28
LITHIUM BA
TTER
Y HANDLING AND USAGE
FLYING –––––––––––––––––––––––––––––––––
The Razor 3D ARF is a great-fl ying model that fl ies smoothly
and predictably. The Razor does not, however, 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 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.
FLIGHT
For reassurance and to keep an eye on other traffi c, it is a good idea
to have an assistant on the fl ight line with you. Tell him to remind
you to throttle back once the plane gets to a comfortable altitude.
While full throttle is usually desirable for takeoff, most models fl y
more smoothly at reduced speeds.
Take it easy with the Razor for the fi rst few fl ights, gradually
getting acquainted with it as you gain confi dence. Adjust the trims
to maintain straight and level fl ight. After fl ying around for a
while and while still at a safe altitude with plenty of fuel, practice
slow fl ight and execute practice landing approaches by reducing
the throttle to see how the model handles at slower speeds. Add
power to see how the model climbs as well. Continue to fl y around,
executing various maneuvers and making mental notes (or having
your assistant write them down) of what trim or C.G. changes may
be required to fi ne tune the model so it fl ies the way you like. Mind
your fuel level, but use this fi rst fl ight to become familiar with your
model before landing.
LANDING
To initiate a landing approach, lower the throttle while on the
downwind leg. Allow the nose of the model to pitch downward to
gradually bleed off altitude. Continue to lose altitude, but maintain
airspeed by keeping the nose down as you turn onto the crosswind
leg. Make your fi nal turn toward the runway (into the wind)
keeping the nose down to maintain airspeed and control. Level the
attitude when the model reaches the runway threshold, modulating
the throttle as necessary to maintain your glide path and airspeed. If
you are going to overshoot, smoothly advance the throttle (always
ready on the right rudder to counteract torque) and climb out to
make another attempt. When you’re ready to make your landing
fl are and the model is a foot or so off the deck, smoothly increase
up elevator until it gently touches down. Once the model is on the
runway and has lost fl ying speed, hold up elevator to place the tail
on the ground, regaining tail wheel control.
One fi nal note about fl ying your model. Have a goal or fl ight plan
in mind for
every
fl ight. This can be learning a new maneuver(s),
improving a maneuver(s) you already know, or learning how the
model behaves in certain conditions (such as on high or low rates).
This is not necessarily to improve your skills (
though it is never a
bad idea!)
, but more importantly so you do not surprise yourself
by impulsively attempting a maneuver and suddenly fi nding that
you’ve run out of time, altitude or airspeed. Every maneuver should
be deliberate, not impulsive. For example, if you’re going to do a
loop, check your altitude, mind the wind direction (anticipating
rudder corrections that will be required to maintain heading),
remember to throttle back at the top, and make certain you are on
the desired rates (high/low rates). A fl ight plan greatly reduces the
chances of crashing your model just because of poor planning and
impulsive moves.
Remember to think.
Have a ball! But always stay in control
and fl y in a safe manner.
GOOD LUCK AND GREAT FLYING!
