4-3/4"). Remove the engine from
the fuselage, then position the cowl on the fuselage so
the forward edge is 1/8" aft of the measurement you just
made. Use a felt-tip marker to mark the position of the
head onto the cowl surface.

Trimming the Cowl:

❏ Using the mark just made, trim the cowl to fit around

the head of the engine. Use the same template method
to locate the needle valve also. It is best to start small
and enlarge the hole for a proper fit. Test fit the cowl to
check if enough material has been removed. Continue
the test fit/trim process until there is sufficient clearance
between the cowl and engine.

Reinforcing the Cowl:

❏ Reinforce the seam of the cowl using the 12" x 7/8"

fiberglass cloth (included in the kit) and Medium CA.

The fiberglass is best applied by applying the CA, then
using a scrap from one of the parts bag, press the
fiberglass to the cowl. Glue the scrap saved from the
wing fairing to add support to any areas that could flex
excessively. Cut out an opening in the bottom of the
cowling to allow the air to escape from the cowling
during flight.

23

Attach the Cowl to the Fuselage:

❏ Use a card stock template to locate the front

bulkhead

on the fuselage. Position the cowl with the
spinner and propeller installed on the engine. Drill four
positions (2 on each side), as shown in the photo using
a 1/16" drill bit. Remove the cowl and place a drop of
Thin CA into the hole, but don’t fill the hole. This is to
harden the wood so that the screw does not pull out of
the wood.

Painting the Cowl:

❏ Fill all the seams that are on the cowl using the same

method that was used on the wheel wants. Paint the
cowl to match the trim that is on the fuselage. We used
LustreKote

™

Missile Red, Royal Blue and White, as they
are a very good match to the colors on the fuse. Feel
free to use any fuelproof paint you are the most
comfortable using. We painted the wheel pants and
cowl at the same time.

Install the Aileron Servo:

❏ Install the aileron servo as shown. Make sure that the

servo is centered in the servo box.

Install the Aileron Torque Rod Connector:

❏ Locate the aileron torque rod connector on the

parts tree. The correct connectors have a larger hole for
the torque rods to thread into. Thread the connector
onto the torque rod fully until it is slightly below the end
of the torque rod.

Prepare the Aileron Linkages:

❏ Thread a nylon clevis 14 turns onto a 6" threaded

rod. Cut a 1/4" piece of fuel tubing and slide it partially

onto the clevis. Prepare two rod assemblies.

Bending the Aileron Linkages:

❏ Attach the clevises to the aileron torque rod

connectors. Mark the position where the linkage

Install the Radio

24

intersects the aileron servo horn with the aileron
aligned to neutral. Bend the linkage 90° at this point
using pliers.

Connect the linkage to the servo:

❏ Use a nylon pushrod connector to attach the

linkage to the servo. Use a Dremel

®

MultiPro™or wire
cutter to trim the excess linkage above the connector.
Check that the ailerons are even and neutral. Adjust the
clevises to achieve a neutral position for the aileron if
they are not even. Slide the fuel tubing over the clevises
to secure them to the aileron torque rod connector.

Optional Dual Aileron Servos

❏ Another option that can be used is the installation of

two aileron servos. This will provide more authority to
the ailerons if your intention is doing “high stress”
maneuvers. A“Y” connector can be used to do a simple
couple of these servos. For those that have a computer
radio, the servos can be “mixed” to provide other
functions other than that of ailerons. It is up to you as to
the function they will perform. Although not necessary,
the most common use is as flaps. By having both
ailerons “drop” around 1/4", the landing speed of the
Extra can be reduced, lowering the changes of the wing
stalling at the lower speed.

Install the Radio Components:

❏ After installing the rubber grommets and bushings

according to the radio manufacturer’s instructions,
position the servos in the servo tray as shown. Route
the servo leads forward. Mount the switch opposite of
the exhaust. We used the Great Planes Switch/Charge
Jack (GPMM1000) to allow for easy and convenient
checking and charging of the receiver battery. Plug the
servos into the receiver according to the radio
instructions. Wrap the receiver and battery in foam to
prevent any damage from the vibration of the engine. It
is not necessary to secure the battery and receiver at
this time, as they may need to be repositioned during
the balancing of your aircraft. Just remember after
balancing that they are secure in the fuselage.

