[[email protected]]
Radio Control Slope Soaring Dave Garwood
Guest columnist, Bruce DeVisser, on scale Slope Soaring
A gaggle of 3-meter DAW
Ka-6 EPP sailplanes work
to get into formation for
synchronized sloping, flown
by the Aliso Viejo Gang of
Southern CA. They take
advantage of EPP resilience
as they nudge into position.
DeVisser photo.
A fun-fly event for scale Schweizer sailplanes was held at
the famous Torrey Pines CA gliderport. Ren DiLeo photo.
This Reichard LF-107
Lunak, an 11-pound,
4-meter ARF from
Hobby Club, was
built by Jonathan
Alpert of Laguna
Nigel CA. Bruce
DeVisser photo.
Here is a sampling of what is available
from Hobby Club in small to midsize ARF
scale Sailplanes. DeVisser photo.
IN THE RC SKIES, few models look as serene and as sophisticated as
a long-wing Scale glider in flight. For nearly 20 years, the South Bay
Soaring Society (SBSS) has run the impressive Los Banos Scale
Sailplane Event at the magnificent Los Banos Reservoir RC flying site
in north central California.
This month I have a guest columnist, Bruce DeVisser, from San
Jose, California. Bruce is an SBSS officer who wrote about scale RC
Slope Soaring. In the current context “scale” means a radio-controlled
model of a full-size sailplane, either modern or vintage, and “power
scale soaring” or “PSS” refers to a radio-controlled, unpowered model
of a full-size, powered prototype, either propeller or jet.
Here is Bruce:
“What attracts modelers to scale Slope Soaring? The answer is
simple—Slope Soaring is a lot of fun, and those who are interested in
scale models want to fly their scale sailplanes on the slope, too.
“There is no fundamental difference between PSS and scale
sailplane Slope Soaring—okay, roll rate is much higher with a PSS
model. There is another difference. As long as the wind blows, you can
keep flying. There is no dependence on searching out a thermal to
maintain altitude, and if you want to loop or roll there is lift for
recovery to the original altitude.
“If one were to ask a group of RC pilots what type
of models were used for Slope Soaring, I believe
the answers would mostly describe sport
sailplanes, purpose-designed Slope Soaring or racing models, and PSS
aircraft. If one were to ask about scale sailplanes and Slope Soaring,
many people would say scale sailplanes are only used for aerotowing.
Although that may be true for a large segment of the scale sailplane
community, many dedicated slopers only fly their ‘scalies’ on the slope,
and forego a tow release, practically a standard feature on a scale
sailplane.
110 MODEL AVIATION
08sig4xx_00MSTRPG.QXD 6/23/11 1:31 PM Page 110
August 2011 111
launched off of a hilltop or by use of a bungee
or winch, because they could only descend to
land after launching. Therefore, slope models
generally are gliders because they cannot
achieve thermal flight, but they do very well in
the much stronger lift on the slope.
“Vintage sailplane models, such as the
well-known Minimoa, can have light wing
loading, thick airfoils, and therefore a lot of
drag, making them difficult to fly in strong
slope winds unless a provision is made to add
ballast.
“Modern sailplanes benefit from years of
airfoil research that has produced thinner
airfoils with greater lift, and designers have
followed a parallel path in producing efficient
airfoil shapes for flying models of all types. It
is possible to use a more efficient modern
airfoil with a thinner profile on a vintage
sailplane, but the appearance is not as pleasing
to the eye as the prototypical thicker ones—it
just doesn’t look right—so ballast is an easily
available remedy.
“The thinner airfoils of full-scale modern
sailplanes, such as a DG-600, don’t often work
well in model size until the model scale
approaches ½ scale. Efficient model airfoils
have been developed that look the part, giving
model designers the tools they need to have a
model that flies as good as it looks.
“One interesting outcome of this is that
virtually any modern scale sailplane model
“In the 1980s I had an introduction to scale
sailplanes and Slope Soaring while working in
Europe. While there I met several friendly,
knowledgeable, enthusiastic modelers, and
observed their beautiful models soaring in
mountain conditions.
