[[email protected]]
Radio Control Soaring Lee Estingoy
What is F3J and why does it matter?
Preparation is everything in F3J. A pilot
can use a backup model if something
happens to the primary on launch. Teams
generally have their models ready to fly at
the flip of a transmitter switch.
Jim Monaco (L) and a large guy from Denver work a tow. The monofilament line is
stretchy and a pulley is used, so the towers only cover maybe 50 feet. Imagine the force
that two men with a pulley can generate for a model.
Cody Remington signals his tow people
that he wants to launch with the line to his
left. Teams have two lines ready for
launch. If one breaks, they use the backup.
Pointy noses score points in F3J. Points decline gradually on the tape’s length. Pilots
generally drive their models into the ground, to ensure that they don’t slide past the
target. The tape is anchored at the 100-point mark and might be swung out to measure a
landing score.
MOST OF US are familiar with
traditional Thermal Duration (TD) and
most of us have heard of F3J Soaring, but
I’ll wager that not many out there
understand the subtle differences between
the two contest formats. I certainly didn’t.
One of the premier F3J events held in
the US is the F3J in the Rockies contest. I
made the quick hop from Kansas City,
Kansas, to Denver, Colorado, to check it
out.
What does “F3J” mean? It is the
citation to the FAI rule book, which details
the rules for the contest.
What is the executive summary of
F3J’s rules? All pilots are given a flight
window of 10 minutes. They must launch
simultaneously, and each is awarded a
point for every second the glider is in the
air.
Time spent on the towline is not
counted for points and is subtracted from
the time score. There is a precision landing
component, with a decremented measuring
tape anchored at one end. That point is the
November 2009 127
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:52 PM Page 127
target for maximum points.
The towline is monofilament, and the
distance to the turnaround is carefully
measured to be the same for all
competitors. Human muscle power provides
power for the tow; two people pull the 150-
meter line on the launch command. Scores
from preliminary rounds determine which
pilots make the flyoff, to determine the
winner.
The F3J World Championship is held
every other year. The next will be at Dole-
Tavaux, France, July 29-August 8, 2010.
The US team selection was held September
5-7, 2009, in Denver.
What are the primary differences between
F3J and US TD contests? Simultaneous
launches
. F3J in the Rockies was a model of
efficiency. There was a public-address
system with speakers placed near each
launch station. The system played a
prerecorded countdown and launch
announcement, along with announcements
signaling the end of the flight window.
Everybody launched simultaneously. Some
US contests do use the “man-on-man”
format, which is similar. Theoretically, this
exposes all pilots in the flight group to
identical weather conditions, as opposed to
some TD contests that cycle through pilots
in the course of a round, so that not all
pilots are in the air at the same time.
The next most obvious difference is the
use of the springy monofilament towline to
launch each aircraft. The line is pulled by a
team of two tow people in F3J and an
electric winch and braided nylon line in
TD.
The F3J system can impart tremendous
amounts of energy into the airframe in a
short time. This adds an entire level of
difficulty to F3J, because each team of
fliers is responsible for its own tow people.
In TD, we’re used to getting our models
and our stopwatches to the field. Consider
having to get somebody to sit out in a field
for many long hours, waiting for brief
(roughly 10 seconds of) tow activity.
I was shanghaied into the launch crew
for a team in Denver. I was amazed by
how much force we could put into the line
and, ultimately, the model. There is a
system of pulleys in use, so the actual
pulling “run” is rather short.
There are strategic differences between
F3J and TD. The top echelons of pilots in
both classes usually make the goal flight
times.
In F3J, the pilot can choose to take a
shorter launch, leaving more of a flight
window and less time on the line. That
gives the ability to theoretically score
more points than a pilot who stayed on tow
longer. There’s quite a bit of gambling
going on.
Regarding airframe comparisons, the
brutal launches make sturdy sailplanes a
requirement in F3J. Its landing
requirements deduct 5 points for every
meter from the target spot. This is easy
when compared to TD.
A TD contest generally subtracts 1
point per inch from the target spot. This
means that the TD aircraft generally have
larger flaps and more area in their
elevators and rudders than their F3J
counterparts, to give more pinpoint
control.