Prepare the Elevator Splitter:

❏ Using three M2 x 16 screws, one M2 nut and the

nylon splitter plate, assemble the elevator splitter as

shown in the photo.

25

Prepare the Elevator Pushrods:

❏ After sliding a 1/4" piece of fuel tubing onto a clevis,

thread the clevis onto the center screw 14 turns.
Completely thread the white inner pushrods onto the
two outer screws as shown.

Install the Outer Pushrod Tubes:

❏ Roughen the outside of the pushrod tubes using

80-grit sandpaper. Slide the outer pushrod tubes into
the fuselage from the slots that are closest to the
elevator. Leave 2-1/2" of the tube outside of the
fuselage. Secure the tubes to the fuselage using
Medium CA.

Install the Elevator Pushrods:

❏ Slide the pushrod assembly into the outer pushrod

tubes. Attach the clevis to the servo horn and slide the

fuel tubing into position.

Prepare the Elevator Clevises:

❏ Collect two each: clevises, 1-5/8" threaded studs

and 1/4" pieces of fuel tubing. Slide the 1/4" pieces of
fuel tubing onto the clevises. Thread the clevises onto
the threaded studs 14 turns. The clevises attach to the
end of the stud that has fewer threads.

Install the Elevator Clevises:

❏Thread the elevator clevises into the inner pushrods.

Only a few turns are required at this time, as the final
adjusting will take place in a later step.

26

Marking the Position of the Control Horns:

❏ Attach the clevises onto the control horns. Position

the control horn on the elevator so that the pushrod will
operate without any binding. The control horn should
also be aligned with the hinge line of the elevator as
shown in the drawing. Mark the position of the two holes
in the control horn using a felt-tip pen.

Install the Control Horns:

❏ Drill two 1/8" holes through the elevator at the marks.

Insert two M2 x 16 screws through the control horn and

the elevator, finally screwing them into the control horn
backplate. Harden the underlying control surface by
gently puncturing the covering using a T-pin. Use Thin
CAto harden the balsa underneath the covering. T ighten
the screws, being careful not to damage the underlying
balsa. Cut off the excess threads using a wire cutter or a
Dremel MultiPro with a cut-off wheel. Repeat this
process for the other elevator half. Adjust the clevises,
threading them in or out, to level the elevators with the
servo in a centered position. Slide the 1/4" fuel tubing
into position after the elevators are adjusted.

Install the Rudder Pushrod:

❏ Install the rudder pushrod using the same method

as the elevator pushrods. The exit on the fuselage may
need to be opened up slightly to accept the outer tube.
Enlarge it towards the bottom of the elevator to prevent
any interference with the former.

Prepare the Rudder Inner Pushrod:

❏ Cut 1/4" off one end of the inner pushrod. Thread a

“Z” bent wire into the inner pushrod until the threads are
fully into the inner pushrod.

27

Install the Inner Pushrod:

❏ Remove the servo horn from the rudder servo and

place the “Z” bend through a servo horn. Slide the inner
pushrod into the outer pushrod and attach the servo
horn to the rudder servo. Build a small brace from
mixing sticks to secure the outer pushrod tubes for the
elevator and rudder as shown.

Install the Rudder Clevis:

❏ Assemble a rudder clevis assembly using the same

procedure that was used for the elevator clevis. Thread
the clevis into the inner pushrod. Attach a control horn
to the clevis and position it onto the rudder. After making
sure that the rudder linkage will not bind, mark the
position of the control horn on the rudder.

Attach the Rudder Control Horn:

❏ Drill two 1/8" holes through the rudder at the marks.

Harden the underlying balsa with Thin CA, then insert two
M2 x 16 screws through the control horn and the rudder,
finally screwing them into the control horn backplate.

Tighten the screws, being careful not to damage the
underlying balsa. Cut off the excess threads using a wire
cutter or a Dremel MultiPro with a cut-off wheel. Adjust the
clevis, threading it in or out, to neutralize the rudder with
the servo in neutral. Slide the 1/4" fuel tubing into position
after the rudder has been adjusted.