“The flying was not always in true slope
conditions—the models could range out over
the mountain valley and pick up thermals (in
my club we call this Slermal flying), but there
was plenty of slope action going on with
screaming high-speed passes and aerobatics.
Some weeks later I was able to visit a vacation
area where you could fly models in a more
usual slope setting—a grassy meadow on a
hillside—but the lift and action were both
good.
“Scale sailplane modeling developed
primarily in Europe, motivated by the rich
history of full-scale glider and sailplane
development that started there and continues
still. It wasn’t long before scale sailplane
modeling started in the US with Europeanmade
models acquired from makers such as
Multiplex, Graupner, and Rosenthal. Europe is
still a leading source of scale sailplane models
today.
“Flying scale models of any kind is not for
everyone and the definition of what constitutes
a scale model varies from person to person,
mostly by degrees of fidelity to scale. In my
experience, those who fly scale sailplane
models want something that looks much like
the full-scale prototype, on the ground and in
the air, and individual taste varies from sport
or semiscale to ‘scale maniacs’ who insist on
modeling every detail.
“As with any scale model, how well it flies
and how easy it is to fly are concerns, and
although the size of the model can make a big
difference, slope lift will accommodate
smaller scale model sailplanes than a thermal
flight will.
“One item common to any model flown on
the slope is wing loading and the ability to
penetrate the air when the wind is strong. This
applies particularly to scale sailplanes.
“Wait, what about gliders? This is one of
those areas where terminology can cause
confusion, so let’s define a glider as an aircraft
that does not have the ability to sustain flight
from naturally occurring thermal activity
(rising heated air), whereas a sailplane can
‘sail’ in and gain altitude from thermals.
“In the early days of nonpowered flying,
every aircraft was a glider, whether being
Above: Ken Kaye launches his
27-pound, 1/3-scale, 6-meter
Ripo DG-800 at California’s
Los Banos Reservoir. DeVisser
photo.
Willy Grundler and his Vintage
2.6-meter SG-38 Schulgleiter
(training glider) from the Krick
kit enjoys slope lift at Los
Banos. DeVisser photo.
08sig4xx_00MSTRPG.QXD 6/23/11 1:32 PM Page 111
will fly well on the slope even if it has really
good thermal performance, and usually
without adding ballast.
“When it comes to flying scale models on
the slope, important considerations are the
launch method and the landing area.
Launching a sailplane successfully into slope
lift requires some planning. A launcher cannot
accelerate a typical model to stable flying
speed with a simple push off. The technique is
to launch the model directly into the wind, in a
slightly nose down attitude, following the
slope face until safe flying speed is reached
before leveling off.
“One difference compared to other types of
slope models is the tendency for a wing to lift
up at the point of release if not directly into the
wind, leading to loss of control. Larger
wingspans increase this tendency, so take your
time to assess the wind conditions and, if
possible, get an experienced person to launch
for you.
“Once you are flying, the main difference
is style. Large graceful maneuvers are the
strength of scale sailplanes, along with an
ability to climb to the top of a lift wave or
bubble.
“At my club’s main slope site, Los Banos
Creek Reservoir in Central California, we can
fly to the limit of eyesight in two or three wind
directions while only 500 to 700 feet above us
with good lift conditions. Lift can shut down
suddenly at many sites, so always keep a
landing plan in the back of your mind.
“Slope fliers often tolerate very difficult
landing areas in order to fly at a slope site with
great wind and lift, and the models they fly are
built for this. Scale sailplane construction
varies from all balsa wood to all-molded
fiberglass, and they are not designed to
withstand repeated rough landings.
“Scale sailplanes typically have larger
wingspans than other slope models, ranging
from about 120-240 inches (3-6 meters), and
weigh more—from about 6-36 pounds (3-16
kilograms)—requiring a larger landing area
and gentle touchdowns—no dorking these
models into terra firma!
“This doesn’t mean a flat field is
required—a large shallow angle slope face is
easy to land on headed up the hill or even
across the face—but the surface has to be
good. Even full-scale sailplanes land this way
at some flying sites. When you see scale Slope
Soaring event articles online and in print they
mostly show the best sites such as Los Banos,
California; Point of the Mountain, Utah; Lake
Wilson, Kansas; Torrey Pines, California; and
similar places, but there are many suitable
sites around the country.
