Reigning in model performance
[[email protected]]
Free Flight Duration Louis Joyner
Also included in this column:
• E-36 provisional electric event
update
• FF Team Selection report
• Junior Team Selection update
Above: Roger Morrell winds a rubber
motor using outside-the-model system. He,
Walt Ghio, and Bob Piserchio maxed nine
rounds to make the US FIB team. Tiffaney
O’Dell photo.
Right: Steve Spence helps his dad Henry
work on his folding-wing F1C model. Steve
placed third to make the US F1A Towline
Glider team. O’Dell photo.
AS FF MODELS improve, the number of
flying sites that can accommodate them
lessen. And many of those flying sites are,
of necessity, located far away from
population centers. (The California site is
not called “Lost Hills” for nothing.)
No wonder that so few people,
including most AMA members, have ever
seen a contest FF Duration model in
action.
To allow FF models to be flown on
small fields and to attract new people to
FF, model performance must be limited.
(The Flying Aces Club has done this
successfully by concentrating on Scale
models that, by their nature, have relatively
low performance compared to out-and-out
FF Duration models.)
There is a need for low-performance,
small-field FF Duration events that will
allow us to fly at sites that are close to
population centers and, it is hoped, expose
more people to FF.
For the existing Duration events the
rules-makers have, through the years,
limited performance by reducing altitude in
the climb and by increasing the rate of sink
in the glide. But modelers are a competitive
and ingenious lot. Every rule to decrease
model performance has been answered by
improvements in model design,
construction, and flying tactics.
Most rules changes lead to an increase
in a model’s cost and complexity. Changes
in aircraft specifications can have a major
cost impact.
A competitive FAI flier usually has
$1,000-$2,000 tied up in each model and
typically has at least four. A rules change
that would make those models no longer
legal might turn that modeler from FF to
stamp collecting or fly-fishing.
We need to look at the ways we fly the
models we have now. The problem is
usually not performance per se, but with
models flying off the field.
For more than a half century we have
had a simple and reliable way to limit
model performance: the DT. Controlled by
an onboard timer or fuse, the DT pops the
May 2007 137
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Rex Hinson’s E-36 model uses Dick Ivers’ electronic timer to control motor run and DT.
For DT a hot wire burns through a rubber band, releasing a line to the stabilizer. Hinson
photo.
On another version of his Sparks E-36, Rex uses an early prototype of the new Texas
Timers Micro E. See text for more about timers and Sparks E-36. Hinson photo.
tail up, putting the aircraft into a deep stall
so it descends rapidly and safely to the
ground. (For lightly loaded models, more
radical DT arrangements such as pop-off
or folding wings may be necessary to get
the model down from a strong thermal.)
The distance a model travels
downwind is a function of climb altitude,
dead-air glide rate of sink, thermal
activity, and wind speed. Only altitude
and sink rate are influenced by model
specifications.
Many of us have had the enjoyable
experience of a contest day with virtually
no wind and gentle thermals. Chases are
measured in feet—not miles.
Even on a more typical day, wind
speed and thermal activity are lower in the
morning, building to a peak at
midafternoon, and then dropping back
toward evening. However, the way many
contests are run pushes the flying into the
time of day that is most likely to carry
models off the field.
A better approach would be to start
early, say 30 minutes after sunup; suspend
flying during the middle of the day, when
wind and thermal activity peak; and then
resume flying in the late afternoon.
Maximums could—and should—be
adjusted to suit atmospheric conditions
and keep models on the field. Such an
approach is easy when flying by rounds
from designated pole positions, as with
the FAI events.
A good example was F1B at the 2006
Nats. Event Director Chuck Markos had
read the weather forecasts, which called
for increasing wind during the day. He set
a higher than normal first-round max,
knowing that it would most likely be the
longest max of the day.
As the wind increased, Chuck
decreased the max to suit the conditions.
The result was that only two or three
flights went off the field.
Another approach that works for FAI
events with a small number of contestants is to
vary round length to suit weather and retrieval
conditions. Rounds are set at the usual one
hour, but they can be shortened by unanimous
consent of the fliers involved.
Compressing the rounds allows more
flights to be fit in before thermal and wind
activity pick up, yet it allows a competitor the
full hour if he or she needs it for a long chase,
model repair, or simply to rest.
With the current AMA rules, modelers
can fly when they want and often from
where they want. This makes it impossible
for the CD to change the max after the start
of the contest day.
Perhaps we need to investigate ways to
allow adjustments in the max during the
course of the contest. The simplest way
would be to fly all AMA events in rounds,
with max times adjusted up or down for
each round to suit conditions.
Another method would be to require a
certain number of flights be completed
during a set time period. At the end of that
period, the CD would evaluate weather
conditions and adjust max length for
another group of flights.