V-tails are much more common in F3J,
because they are shown to provide a
lighter airframe and offer some reduction
in drag.
A final point of evolutionary
divergence is that the F3J fliers generally
“land” their models by literally driving
their noses into the ground. Therefore, F3J
gliders have pointy noses and fuselages
that are built to survive this kind of abuse.
TD aircraft generally aren’t driven into
the ground, although some contests allow
the use of pointed teeth, or skegs, to keep
the models from sliding on touchdown.
Why does F3J matter? This question is
best answered by suggesting that F3J is to
Soaring as soccer is to football. F3J is the
format for the rest of the world, whereas
TD is basically limited to the US.
Given that the format is much more
popular in Europe and that most of the
leading airframe manufacturers are European,
there are generally more evolutionary cycles
for F3J models than TD models. This results
in F3J competitors having more of a variety in
airframes and airfoils.
F3J in the Rockies was a bit more
interesting than the standard US TD contest.
With the preliminaries and flyoff system,
there are many more competitors in position
to win the competition during the flyoff. The
launch schedule is easy to follow, and the
Denver event literally ran like clockwork.
Many US TD contests have moved to a
man-on-man format as well. One segment
of US Soaring that is moving to rules that
are similar to those in F3J rules is electric
F5J. This is not an FAI classification, but
rather a proposed set of rules that runs the
contests in a manner similar to F3J.
Pilots have a working time, and their
motor run times are counted against the final
score. That encourages shorter motor runs and
more thermaling, compared with the previous
strategy of climbing to the moon and coasting
to the ground without the need to work the
model to find thermals. MA
Sources:
F3J in the Rockies information:
www.rmsadenver.com/f3j_in_the_rockies.
htm
F3J rules:
ftp://www.fai.org/sporting_code/sc4/sc4_f
3_soaring_09.pdf
US F3J team:
www.usf3jteam.com
US F3J team selection for 2010:
www.rmsadenver.com/f3jts.htm
League of Silent Flight
www.silentflight.org
Edition: Model Aviation - 2009/11
Page Numbers: 127,128
Edition: Model Aviation - 2009/11
Page Numbers: 127,128
[[email protected]]
Radio Control Soaring Lee Estingoy
What is F3J and why does it matter?
Preparation is everything in F3J. A pilot
can use a backup model if something
happens to the primary on launch. Teams
generally have their models ready to fly at
the flip of a transmitter switch.
Jim Monaco (L) and a large guy from Denver work a tow. The monofilament line is
stretchy and a pulley is used, so the towers only cover maybe 50 feet. Imagine the force
that two men with a pulley can generate for a model.
Cody Remington signals his tow people
that he wants to launch with the line to his
left. Teams have two lines ready for
launch. If one breaks, they use the backup.
Pointy noses score points in F3J. Points decline gradually on the tape’s length. Pilots
generally drive their models into the ground, to ensure that they don’t slide past the
target. The tape is anchored at the 100-point mark and might be swung out to measure a
landing score.
MOST OF US are familiar with
traditional Thermal Duration (TD) and
most of us have heard of F3J Soaring, but
I’ll wager that not many out there
understand the subtle differences between
the two contest formats. I certainly didn’t.
One of the premier F3J events held in
the US is the F3J in the Rockies contest. I
made the quick hop from Kansas City,
Kansas, to Denver, Colorado, to check it
out.
What does “F3J” mean? It is the
citation to the FAI rule book, which details
the rules for the contest.
What is the executive summary of
F3J’s rules? All pilots are given a flight
window of 10 minutes. They must launch
simultaneously, and each is awarded a
point for every second the glider is in the
air.
Time spent on the towline is not
counted for points and is subtracted from
the time score. There is a precision landing
component, with a decremented measuring
tape anchored at one end. That point is the
November 2009 127
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:52 PM Page 127
target for maximum points.
The towline is monofilament, and the
distance to the turnaround is carefully
measured to be the same for all
competitors. Human muscle power provides
power for the tow; two people pull the 150-
meter line on the launch command. Scores
from preliminary rounds determine which
pilots make the flyoff, to determine the
winner.
