Black Horse Model Pitts BH85-A User manual

Instruction Manual book
Made in Vietnam.
Item code: BH85-A.
95% ALMOST READY TO FLY
ALL BALSA - PLY WOOD CONSTRUCTION.
COVERED WITH ORACOVER.
 Wingspan: 1,500mm 59.06 in).
 Length: 1,330mm (52.36 in).
 Weight: 4.7kg (10.34 lbs).
 Wing area: 74dm2.
 Wing loading: 64 g/dm2.
 Wing type: Naca Airfoil.
 Gear type: Aluminium Hi-grade for
main gear and spring wire for tail gear
(included).
Parts listing required (not included).
 Radio: 06 channels.
SPECIFICATION
PITTS
 Servo: 07 servos.
 Servo mount: 42mm x 21mm.
 Engine: 120 - 2 stroke; O.S.GT 22cc Gas.
 Motor: Brushless outrunner 1800-2300W, 450KV.
 Propeller: Suit with your engine.
Recommended motor and battery set up (not included):
 Motor: RIMFIRE.120.
 Lipo cell: 6 cells 4,000-5,000mAh.
 ESC: 80A.
 Receiver battery: 4.8-6V/ 1200-2000mAh NiMH.
New improvement.

PITTS Item code: BH85-A Instruction Manual
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Some more parts.
HARDWARE PACK
COWLING.
Landing gear.....
This instruction manual is designed to help you build a great ying aeroplane. Please read this manual thoroughly
before starting assembly of your PITTS. Use the parts listing below to identify all parts.
Please trial fit all the parts. Make sure you have
the correct parts and that they t and are aligned
properly before gluing! This will assure proper
assembly. PITTS ARF is hand made from natural materi-
als,everyplaneisuniqueandminoradjustmentsmayhave
to be made. However, you should nd the t superior and
assembly simple.
The painted and plastic parts used in this kit are fuel
proof. However, they are not tolerant of many harsh
chemicals including the following: paint thinner, C/A
glue accelerator, C/A glue debonder and acetone. Do
not let these chemicals come in contact with the colors
on the covering and the plastic parts.
FUSELAGE ASSEMBLY
(1) Fuselage.
WING ASSEMBLY
(1) Right wing half with pre-installed aileron.
(1) Left wing half with pre-installed aileron.
TAIL SECTION ASSEMBLY
(1) Vertical stabilizer with pre-installed rud-
der.
(1) Horizontal stabilizer with pre-installed
elevator halves.
To avoid scratching your new airplane, do not
unwrap the pieces until they are needed for
assembly. Cover your workbench with an old towel or
brown paper, both to protect the aircraft and to protect
the table. Keep a couple of jars or bowls handy to hold
the small parts after you open the bag.
SUGGESTION
NOTE
Please be aware that this aeroplane is not a toy and if assembled or used incorrectly it is capable of causing
injury to people or property. WHEN YOU FLY THIS AEROPLANE YOU ASSUME ALL RISK & RESPONSIBILITY.
If you are inexperienced with basic R/C ight we strongly recommend you contact your R/C supplier and join your
local R/C Model Flying Club. R/C Model Flying Clubs offer a variety of training procedures designed to help the new
pilot on his way to successful R/C ight. They will also be able to advise on any insurance and safety regulations
that may apply.
WARNING
Thick cyanoacrylate glue.
30 minute epoxy.
5 minute epoxy.
Hand or electric drill.
Assorted drill bits.
Modelling knife.
Straight edge ruler.
2mm ball driver.
Phillips head screwdriver.
220 grit sandpaper.
90° square or builder’s triangle.
Wire cutters.
Masking tape & T-pins.
Thread-lock.
Paper towels.
TOOLS & SUPPLIES NEEDED
PARTS LISTING