Install the Outer Throttle Tube:

❏ Install the Outer Throttle Tube as shown in the photo.

On a two-stroke, the Outer Throttle Tube should be at
least 1/4" past the firewall.

28

Trimming the Outer Throttle Tube:

❏ Trim the opposite end of the outer tube so it is flush

with the servo tray former. Attach the “Z” bend of the
throttle pushrod to the throttle lever and slide the

pushrod into the outer tube.

Attach the Pushrod to the Servo:

❏ Move the throttle stick and trim lever on the transmitter

into the center, or neutral position. Turn on the transmitter
and receiver. Attach the servo horn so that it is 90° to
the servo (The rudder and elevator servos are shown in
this position). Anotch can be cut in the servo tray former
to assist in securing the outer throttle pushrod. Move
both the throttle stick and trim to the fully open position.
Open the carburetor to fully open by moving the linkage.
Mark the throttle linkage and make a “Z” bend to attach
the linkage to the servo arm. Move the throttle stick and
trim to the fully closed position and check that the
carburetor is fully closed. If not, move the position of the
linkage away from the center of the servo arm, or
towards the center on the carburetor lever. If the servo
is binding (signified by a humming sound) change the
throttle linkage opposite of that mentioned above. After
the carburetor can be operated smoothly from fully open
to fully closed, turn off the receiver and transmitter.

Install the Instrument Panel:

❏ Trim the instrument panel decal from the decal

sheet. Install it as shown in the photo. You will need to
trim the upper portion of the decal flush with the top of
the fuselage.

Attaching the Canopy:

❏ Trim the canopy using polycarbonate scissors or a

hobby knife. Before gluing the canopy would be a good
time to detail the cockpit of your aircraft. A Williams
Brothers 1/6 Scale Pilot (WBRQ2484) would be a great
addition to add realism to your Extra 300S. Glue the
canopy in place using Z-R/C-56 adhesive. Af ter the glue
has dried, apply the gold striping tape.

Special Note: Do not confuse this procedure with
“checking the C.G.” or “balancing the airplane fore
and aft.”

❏ 1. Attach the wing and engine as if the aircraft is

ready to fly.

❏ 2. With the wing level, lift the model by the engine

propeller shaft and the fin post (this may require two
people). Do this several times.

Balance the Airplane Laterally

Install the Canopy

29

❏ 3. If one wing always drops when you lift the model,

it means that side is heavy. Balance the airplane by
gluing weight to the other wing tip. Note: An airplane
that has been laterally balanced will track better in loops
and other maneuvers.

Note: This section is very important and must not be
omitted! A model that is not properly balanced will be
unstable and possibly unflyable.

❏ 1. Accurately mark the balance point on the bottom of

the wing on both sides of the fuselage. The balance point
is located 2-1/8" from the front of the wing fairing to the
back. This is the balance point at which your model
should balance for your first flights. Later, you may wish
to experiment by shifting the balance up to 3/8" forward
or back to change the flying characteristics. Moving the
balance forward may improve the smoothness and
arrow-like tracking, but it may then require more speed
for takeoff and make it more difficult to slow down for
landing. Moving the balance aft makes the model more
agile with a lighter and snappier “feel” and often improves
knife-edge capabilities. In any case, please start at the
location we recommend and do not at any time balance
your model outside the recommended range.

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

the model installed (ready to fly), and an empty fuel
tank, hold the model at the marked balance point with
the stabilizer level.

❏ 3. Lift the model. If the tail drops when you lift, the

model is “tail heavy” and you must add weight* to the
nose. If the nose drops, it is “nose heavy” and you must
add weight* to the tail to balance. Note: Nose weight may
be easily installed by using a Heavy S pinner Hub or gluing
lead weights to the firewall. Tail weight may be added by
using Great Planes (GPMQ4485) “stick-on” lead weights,
and later, if the balance proves to be OK, you can open
the fuse bottom and glue these in permanently.

