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Twin Otter ARF Assembly Manual
Flight Preparations
Flight preparations should be performed each time
you travel to the flying field. Because your model will
encounter a variety of situations, it is best to keep an
eye on the various components of your model to keep
it in the best flying condition.
Checking the Frequency
When using a Spektrum radio system, follow the
guidelines for use of DSM radio systems at your
particular field.
Checking the Controls
Before starting your engine, check to make sure the
controls are operating in the correct directions and the
linkages and surfaces are not binding anywhere. Also
look at the clevises and clevis retainers to make sure
they are secure and will not come loose or fail in flight.
Fueling Your Model
Fill the fuel tank with the proper fuel. Fill the tank by
connecting the fuel pump to the line going to the
needle valve or to the fuel dot on the side of the cowl.
Disconnect the fuel line attached to the pressure fitting
of the muffler; your tank is full when fuel begins to run
out of the pressure or vent line. Reconnect the fuel
lines to the needle valve assembly or insert the plug
into the fuel dot and connect the line to the muffler.
Note:
It is very important to reconnect the lines to
the correct place. If they are reconnected
incorrectly, the engine will not run properly.
Maintaining Your Model
The following is a check list you should follow
every time you have completed a flying session with
your model. Doing so will keep your aircraft in the best
flying condition.
Clean Up
After a long flying session with your model, you will
want to clean it before loading it into your vehicle to
head home. Use a cleaner and a paper towel to wipe
down the exterior of your plane, removing the fuel
residue. Remember, a clean airplane will last longer
since the fuel won’t be able to soak into any exposed
wood.
Checking the Propeller
Check to make sure the propeller is tightly secured to
the engine. If not, remove the spinner and use a
wrench to tighten it. If you have had any not so great
landings, you will want to inspect the propeller for any
damage. Small nicks and scratches can quickly
become fractures, causing the propeller to be unsafe
for flight. Always carry a few spare propellers so a
damaged propeller can be replaced at the field,
increasing your flying time per trip to the field.
Checking the Clevises
Inspect the aileron, elevator and rudder clevises to
make sure they are connected and in good working
order. If you find a clevis that is showing signs of wear
or is broken, replace it with a new clevis. Also check
the nylon connectors at the servo for any wear or
damage. If they look worn or in bad shape, replace
them as well.
Checking the Control Horns
Inspect the control horns to make sure they have not
crushed the wood of the control surface. If so, remove
the control horn screws to remove the control horn.
Place 2–3 drops of thin CA into each of the screw
holes. In addition, use a T-pin to poke small holes in
the covering in the area where the control horn
mounts, then saturate the area with thin CA. This will
harden the wood and give the control horns a solid
surface to be mounted to.
Checking the Wheel Collars
Check the setscrews on the wheel collars for the main
and tail wheel to make sure they are not loose. Use a
hex wrench to tighten the setscrews. It is suggested if
they loosen frequently to remove them, reapply
threadlock to the setscrews, then secure the wheel
collars back into position.
Check the Muffler Bolts
Use the appropriate hex wrench to make sure the
hardware holding the muffler onto the engine is tight
and has not vibrated loose during flight.
Check the Engine Mount Bolts
Remove the spinner (if used) and propeller from the
engine. Remove the cowling , and if necessary
remove the muffler to gain access to the engine
mounting bolts. Use a Phillips screwdriver or hex
wrench to make sure the four bolts securing the
engine to the mount or firewall are tight.