PITTS Item code: BH85-A Instruction Manual
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This model is highly pre-fabricated and can be built in
a very short time. However, the work which you have to
carry out is important and must be done carefully. The
model will only be strong and y well if you complete
your tasks competently - so please work slowly and
accurately.
When self-tapping screws have to be screwed into
wood, apply a little white glue to prevent them
shaking loose: just squirt white glue into the hole
and t the screw.
Caution: This model is not a toy!
If you are a beginner to this type of powered model,
please ask an experienced model yer for help and
support. If you attempt to operate the model without
knowing what you are doing you could easily injure
yourself or somebody else. Please keep your safety
and well-being in mind at all times.
Important: Before you start construction
Even if you have built a large number of RC models
please read right through these instructions and check
all the kit components against the parts list. We have
taken great trouble to keep construction as simple as
possible, without making any compromises in the area
of safety.
Note regarding the lm covering
Minor creases or bubbles may develop in the lm
covering due to major uctuations in weather conditions
(temperature, humidity etc.); in rare cases you may
even nd a slight warp in a component. These minor
faults are in the nature of lm-covered built-up wooden
structures, and can easily be corrected using a heat
gun, as commonly used for modelling.
Creases: Blow warm air over the area and rub
down with a soft cloth.
Wing wrap: Hold the panel twisted gently in
the opposite direction to the wrap,and
apply warm air to remove the creases
from the covering.
Caution! do not heat the lm more than is absolutely
necessary. If the air or the iron is too hot, the lm may
melt and holes may be formed.
+ This is not a toy.
+ Be sure that no other yers are using your radio
frequency.
+ Do not smoke near fuel.
+ Store fuel in a cool, dry place, away from children
and pets.
+ Wear safety glasses.
+The glow plug clip must be securely attached to the
glow plug.
+ Do not ip the propeller with your ngers.
+ Keep loose clothing and wires away from the propel-
ler.
+ Do not start the engine if people are near. Do not
stand in line with the side of the propeller.
+ Make engine adjustments from behind the propeller
only. Do not reach around the spinning propeller.
SAFETY PRECAUTION
REPLACEMENT LARGE PARTS
A: Cowling.
B: Wing panel (B1, B2, B3, B4).
C: Fuselage - Vertical stab set.
D: Horizontal stabilizer.
E: Rudder.
F. Aluminium wing dihedral brace.
G: Decal sheet.
K: Pilot.
B1
B2
B3
B4
A
G
F
D
C
K
E

PITTS Item code: BH85-A Instruction Manual
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 1) Install the rubber grommets and brass
eyelets on to the aileron servos.
 2) Using a modeling knife, remove the
covering from over the pre-cut servo arm exit hole on
the aileron servo tray / hatch. This hole will allow the
servo arm to pass through when installing the aileron
pushrods.
2. INSTALLING THE AILERON SERVOS
Assemble then apply drops of thin
C/A to center of hinge,on both sides.
Temporary pin to
keep hinge centered.
1. INSTALLING THE AILERONS
I. AILERON
Test t the ailerons to the wing with the hinges. If the
hinges don’t remain centered, stick a pin through the
middle of the hinge to hold it in position.
Servo tray
Remove the covering
REPLACEMENT SMALL PARTS
Aileron
Aileron
Bottom side.
Bottom side.
1. Plastic - engine mount.
2. Wheels.
3. Wheel pants (left & right).
4. Aluminium landing gear.
5. Wing strut.
7. Tail gear set.
8. Fuel Tank
9. Spinner.
2x10mm
3x12mm
8
3 x 15mm
7
91
4x30mm
4x20mm 5x45mm
4
3
4x70mm
4x30mm
22
3x10mm
3x25mm
5
5a
5b
5c

PITTS Item code: BH85-A Instruction Manual
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3) Using the thread as a guide and using mask-
ing tape, tape the servo lead to the end of the thread:
carefully pull the thread out. When you have pulled the
servo lead out, remove the masking tape and the servo
lead from the thread.
Drill a hole
1.5mm
Secure
Electric wire
 4) Place the servo into the servo tray. Center
the servo within the tray and drill 2.5mm pilot holes
through the block of wood for each of the four mount-
ing screws provided with the servo.
Electric wire
Drill a hole
1.5mm
2x10mm
Secure
 5) Repeat the procedure to install the aileron
servos in the other wing half.
3. INSTALLING THE AILERON CONTROL HORN
 1) Remove the covering from the slot on the bot-
tom of the aileron.
 2) Insert the control horn into the slot and secure
it by A+B Epoxy glue.
1. A+B Epoxy glue
2. Push in
Aileron
control horn
4. INSTALLING THE AILERON LINKAGES
 3) Repeat the procedure to install the
control horn on the other aileron.
Installing the aileron linkages as pictures below.
100mm
Snap keeper.
M2 lock nut
Bend
Silicone tube