“If you are a slope flier with an interest in
trying scale sailplane sloping, the best
introduction is to get some stick time with a
fellow pilot who has experience and a suitable
model, with the goal of an initial flight
introduction without launch or landing
worries. A competent aileron pilot should be
able to handle a scale model, although having
experience with rudder and aileron is a benefit.
Scale sailplane models, especially vintage
types, turn much better when rudder is used
along with aileron and elevator.
“Once you get to the point of wanting your
own model, starting out smaller, lighter, and
simpler is better. Two gliders that tolerate
rougher slope conditions and are good as slope
sailplane trainers are scale EPP sailplanes such
as the 3-meter Ka-6, or the Schweizer 1-26 in
60-inch or 2-meter size. Both are designed by
Dave Sanders and available from Sky King
RC Products. These are easy to build and fly at
a reasonable price, and they bounce!
“If you feel you have enough experience, a
suitable flying site, and want a hard-body
sailplane, there are dozens of choices, but try
to stay in the lighter and cheaper 2.5- to 4-
meter range such as the Hobby Club semiscale
series, ICARE RC standard series, or similar
models. Most of these models have a
fiberglass fuselage and a balsa-covered foam
wing.
“If you are into building your own, there is
a wealth of plans and kits available for all
types of sailplanes, both vintage and modern,
many designed with sloping in mind. Check
out Island Models laser-cut vintage kits,
Traplet Plans Service, and Tom Martin RC.
There are also many neat accessories such as
pilots, instrument panels, and more.
“Further information can be found in
popular web forums, on club websites,
and in specialty magazines such as Flying
Scale Models from Britain and Aufwind
English from Germany. Any articles
written by Chris Williams (various
British model magazines) are worth
having as reference, and his scale
sailplane plans are first-rate. I have
included some information in the
‘Sources’ listing.” MA
Sources:
Bruce DeVisser
[email protected]
Graupner
www.graupner.de/en
Hobby Club
(949) 425-1362
www.hobbyclub.com
ICARE Sailplanes and Electrics
(450) 449-9094
www.icare-rc.com
Multiplex
(858) 748-8440
www.multiplexusa.com
Rosenthal Flugmodelle
[email protected]
http://rosenthal-flugmodelle.com
Sky King RC Products
(605) 878-1880
www.skykingrcproducts.com
Soar Utah
www.soarutah.org
SBSS
www.sbss.org
Tom Martin Radio Control
(816) 331-8807
www.tmrcsailplanes.com
Traplet Publications
(217) 355-2970
www.traplet.com
League of Silent Flight
www.silentflight.org
Edition: Model Aviation - 2011/08
Page Numbers: 110,111,112
Edition: Model Aviation - 2011/08
Page Numbers: 110,111,112
[[email protected]]
Radio Control Slope Soaring Dave Garwood
Guest columnist, Bruce DeVisser, on scale Slope Soaring
A gaggle of 3-meter DAW
Ka-6 EPP sailplanes work
to get into formation for
synchronized sloping, flown
by the Aliso Viejo Gang of
Southern CA. They take
advantage of EPP resilience
as they nudge into position.
DeVisser photo.
A fun-fly event for scale Schweizer sailplanes was held at
the famous Torrey Pines CA gliderport. Ren DiLeo photo.
This Reichard LF-107
Lunak, an 11-pound,
4-meter ARF from
Hobby Club, was
built by Jonathan
Alpert of Laguna
Nigel CA. Bruce
DeVisser photo.
Here is a sampling of what is available
from Hobby Club in small to midsize ARF
scale Sailplanes. DeVisser photo.
IN THE RC SKIES, few models look as serene and as sophisticated as
a long-wing Scale glider in flight. For nearly 20 years, the South Bay
Soaring Society (SBSS) has run the impressive Los Banos Scale
Sailplane Event at the magnificent Los Banos Reservoir RC flying site
in north central California.
