8
❑
5. Mark the location in the fuselage where to position
the battery to balance. Remove the pins if you used them.
Set a Flight Timer
It’s better to limit your fl ying time with a timer set to a pre-
calculated time instead of waiting for the LVC (low voltage
cutoff) in your ESC to kick in or until you notice a decrease
in fl ight performance. By then, it may be too late to make
more than one landing attempt. And it can be stressful to
your batteries, eventually decreasing performance in the
long-run.
Typical, average battery consumption with the Flyzone
Extra is approximately 200mAh/minute on 3S with the
included PowerFlow 10 x 4.5 propeller (but can be as low
as 150mAh/min. or as high as 280mAh/min.). Your fl ying
style/throttle use, battery condition and weather conditions
may cause the fi gures to vary, so until you know for sure,
start by setting your timer conservatively to 5 minutes.
If your transmitter has a timer built in, link the timer to
your throttle stick so only motor run time is counted. Fly
until the timer sounds then land. Note the time on your
transmitter and charge the battery. If your charger has a
digital readout (indicating how much capacity it took to
recharge which equals the capacity used during the fl ight),
divide the capacity that went back into your battery by the
fl ight time to calculate your
average battery consumption
for that fl ight. Divide 80% of your battery capacity by that
consumption rate to determine your new target fl ight time.
EXAMPLE:
Suppose you are using an 1800mAh battery.
And after you landed the motor run time on the timer in
your transmitter was 5:30 (that’s 5.5 minutes). And say it
took 950mAh to recharge your battery.
Divide 950mAh by 5.5 minutes to calculate an average
battery consumption rate of about 170mAh-per-minute.
Your
limit
or
target
capacity to use from a LiPo is a maximum
of 80% of its capacity. So for a 1800mAh battery it is 1440mAh
(1800mAh x .8 = 1440mAh). 1440mAh divided by 170mAh/
minute = 8.47 minutes (we’ll round down to 8-1/2 minutes).
On your second fl ight perhaps set your timer to 7 minutes
and repeat the procedure to continue to log data for
calculating average target fl ight times.
The more data you log and the more calculations you do the
more accurate your calculated fl ight times will be so you never
have an unplanned dead-stick landing or over discharge your
batteries. Keep in mind that changing propellers or fl ying
style/throttle use and sometimes even weather conditions
can affect current use, so plan accordingly.
On page 10 is a worksheet you can use for recording fl ight
times and recharge capacity to calculate target fl ight
times (as well as average, in-fl ight current which is also
useful data). The second row contains formulas for the
calculations for that row. Row #1 is already fi lled out with
fi gures from the example.
Additionally, or if you don’t have a charger with a digital
readout to fi nd out how much capacity you used during
a fl ight, use a LiPo cell checker to check individual cell
voltage after each fl ight. The resting, non-loaded, individual
cell voltage after a fl ight should be no less than
3.7 V/cell
.
FLYING
The ESC has an “arming” procedure that prevents the
motor from running when you connect the motor battery.
To start the motor when you are ready to fl y, fi rst turn on the
transmitter and lower the throttle stick all the way to “off.”
Connect the battery. Advance the throttle all the way, hear
the beeps from the motor, then lower the throttle stick and
hear the beeps again. The motor is now “armed” and the
propeller will turn the next time the throttle is advanced.
The Extra doesn’t exhibit any unexpected fl ight tendencies
that require informing you about ahead of time. It’s a mid-
wing, aerobatic sport plane, so it is very neutral with no
self-righting tendencies intended for intermediate pilots
at least. In the event of a rough landing the wheel pants
will disengage from the landing gear covers to prevent
damage. If landing in rough or tall grass you may as well
remove the pants and landing gear covers altogether.