*If possible, first attempt to balance the model by
changing the position of the receiver battery and
receiver. If you are unable to obtain good balance by
doing so, then it will be necessary to add weight to the
nose or tail to achieve the proper balance point.

❏ 1. Wrap the receiver and battery in 1/2" foam rubber

(Hobbico HCAQ1050) securing the foam with
rubber bands.

❏ 2. Protect both components from fuel leakage by

sealing them in plastic wrap or plastic bags. Seal the
plastic closed with masking tape.

❏ 3. We installed a pushrod tube (not included in the kit)

along the bottom of the fuse, on the inside, as a conduit
for the antenna. The antenna was then inserted and
pushed to the aft end of the fuse.

❏ 4. The receiver and battery may be secured with

additional layers of foam rubber to wedge them in place.

❏ 5. Make sure the control surfaces move in the proper

direction as illustrated in the following sketch:

❏ 6. Adjust your pushrod hookups as necessary to

provide the proper control surface movements as listed.

CARBURETOR WIDE OPEN

NOSE WHEEL TURNS RIGHT

RUDDER MOVES RIGHT

LEFT AILERON MOVES DOWN

RIGHT AILERON MOVES UP

ELEVATOR MOVES UP

4-CHANNEL

TRANSMITTER

(STANDARD MODE 2)

4-CHANNEL RADIO SETUP

TRANSMITTER

4-CHANNEL

TRANSMITTER

4-CHANNEL

TRANSMITTER

4-CHANNEL

Install Receiver, Battery and Antenna

Balance Your Model

30

We recommend the following control surface throws:
Note: Throws are measured at the widest part of the

elevators, rudder, and ailerons.
ELEVATOR: (High Rate) (Low Rate)

5/16" (8mm) up 1/4" (6mm) up
and down and down

RUDDER: right as much left as much

as possible as possible

AILERONS: (High Rate) (Low Rate)

7/16" (11mm) up 5/16" (8mm) up
and down and down

The surface throws and balance for this aircraft have
been extensively tested. We are confident that they
represent the settings at which this model flies best.
Please set up your aircraft to the specifications listed
above. If, after a few flights, you would like to adjust the
throws to suit your tastes, that is fine. Too much throw
can force the plane into a stall or a surprise snap roll, so
remember...“more is not better.”

Charge the batteries

Follow the battery charging procedures in your radio
instruction manual. You should always charge your
transmitter and receiver batteries the night before you
go flying, and at other times as recommended by the
radio manufacturer.

Balance the propeller

Balance your propellers carefully before flying. An
unbalanced prop is the single most significant cause of
damaging vibration. Not only will engine mounting
screws and bolts vibrate out, possibly with disastrous
effect, but vibration will also damage your radio receiver
and battery. Vibration will cause your fuel to foam, which
will, in turn, cause your engine to run rough or quit.

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

Find a safe place to fly

The best place to fly your R/C model is an AMA
(Academy of Model Aeronautics) chartered club field.
Ask your hobby shop dealer if there is such a club in
your area and join. Club fields are set up for R/C flying
and that makes your outing safer and more enjoyable.
The AMA also can tell you the name of a club in your
area. We recommend that you join AMAand a local club
so you can have a safe place to fly and have insurance
to cover you in case of a flying accident. (The AMA
address is listed on page 5 of this instruction book).

If a club and its flying site are not available, you need to
find a large, grassy area at least 6 miles away from any
other R/C radio operation like R/C boats and R/C cars
and away from houses, buildings and streets. A
schoolyard may look inviting but it is too close to people,
power lines and possible radio interference.

Ground check the model

If you are not thoroughly familiar with the operation of
R/C models, ask an experienced modeler to check to
see that you have the radio installed correctly and that
all the control surfaces do what they are supposed to.
The engine operation also must be checked and the
engine “broken-in” on the ground by running the engine
for at least two tanks of fuel. Follow the engine
manufacturer’s recommendations for break-in. Check to
make sure all screws remain tight, that the hinges are
secure and that the prop is on tight.

