48 M ODEL AVIATION
IT’S A MATTER of position. Who knew
that when you received the big-game tickets
for seats on the 50-yard line, you would be
sitting behind the only set of adult triplets in
the United States who are seven feet, three
inches tall, and wearing huge headgear
designed to spur on the home team!
Position, or placement, has to do with
many things. The marketplace comes to
mind, as do lane assignments in the
Olympics, holding a hammer, and placing
your hands on the computer keyboard.
The same is true for aeromodeling. The
designer takes into consideration the
elements of the aircraft and its specific
relationships. We often become static in our
thinking relative to these areas, then people
such as aircraft designer Burt Rutan come
along and cause us to rethink our approach.
The Voyager (the first nonstop,
nonrefueled flight around the world) was
something of a shock, and Burt’s more
recent design, the Proteus (a high-altitude,
multimission aircraft), is even more so. The
description heard from some is that the
special-purpose Proteus resembled “two
dragonflies mating.”
The configuration of wings and tails and
bodies does not fit our view of what an
airplane should look like. The important
thing is that Burt’s ideas work because they
adhere to the laws of nature.
We must look not only at the designs we
use, but at the methods as well. While
finding the position of the center of gravity
(CG), the relationships of various
dimensions and other factors are important.
There are other things to consider
operationally. Let’s look at some of those;
for the most part, I will be addressing RC
(Radio Control).
Your transmitter has a fairly standard
layout no matter what brand you buy. The
control sticks, trim levers, and auxiliary
switches (if any) tend to fall into this
standard pattern. It’s true that the more
complicated many-channel units tend to use
a greater variety of switch placements, but
not the simpler sets.
In the past I’ve written about whether
to buy the more common Mode II or the
Mode I type. In many cases it boils down
to the availability of instructors. Mode II
fliers (elevator/aileron on the right stick)
outnumber the Mode I types, but that’s
not to say you won’t be able to locate
help for Mode I.
Some instructors are capable of
switching from one mode to the other. You
might not find Mode I equipment as readily
available in the hobby shop, but with some
sets you can easily convert the unit from one
mode to the other.
Notice I haven’t mentioned single-stick.
That’s primarily because it’s almost
nonexistent now.
Have you thought about whether you’re
going to be a thumb pilot or a finger flier?
Spend some time at the field and watch how
people manipulate the sticks. I’ll bet you find
that the majority of pilots place their thumbs
on the top of the stick. That’s the reason the
top of most transmitters are knurled.
Other fliers hold the stick with the
thumb and first finger. A few curl the first
finger around the stick and place the thumb
on top. Which is best?
Most people feel that the finger/thumb
combination provides the most precise
control.
If that’s true, why do the majority still
“thumb fly”?
Take an informal poll and you’ll
probably discover that the majority of
“thumbers” are older RC fliers or younger
pilots taught by older instructors.
In the early RC days, the radios were not
simultaneous or proportional-control
transmitters, and you had to toggle or
“thumb” a sticklike switch to control the
model. The carryover to the newer equipment
was placing the thumb on the top of the stick.
“If I ‘finger-fly,’ I find it harder to hold
the transmitter!” you might say. That’s true.
However, wearing a lanyard around your
neck or using a transmitter tray easily
solves that problem. This takes care of
trying to hold plastic with slick, fuel-soaked
hands, and the support supplied by the
lanyard or tray allows you to reach for trim
levers or switches more safely.
If you can learn to finger-fly, you’ll
probably want slightly longer sticks. Many
radios have an adjustment process to
accommodate stick length. Remember that
a longer control lever allows finer, moreprecise
movement. Your fine motor skills
don’t have to be quite as sharp.
Many of the younger generation have
been raised with joystick video games.
They are real “stick floppers,” and need to
concentrate on making smaller, slower
stick movements.
What other position issues should be
considered?
How about where you place switches
and charging jacks on your model? Don’t
put them where they can be “boiled in oil.”
Keep them away from the exhaust-outlet
side of the engine or the bottom of the
fuselage, where everything seems to
collect!
Yes, you Electric fans can just snicker
and read on!
Where do you place the propeller on the
crankshaft in relation to the compression
point? Many modelers place it close to a
three o’clock position. I put it near one
o’clock. It seems more comfortable for
getting my hand out of the way if I’m handstarting
the engine.
This is not much of an issue with an
electric starter. My suggestion is to check
out two things: find out what gives you the
most comfort and check what position the
prop will be in for landing if the engine
stops because it runs out of fuel. You’ll be
less likely to nick a blade if the prop stops
in a horizontal position.
Read on, Electric fliers.
How do I hold the model when
starting it?
What you should be asking is how
should the person assisting hold the model?
It is always a good idea to have someone
“pitting” for you when you start it!
There are too many possibilities for
problems if you are alone at the field. A
prop accident is one of many. Remember
that because of the nature of our activity, we
are often in a very isolated location.
Most modelers reach around the prop,
and grasp the front of the fuselage with
the left hand and prop the model with the
right. Assuming you have an assistant,
he or she typically holds the rear part of
the fuselage.
Have the assistant hang on to the rear
of the fuselage with one hand and hold the
leading edge of the wing with the other.
Have that person positioned on the side,
away from the needle valve; that way,
when or if you need to adjust the needle
Bob Underwood
N e w c o m e r s
32 Hollandbush Ct., St. Charles MO 63376
We must look
not only at
the designs we use,
but at the
methods as well.
50 M ODEL AVIATION
valve, you can move to the unoccupied
side of the model to do so.
In a number of cases I’ve watched the
helper get directly behind the model and
grasp the leading edge of the stabilizer.
Although this should be acceptable,
the tail assembly isn’t the most wellattached
part of the model; anyone who
has been around for a few years has
probably witnessed this.
There are devices available to put in the
ground or anchor to your field box to
allow the model to be “held” during the
starting process. If used, make certain
these devices are well “grounded.”
One technique often used when the
pilot is checking the high-throttle setting
is to straddle the fuselage in front of the
stab, allowing your legs to capture the
model. There are some safety problems
with this.
One problem is the process of stepping
over the fuselage (and back) and the other
involves the transmitter antenna.
In this position, if you lean over with the
antenna extended, it’s easy to forget about
the antenna and wind up with it in the prop.
Bad things happen when a metal antenna
hits a spinning prop!
Following are other position concerns.
1) Does your engine have a remote
needle valve, or is it a fraction of an inch
behind the prop? Fortunately, most valves
are angled back after they’re mounted.
Others are at the rear of the engine or can
be placed away from the engine.
2) Is your battery going to be in the
same area as your fuel tank? If so, seal it in
a plastic bag. Fittings do leak sometimes.
3) Are your control horns positioned
so the pivot point on the clevis is lined up
on the hinge line? If not, you are not
going to get equal travel in both
directions for that control surface.
4) Where is the receiver antenna
located? Hopefully it’s not threaded neatly
through a nest of servos or doubled back
on its own length.
5) Is your receiver nestled comfortably
in its little foam bed? Or is it shoved
rudely into a hard, dark corner to soak up
all that vigorous vibration produced by
your out-of-balance prop? You do balance
your prop, don’t you?
6) Does your engine’s glow plug angle
forward toward the prop? If so, consider
getting a remote plug attachment for it. Or
you could buy extra medical coverage.
7) Do you use a lanyard to hold the
transmitter? What do you do with it when
you are leaning over to start the engine or
adjust the needle valve? Tuck the lanyard
in somewhere, hold it, or throw it around
to your back until you stand up to clip it
onto your transmitter.
8) Where do you keep your club and
AMA membership cards?
The flying season is here, and we all want
to have some fun! MA