The F3J World Championship is held
every other year. The next will be at Dole-
Tavaux, France, July 29-August 8, 2010.
The US team selection was held September
5-7, 2009, in Denver.
What are the primary differences between
F3J and US TD contests? Simultaneous
launches
. F3J in the Rockies was a model of
efficiency. There was a public-address
system with speakers placed near each
launch station. The system played a
prerecorded countdown and launch
announcement, along with announcements
signaling the end of the flight window.
Everybody launched simultaneously. Some
US contests do use the “man-on-man”
format, which is similar. Theoretically, this
exposes all pilots in the flight group to
identical weather conditions, as opposed to
some TD contests that cycle through pilots
in the course of a round, so that not all
pilots are in the air at the same time.
The next most obvious difference is the
use of the springy monofilament towline to
launch each aircraft. The line is pulled by a
team of two tow people in F3J and an
electric winch and braided nylon line in
TD.
The F3J system can impart tremendous
amounts of energy into the airframe in a
short time. This adds an entire level of
difficulty to F3J, because each team of
fliers is responsible for its own tow people.
In TD, we’re used to getting our models
and our stopwatches to the field. Consider
having to get somebody to sit out in a field
for many long hours, waiting for brief
(roughly 10 seconds of) tow activity.
I was shanghaied into the launch crew
for a team in Denver. I was amazed by
how much force we could put into the line
and, ultimately, the model. There is a
system of pulleys in use, so the actual
pulling “run” is rather short.
There are strategic differences between
F3J and TD. The top echelons of pilots in
both classes usually make the goal flight
times.
In F3J, the pilot can choose to take a
shorter launch, leaving more of a flight
window and less time on the line. That
gives the ability to theoretically score
more points than a pilot who stayed on tow
longer. There’s quite a bit of gambling
going on.
Regarding airframe comparisons, the
brutal launches make sturdy sailplanes a
requirement in F3J. Its landing
requirements deduct 5 points for every
meter from the target spot. This is easy
when compared to TD.
A TD contest generally subtracts 1
point per inch from the target spot. This
means that the TD aircraft generally have
larger flaps and more area in their
elevators and rudders than their F3J
counterparts, to give more pinpoint
control.
V-tails are much more common in F3J,
because they are shown to provide a
lighter airframe and offer some reduction
in drag.
A final point of evolutionary
divergence is that the F3J fliers generally
“land” their models by literally driving
their noses into the ground. Therefore, F3J
gliders have pointy noses and fuselages
that are built to survive this kind of abuse.
TD aircraft generally aren’t driven into
the ground, although some contests allow
the use of pointed teeth, or skegs, to keep
the models from sliding on touchdown.
Why does F3J matter? This question is
best answered by suggesting that F3J is to
Soaring as soccer is to football. F3J is the
format for the rest of the world, whereas
TD is basically limited to the US.
Given that the format is much more
popular in Europe and that most of the
leading airframe manufacturers are European,
there are generally more evolutionary cycles
for F3J models than TD models. This results
in F3J competitors having more of a variety in
airframes and airfoils.
F3J in the Rockies was a bit more
interesting than the standard US TD contest.
With the preliminaries and flyoff system,
there are many more competitors in position
to win the competition during the flyoff. The
launch schedule is easy to follow, and the
Denver event literally ran like clockwork.
Many US TD contests have moved to a
man-on-man format as well. One segment
of US Soaring that is moving to rules that
are similar to those in F3J rules is electric
F5J. This is not an FAI classification, but
rather a proposed set of rules that runs the
contests in a manner similar to F3J.
Pilots have a working time, and their
motor run times are counted against the final
score. That encourages shorter motor runs and
more thermaling, compared with the previous
strategy of climbing to the moon and coasting
to the ground without the need to work the
model to find thermals. MA
Sources:
F3J in the Rockies information:
www.rmsadenver.com/f3j_in_the_rockies.
htm
F3J rules:
ftp://www.fai.org/sporting_code/sc4/sc4_f
3_soaring_09.pdf
US F3J team:
www.usf3jteam.com
US F3J team selection for 2010:
www.rmsadenver.com/f3jts.htm
League of Silent Flight
www.silentflight.org