Range check your radio

Wherever you do fly , you need to check the operation of
the radio before every time you fly. First, make sure no
one else is on your frequency (channel). With the
transmitter antenna collapsed and the receiver and
transmitter on, you should be able to walk at least 100
feet away from the model and still have control. Have
someone help you. Have them stand by your model and
while you work the controls, tell you what the various
control surfaces are doing.

Pre-Flight

Control Surface Throws

31

Repeat this test with the engine running at various
speeds with an assistant holding the model. If the
control surfaces are not always acting correctly, do not
fly! Find and correct the problem first.

Engine safety precautions

Note: 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 flames, as fuel is very flammable. Do not
smoke near the engine or fuel and remember that the
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, as
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 items such as these away from the prop: loose
clothing, shirt sleeves, ties, scarfs, long hair or loose
objects (pencils, screwdrivers) that may fall out of shirt
or jacket pockets into the prop.

Use a “chicken stick” device or electric starter follow the
instructions supplied with the starter or stick. Make certain
the glow plug clip or connector is secure so that it will not
pop off or otherwise get into the spinning propeller.

Make all engine adjustments from behind the rotating
propeller. The engine gets hot! Do not touch it during or
after operation. Make sure fuel lines are in good
condition so fuel will not leak onto a hot engine, causing
a fire.

To stop the engine, cut off the fuel supply by closing off
the fuel line or follow the engine manufacturer’s
recommendations. Do not use hands, fingers or any
body part to try to stop the engine. Do not throw
anything into the prop of a running engine.

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

General

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

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

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

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

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

Radio control

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

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

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

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

The model is a great flying sport scale airplane that flies
smoothly and predictably, yet is highly maneuverable.
Compared to other taildraggers, its flight characteristics

AMA Safety Code (Excerpt)

32

are quite docile and forgiving. It does not, however,
have the self-recovery characteristics of a primary R/C
trainer; therefore, you must either have mastered the
basics of R/C flying or obtained the assistance of a
competent R/C pilot to help you with your first flights.

Takeoff: If you have dual rates on your transmitter, set
the switches to “high rate” for takeoff, especially when
taking off in a crosswind. Although this model has good
low speed characteristics, you should always build up
as much speed as your runway will permit before lifting
off, as this will give you a safety margin in case of a
“flame-out.” When you first advance the throttle and the
tail begins to lift, the plane will start to turn left (a
characteristic of all “tail draggers.”) Be ready for this and
correct by applying sufficient right rudder to hold it
straight down the runway. The left-turning tendency will
go away as soon as the tail is up and the plane picks up
speed. Be sure to allow the tail to come up. Depending
on the surface you are flying from, you will need to
apply very little to no up elevator until flying speed is
obtained. Do not hold the tail on the ground with too
much up elevator, as the model will become airborne
prematurely and will possibly stall. When the plane has
sufficient flying speed, lift off by smoothly applying up
elevator (do not “jerk” it off to a steep climb!) Then climb
out gradually.

Flying: We recommend that you take it easy with your
model for the first several flights, gradually “getting
acquainted” with this realistic plane as your engine gets
fully broken-in. Add and practice one maneuver at a
time, learning how she behaves in each. For ultra­smooth flying and normal maneuvers, we recommend
using the “low rate” settings as listed on page 31. “High
rate” elevator may be required for crisp snap rolls and
spins. “High rate” rudder is best for knife edge. Speed is
the key to good knife-edge performance.

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

If, while flying, you notice any unusual sounds, such as
a low-pitched “buzz,” this may be an indication of
control surface “flutter.” Because flutter can quickly
destroy components of your airplane, any time you
detect flutter you must immediately cut the throttle and
land the airplane! Check all servo grommets for
deterioration (this will indicate which surface fluttered)
and make sure all pushrod linkages are slop-free. If it
fluttered once, it probably will flutter again under similar
circumstances unless you can eliminate the slop or
flexing in the linkages. Here are some things which can
result in flutter: excessive hinge gap; not mounting
control horns solidly; sloppy fit of clevis pin in horn;
elasticity present in flexible plastic pushrods; side-play
of pushrod in guide tube caused by tight bends; sloppy

fit of Z-bend in servo arm; insufficient glue used when
gluing in the elevator joiner wire or aileron torque rod;
excessive flexing of aileron, caused by using too soft
balsa aileron; excessive “play” or “backlash” in servo
gears and insecure servo mounting.

