Wrinkles From Covering
I said a little bit earlier, this plane has to have
the best covering job of any ARF that I have ever seen.
It came out of the box with the covering very tight
and there were very few wrinkles in the covering. To
be exact, I had to look really hard to find wrinkles
in the covering. Even though the covering looks great
coming out of the box, it's still a good idea to go
ahead and go over it with a heat gun and a covering
iron. This will remove any wrinkles that might be there,
attach the covering to the plane structure, and fully
tighten the covering so that it won't develop wrinkles
later on. To accomplish this I used a heat gun, a bare
covering iron, and a covering iron that has a hot sock
on it to prevent scratching the covering. Use the chart
below as a guide for the temperature settings when working
the covering of the Falcon 56.
F (104° C)
F (148° C)
F (177° C)
got a pretty standard routine that I use whenever I'm
dealing with the covering on an ARF. First I use the
uncovered iron to go over all of the edges of the covering
on the plane. This includes all areas such as the wing
saddle and inside of hatch areas as well. Also don't
forget to go over any seams where two pieces of covering
material are joined. It's really important to do this
in order to ensure that the covering edges are firmly
ironed down. If not they risk pulling loose as we start
shrinking the covering. After the edges are all sealed
the next step is to shrink the covering. Use a heat
gun to shrink all of the covering. Even though the covering
may not have any wrinkles it's still important to shrink
the covering as this will help prevent the covering
from wrinkling later on. After finishing up with the
heat gun the last step is to go over the covering with
an iron that has a sock on it. This will secure the
covering to the wood of the plane to keep it in place.
Use a sock on the iron to prevent the covering from
getting scratched by the iron.
wanted to show a few pictures of the wing here for a
reason here. As you can see in the pictures I used the
same techniques as I did for the rest of the plane,
with one small exception. I didn't get the edge of the
blue covering firmly secured to the covering below it,
and when I hit it with the heat gun it had bad results.
As you can see in the last picture, the heat caused
the blue to "pucker" and pull away from the
covering below it. Make sure that all the edges are
completely sealed before shrinking with a heat gun.
When this pucker happens the only way to repair it is
to use Monokote and put a small strip over the affected
of the control surfaces on the Falcon 56 MKII are attached
using standard CA hinges. The ailerons are operated
by torque rods attached to one aileron servo located
on the center of the wing. The first step to installing
the CA hinges is to place a small pin in the center
of each hinge. This is done in order to keep the hinge
from being pushed too far into either side as they are
installed. Place the hinges into the pre-cut slots on
the trailing edge of the wing in preparation to installing
the ailerons. As each aileron is installed epoxy is
used to secure the aileron to each torque rod. Before
applying epoxy use sandpaper to rough up the torque
rods in order for the epoxy to have more surface to
"grip" to. Before actually applying epoxy
it might be a good idea to practice how you are going
to install the aileron to the wing. This will let you
work out exactly how you are going to proceed as the
aileron is installed. Apply epoxy to the pre-cut slot
in the aileron, making sure to get epoxy down in the
hole for the torque rod arm. Now slide the aileron onto
the previously installed CA hinges and slide the aileron
applying CA to the hinges the wing will have to set
while the epoxy cures. To hold the aileron in place
while the epoxy cures there are several things that
need to be done. First place plastic sheet between the
torque rod and the trailing edge of the wing. This is
done so that epoxy will not get into this gap and cause
the ailerons to not operate properly. I used a small
straight edge slipped behind the torque rods to ensure
that the torque rod is fully pushed into the slot in
the aileron. Use tape to hold everything in place while
the epoxy cures. Once the torque rods are set the CA
hinges can now be attached. Flex the aileron in one
direction and apply 4-5 drops of CA to each hinge. Then
turn the wing over and flex the aileron in the other
direction and apply 4-5 more drops of CA to the other
side of each hinge. Allow the CA to fully set and then
flex the aileron several times in both directions. One
last thing to check is that there is no excess epoxy
built up on the torque rod or in the gap between the
aileron and trailing edge of the wing. If there is any
build-up simply use the tip of a hobby knife to "pick"
the epoxy out of the gap. Make sure that each aileron
moves freely in both directions.
The Wing Halves
Falcon 56 has a two-piece wing, which is joined using
a plywood dihedral brace to set the proper dihedral
angle in the wing. One thing that I stress to a lot
of people when doing steps like joining the wing halves
is to test fit everything before using any adhesives.
