122 M ODEL AVIATION
TEam SElEcTioN FiNalS: This past
October, the top Fédération Aéronautique
Internationale (FAI) fliers in the country met
at Lost Hills CA to select the nine team
members who will represent the United
States at the 2001 World Championships.
The team members are: F1A Glider—
Steve Spence, Lee Hines, Andrew Barron;
F1C Power—Ed Keck, Randy Archer, Ken
Oliver; and F1B Wakefield—Roger
Morrell, Blake Jensen, Walt Ghio.
All are former team members. Steve
Spence and Ed Keck are the only repeaters
from the 1999 team that flew at the World
Championships in Israel. The 2001 World
Championships will be held at Lost Hills
October 8-13.
There were 25 contestants in F1A, 40 in
F1B, and 24 in F1C. The contest consisted
of 14 rounds, held during two days. Only
four maxed out in Glider; five maxed in
Wakefield; and 10 maxed in Power.
Glider was decided with a five-minute
max immediately following the second day
of flying. Andy Barron and Steve Spence
made the 300 seconds, and Lee Hines
outglided Chuck Markos by less than half a
minute to secure the third team spot.
In Wakefield, all five competitors made
the five-minute late-afternoon flyoff. The
team was decided with an early-morning
flight the following day. No one made the
10-minute max; Walt Ghio did almost 71⁄2
minutes; Blake Jensen was 10 seconds
behind; and Roger Morrell did 409 seconds
for the third spot.
In Power, eight of the 10 contestants
made the five-minute afternoon flyoff. A
few minutes before the start of the flyoff
the next morning, former World Champion
Randy Archer popped off a test flight on
his new geared model he planned to use as
a backup. The model stalled in the glide.
A screw was tweaked, and the second test
flight looked good. The model dethermalized
(DTed) just before the start of the round.
There was a long wait, then engine problems
with the conventional model forced Randy to
go to the backup geared model with only
roughly a half-minute left in the 10-minute
launch window.
After a spectacular climb, Randy ended
up with the top score—539 seconds—
Louis Joyner, 183 Civitas St., Mt. Pleasant SC 29464
FREE FLIGHT DURATION
The 2001 US team (L-R): F1A—Steve Spence, Lee Hines, Andrew Barron; F1C—Ed
Keck, Randy Archer, Ken Oliver; F1B—Roger Morrell, Blake Jensen, and Walt Ghio.
Two-time F1C World Champ Randy Archer (L) used this geared model in early-morning
flyoff. Roger Morrell (center) and Blake Jensen made the Wakefield team.
Jim Lueken made it to the flyoff using this
Burdov model from Star Link. Notice the
air-speed meter in foreground.
approximately one minute under the 10-
minute goal.
Randy later said he thought he could
have made the 10 minutes with the other
model, with which he had more
experience. Rounding out the Power team
was Ed Keck, who was second at the last
World Championships, and Ken Oliver.
F1A Towline Glider, F1B Wakefield
Rubber, and F1C Power represent the most
highly evolved forms of Free Flight
aeromodeling.
High-tech materials such as carbon
and Kevlar™ have replaced balsa, for the
most part. Covering is usually some sort
of plastic film—not tissue. Electronic or
mechanical timers control functions to
optimize flight patterns. Models are
precision-built pieces of sporting
equipment.
For those not familiar with the three FAI
events, here is a brief rundown.
F1A Towline Glider is seemingly the
simplest event. The model, which typically
spans 90-100 inches and weighs slightly
more than 14 ounces, is towed aloft by a
50-meter (164-foot) line, much like flying
a kite. Timing starts when the model is
released from the line.
To be competitive nowadays requires a
circle-tow-and-bunt model. Circle-towing,
which has been around for more than a
quarter of a century, allows the model to
glide in a tight circle while still connected
to the towline.
This allows the flier to search the air
for thermals or to position the model
underneath other models that seem to be in
good air.
Once the decision is made to launch,
the flier begins a fast run that accelerates
the model to the top of the line. This high
tension unlatches the towhook connecting
the line to the model, then the flier releases
March 2001 123
Lee Hines used this six-panel-wing towline to gain a spot on the F1A Glider team. The
model’s wingspan is roughly 2,290 millimeters—approximately 90 inches.
Walt Ghio launches. Makarov wing airfoil,
tape invigorators give model great glide.
Power: 28 strands 1⁄8-inch May 99 Tan II.
the bottom end of the line. Drag of the line
pulls the top end of the line off the hook,
and the flight time commences.
The model continues upward because
of the high speed and high line tension,
well above the height of the towline. This
zoom-launch, which can gain 30 feet or
more, is followed by a quarter outside
loop, called a bunt, which pushes the nose
of the almost-vertical model over into
glide position.