For instance, flights 1, 2, and 3 must be
flown between 8 a.m. and 11 a.m. Flights 4
and 5 must be flown between 11 a.m. and 1
p.m., and so on. Better yet, take a break
midday and pick back up at 3 p.m. or 4
p.m. The max times would not necessarily
have to follow the standard length and
order established for that event and
category.
The goal should be to adjust the flying
schedule to take maximum advantage of
weather conditions, to minimize the
number of flights going off-site. (For
record purposes the standard max times
and flight order would need to apply.)
E-36 Update: The provisional E-36
electric-power event seems to be attracting
increased interest and will be flown at this
year’s Nats. Several suppliers have stepped
up to make getting started easier.
BMJR Model Products is kitting Rex
Hinson’s Sparks design, which was
detailed in the November 2006 FF
Duration column. The February 2007
National Free Flight Society (NFFS)
Digest featured a construction article for
the kit. The laser-cut kit sells for $38.75
138 MODEL AVIATION
05sig5.QXD 3/23/07 9:45 AM Page 138
plus shipping and handling. Visit the
company’s Web site at www.bmjrmodels.com
for more information.
Two suppliers are offering timers
designed for the E-36 event. Hank Nystrom
of Texas Timers has developed the Micro E
mechanical timer. The faceplate measures
21/8 x 15/16 inches and weighs 7.2 grams,
including the snubber capacitor and wires.
Run time can be set for up to 30 seconds.
(Motor run for the E-36 event is 25
seconds.)
Based on the popular Micro I pinch-off
timer for Gas models, the Micro E will be
familiar to many Power fliers. Check the
Web site at www.texastimers.com for the
price.
Dick Ivers’ E-36 electronic timer offers
motor run and DT functions. The motor run
features a soft start and electrodynamic
braking at the end of the run. The timer can
trip the DT via servo or by using a hot wire
to burn through a rubber band. The timer
measures just less than 1 inch square and
weighs 2.5 grams without wires or cables.
The price is $35 plus $4 shipping and
handling. A start switch, hotwire board, and
cables are extra. E-mail Dick at rivers@
rcn.com for additional information.
US Team for 2007 FF World
Championships: Weather conditions were
anything but easy at the US Team Selection
Finals held in October at Lost Hills,
California. The 71 contestants vying for the
nine team slots encountered rain, dust, and
winds up to 40 mph.
“The weather was really screwy,” said
F1B Event Director Walt Rozelle. “I even
saw a little bit of hail at one point.” (Other
event directors were Martin Cowley for
F1A and Doug Galbreath for F1C.)
The normal Team Selection Finals
format is for two of the three events to be
flown each day, with the contestants in the
third event timing. During the three-day
period that should mean each contestant
flies seven rounds on each of two days,
plus flyoffs.
For this contest F1B and F1C
contestants were only able to get in two
rounds each before weather conditions
forced finals CD and reigning F1A World
Champion Mike McKeever to cancel flying
for the rest of the first day.
Weather conditions were better the
second day, allowing F1A and F1B
contestants to get in the scheduled seven
rounds. That left only three people maxed
out in F1B, so the US Team of Walt Ghio,
Roger Morrell, and Bob Piserchio was set
without the need for a flyoff. (Walt and
Bob made the team for the first time in
1977.) Bob Biederon dropped two seconds
in the last round to finish fourth.
On the third day F1A fliers flew six
rounds. Brian Van Nest was the only flier
to max all 13 rounds. Joining him on the
F1A team are Ken Bauer, who dropped 11
seconds in the ninth round, and Steve
Spence, who dropped 19 seconds in that
same round. Dave Edmonson is the
alternate.
In F1C 13 fliers maxed out after six
rounds. A single flyoff determined the team
of Bucky Servaites, with 397 seconds; Ron
McBurnett, with 283; and Dick “Fast
Richard” Mathis, with 340. The alternate is
Don Chesson at 337 seconds.
The FF World Championships will be
June 24-July 1 in Odessa, Ukraine. Mike
McKeever will be there defending his F1A
title. Blake Jensen will be the team
manager and Jim Parker will be the
assistant.
In addition, 2004 Junior FF World
Champion John Lorbiecki will be present to
defend his F1C title. (If a Junior World
Champion ages up to the next class, as John
did, he is allowed to defend his title at the
World Championships.)
Junior Team Selection Update: The Junior
FF World Championships, flown in evennumbered
years, consists of three events:
F1A Towline Glider, F1B Rubber, and F1P
Power. Instead of a single finals, as is used
for the Senior team, the 2008 US Junior
Team will be selected based on
performances at contests across the
country, including the 2007 Nats.
The deadline for entry in the program is
July 1, 2007. For more information about
the Junior program, check the NFFS Web
site at www.freeflight.org or E-mail Jim
Parker at [email protected]. MA