Radio Control Helicopters - 2009/12

Gary Wright talks about electric helicopters
[[email protected]]
Radio Control Helicopters Mark Fadely
Also included in this column:
• How to do pirouetting flips
Gary Wright has helped many companies with electric-power
product development during the last 20 years.
This image depicts a pirouetting flip with the related transmitter-stick inputs. Two
complete pirouettes are actually performed in this example.
“Media row” at the 2009 IRCHA Jamboree, during the IAN
contest. If you think you are good enough, a trip to this event to
get noticed is a must.
Mikado’s Logo 600 during a demo at the
2009 IRCHA Jamboree. The German
company specializes in electric-powered
helicopters and flybarless designs.
HELLO! I’m glad that you’re bravely
entering the helicopter arena this month. You
have to love the extended helicopter
coverage you are seeing in MA.
Pilots often ask, “When are we going to
see more helicopters in the magazine?” That
time is now! The emphasis can’t always be
skewed toward the rotary world, but it is nice
when we get extra exposure.
I’ll dive in with more information from the
IRCHA (International Radio Controlled
Helicopter Association) Jamboree: the crown
jewel event for the wigged-out helicopter
lovers. You’ll have to read about it in this
issue’s feature article, but let’s delve a bit
deeper into some of the information gathered
there.
There were a ton of electric-powered
helicopters at this year’s Jamboree. The
electric side of the hobby has had its
struggles and growing pains throughout
2009. Batteries and speed controls have been
expensive and sometimes not all that
reliable. Manufacturers have taken notice,
resulting in the production of much better,
less expensive products.
I was pleasantly surprised to see my
friend, Gary Wright, at the event this year.
He is a pioneer in RC electric development.
Gary is one of the most knowledgeable
people in the hobby, and he was a fine
competition 3-D pilot. He was up there
with Curtis Youngblood during the last
decade.
Gary was kind enough to answer a few
questions I thought our readers would be
interested in knowing the answers to.
MF: Gary, there are so many more electric
helicopters in the marketplace today. What
changes have you seen in motors,
electronics, and batteries over the years?
GW: Batteries are the only things that have
changed significantly. Electric motors and
speed controls have gotten better, but it has
been incremental.
Lithium-Polymer batteries with high
discharge rates have changed RC electric
flight. A lot more power is available from a
lot lighter pack. The old Nickel-Metal
batteries were really heavy.
December 2009 121
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122 MODEL AVIATION
Daniel Jetschin, one of Germany’s top pilots, flew this electric 90-
size Aurora during the noon demos at the Jamboree.
The 90-size electric helicopters are gaining popularity. Jamie
Robertson flew this prototype Align T-Rex 700 to a win at this
year’s XFC.
One thing a lot of pilots don’t realize is
that they may not even need the expensive
high-C Li-Poly packs. If you are going to fly
over six minutes, then the lower, less costly
packs will work just fine.
MF: So if you are not flying radical 3-D,
then you are probably better off with the
cheaper batteries?
GW: That’s right. Most pilots would really
benefit by getting longer flights for more
training time, and they would be saving
money at the same time.
One big difference between electric vs.
nitro power is that the high-discharge
batteries can be drained very quickly. That is
the biggest difference today. You can
essentially drain the fuel tank in four
minutes. If you could burn all of your nitro
fuel in a 90-size heli in four minutes, then
you could have the same power as the
electrics.
MF: What size helicopter would you
recommend for a pilot who wanted to learn
and progress with total electric power?
GW: They don’t really rate electric helis the
same as nitro. Electrics are referred to by
battery size.
A new pilot could get a six-cell heli that
could be set up to provide good flying power
for 15 minutes. That is a real luxury to have
that kind of flight time and not have to worry
about tuning needles on a nitro machine.
I would recommend a beginner pilot get a
500-size model, and after he is ready then he
might move onto a 600 or 700.
Thanks for sharing that good information,
Gary. You have been an inspiration to so
many pilots through the years.
Pirouetting Flips: I can’t tell you how many
times I have been asked how to do a “piro
flip.” The proper name of the trick is a
pirouetting flip.
Most aerobatic helicopters are capable of
performing the maneuver. It does not
demand a great deal of power or aggressive
capabilities from the machine.
Many months ago, the subject was
covered in this column. This time I thought
you all would appreciate a visual
representation of the maneuver while I write
about it.
I fired up the RealFlight simulator, and
stick-stirring ensued. As do many
complicated maneuvers, the piro flip seems
easy to do after you have it mastered.
However, it might seem impossible during
the early learning stages.
The best recommendation is to keep
trying this complicated move on a simulator
until your thumbs are numb. There is no
substitute for practice.
The piro flip is like no other maneuver,
and it involves a sophisticated control-input
sequence. Many times, a pilot will begin to
do the move using timing and a basic
knowledge of the required stick inputs.
That is a dangerous way to try it on a
real machine. If your timing is a bit off, the
model could end up in an attitude that is
completely foreign to the pilot, which might
result in a crash.
As can all maneuvers, the piro flip can
be broken down into segments that can be
learned as small parts of the full maneuver.
Basic control inputs on a Mode 2
transmitter are to stir the right (cyclic) stick,
while the left stick (rudder) is deflected and
held to perform a constant yaw rotation.
While these control inputs are being
executed, the helicopter will flip while the
tail is spinning. Then the pilot needs to
coordinate the positive and negative
collective to maintain a constant altitude.
The rotation of the cyclic stick has to
match the rotation of the model at all times,
or the maneuver will go awry.
Synchronizing the cyclic is the most
troublesome thing to master.
Pilots often ask, “Should I watch the
nose or the tail to stay in sync?” It doesn’t
matter which end of the helicopter you key
in on, as long as you remain consistent.
Once you input a few wrong stick positions,
the machine will be heading out of control
in a hurry.
In the picture from my simulator, you
can see that there is a limited amount of
stick inputs during the maneuver. That
usually surprises pilots.
When you watch a piro flip being
performed, it seems like a lot of control
must be required. It is actually the opposite.
The images of the helicopter have been
spread out so you can see the orientations
better.
In a real-world example of the move, the
model should stay in the same space and
perform the flip around itself, with no
altitude or horizontal position changes. The
maneuver shown is a two-piro version,
meaning that there is one pirouette during
the first half flip and another full pirouette
during the second half flip. The helicopter
ends in the same orientation as it started.
When I learned the trick, I did the onepirouette
type, which has only one pirouette
during the whole flip. That version of the
maneuver requires much more cyclic input
and loads the helicopter much harder. The
two- or three-pirouette-per-flip variations
are much more elegant and pretty to watch.
I hope the illustration will help some of
you better understand the nuances of this
difficult and exciting move. Don’t be afraid
to ask other pilots for help when you are
attempting to learn something.
That is it for this time. I hope you’ll be back
for more RC helicopters next month. MA
Sources:
IRCHA
www.ircha.org
RealFlight
www.realflight.com
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