Landing: When it’s time to land, fly a normal landing
pattern and approach. The model will probably bleed off
airspeed more rapidly than the sport planes you are
used to. For this reason, keep a few clicks of power on
until you are over the runway threshold. For your first
landings, plan to land slightly faster than stall speed and
on the main wheels, as this is the easiest way to land
your model. Later, with a little technique, you will find
you can make slow, 3-point landings.

Ailerons – Hinged control surfaces located on the
trailing edge of the wing, one on each side, which
provide control of the airplane about the roll axis. The
control direction is often confusing to first time
modelers. For a right roll or turn, the right hand aileron
is moved upward and the left hand aileron downward
and vice versa for a left roll or turn.

Canard – A unique type of airplane, in which the wing
is located near the back of the fuselage and the
horizontal stabilizer is located at the nose of
the fuselage.

Carburetor – The part of the engine which controls the
speed or throttle setting and lean/rich mixture via setting
of the needle valve.

Charge Jack – The plug receptical of the switch
harness which the charger is plugged into to charge the

airborne battery. An expanded scale voltmeter (ESV)
can also be plugged into it to monitor battery voltage
during a flying session. It is advisable to mount the
charge jack in an accessible area of the fuselage so an
ESV can be used without removing the wing.

Charger – Device used to recharge batteries and is
usually supplied with the radio if NiCd batteries
are included.

Chicken Stick – A hand held stick used to flip start a
model airplane engine.

Glossary of Terms

33

Words show in italics are defined elsewhere in this glossary.

Clunk – A weighted fuel pick up used in a fuel tank to
assure the intake line is always in fuel.

Clevis – Asmall clip which is threaded or soldered onto
the wire end of a pushrod and connects the pushrod to
the control horn of a control surface. The threads allow
fine adjustment of length of the pushrod.

Computer Radio – A radio control unit in which the
transmitter has several advanced functions which can
be programmed completely to fine tune an airplane
without making mechanical changes.

Control Horn – The arm which is attached to a control
surface at the hingeline and is connected to a pushrod.

Dead Stick – A term used to describe unpowered flight
(glide) when the engine quits running.

Delta Wing – An airplane with a triangle shaped wing.
Delta wings have no horizontal stabilizer.

Dihedral – The V shaped bend in the wing. Typically
more dihedral causes more aerodynamic stability in an
airplane, and causes the rudder to control both the roll

and yaw axis. This is why some trainers and
sailplanes require only 3-channels of radio control—i.e.,
having no ailerons.

Electric Starter – A hand held, electric motor used for
starting a model airplane engine.

Elevator – Hinged control surface located at the trailing
edge of the horizontal stabilizer, which provides control
of the airplane about the pitch axis and causes the
airplane to climb or dive. The correct direction of control
is to pull the transmitter elevator control stick back,
toward the bottom of the transmitter, to move the
elevator upward, which causes the airplane to climb
and vice versa to dive.

Elevon – Control surfaces used on a flying wing or
Delta Wing type airplanes, located at the trailing edge
of the wing like ailerons. Elevons move both up or down
together to control the pitch axis like an elevator, and
move differentially to control the roll axis like ailerons.
Elevons require either a mechanical or electronic
channel mixer.

Engine – The source of thrust of an airplane.
Expanded Scale Voltmeter (ESV) – Device used to

read the battery voltage of the on board battery pack or
transmitter battery pack.

Flaps – Hinged control surface located at the trailing
edge of the wing inboard of the ailerons. The flaps are
lowered to produce more aerodynamic lift from the
wing, allowing a slower takeoff and landing speed.
Maneuvering flaps move up and down in conjunction
with the elevator, and enhance the pitch control of the
airplane. This is used on some aerobatic type of
models, and requires a mechanical or electronics
channel mixer. Note: Flaps and Maneuvering Flaps are
advanced features and are not necessary or
recommended on trainer aircraft.