This month I have a guest columnist, Bruce DeVisser, from San
Jose, California. Bruce is an SBSS officer who wrote about scale RC
Slope Soaring. In the current context “scale” means a radio-controlled
model of a full-size sailplane, either modern or vintage, and “power
scale soaring” or “PSS” refers to a radio-controlled, unpowered model
of a full-size, powered prototype, either propeller or jet.
Here is Bruce:
“What attracts modelers to scale Slope Soaring? The answer is
simple—Slope Soaring is a lot of fun, and those who are interested in
scale models want to fly their scale sailplanes on the slope, too.
“There is no fundamental difference between PSS and scale
sailplane Slope Soaring—okay, roll rate is much higher with a PSS
model. There is another difference. As long as the wind blows, you can
keep flying. There is no dependence on searching out a thermal to
maintain altitude, and if you want to loop or roll there is lift for
recovery to the original altitude.
“If one were to ask a group of RC pilots what type
of models were used for Slope Soaring, I believe
the answers would mostly describe sport
sailplanes, purpose-designed Slope Soaring or racing models, and PSS
aircraft. If one were to ask about scale sailplanes and Slope Soaring,
many people would say scale sailplanes are only used for aerotowing.
Although that may be true for a large segment of the scale sailplane
community, many dedicated slopers only fly their ‘scalies’ on the slope,
and forego a tow release, practically a standard feature on a scale
sailplane.
110 MODEL AVIATION
08sig4xx_00MSTRPG.QXD 6/23/11 1:31 PM Page 110
August 2011 111
launched off of a hilltop or by use of a bungee
or winch, because they could only descend to
land after launching. Therefore, slope models
generally are gliders because they cannot
achieve thermal flight, but they do very well in
the much stronger lift on the slope.
“Vintage sailplane models, such as the
well-known Minimoa, can have light wing
loading, thick airfoils, and therefore a lot of
drag, making them difficult to fly in strong
slope winds unless a provision is made to add
ballast.
“Modern sailplanes benefit from years of
airfoil research that has produced thinner
airfoils with greater lift, and designers have
followed a parallel path in producing efficient
airfoil shapes for flying models of all types. It
is possible to use a more efficient modern
airfoil with a thinner profile on a vintage
sailplane, but the appearance is not as pleasing
to the eye as the prototypical thicker ones—it
just doesn’t look right—so ballast is an easily
available remedy.
“The thinner airfoils of full-scale modern
sailplanes, such as a DG-600, don’t often work
well in model size until the model scale
approaches ½ scale. Efficient model airfoils
have been developed that look the part, giving
model designers the tools they need to have a
model that flies as good as it looks.
“One interesting outcome of this is that
virtually any modern scale sailplane model
“In the 1980s I had an introduction to scale
sailplanes and Slope Soaring while working in
Europe. While there I met several friendly,
knowledgeable, enthusiastic modelers, and
observed their beautiful models soaring in
mountain conditions.
“The flying was not always in true slope
conditions—the models could range out over
the mountain valley and pick up thermals (in
my club we call this Slermal flying), but there
was plenty of slope action going on with
screaming high-speed passes and aerobatics.
Some weeks later I was able to visit a vacation
area where you could fly models in a more
usual slope setting—a grassy meadow on a
hillside—but the lift and action were both
good.
“Scale sailplane modeling developed
primarily in Europe, motivated by the rich
history of full-scale glider and sailplane
development that started there and continues
still. It wasn’t long before scale sailplane
modeling started in the US with Europeanmade
models acquired from makers such as
Multiplex, Graupner, and Rosenthal. Europe is
still a leading source of scale sailplane models
today.
“Flying scale models of any kind is not for
everyone and the definition of what constitutes
a scale model varies from person to person,
mostly by degrees of fidelity to scale. In my
experience, those who fly scale sailplane
models want something that looks much like
the full-scale prototype, on the ground and in
the air, and individual taste varies from sport
or semiscale to ‘scale maniacs’ who insist on
modeling every detail.
“As with any scale model, how well it flies
and how easy it is to fly are concerns, and
although the size of the model can make a big
difference, slope lift will accommodate
smaller scale model sailplanes than a thermal
flight will.
“One item common to any model flown on
the slope is wing loading and the ability to
penetrate the air when the wind is strong. This
applies particularly to scale sailplanes.