Also, it's important to practice putting your parts
together dry. This will help prevent making mistakes
after the epoxy is applied. As I was test fitting the
wing halves together I noticed that the dihedral brace
would slip into the sockets in the wings a bit farther
than half way. So to keep the brace in the proper position
I simply stuck a couple of straight pins into the brace
at the center point. To join the wing halves I used
30-minute epoxy so I would have plenty of time to join
the parts before the epoxy set. I applied epoxy to the
engine outer edge of the wing half as well as into the
dihedral brace socket. And lastly, before putting the
brace into the wing half I applied a coat of epoxy to
one half of the brace as well.
the epoxy applied to one half of the wing the dihedral
brace is inserted into the socket in the wing. With
the brace in place epoxy is then applied to the other
wing half. Slide the second wing half on to the dihedral
brace and push the two halves together, the pins holding
the brace in place can now be pulled out. Before securing
the two wings halved together take some time to clean
up any epoxy that has been squeezed out between the
wing halves. A paper towel with a bit of alcohol on
it will make quick work of cleaning up the epoxy. After
the joint is cleaned up use tape to hold the wing halves
together while the epoxy sets. Set the wing out of the
way and allow time for the epoxy to properly set before
removing the tape.
up is to install the aileron servo. The Falcon 56 uses
a pre-assembled hardwood mount that will need to be glued
in place after the wing halves are joined. The wing
already has the cutout in to accommodate the aileron
servo so this will be used to position the servo mount.
Place the mount in position over the cutout and mark
the location. I prefer to use Sharpie markers for marking
such things because it is easy to clean up with a cloth
and a bit of alcohol. After the position is marked the
covering will need to be removed. While the instructions
call for using a hobby knife to cut away the covering
I prefer to not use them. It's too easy to cut too deeply
into the wood and weaken the structure. I prefer to
use a soldering iron to melt away the covering. Simply
draw a hot soldering iron along your marked line to
melt the covering, and then remove the covering from
your marked area. Use medium or thick CA to glue the
servo mount into place after the covering is removed.
Next place the aileron servo I mount in order to mark
the location for the servo mounting holes. I like to
use the Great Planes Dead Center Hole locator for marking
holes. It's easy to use and does a great job of marking
the true center of the hole.
marking the mounting holes they are drilled out with
a small drill bit. Use the servo mounting screws to
cut threads into the mounting hole. After cutting the
threads wick a little bit of CA into the threads to
harden the wood. Make sure that the CA is completely
dry before putting the screws in place. Mount the servo
in place in the servo mount.
mounting the aileron servo the torque rods and pushrods
are installed. The horn brackets are screwed into place
on the torque rods, making sure that each horn is screwed
in place by the same amount on each torque rod. Next
assemble two 10" pushrods by screwing the metal
clevises in place on each toque rod. When preparing
the torque rods I like to ensure that the ailerons are
centered. To do this I use craft sticks (popsicle sticks)
and a clamp. Place a stick on each side of the wing
and then place a clamp in place. This will keep the
aileron in the neutral center position while the pushrods
are measured and assembled. Next attach a pushrod to
each horn on the torque rods. Before bending the pushrods
center the aileron servo in order to bend the pushrods
to the proper length. Using a pair of pliers mark the
length of the pushrod and then bend the rods upwards
at a 90 degree angle. If it is difficult to bend the
rods in place you can mark them with a pen and then
remove them from the wing in order to bend them.
the rods are bent I then assembled them in place on
the servo control arm using the provided L-brackets.
After each pushrod is connected to the servo arm then
snip off the excess pushrod.
and Elevator Installation
next are the vertical stabilizer and the elevator assembly
and installation. The installation steps were a bit
different for the Falcon 56 than most other planes that
I've seen. The horizontal and vertical stabilizer is
first assembled together and then attached to the plane.
The first step here is to trim the covering off of the
bottom of the vertical stabilizer in preparation for
gluing it in place. First place the stab in position
and use a marker to trace a cut line on the stab. The
instructions call for cutting the covering to remove
it, but as I stated above I prefer to use a soldering
iron to prevent cutting too deep and weakening the structure.
After trimming away the covering 30-minute epoxy is
mixed and applied to the bottom portion of the stab.
stab is then inserted into place on the horizontal stabilizer.
Use a paper towel with alcohol on it to clean up any
epoxy that gets squeezed out of the joint. Use tape
to hold the stab in position while the epoxy sets. Using
a square helps to ensure that they stab is properly
aligned with the horizontal stabilizer.
attaching the stab assembly to the fuselage check to
ensure that the horizontal stabilizer is level with
the wing when viewed from behind the plane. If it's
not level sand down one side of the fuselage until it
is level with the wings. Before attaching the assembly
ensure the covering on the underside of the horizontal
stabilizer is removed as well as the covering under
the forward position of the vertical stab.