Flaperon – Control Surfaces on a standard type
airplane, located at the trailing edge of the wing, which
function as ailerons by moving differentially, and as
flaps by moving up or down together. Flaperons require
either a mechanical or electronic channel mixer. Note:
Flaperons are an advanced feature and are not
recommended on trainer aircraft.

Flight Box – A special box used to hold and transport
all equipment used at the flying field.

Flight Pack – or Airborne pack. All of the radio
equipment installed in the airplane, – i.e., Receiver,

Servos, Battery and Switch Harness.
Foam Rubber – A soft foam material used to wrap the

receiver and airborne battery for vibration dampening
in the airplane.

Fuel Over Flow Line (Vent) – The fuel line which is
either open to atmospheric pressure or attaches to the
muffler pressure nipple, to pressurize the fuel tank for
better fuel flow to the engine. This is the line through
which the fuel will overflow when the tank is full.

Fuel Pick Up Line – The fuel line in the fuel tank
through which the fuel travels to the carburetor.
Typically a flexible tube with a weight or “Clunk” on the
end which allows it to follow the fuel with changes in
aircraft altitude. This is the line through which the tank
is filled.

Fuel Tank – The container which holds the fuel in
an airplane.

Fuselage – The body of an airplane
Fun Fly Airplane – A specialty model designed to be

very lightweight and perform very tight, rapid,
maneuvers such as loops and rolls.

Glow Plug Clip/Battery – A 1.2 volt battery, which is
connected to the glow plug on a model airplane engine

34

Words show in italics are defined elsewhere in this glossary.

for starting. The battery is removed once the engine is
running steadily.

High Wing – An airplane with the wing mounted on top
of the fuselage.

Hinge – Aflexible or hinged blade which is glued into a
control surface and trailing edge to allow control surface
deflection or movement. Note: It is extremely important
that all hinges are permanently glued into both the
control surface and trailing edge. Improper gluing will
cause a crash.

Horizontal Stabilizer – The horizontal tail surface at
the back of the fuselage which provides aerodynamic
pitch stability and control to the airplane.

Low Wing – An airplane with the wing mounted on the
bottom of the fuselage.

Main Landing Gear – The landing gear and wheels
which are usually on the bottom of the fuselage under
the wing on a high wing airplane, or on the bottom of the
wing on a low wing airplane.

Mid Wing – An airplane with the wing mounted in the
center of the fuselage, between the top and bottom.

Muffler – A device attached to the exhaust stack of the
engine to reduce noise, and increase back pressure
which helps low speed performance. Note: Most R/C
Clubs require the use of mufflers.

Needle Valve – Adjustment on a carburetor used to set
proper fuel mixture. Some carburetors have separate
needle adjustments for low and high throttle. Typically
turning the needle clockwise (screwing in) leans the mixture
and vice versa. However, there are a few exceptions. Refer
to the engine manufacturer’s instructions.

NiCd – Nickel Cadmium battery. Rechargeable
batteries which are typically used as power for radio
control transmitters and receivers.

Nitro – NitroMethane, a fuel additive which increases a
model airplanes’ ability to idle low and improves high
speed performance. Ideal nitro content varies from
engine to engine. Refer to the engine manufacturer’s
instructions for best results. Nitro content in fuel is
indicated by the Nitro percent of the fuel.

Nose Gear – The landing gear at the nose of the
airplane if the airplane is a Tricycle landing gear type.

Typically connected to the rudder servo for steering
while on the ground.

Pattern Airplane – A model airplane designed to
perform precision aerobatics.

Pitch Axis – The airplane axis controlled by the
elevator. Pitch is illustrated by holding the airplane at
each wingtip. Raising or lowering the nose is the pitch
movement. This is how the climb or dive is controlled.

Pushrod – A rigid piece of wood, fiberglass, nylon or
steel used to transfer movement from a servo to a
control surface or throttle.

Pylon Racing Airplane – A model airplane designed
for racing. They are flown around a set course of
three (3) “Pylons.”

Receiver (Rx) – The radio unit in the airplane which
receives the transmitter signal and relays the control to
the servos. This is somewhat similar to the radio you may
have in your family automobile, except the radio in the
airplane perceives commands from the transmitter and the
radio in your car perceives music from the radio station.