“Wait, what about gliders? This is one of
those areas where terminology can cause
confusion, so let’s define a glider as an aircraft
that does not have the ability to sustain flight
from naturally occurring thermal activity
(rising heated air), whereas a sailplane can
‘sail’ in and gain altitude from thermals.
“In the early days of nonpowered flying,
every aircraft was a glider, whether being
Above: Ken Kaye launches his
27-pound, 1/3-scale, 6-meter
Ripo DG-800 at California’s
Los Banos Reservoir. DeVisser
photo.
Willy Grundler and his Vintage
2.6-meter SG-38 Schulgleiter
(training glider) from the Krick
kit enjoys slope lift at Los
Banos. DeVisser photo.
08sig4xx_00MSTRPG.QXD 6/23/11 1:32 PM Page 111
will fly well on the slope even if it has really
good thermal performance, and usually
without adding ballast.
“When it comes to flying scale models on
the slope, important considerations are the
launch method and the landing area.
Launching a sailplane successfully into slope
lift requires some planning. A launcher cannot
accelerate a typical model to stable flying
speed with a simple push off. The technique is
to launch the model directly into the wind, in a
slightly nose down attitude, following the
slope face until safe flying speed is reached
before leveling off.
“One difference compared to other types of
slope models is the tendency for a wing to lift
up at the point of release if not directly into the
wind, leading to loss of control. Larger
wingspans increase this tendency, so take your
time to assess the wind conditions and, if
possible, get an experienced person to launch
for you.
“Once you are flying, the main difference
is style. Large graceful maneuvers are the
strength of scale sailplanes, along with an
ability to climb to the top of a lift wave or
bubble.
“At my club’s main slope site, Los Banos
Creek Reservoir in Central California, we can
fly to the limit of eyesight in two or three wind
directions while only 500 to 700 feet above us
with good lift conditions. Lift can shut down
suddenly at many sites, so always keep a
landing plan in the back of your mind.
“Slope fliers often tolerate very difficult
landing areas in order to fly at a slope site with
great wind and lift, and the models they fly are
built for this. Scale sailplane construction
varies from all balsa wood to all-molded
fiberglass, and they are not designed to
withstand repeated rough landings.
“Scale sailplanes typically have larger
wingspans than other slope models, ranging
from about 120-240 inches (3-6 meters), and
weigh more—from about 6-36 pounds (3-16
kilograms)—requiring a larger landing area
and gentle touchdowns—no dorking these
models into terra firma!
“This doesn’t mean a flat field is
required—a large shallow angle slope face is
easy to land on headed up the hill or even
across the face—but the surface has to be
good. Even full-scale sailplanes land this way
at some flying sites. When you see scale Slope
Soaring event articles online and in print they
mostly show the best sites such as Los Banos,
California; Point of the Mountain, Utah; Lake
Wilson, Kansas; Torrey Pines, California; and
similar places, but there are many suitable
sites around the country.
“If you are a slope flier with an interest in
trying scale sailplane sloping, the best
introduction is to get some stick time with a
fellow pilot who has experience and a suitable
model, with the goal of an initial flight
introduction without launch or landing
worries. A competent aileron pilot should be
able to handle a scale model, although having
experience with rudder and aileron is a benefit.
Scale sailplane models, especially vintage
types, turn much better when rudder is used
along with aileron and elevator.
“Once you get to the point of wanting your
own model, starting out smaller, lighter, and
simpler is better. Two gliders that tolerate
rougher slope conditions and are good as slope
sailplane trainers are scale EPP sailplanes such
as the 3-meter Ka-6, or the Schweizer 1-26 in
60-inch or 2-meter size. Both are designed by
Dave Sanders and available from Sky King
RC Products. These are easy to build and fly at
a reasonable price, and they bounce!
“If you feel you have enough experience, a
suitable flying site, and want a hard-body
sailplane, there are dozens of choices, but try
to stay in the lighter and cheaper 2.5- to 4-
meter range such as the Hobby Club semiscale
series, ICARE RC standard series, or similar
models. Most of these models have a
fiberglass fuselage and a balsa-covered foam
wing.