To control all this, an electronic or
mechanical timer is used in combination
with a towhook that pivots fore and aft.
When the model is under straight tow,
the hook pulls forward; this pulls the
rudder straight or slightly left, to give a
straight tow. When tension on the towline
is released, the hook swings back and the
rudder goes sharply right, to give a tight
circle on tow.
Often, the towhook is also connected to
a wing-wiggler that adjusts the angle of
one wing (all these models have two-piece
wings). This allows optimum wash-in
settings for straight tow, circle-tow, and
glide.
At the rear of the model, the stabilizer
is typically set slightly up from the glide
position during tow, to give increased line
tension and make towing easier—
especially in calm conditions.
At the end of the zoom, the stabilizer
moves down sharply for a brief instant to
cause the bunt, then it moves to the glide
position. There are often two glide
Power F1C team member Ken Oliver cleans the oil from his model while Kenny
Happersett (Fountain Valley CA) watches. Notice the tiplets on the wing.
settings: a fast glide used for 10-20
seconds, to dampen any stalls, and a
slightly more “up” slow-glide position, for
maximum duration.
For models equipped with an
electronic timer, adjustments are made via
a laptop or a palm-size computer,
allowing optimum settings for various
weather conditions to be stored and
downloaded as needed.
The tremendous launch loads have
lead to the almost universal use of carbon
fiber for glider wings. The spar is roughly
a half-inch square at the center, tapering
toward the tips. Top and bottom spar caps
are unidirectional carbon, close to 1⁄16-
inch thick.
The D-box, which provides torsional
stiffness, is a vacuum-molded shell of
carbon cloth and epoxy with the fibers
running at 45°. Structure is minimal aft
of the spar, with carbon-capped balsa
ribs and a narrow carbon-fiber trailing
edge.
F1B Wakefield models are limited to 35
grams (slightly more than an ounce) of
rubber and a minimum all-up weight of
just more than eight ounces. Fuselage
length is roughly 49 inches, with
wingspans ranging from approximately 63
inches to slightly more than six feet.
With the limited amount of rubber
available, getting the maximum useful
energy out of it is the key. This begins
with carefully selecting and testing
rubber batches, then each individual
motor.
(An informal and unscientific survey
showed a preference for the May 99 batch
of Tan II rubber; most people used 26 or
28 strands of the 1⁄8-inch width.)
Motors are stretch-wound to nearbreaking,
and they are used once.
Typical turns are in the 400-500 range.
Many people, including the three team
members, use torque-actuated variablepitch
units that hold the blades at high
pitch during the power burst, then
decrease the pitch as the torque
decreases.
Propeller blades are fiberglass clothcovered
carved balsa or molded carbon
fiber over foam. The typical diameter is 24
inches, with a nominal pitch of roughly 29
inches. This gives a motor run of
approximately 45 seconds.
Construction practices follow the glider
model, but with spar sizes scaled down to
reflect the smaller, more lightly stressed
Wakefield wing.
The motor tube is typically made from
Russian aramid fiber and epoxy. The
tailboom is a thin, tapered tube of
unidirectional carbon and aluminum.
A clockwork or electronic timer is used
to control flight functions, which typically
include a two- or three-position auto
rudder, a VIT (variable incidence
tailplane), and a wing-wiggler.
The auto rudder is held slightly left
during the power run, then is released to
the glide position near the end of the motor
run. (Almost everyone flies F1B in a right
power-right glide pattern.)
The VIT holds the stabilizer trailing
edge down roughly 1⁄8 inch during the
first three to four seconds of the flight,
to reduce loping tendency during the
power burst.
A wing-wiggler is often used to hold
the trailing edge of the left wing half up
slightly throughout the power phase of
flight, to minimize the right wing’s
tendency to drop at the end of the burst.
Launching is near-vertical with a hard
throw. On many models, a timeroperated
delay mechanism starts the
propeller turning, and the model
accelerates in a steep climb through the
power burst. Even the cruise, although
slow, keeps the nose well up, to give a
height of well above 300 feet.
F1C Power models use 2.5cc (.15
cubic-inch) engines running on an 80/20
alcohol/oil mixture. Rpm is roughly
30,000. The engine run is limited to five
seconds. A typical model spans 100
inches or more, and weighs
approximately 28 ounces.
Construction usually follows that of
the other two FAI models, with a carbonfiber
D-box wing covered with plastic
film. Some still use aluminum-covered
balsa wings.
Considerable effort goes into
streamlining the models, with fully-cowled
engines and folding carbon-fiber propellers.