Roll Axis – The airplane axis controlled by the
ailerons. Roll is illustrated by holding the airplane by
the nose and tail. Dropping either wingtip is the roll
movement. This is used to bank or turn the airplane.

Rudder – Hinged control surface located at the trailing
edge of the vertical stabilizer, which provides control
of the airplane about the Yaw Axis and causes the
airplane to Yaw left or right. Left rudder movement
causes the airplane to Yaw left and right rudder
movement causes it to Yaw right.

Sailplane – An airplane which flies without an engine.
Sailplanes are designed to ride on warm, rising air
currents, called thermals. Sailplanes are launched by
several methods; a giant sling shot called a high start, a
winch which pulls the sailplane up like a kite, or with the
assistance of a small engine or electric motor.

Servo – The electronic/ mechanical device which
moves the control surfaces or throttle of the airplane
according to commands from the receiver. The radio
device which does the physical work inside the airplane.

Servo Output Arm – The removable arm or wheel
which bolts to the output shaft of a servo and connects
to the pushrod.

35

Words show in italics are defined elsewhere in this glossary.

Spinner – The nose cone which covers the hub of
the propeller.

Sport Airplane – A model which possesses some
attributes of many of the specialty airplanes and are
best for general flying as they are the most versatile
and durable.

Switch Harness – The on/off switch for the flight pack
which is mounted in an accessible location on
the fuselage.

Tachometer – An optical sensor designed specifically
to count light impulses through a turning propeller and
read out the engine RPM.

Tail Wheel – The wheel at the tail of the airplane
on standard landing gear or tail dragger type
airplanes. Steering is typically coupled to the rudder for
ground handling.

Threaded Horns – Small nylon horns which thread
onto the threaded portion of the aileron torque rods
and connect to the clevis of the aileron pushrods.

Torque Rods – Rigid bent wire rods inserted into
ailerons, running along the wing trailing edge and
bent down to connect to the aileron servo pushrods.

Trainer Airplane – A model designed to be inherently
stable and fly at low speeds, to give first time modelers
time to think and react as they learn to fly.

Transmitter (Tx) – The hand held radio controller.This
is the unit that sends out the commands that you input.

Transmitter Modes –
Mode I. Left hand stick controls elevator and rudder.

Right hand stick controls throttle and aileron.
Mode II. Left hand stick controls throttle and rudder.

Right hand stick controls elevator and aileron. Mode II
is by far the most popular in the United States.

Mode III. Left hand stick controls throttle and aileron.
Right hand stick controls elevator and rudder.

Single Stick. Aspecial transmitter with only one stick.
Elevator and Aileron are controlled with the stick.
Rudder is controlled by twisting the end of the stick.

Throttle is controlled by a lever on the top or side of the
transmitter. Note: Single stick equipment is no longer
being produced by most of the radio manufacturers.

V-Tail – An airplane which has two tail surfaces in the
shape of a V, in lieu of a vertical stabilizer and
horizontal stabilizer. The control surfaces on a V-tail
are called ruddevators and function both in the same
direction as an elevator and in opposite directions as
a rudder.

Vertical Stabilizer – The non-moving surface that is
perpendicular to the horizontal stabilizer and provides
lateral stability. This is the surface the rudder attaches to.

Wheel Collar – Asmall, round retaining device used to
keep wheels from sliding off an axle.

Wing - The main lifting surface of an airplane.
Yaw Axis – The airplane axis controlled by the rudder.

Y aw is illustrated by hanging the airplane level by a wire
located at the center of gravity. Left or right movement
of the nose is the Yaw movement. Many aircraft are not
equipped with ailerons and the roll and Yaw axis are
controlled by the rudder. This is due to the larger
amount of dihedral in the wing. This is why most
trainer aircraft have a larger amount of dihedral.

Z Bend – A simple Z shaped bend in the wire end of a

pushrod which is used to attach the pushrod to a servo
output arm.

Z Bend Pliers – An inexpensive plier type tool used for
easily making perfect Z bends.

36

Printed in the USA 3005117Words show in italics are defined elsewhere in this glossary.