“If you are into building your own, there is
a wealth of plans and kits available for all
types of sailplanes, both vintage and modern,
many designed with sloping in mind. Check
out Island Models laser-cut vintage kits,
Traplet Plans Service, and Tom Martin RC.
There are also many neat accessories such as
pilots, instrument panels, and more.
“Further information can be found in
popular web forums, on club websites,
and in specialty magazines such as Flying
Scale Models from Britain and Aufwind
English from Germany. Any articles
written by Chris Williams (various
British model magazines) are worth
having as reference, and his scale
sailplane plans are first-rate. I have
included some information in the
‘Sources’ listing.” MA
Sources:
Bruce DeVisser
[email protected]
Graupner
www.graupner.de/en
Hobby Club
(949) 425-1362
www.hobbyclub.com
ICARE Sailplanes and Electrics
(450) 449-9094
www.icare-rc.com
Multiplex
(858) 748-8440
www.multiplexusa.com
Rosenthal Flugmodelle
[email protected]
http://rosenthal-flugmodelle.com
Sky King RC Products
(605) 878-1880
www.skykingrcproducts.com
Soar Utah
www.soarutah.org
SBSS
www.sbss.org
Tom Martin Radio Control
(816) 331-8807
www.tmrcsailplanes.com
Traplet Publications
(217) 355-2970
www.traplet.com
League of Silent Flight
www.silentflight.org
Edition: Model Aviation - 2011/08
Page Numbers: 110,111,112
[[email protected]]
Radio Control Slope Soaring Dave Garwood
Guest columnist, Bruce DeVisser, on scale Slope Soaring
A gaggle of 3-meter DAW
Ka-6 EPP sailplanes work
to get into formation for
synchronized sloping, flown
by the Aliso Viejo Gang of
Southern CA. They take
advantage of EPP resilience
as they nudge into position.
DeVisser photo.
A fun-fly event for scale Schweizer sailplanes was held at
the famous Torrey Pines CA gliderport. Ren DiLeo photo.
This Reichard LF-107
Lunak, an 11-pound,
4-meter ARF from
Hobby Club, was
built by Jonathan
Alpert of Laguna
Nigel CA. Bruce
DeVisser photo.
Here is a sampling of what is available
from Hobby Club in small to midsize ARF
scale Sailplanes. DeVisser photo.
IN THE RC SKIES, few models look as serene and as sophisticated as
a long-wing Scale glider in flight. For nearly 20 years, the South Bay
Soaring Society (SBSS) has run the impressive Los Banos Scale
Sailplane Event at the magnificent Los Banos Reservoir RC flying site
in north central California.
This month I have a guest columnist, Bruce DeVisser, from San
Jose, California. Bruce is an SBSS officer who wrote about scale RC
Slope Soaring. In the current context “scale” means a radio-controlled
model of a full-size sailplane, either modern or vintage, and “power
scale soaring” or “PSS” refers to a radio-controlled, unpowered model
of a full-size, powered prototype, either propeller or jet.
Here is Bruce:
“What attracts modelers to scale Slope Soaring? The answer is
simple—Slope Soaring is a lot of fun, and those who are interested in
scale models want to fly their scale sailplanes on the slope, too.
“There is no fundamental difference between PSS and scale
sailplane Slope Soaring—okay, roll rate is much higher with a PSS
model. There is another difference. As long as the wind blows, you can
keep flying. There is no dependence on searching out a thermal to
maintain altitude, and if you want to loop or roll there is lift for
recovery to the original altitude.
“If one were to ask a group of RC pilots what type
of models were used for Slope Soaring, I believe
the answers would mostly describe sport
sailplanes, purpose-designed Slope Soaring or racing models, and PSS
aircraft. If one were to ask about scale sailplanes and Slope Soaring,
many people would say scale sailplanes are only used for aerotowing.
Although that may be true for a large segment of the scale sailplane
community, many dedicated slopers only fly their ‘scalies’ on the slope,
and forego a tow release, practically a standard feature on a scale
sailplane.