30-minute epoxy to the fuselage saddle and the strip
of covering you removed for the vertical stab. Position
the assembly in place and wipe any excess epoxy away.
Use tape, or other means, to secure the assembly in
place while the epoxy sets.
elevator consists of two panels connected with a joiner
rod. Before epoxying the rod in place check the alignment
on it when installed to ensure that the leading edge
of the elevators form a straight line. If not, simply
flex the joiner rod to adjust the alignment. Rough up
the joiner rod with sandpaper and then epoxy it in place
on the elevator halves.
elevators are hinged using standard CA hinges. They
are installed in the same manner as the ailerons earlier
in the assembly process, so I won't go into the steps
attaching the elevator the rudder is then hinged in
place to complete the assembly of the tail section of
the plane. Once again CA hinges are used following the
instructions outlined earlier.
Control Horns, and Servo installation
pushrods for the Falcon are made by a method that has
been used for years to build light yet strong pushrods.
The pushrods are constructed from dowel rods with metal
pushrods attached to each end of the dowel, using heat
shrink to hold the metal portions in place. The first
step to building the pushrods is to bend approximately
1/4" of the threaded end to a 90 degree bend. The
dowel portions of the pushrods have a groove with a
hole drilled through it to accommodate the metal ends.
Insert the bent portion of the metal rod into the hole
drilled through the dowel, and then fit the rod into
the groove in the dowel. A piece of heat shrink is then
slid over this and heated to secure the metal portion
to the wooden dowel.
installing the pushrods down through the fuselage the
exits need to be cut out. A sharp hobby knife makes
short work of doing this. Once the pushrods are run
down through the fuselage screw a clevis on each one.
Connect the clevis to the rudder control horn and place
it into position on the rudder. Mark the hole locations
and drill the holes with a small drill bit. Harden the
drilled holes with thin CA. When the CA has dried install
the control horn into place on the rudder. The control
horn for the elevators is installed in the same manner.
installing the control horns the pushrods now need to
be cut to the proper length. In the same manner that
we centered the ailerons use two craft sticks and clamps
to center the elevator and rudder when installing the
pushrods. Set the servo arms to the center position
and mark where the pushrods need to be bent.
a pair of pliers to bend the pushrod to a 90-degree
angle. Using the L-bracket as a guide clip off the excess
pushrod. Then install the pushrods to the appropriate
the Engine and Fuel Tank
method used to mount the engine on the Falcon 56 is
a bit different than some may be used to these days.
Instead of an engine mount that bolts to the firewall
the Falcon mounts directly to frame rails that are part
of the fuselage structure. The engine is bolted to a
"U" shaped mount which is then fastened to
the frame rails of the plane. This method of mounting
engines has been around for decades and does hold some
advantages to the new engine mountings.
engine compartment is bare wood and will need
to be sealed to prevent fuel and exhaust reside
from soaking into the wood and weakening it. Where
there are many methods for fuel proofing I prefer
to use epoxy applied with heat to accomplish this.
Using 30-minute epoxy apply a "blob"
of epoxy with a disposable brush and heat it with
a covering heat gun. This will thin out the epoxy
to the consistency of water, which will let you
brush it to cover the bare wood. Heating epoxy
like this also allows it to soak into the pores
of the wood which I feel will better seal it.
In addition to the engine compartment the fuel
tank compartment also needs to be sealed. This
needs to be done so that fuel leaking from the
tank won't soak into the fuselage and weaken it.
inside slot on the wooden mounting bracket for
the engine was a bit narrow to fit the OS 46 AX
that was used on this plane. This required that
approximately 1/8" be trimmed from each arm
of the bracket on the inside of the bracket. This
was easily accomplished with a scroll saw, but
a handheld saw could get it done just as easily.
fitting the engine in the plane shows that the
46 AX will sit at the very back of the mounting
bracket. Using a clamp to hold the engine in place
makes it very easy to mark the mounting holes
using a Dead Center Locator.
marking the mounting holes they are then drilled
0.455 cu in (7.5 cc)
Bore: 0.866 in (22.0 mm)
Stroke: 0.772 in (19.6 mm)
Practical rpm: 2,000-17,000
Output: 1.65 hp @ 16,000 rpm
Weight w/muffler: 17.2 oz (489 g)
Includes: #A3 glow plug, E-3010 muffler
Requires: glow fuel, prop
Recommended Props: 10.5x6, 11x6-8,
the replacement for the high-performance
46FX, it's no wonder that the .46 AX shares
many of its features. The raw power. A remote
needle valve. Mounting bolt patterns. A
balanced "D"-cut crankshaft supported
by dual bearings. CNC-machining for the
piston and other parts. And the same exclusive
ABL cylinder liner that has made FX reliability
a byword. But all the same, the 46AX is
a different ? and better ? engine. Why?