As in the other two events, electronic or
clockwork timers are used to control flight
functions. These include VIT, auto rudder,
and wing-wiggler, used to give a straight
vertical climb.
After the timer cuts the engine, the
model coasts up, gaining additional
altitude, then bunts over into the glide.
The fast glide-slow glide is also popular
to settle the model down after the bunt.
The sound and sight of these unmuffled
models climbing straight up has to be one
of the most exciting images in modeling.
Think of vertical drag racing.
Final observations:
• The overall quality of models has
improved greatly, and almost everyone
flies “high-tech” models. Much of this is
no doubt attributed to the elimination of
the builder-of-the-model rule, which
allows modelers to purchase high-quality
components and models from the
Ukraine, Russia, and few domestic
sources. You no longer need a machine
shop to fly the FAI events.
However, many people do still build
their own models. Almost the only
“bought” piece on Walt Ghio’s model is
the Andriukov variable-pitch front end.
• Model development seems to have
plateaued, with subtle refinements rather
than radical improvements. The climb
speed in F1B has slowed, with longer
motor runs, placing less emphasis on
drag in the power burst and more on the
cruise and glide.
Walt Ghio and Roger Morrell used
undercambered stabilizers, ostensibly to
help prevent stalling during the steep,
slow cruise. (The recent trend has been
semisymmetrical stabilizer airfoils, such
as the Wobbeking.) Walt also used a
more cambered wing airfoil—a Makerov
glider airfoil—equipped with turbulator
and invigorators on the upper surface.
In Glider, Randy Archer and Victor
Stamov showed me their RC-DT feature. It
is a removable pod that plugs onto the top
of the fuselage and allows radio-activated
March 2001 125
DT during test flights. It is removed for
official flights.
(RC-DT is only allowed for contest
flights in F1C Power for motor stop or DT.)
RC-DT should be a great asset for
those of us who test-fly on small
fields.
Perhaps the biggest innovation at
this Finals was the Verbitsky
“Reductor.” Former World Champion
Evgeny Verbitsky introduced the
geared model several years ago. It
features a planetary gear system of his
design that allows the engine to swing
a much larger, more efficient propeller
(roughly 12 inches vs. seven inches).
Evgeny recently made a small batch
(probably half a dozen) for sale. The climb
is very good, and the sound is incredible.
• There is no room for mistakes. To
make the team, you have to make the
flyoff. Launch in bad air, set the timer
wrong, or make any one of dozens of
other mistakes, and you drop a round and
lose a chance at the flyoff and a team
slot.
Thorough preparation and mental
concentration are two keys to success.
• Test-flying during the contest is important.
Perhaps it was because high winds limited
practice time before the contest, but there was
considerably more practice-flying between
rounds than at previous finals.
Some of the Power fliers made two or
three check-flights during the 40-minute
break between each round. It was
suggested that this was more for the flier
to keep his launch technique warmed up
than to tweak the model’s settings.
• Thermal detection was mostly electronic.
Only a few people used cattail fluffies,
and no one used soap bubbles.
Most power and Wakefield fliers used
some sort of thermister to measure airtemperature
changes; most were directreading
and a few were recording meters.
Many people used wind meters as well as
thermistors.
(Glider fliers pick lift based on the
feel of the model on the line—none of
this electronic stuff for them.)
However, piggybacking was the
easiest and safest way to go, with the
large number of people flying.
• Frequent long periods of calm
resulted in 20 or 30 Wakefield fliers
standing around, with motors (and
nerves) wound, waiting for a slight
breeze that might indicate a thermal.
No one wanted to go first.
When a thermal did come through,
there was a ripple down the line as
models were launched toward the
thermal. However, picking air wasn’t a
sure thing.
• Quite a few modelers were there from
the Ukraine, to help their American
friends. This added an international
flavor to the contest and provided the
opportunity for many of us to visit with
the people who helped create the
modern high-tech FAI models.
Former World Champion Victor
Stamov assisted former US team
member Randy Archer.
Igor Vivchar (and New Zealander
John Malkin) cheered Roger Morrell on
to a team place.
Vasily Beschasny divided his time
between helping Don Zink with Glider
and chasing for Fred Pearce in Wakefield.
Evgeny Verbitsky brought geared
models for Randy Archer and several
others. He also took advantage of the
weather and the field, and did a bit of
test-flying.
Current World Champion Oleg
Kulakovsky visited three-time World
Champion Alexander Andriukov, who
now lives in California, and flew in his
first US Finals.
• Most importantly, a contest such as this
can’t be put on without many dedicated
volunteers. Thanks to Contest Director
George Batiuk and all the team. Thanks
also to the spouses, sons, daughters, and
other folks who helped time. We
appreciate the effort. MA
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