PITTS Item code: BH85-A Instruction Manual
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Repeat the procedure to install the other aileron
linkages in the other wing half.
After both linkages are completed. connect both of
the aileron servo loads using a Y-harness you have
purchased.
Using pliers, carefully make a 90 degree bend down at
the mark made. Cut off the excess wire, leaving about
6mm beyond the blend.
Flaslink
Pushrod wire Control horn
Repeat the procedure to install the opposite wing
half.
See pictures below:
See pictures below:
II. INSTALLING THE ENGINE MOUNT
OPTION 1: ELECTRIC MOTOR
There are two options:
1. Electric motor
2. Engine mount.
Drill a hole
5.2mm diameter
Cut.
4x70mm
4x30mm
Insert the 90 degree bend down through the hole in the
control horn. Install one nylon snap keeper over the
wire to secure it to the control horn. Install the control
horn retaining screw and remove the masking tape
from the aileron.

PITTS Item code: BH85-A Instruction Manual
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Locate the long piece of wire used for the throttle push-
rod. One end of the wire has been pre-bend in to a “Z”
bend at the factory. This “Z” bend should be inserted
into the throttle arm of the engine when the engine is
tted onto the engine mount. Fit the engine to the engine
mount using the screws provided.
OPTION 2: ENGINE MOUNT
4x30mm
1. INSTALLING THE STOPPER ASSEMBLY
1) The stopper has been pre-assembled at the
factory.
2) Using a modeling knife, cut one length of silicon
fuel line (the length of silicon fuel line is calculated by
how the weighted clunk should rest about 8mm away
from the rear of the tank and move freely inside the
tank). Connect one end of the line to the weighted
clunk and the other end to the nylon pick up tube in
the stopper.
3) Carefully bend the second nylon tube up at a 45
degree angle (using a cigarette lighter). This tube will
be the vent tube to the mufer.
4) Carefully bend the third nylon tube down at a 45
degree angle (using a cigarette lighter). This tube will
be vent tube to the fueling valve.
When the stopper assembly is installed in the tank, the
top of the vent tube should rest just below the top sur-
face of the tank. It should not touch the top of the tank.
III. FUEL TANK
To carburetor
fuel inlet
Atter conrming the direction
(see front view of fuel tank). Insert and tighten the screw.
Be sure to equip
air vent pipe.
Tubing for
re-fuelling
Not included.
Tygon tubing (Gas). And
silicone tubing (Methanol).
5mm
Throttle pushrod

PITTS Item code: BH85-A Instruction Manual
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5) Test t the stopper assembly into the tank. It may
be necessary to remove some of the ashing around
the tank opening using a modeling knife. If ashing is
present, make sure none of it falls into the tank.
6) When satised with the alignment of the stopper
assembly tighten the 3mm x 20mm machine screw until
the rubber stopper expands and seals the tank opening.
Do not over tighten the assembly as this could cause
the tank to split.
7) Using a modeling knife, cut 3 lengths of fuel line
150mm long. Connect 2 lines to the 2 vent tubes and 1
line to the fuel pickup tube in the stopper.
8) Feed three lines through the fuel tank
compartment and through the pre-drilled hole in the
rewall. Pull the lines out from behind the engine, while
guiding the fuel tank into place. Push the fuel tank as
far forward as possible, the front of the tank should just
about touch the back of the rewall.
Blow through one of the lines to ensure the fuel lines
have not become kinked inside the fuel tank compart-
ment. Air should ow through easily.
9) To secure the fuel tank in place, apply a bead of
silicon sealer to the forward area of the tank, where it
exits the fuselage behind the engine mounting box and
to the rear of the tank at the forward bulkhead.
Do not secure the tank into place permanently until after
balancing the airplane. You may need to remove the
tank to mount the battery in the fuel tank compartment.
Pushrod wire
Install one adjustable metal connector through the third
hole out from the center of one servo arm, enlarge the
hole in the servo arm using a 2mm drill bit to accommo-
date the servo connector. Remove the excess material
from the arm.
After installing the adjustable metal connector apply
a small drop of thin C/A to the bottom nut. This will
prevent the connector from loosening during ight.
2. INSTALLING THE THROTTLE PUSHROD
IV. COWLING
1) Slide the berglass cowl over the engine and
line up the back edge of the cowl with the marks you
made on the fuselage.
2) While keeping the back edge of the cowl ush
with the marks, align the front of the cowl with the
crankshaft of the engine. The front of the cowl should
be positioned so the crankshaft is in nearly the middle
of the cowl opening. Hold the cowl rmly in place using
pieces of masking tape.
Fuel tank
Tie wrap
Cut
Throttle pushrod
Throttle servo
Secure
Connector
Servo arm
Cowl area cutout
for mufer
Cowl area cutout
for engine head.