Because times change and technology advances.
And because O.S. uses the best of both to
make a good engine a better engine.
the 46FX's durable ABL (Advanced Bimetallic
Liner) plating, as well as a new design
that automatically centers, levels and
seats the head during re-replacement.
Head snugs down with only four screws
? not six.
tapered low-end needle eliminates surging
at transition, ensuring exceptionally
smooth, consistent throttle control from
idle to top speed.
liner ports and a ball-milled inlet port
minimize turbulence during fuel/air mixing,
making combustion and power output more
high-speed needle bracket simplifies horizontal/vertical
mounting ? and can be replaced in just
vibration-induced "creep" and
re-sets with a ratchet spring on the high-speed
needle and O-ring seals on both needles.
A simple rotor guide screw replaces the
throttle stop screw ? and eliminates spring-related
a new low-noise E-3010 muffler and 2-year
a lock nut and longer crankshaft with
more thread length, for better prop nut
engagement and greater pilot safety.
View online manual for the OS 46 AX
nuts are installed in each hole in order to mount the
engine to the wooden mounting bracket.The instructions
for the Falcon 56 call for mounting the fuel tank compartment
hatch later on during the assembly of the plane. But
I found that it was next to impossible to drill out
the mounting screw holes for the hatch with the engine
installed. So I would recommend that anybody assembling
this plane actually drill the holes now before the engine
have been mounted. Before the engine can be mounted
on the place a notch needs to be made for the engine
needle valve to clear the fuselage sides.
the OS 46 the needle valve position can be changed so
that the needle valve points upwards instead of to the
sides, and this could have been done to prevent having
to modify the fuselage sides. It's a personal preference
in that I like to have the needle valve pointing out
away from the sides of the engine. But others may prefer
to not have to cut the sides of the plane and have the
needle valve pointing upwards. Cutting out an area for
the needle valve is fairly easy to do. First mark the
area that needs to be modified. Then use a Dremel tool
with a sanding disk to remove the material of the cutout.
The wooden mounting bracket will sit on top of frame
rails that are part of the fuselage. There is a notch
already cut into each frame rail for the blind nuts
of the mounting bracket. Depending on the engine used
these notches may need to be enlarged a bit, as I had
to do for the OS 46 AX.
instructions call for using epoxy to mount the bracket
in place in the fuselage, but they do offer the option
of making it removable by using screws to mount it in
the plane. I chose this route of mounting the engine
as I felt it would be easier to do any maintenance on
it. To do this I used the screws on each side of the
engine. The screw holes are drilled out, have threads
cut by the screw, and using thin CA hardens the threads.
With the engine mounted in place the throttle pushrod
can be assembled and mounted on the carburetor control
arm. A pushrod tube is included for the throttle pushrod.
This is mounted in the predrilled holes in the formers
located on the right-hand side of the fuel tank compartment.
A small amount of thick CA on the outside of the pushrod
tube at each former will hold it in place. The throttle
pushrod is routed back to the throttle servo. Included
is an EZ connector to connect the pushrod to the throttle
servo control arm.
the pushrod so that proper throw for the carburetor
can be achieved without binding the pushrod. Mounting
the engine can be finished now by attaching the muffler
to the engine, or this can be left off, as it may be
easier to finish assembling the plane without it in
Main Landing Gear Installation
main landing gear are pre-bent steel gear that are installed
on the bottom of the fuselage. The gear mount in a precut
slot in the fuselage that has holes drilled in them
to place the gear wires in. Once the landing gear wires
are in place two nylon straps are used to hold the wire
in place. Use the straps to mark where the holes should
be drilled to mount them. After drilling the holes use
the mounting screw to cut threads into the wood of each
thin CA to harden the threads of the holes. After the
CA has completely dried use the provided screws to mount
the nylon straps that hold the gear in place.
mount the wheels first mount a wheel collar on the inside
of the landing gear wire. A bit of blue threadlock on
the allen screw will help in preventing it from coming
loose in flight. The wheel is mounted next and held
in place by an outer wheel collar. Although it doesn't
call for it in the plans, I prefer to place a small
piece of fuel tubing on the axle. This will keep the
wheel collars and wheels in place if they do come loose
in flight. This little trick has saved me more than
Nose Gear Installation
fuselage for the Falcon 56 comes with the front gear
mounting bracket already installed. Take a few moments
to check that the nuts are indeed tight on the bracket
before mounting the nose gear. Before installed in the
nose gear install the wheel on the gear in the same
manner as the main gear wheels were installed earlier.
