Top Flite TOPA0708 - Manual (Page 31)

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of the servos, size and loads on control surfaces, and
added features should be considered as an increase
to these minimums. Batteries should be able to sustain
power to the onboard radio components for a minimum
of one hour total fl ying time before recharging.
Both redundant and fail-safe battery systems are
recommended.
There is no minimum engine displacement limit, as
it is the position of this body that an underpowered
aircraft presents a greater danger than an overpowered
aircraft. However, the selection of engine size relative
to airframe strength and power loading mandates good
discretionary judgment by the designer and builder.
Current AMA maximums for engine displacement are
6.0 cu. in. for two-stroke and 9.6 cu. in. for four-stroke
engine. These maximums apply only to AMA Sanctions
concerning competition events (such as 511, 512, 515
and 520) and, as such, the maximums apply. All IMAA
(non competition) events should be sanctioned as Class
“C” events, in which these engine size maximums do
not apply.
Generally, it is recommended that no attempt should
be made to fl y a radio controlled model aircraft with
a gasoline engine in which the model aircraft weight
would exceed twelve (12) pounds (underpowered) per
cubic inch of engine displacement, or be less than fi ve
(5) pounds (overpowered) per cubic inch of engine
displacement. Example: Using a 3 cu. in. engine, a
model would likely be underpowered at an aircraft
weight greater than 36 pounds. With the same engine,
an aircraft weighing less than 15 pounds would likely
be overpowered.
Servo arms and wheels should be rated heavy duty.
Glass-fi lled servo arms and control horns are highly
recommended.
Propeller tips should be painted or colored in a visible
and contrasting manner so as to increase the visibility
of the propeller tip arc.
FLYING
The Giant Spitfi re ARF is a great-fl ying model that fl ies
smoothly and predictably. However, it does not possess
the self-recovery characteristics of a primary R/C trainer
and should be fl own only by experienced R/C pilots.
FUEL MIXTURE ADJUSTMENTS
A fully cowled engine may run at a higher temperature
than an un-cowled engine. For this reason, the fuel
mixture should be richened so the engine runs at about
200 rpm below peak speed. By running the engine
slightly rich, you will help prevent dead-stick landings
caused by overheating.
CAUTION (THIS APPLIES TO ALL R/C AIRPLANES):
If, while fl ying, you notice an alarming or unusual
sound such as a low-pitched “buzz,” this may indicate
control surface fl utter. Flutter occurs when a control
surface (such as an aileron or elevator) or a fl ying
surface (such as a wing or stab) rapidly vibrates up
and down (thus causing the noise). In extreme cases,
if not detected immediately, fl utter can actually cause
the control surface to detach or the fl ying surface
to fail, thus causing loss of control followed by an
impending crash. The best thing to do when fl utter
is detected is to slow the model immediately by
reducing power, then land as soon as safely possible.
Identify which surface fl uttered (so the problem may
be resolved) by checking all the servo grommets
for deterioration or signs of vibration. Make certain
all pushrod linkages are secure and free of play. If
it fl uttered once, under similar circumstances it will
probably fl utter again unless the problem is fi xed.
Some things which can cause fl utter are; Excessive
hinge gap; Not mounting control horns solidly; Poor
fi t of clevis pin in horn; Side-play of wire pushrods
caused by large bends; Excessive free play in servo
gears; Insecure servo mounting; and one of the most
prevalent causes of fl utter; Flying an over-powered
model at excessive speeds.
TAKEOFF
Before you get ready to takeoff, see how the model
handles on the ground by doing a few practice runs at
low speeds on the runway. Hold “up” elevator to keep
the tail wheel on the ground. If necessary, adjust the tail
wheel so the model will roll straight down the runway. If
you need to calm your nerves before the maiden fl ight,
shut the engine down and bring the model back into
the pits. Top off the fuel, then check all fasteners and
control linkages for peace of mind.
Remember to takeoff directly into the wind. When you’re
ready, point the model straight down the runway, hold
a bit of up elevator to keep the tail on the ground to
maintain tail wheel steering, then gradually advance
the throttle. As the model gains speed, decrease up
elevator allowing the tail to come off the ground. One
of the most important things to remember with a tail
dragger is to always be ready to apply right rudder to
counteract engine torque. Gain as much speed as your
runway and fl ying site will practically allow before gently
applying up elevator, lifting the model into the air. At
this moment it is likely that you will need to apply more
right rudder to counteract engine torque. Be smooth
on the elevator stick, allowing the model to establish a
gentle climb to a safe altitude before turning into the
traffi c pattern.
We normally fl y our fi rst fl ight with the landing gear down.
If for some reason the plane has to be landed quickly,
for example a dead stick landing, we can concentrate
on the landing.