PITTS Item code: BH85-A Instruction Manual
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5) Drill four 2.5mm pilot holes through both the
cowl and the side edges of the rewall.
Using a 3mm drill bit, enlarge the four holes in the
cowling.
1) Elevator install as same as the way of aileron.
Please see pictures below.
V. INSTALLING HORIZONTAL
STABILIZER
2) Using a modeling knife, cut away the cov-
ering from the fuselage for the stabilizer and
remove it.
3) Draw a center line onto the horizontal stabilizer.
Then put the horizontal into the fuselage.
4) Check the t of the horizontal stabilizer in its
slot. Make sure the horizontal stabilizer is square and
centered to the fuselage by taking measurements, but
don’t glue anything yet.
B B
A A
3) Slide the cowl back over the engine and secure
it in place using four wood screws. See picture below.
4) Install the mufer and mufer extension onto
the engine and make the cutout in the cowl for mufer
clearance. Connect the fuel and pressure lines to the
carburetor, mufer and fuel ller valve.
Drill a hole
2.5mm
3x12mm Secure
5) With the horizontal stabilizer correctly aligned,
mark the shape of the fuselage on the top and bottom
of the tail plane using a water soluble / non permanent
felt-tip pen.
Check to mark sure the wing and stabilizer are
paralell. If they are not, lightly sand the opening
in the fuselage for the stabilizer until the stabilizer
is paralell to the wing, but don’t glue anything yet.
A A
A = A
Push in
Top side
Mark line

PITTS Item code: BH85-A Instruction Manual
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6) When you are sure that everything is aligned
correctly, mix up a generous amount of 30 minute
epoxy. Apply a thin layer to the top and bottom of the
stabilizer mounting area and to the stabilizer mounting
platform sides in the fuselage. Slide the stabilizer in
place and re-align. Double check all of your measure-
ments one more time before the epoxy cures. Remove
any excess epoxy using a paper towel and rubbing
alcohol and hold the stabilizer in place with T-pins or
masking tape.
5) Remove the stabilizer. Using the lines you just
drew as a guide, carefully remove the covering from
between them using a modeling knife.
When cutting through the covering to remove it, cut
with only enough pressure to only cut through the
covering it’s self. Cutting into the balsa structure may
weaken it. This could lead to possible failure during
ight.
Remove
the covering.
Bottom side.
Bottom side.
control horn
1. A+B Epoxy glue
2. Push in
Elevator control horn
Drill a hole
1.5 mm
ELEVATOR CONTROL HORN
INSTALLATION
Elevator control horn install as same as the way of
aileron control horn. Please see pictures below.
After the epoxy has fully cured, remove the mask-
ing tape or T-pins used to hold the stabilizer in place
and carefully inspect the glue joints. Use more epoxy
to ll in any gaps that may exits that were not lled
previously and clean up the excess using a paper tow-
el and rubbing alcohol.
Bottom side.
Mark line.
Top side
A/B Epoxy glue
Bottom side.
A/B Epoxy glue
Remove
the covering.
Top side.