Slide the gear into the nose wheel bracket and then
check the level of the fuselage before securing it in
place. When satisfied that the fuselage is level secure
the front gear in place by using the steering control
arm to hold the gear. The arm will need to point away
from the firewall in order to be able to steer the nose
wheel in both directions.
steering pushrod guide tube is installed in the left
side of the fuselage in the same manner as the throttle
pushrod tube. Assemble the steering pushrod with a clevis
and silicon retainer ring and attach to the steering
arm on the nose wheel. The steering pushrod attaches
to the rudder servo control arm by bending and cutting
the pushrod and then using a L-bracket retainer.
Tank Assembly and Installation
included fuel tank is set up in the same manner as most
standard fuel tanks. It consists of a clunk (weighted
fuel pickup), fuel tubing, rubber stopper, and back
plates to compress the stopper. When the tank is assembled
the stopper is squeezed between the two plates, which
causes it to seal around the neck of the tank opening.
The stopper comes completely sealed so that it can be
used as either a 2-line or 3-line setup. The Falcon
will use a 2-line setup; so only two holes in the stopper
need to be opened up. This is easily done using a small
drill bit. With the stopper opened up two aluminum tubes
are ran through the stopper. One tube will connect to
the supplied fuel line and then to the clunk. This needs
to be cut to length so that the clunk sits approximately
1/4" from the back of the tank, and so that the
clunk can move freely around the tank when it is inverted.
The other tube is bent upwards towards the top of the
fuel tank. This is the vent line that allows the tank
to be pressurized by the muffler. Cut a 45° angle on
the tube so that it can vent properly.
stopper assembly is then inserted into the tank, ensuring
that the tubes are properly positioned. Tighten the
screw on the assembly to squeeze the two plates together
and expand the stopper to seal on the tank neck. Be
sure to not over tighten the stopper as this can result
in the tank splitting. One final thing I prefer to do
is to label each tube so that I always know which one
is the vent and which one is the fuel pickup line.
the fuel pickup line and the muffler vent line to the
fuel tank and insert it into the tank compartment. Pad
the tank with foam to prevent vibration from forming
bubbles in the tank during flight. Install the tank
hatch on the compartment. To complete the tank installation
connect the lines to the muffler and the carburetor.
Because of the position of the needle valve it can be
difficult to disconnect the fuel line in order to fill
the tank. To fix this simply cut the fuel line a few
inches from the needle valve assembly, then insert a
piece of the remaining aluminum tubing to re-join the
fuel line. Now when it's time to fill the tank,
separate the fuel tube where it's joined.
canopy is installed on the top of the wing, in the center
of the wing. To help the wing "grip" the adhesive
rough up the edge of the canopy with a piece of sandpaper.
While there are a lot of different adhesives for attaching
canopies I prefer to use Formula 560. It's easy to work
with and does a great job of holding the canopy in place.
Run a bead of the glue around the entire bottom of the
canopy. I like to wait for a few minutes to let the
glue "firm up" a bit before putting the canopy
in place, I feel this helps to keep the glue from running
as much. Place the canopy in position on the wing and
secure it in place with a piece of tape.
a clean install clean up any excess glue before it dries.
When satisfied with the position firmly secure it in
place with tape and leave it to dry overnight. If any
excess glue still shows it can be trimmed off with the
sharp point of a hobby knife.
final assembly of the Falcon consists of installing
the receiver for the radio, the switch, and the battery.
The best place that I found to install the radio gear
was between the tank compartment and the servo tray.
The only problem with doing that was that the bottom
of that area was open and covered with covering material.
I was afraid that if the battery weight pressed on the
covering while in flight it could break through and
allow the radio gear to fall out. To correct this I
glued several craft sticks across the opening to form
a floor for this area. I also installed a piece of wood
across the opening in the left side of this area in
order to serve as a mount for the radio switch and charging
The C.G. range for this aircraft is 3" to 3-1/2"
behind the leading edge of the wing.
For initial flights balance the plane 3-1/4" behind
the leading edge of the wing.
Falcon includes a set of self-adhesive decals that can
be used to "dress up" the plane. Simply cut
them out and stick them to the surface of the plane.