110 MODEL AVIATION
08sig4xx_00MSTRPG.QXD 6/23/11 1:31 PM Page 110
August 2011 111
launched off of a hilltop or by use of a bungee
or winch, because they could only descend to
land after launching. Therefore, slope models
generally are gliders because they cannot
achieve thermal flight, but they do very well in
the much stronger lift on the slope.
“Vintage sailplane models, such as the
well-known Minimoa, can have light wing
loading, thick airfoils, and therefore a lot of
drag, making them difficult to fly in strong
slope winds unless a provision is made to add
ballast.
“Modern sailplanes benefit from years of
airfoil research that has produced thinner
airfoils with greater lift, and designers have
followed a parallel path in producing efficient
airfoil shapes for flying models of all types. It
is possible to use a more efficient modern
airfoil with a thinner profile on a vintage
sailplane, but the appearance is not as pleasing
to the eye as the prototypical thicker ones—it
just doesn’t look right—so ballast is an easily
available remedy.
“The thinner airfoils of full-scale modern
sailplanes, such as a DG-600, don’t often work
well in model size until the model scale
approaches ½ scale. Efficient model airfoils
have been developed that look the part, giving
model designers the tools they need to have a
model that flies as good as it looks.
“One interesting outcome of this is that
virtually any modern scale sailplane model
“In the 1980s I had an introduction to scale
sailplanes and Slope Soaring while working in
Europe. While there I met several friendly,
knowledgeable, enthusiastic modelers, and
observed their beautiful models soaring in
mountain conditions.
“The flying was not always in true slope
conditions—the models could range out over
the mountain valley and pick up thermals (in
my club we call this Slermal flying), but there
was plenty of slope action going on with
screaming high-speed passes and aerobatics.
Some weeks later I was able to visit a vacation
area where you could fly models in a more
usual slope setting—a grassy meadow on a
hillside—but the lift and action were both
good.
“Scale sailplane modeling developed
primarily in Europe, motivated by the rich
history of full-scale glider and sailplane
development that started there and continues
still. It wasn’t long before scale sailplane
modeling started in the US with Europeanmade
models acquired from makers such as
Multiplex, Graupner, and Rosenthal. Europe is
still a leading source of scale sailplane models
today.
“Flying scale models of any kind is not for
everyone and the definition of what constitutes
a scale model varies from person to person,
mostly by degrees of fidelity to scale. In my
experience, those who fly scale sailplane
models want something that looks much like
the full-scale prototype, on the ground and in
the air, and individual taste varies from sport
or semiscale to ‘scale maniacs’ who insist on
modeling every detail.
“As with any scale model, how well it flies
and how easy it is to fly are concerns, and
although the size of the model can make a big
difference, slope lift will accommodate
smaller scale model sailplanes than a thermal
flight will.
“One item common to any model flown on
the slope is wing loading and the ability to
penetrate the air when the wind is strong. This
applies particularly to scale sailplanes.
“Wait, what about gliders? This is one of
those areas where terminology can cause
confusion, so let’s define a glider as an aircraft
that does not have the ability to sustain flight
from naturally occurring thermal activity
(rising heated air), whereas a sailplane can
‘sail’ in and gain altitude from thermals.
“In the early days of nonpowered flying,
every aircraft was a glider, whether being
Above: Ken Kaye launches his
27-pound, 1/3-scale, 6-meter
Ripo DG-800 at California’s
Los Banos Reservoir. DeVisser
photo.
Willy Grundler and his Vintage
2.6-meter SG-38 Schulgleiter
(training glider) from the Krick
kit enjoys slope lift at Los
Banos. DeVisser photo.
08sig4xx_00MSTRPG.QXD 6/23/11 1:32 PM Page 111
will fly well on the slope even if it has really
good thermal performance, and usually
without adding ballast.
“When it comes to flying scale models on
the slope, important considerations are the
launch method and the landing area.
Launching a sailplane successfully into slope
lift requires some planning. A launcher cannot
accelerate a typical model to stable flying
speed with a simple push off. The technique is
to launch the model directly into the wind, in a
slightly nose down attitude, following the
slope face until safe flying speed is reached
before leveling off.