PITTS Item code: BH85-A Instruction Manual
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Repeat the procedure to install the elevator pushrod
on the opposite elevator.
ELEVATOR SERVO INSTALLATION
1) Install the rubber grommets and brass
collets into the elevator servo. Test t the servo into
the servo tray.
2) Mount the servo to the tray using the
mounting screws provided with your radio system.
Bottom side
M2 Lock nut
M2
Elevator pushrod
Bottom side.
Elevator pushrod
Bend 90 degree
Top side
C/A glue.
Bottom side.
C/A glue.
Elevator servo
Secure.
Cut.
Flaslink
Pushrod wire servo arm
Secure.
Snap keeper
Using pliers, carefully make a 90 degree bend down at
the mark made. Cut off the excess wire, leaving about
6mm beyond the blend.
Insert the 90 degree bend down through the hole in the
servo arm. Install one nylon snap keeper over the wire
to secure it to the arm. Install the servo arm retaining
screw.
Elevator pushrod
M2 Lock nut
M2

PITTS Item code: BH85-A Instruction Manual
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VI. RUDDER INSTALLATION
Rudder install as same as the way of aileron. Please
see pictures below.
PARTS REQUIRED
VII. MAIN GEAR INSTALATION
4x20mm 5x45mm
1. RUDDER CONTROL HORN INSTALLATION
2. RUDDER PUSHROD INSTALLATION
Rudder pushrod install as same as the way of elevator
pushrod. Please see pictures below.
Rudder servo install as same as method of
elevator servo.
Rudder control horn install as same as method of
elevator control horn.
3. RUDDER SERVO INSTALLATION
Flaslink
Pushrod wire Servo arm
Snap keeper
Rudder pushrod
Rudder servo
1) Using the hardware provided, mount the main
landing gear to the fuselage.
Secure
Rudder pushrod
Rudder
control horn
M2 Lock nut
M2
2. Push in
1. A+B Epoxy glue
Control horn

PITTS Item code: BH85-A Instruction Manual
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2) Assemble and mounting the wheel pants as
shown in the following pictures.
Repeat the procedure to install the opposite
gear.
 1) Set the tail wheel assembly in place on the
plywood plate. The pivot point of the tail wheel
wire should be even with the rudder hinge line
and the tail wheel bracket should be centered on
the plywood plate.
VIII. MOUNTING THE TAIL WHEEL
BRACKET
Aluminium landing gear
Collar.
M5 nut.
Flat washer.
3 x 12mm
 2) Mark the locations of the two mounting screws.
Remove the tail wheel bracket and drill 2mm pilot holes
at the locations marked.
 3) Secure the tail wheel bracket in place using
three 3mm x 12mm wood screws. Be careful not to
overtighten the screws.
Drill a hole
2mm diameter
Secure
Mark point
Silicone Tube

PITTS Item code: BH85-A Instruction Manual
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 1) Plug the servo leads and the switch lead into
the receiver. You may want to plug an aileron extension
into the receiver to make plugging in the aileron servo
lead easier when you are installing the wing. Plug the
battery pack lead into the switch.
 2) Wrap the receiver and battery pack in the protec-
tive foam to protect them from vibration. Use a rubber
band or masking tape to hold the foam in place.
 3) Position the battery pack and receiver behind
the fuel tank. Use two tie wraps to hold the battery and
receiver securely in place as pictures below.
Do not permanently secure the receiver and battery
until after balancing the model.
 4) Using a 2mm drill bit, drill a hole through the side
of the fuselage, near the receiver, for the antenna to exit.
X. INSTALLING THE RECEIVER
AND BATTERY
Locate the aluminium wing dihedral brace.
XI. WING ATTACHMENT
*** Test t the aluminium tube dihedral brace into each
wing haft. The brace should slide in easily. If not, use
220 grit sand around the edges and ends of the brace
until it ts properly.
Attach the aluminium tube into the fuselage.
481 mm
Aluminium tube. 19mm.
Insert the wing panel as pictures below.
Screw the wing panel in position.
 1) Cut out the switch hole using a modeling knife.
Use a 2mm drill bit and drill out the two mounting holes
through the fuselage side.
 2) Secure the switch in place using the two machine
screws provided with the radio system.
IX. INSTALLING THE SWITCH
Switch
Battery of Receiver
Receiver
Push in
Push in
Push in
Secure
6x45mm

PITTS Item code: BH85-A Instruction Manual
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XII. INSTALLING COCKPIT
FUSELAGE
2. Push in
A/B Epoxy glue.
Pillot
Installing the fuselage hatch as same as picture
below.
Position the canopy so the rear frame on the
canopy is aligned with the rear edge of the cockpit
opening. Use canopy glue to secure the canopy
to the canopy hatch. Use low-tack tape to hold the
canopy in position until the glue fully cures. Wrap
the tape completely around the canopy hatch, as
the tape does not stick well to the covering. We
used balsa sticks to hold the lower edges of the
canopy tightly against the canopy hatch.
Please see pictures below.
Open and Close

