Top Flite J-3 Piper Cub - Manual (Page 15)

Repeat this step on the opposite wing panel. Once you are satis-
fied that the wing panel are aligned properly with both the fin
and stab and each other, "lock" all four strut clevises in place by
tightening the No. 2-56 nut firmly against the back of the clevises
as shown on the plans. DO NOT forget to use small lengths of
fuel tubing over each of the clevises when they are in place on your
airplane. Without these fuel line lengths in place, a clevis could,
under high loads, become "unpinned", leaving the wing without
proper support.
BALANCING
The C.G. range (Center of Gravity) shown on the plans is the ideal
location. DO NOT exceed the rearward limit shown on the plans.
Our prototypes did not require any additional weights to achieve
correct balance. Always balance your aircraft "dry". That is: all
equipment in place, ready to fly, but WITHOUT fuel.
For initial flights it is best if the airplane is slightly nose heavy.
This condition keeps the airplane naturally stable with less chance
of stalling or snap-rolling. A slightly forward C.G. also makes the
controls somewhat less sensitive and lessens the chance of over-
controlling. As flight time and familiarity build up, you may wish
to re-balance your Cub with a more rearward C.G. to increase it's
acrobatic ability. Do this gradually and check control response
at a good altitude.
ENGINE AND RADIO
The engine used in your Cub should be completely broken-in
and have the ability to idle reliably. Be sure that your fuel tank
is properly installed and that the fuel lines are feeding properly.
We have found that running the tank with "manifold pressure" —
a pressure tap nipple, tapped into the muffler with the overflow
fuel line connected to it — greatly enhances fuel feed at all atti-
tudes — the plane may go through — loops, rolls, etc.
Your radio installation should be neat with all connections ab-
solutely secure. Do not fly without fuel line safety tubes over
clevises, as shown on the plans. Set the aileron, elevator and
rudder movements to those shown on the plans. These surface
throws will give you positive control of the airplane without
making it over-sensitive. Later, when you are more familiar with
the airplane, these throws can be changed to suit your flying
style.
Your radio equipment MUST be reliable. DO NOT attempt to
fly with a radio that is suspect in any way.
FLYING
If you are a newcomer to radio control, we do not recommend
that you fly your Cub without the help of an experienced R/C
pilot. Hobby shops in your area can direct you to an organized
R/C club. These clubs can offer the beginner much assistance and
advice and they usually have a flying site that is suitable for radio
controlled aircraft.
We would suggest that for test flights, a calm day be chosen. Test
flying in strong winds can be done but it is more difficult. Al-
though the Cub can be operated out of a relatively small area, a
sanctioned R/C flying site, with plenty of area, free of obstruc-
tions is much more desireable. Your Cub can be flown off either
asphalt or a cut-grass field. Hand launching an aircraft of this
size is not recommended.
With a full tank and the engine idling reliably, point the plane
directly into the wind, advance the throttle slowly and correct
for torque with a small amount of right rudder. The Cub should
be airborne in just a few feet. Don't let the nose come up too
sharply and use both aileron and rudder to keep the wings level
during the climb out. Climb to a comfortable altitude making all
turns gently. You will find that a medium throttle setting on the
average .40 engine is all that is required for normal flight speeds.
Make all trim adjustments at a good altitude. Use the transmitter
trim levers to obtain straight and level flight.
Once you are comfortable with the flying characteristics, throttle
back, while still at altitude and check stall behavior. It should be
gentle and straight without falling off on one wing or another.
Landing approach is best done under about 1/4 throttle (depend-
ing on wind conditions), keeping the wings level. As you approach
the threshold of the runway, you should be about 10 feet in the
air. At threshold, chop the throttle to full idle and settle the air-
plane down gently on the main gear and allow the airplane to roll
to a full stop. The Cub by it's nature, has a great deal of parasitic
drag — struts, landing gear, wheels, wires, etc. This drag can fool
you into making overly long low throttle approaches usually term-
inating short of the runway. Try to remember to use a bit more
throttle on approach and with practice spot landings of con-
siderable accuracy can be made almost every time.
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