“One difference compared to other types of
slope models is the tendency for a wing to lift
up at the point of release if not directly into the
wind, leading to loss of control. Larger
wingspans increase this tendency, so take your
time to assess the wind conditions and, if
possible, get an experienced person to launch
for you.
“Once you are flying, the main difference
is style. Large graceful maneuvers are the
strength of scale sailplanes, along with an
ability to climb to the top of a lift wave or
bubble.
“At my club’s main slope site, Los Banos
Creek Reservoir in Central California, we can
fly to the limit of eyesight in two or three wind
directions while only 500 to 700 feet above us
with good lift conditions. Lift can shut down
suddenly at many sites, so always keep a
landing plan in the back of your mind.
“Slope fliers often tolerate very difficult
landing areas in order to fly at a slope site with
great wind and lift, and the models they fly are
built for this. Scale sailplane construction
varies from all balsa wood to all-molded
fiberglass, and they are not designed to
withstand repeated rough landings.
“Scale sailplanes typically have larger
wingspans than other slope models, ranging
from about 120-240 inches (3-6 meters), and
weigh more—from about 6-36 pounds (3-16
kilograms)—requiring a larger landing area
and gentle touchdowns—no dorking these
models into terra firma!
“This doesn’t mean a flat field is
required—a large shallow angle slope face is
easy to land on headed up the hill or even
across the face—but the surface has to be
good. Even full-scale sailplanes land this way
at some flying sites. When you see scale Slope
Soaring event articles online and in print they
mostly show the best sites such as Los Banos,
California; Point of the Mountain, Utah; Lake
Wilson, Kansas; Torrey Pines, California; and
similar places, but there are many suitable
sites around the country.
“If you are a slope flier with an interest in
trying scale sailplane sloping, the best
introduction is to get some stick time with a
fellow pilot who has experience and a suitable
model, with the goal of an initial flight
introduction without launch or landing
worries. A competent aileron pilot should be
able to handle a scale model, although having
experience with rudder and aileron is a benefit.
Scale sailplane models, especially vintage
types, turn much better when rudder is used
along with aileron and elevator.
“Once you get to the point of wanting your
own model, starting out smaller, lighter, and
simpler is better. Two gliders that tolerate
rougher slope conditions and are good as slope
sailplane trainers are scale EPP sailplanes such
as the 3-meter Ka-6, or the Schweizer 1-26 in
60-inch or 2-meter size. Both are designed by
Dave Sanders and available from Sky King
RC Products. These are easy to build and fly at
a reasonable price, and they bounce!
“If you feel you have enough experience, a
suitable flying site, and want a hard-body
sailplane, there are dozens of choices, but try
to stay in the lighter and cheaper 2.5- to 4-
meter range such as the Hobby Club semiscale
series, ICARE RC standard series, or similar
models. Most of these models have a
fiberglass fuselage and a balsa-covered foam
wing.
“If you are into building your own, there is
a wealth of plans and kits available for all
types of sailplanes, both vintage and modern,
many designed with sloping in mind. Check
out Island Models laser-cut vintage kits,
Traplet Plans Service, and Tom Martin RC.
There are also many neat accessories such as
pilots, instrument panels, and more.
“Further information can be found in
popular web forums, on club websites,
and in specialty magazines such as Flying
Scale Models from Britain and Aufwind
English from Germany. Any articles
written by Chris Williams (various
British model magazines) are worth
having as reference, and his scale
sailplane plans are first-rate. I have
included some information in the
‘Sources’ listing.” MA
Sources:
Bruce DeVisser
[email protected]
Graupner
www.graupner.de/en
Hobby Club
(949) 425-1362
www.hobbyclub.com
ICARE Sailplanes and Electrics
(450) 449-9094
www.icare-rc.com
Multiplex
(858) 748-8440
www.multiplexusa.com
Rosenthal Flugmodelle
[email protected]
http://rosenthal-flugmodelle.com
Sky King RC Products
(605) 878-1880
www.skykingrcproducts.com
Soar Utah
www.soarutah.org
SBSS
www.sbss.org
Tom Martin Radio Control
(816) 331-8807
www.tmrcsailplanes.com
Traplet Publications
(217) 355-2970
www.traplet.com
League of Silent Flight
www.silentflight.org