PITTS Item code: BH85-A Instruction Manual
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Install the spinner backplate, propeller and spinner
cone. The spinner cone is held in place using two
3mm x 15 mm machine screws.
XIII. INSTALLING THE SPINNER
BALANCING
 1) It is critical that your airplane be balanced cor-
rectly. Improper balance will cause your plane to lose
control and crash.
THE CENTER OF GRAVITY IS LOCATED
106MM BACK FROM THE LEADING EDGE OF THE
WING.
 2) Mount the wing to the fuselage. Using a couple
Top side.
Push in
Bottom side.
Secure
Secure
II. WING STRUT
See pictures below
146mm
95mm
90mm
3x10mm
3x25mm
5
5a
5b
5c
5a 5b 5c

PITTS Item code: BH85-A Instruction Manual
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 1) We highly recommend setting up a plane using
the control throws listed.
 2) The control throws should be measured at the
widest point of each control surface.
 3) Check to be sure the control surfaces move in
the correct directions.
Control throw Ailerons:
Low: 10 mm up / down, 10% expo.
High: 15 mm up / down,10% expo.
Control throw Elevators:
Low: 15 mm up / down, 12% expo.
High: 20 mm up / down, 12% expo.
Control throw Rudder:
Low: 20 mm left / right, 15% expo.
High: 25 mm left / right, 15% expo.
CONTROL THROWS
10mm
10mm
15mm
15mm
20mm
20mm
Aileron control
Elevator control
Rudder control
 1) Completely charge your transmitter and receiver
batteries before your rst day of ying.
 2) Check every bolt and every glue joint in your
plane to ensure that everything is tight and well bonded.
 3) Double check the balance of the airplane.
 4) Check the control surface.
 5) Check the receiver antenna . It should be fully
extended and not coiled up inside the fuselage.
 6) Properly balance the propeller.
We wish you many safe and enjoyable ights with
your PITTS.
PRE-FLIGHT CHECK
of pieces of masking tape, place them on the top side
of the wing 106mm back from the leading edge, at the
fuselage sides.
 3) Turn the airplane upside down. Place your ngers
on the masking tape and carefully lift the plane.
Accurately mark the balance point on the top of the
wing on both sides of the fuselage. The balance point
is located 106mm back from the leading edge. This is
the balance point at which your model should balance
for your rst ights. Later, you may wish to experiment
by shifting the balance up to 10mm forward or back to
change the ying characteristics. Moving the balance
forward may improve the smoothness and arrow- like
tracking, but it may then require more speed for take
off and make it more difcult to slow down for landing.
Moving the balance aft makes the model more agile
with a lighter and snappier ”feel”. In any case, please
start at the location we recommend.
With the wing attached to the fuselage, all parts of the
model installed ( ready to y), and empty fuel tanks,
hold the model at the marked balance point with the
stabilizer level.
Lift the model. If the tail drops when you lift, the model
is “tail heavy” and you must add weigh* to the nose. If
the nose drops, it is “nose heavy” and you must add
weight* to the tail to balance.
*If possible, first attempt to balance the model by
changing the position of the receiver battery and re-
ceiver. 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.
CG
106mm
106mm

NEVER y in wet conditions or on
windy or stormy days.
I/C FLINGT WARNINGS
THE PROPELLER IS DANGEROUS.
Keep ngers, clothing (ties, shirt
sleeves, scarves) or any other loose
objects that could be caught or
drawn in, away from the propeller.
Take care at ALL times.
NEVER use damaged or deformed
propellers or spinners.
DO NOT dispose of empty fuel
containers on a re, this can lead to
an explosion.
Keep all onlookers (especially small
children and animals) well back
from the area of operation. This is
a ying aircraft, which will cause
serious injury in case of impact with
a person or animal.
NEVER y near power lines,
aerials or other dangerous areas
including airports, motorways etc.
ALWAYS adjust the engine from
behind the propeller, and do not
allow any part of your body to be in
line with the propeller.
Always operate in open areas, away
from factories, hospitals, schools,
buildings and houses etc. NEVER
y your aircraft close to people or
built up areas.