International Hand Launch Glider Festival 2004 - 2005/01

January 2005 73
by John Erickson
Hand Launch Glider Festival
2004
International
Phil Pearson uses a CNC cutter to shape these Encores’ elliptical tail
surfaces.
The Photon II is one of the few gliders with built-up construction. Its flying
weight is 10.3 ounces. The large center flap is used for glide-path control.
George Joy demonstrates “discus” launching
technique that has become the norm for RC HLGs.
Photo by Oleg Golovidov.
THE PILOT LOOKED worried as his 60-inch glider sank steadily toward the
ground. Suddenly one wing tipped upward. The pilot immediately circled the
model back toward an invisible thermal, and it slowly began to rise. He continued
making tight 15-foot circles, and the glider magically corkscrewed skyward. A
look of relief washed over the pilot’s face; he had just performed a “save.” He
was safe for the next minute or two, and then the next task was at hand.
His timer counted down the seconds left, and as he said “clear,” the pilot
caught the glider, spun 360°, and launched the model up at an initial speed of 90
mph. It climbed to approximately 150 feet, where he leveled it out to begin a
thermal search pattern.
The preceding scenario was replayed countless times during the International
Hand Launch Glider Festival (IHLGF), which is held every first weekend in June
in Poway, California. The Torrey Pines Gulls (TPG) club has hosted this dynamic
Mark Drela launches his SuperGee II. This discus
throw will propel the glider to an altitude of
approximately 150 feet.
Photos by Chris Adams except as noted
74 MODEL AVIATION
John Erickson (left) looks for lift while Lex Mierop keeps track of
pertinent flight information.
L-R: CD Don Richmond, assistant CD Keith Finkenbiner,
and scorer Tom Clarkson rest outside tailored IHLGF
headquarters.
Using Microsoft Access, Tom Clarkson developed the
multifunctional scoring program that was used at the event.
Oleg Golovidov launches his Taboo DLG. This wasn’t at Poway
but shows discus launch to good effect. Peter Jensen photo.
event for the last 11 years, and this contest was as exciting as ever.
The first Hand-Launched Glider (HLG) contest took place in
September 1979. There was a strong following in Southern
California, and the Inland Soaring Society (ISS) in Riverside held an
annual event throughout the 1980s.
As the tasks became more difficult, the sailplanes became more
specialized. Airfoils and planforms were optimized for the 1.5-meter
span, and components got smaller. Materials became stronger and
performance improved, as did the piloting skills.
When the TPG got the chance to receive the baton from the ISS,
it jumped headfirst into the details of running a large event. Now—
owing to the extensive work of Ron Scharck, Tom Clarkson, Don
Richmond, Garth Warner, and many other TPG members—this
contest is the benchmark in the hand-launch world.
The modern HLG is simple, yet sophisticated. It has to withstand
the rigors of launch, be able to cruise across long patches of sky in
search of lift, and then settle down into a butterflylike float when it
encounters rising air. It has to be highly maneuverable for lowspeed
handling, yet hands-off stable when flying at the limits of
eyesight. It needs to be light, yet strong.
This list of design criteria has prompted designers to investigate
other aspects of aviation, including free flight as well as large-scale
soaring for inspiration and technical guidance. The first gliders were
tossed overhand. Now, because of the radical concept of discus
launching, all sailplanes are launched by holding one wingtip,
letting the speed and force created by rotation send the model
airborne.
This technique was perfected and introduced to the hand-launch
community by Dick Barker—a retired aerospace engineer from the
January 2005 75
Arthur Markiewicz, on the right, concentrates on his
flying as Paul Anderson counts down his time.
Clean tail group on one of Phil Barnes’ models.
Small piece of stainless steel wire extending past the
rudder is an antenna.
The top 10 fliers take a moment to pose for the camera. See the results box.
This fleet of SuperGees is charging up between rounds. You can see the
throwing pegs in the wingtips.
A happy Phil Barnes holds his
first-place plaque overhead. He
flew strongly during both days of
the competition.
Seattle, Washington, area. He had seen the ease with which high speeds could
be generated via the discus technique. He also realized that it was much easier
on the pilot’s shoulder.
Dick began designing a line of sailplanes that could take the sideways force
of the launch. From that point, roughly five years ago, the prototypical glider
found at the IHGLF owes its lineage to him.
Constructed from Kevlar, fiberglass, and carbon fiber vacuum-bagged over
a foam core, the glider’s wing has to withstand not only the upward force of
the pullout, but also the torsional force from the wing’s twisting caused by the
throw. The pilot holds onto the wing with a small carbon dowel or blade
securely mounted to the wingtip.
The wing usually has ailerons that control camber and help in slowing the
model. They perform double duty as an aileron and a flap; hence they are
called “flaperons.”
The pod is minimally sized for drag reduction, but it has to be incredibly
strong at the wing-to-pod connection. The pod houses a small 350 mAh NiMH
battery, a six-channel receiver, the elevator and rudder servos, and in some
cases a tiny gyro for the rudder to counteract the glider’s initial yaw during
launch.
The tapered boom is made from wrapped carbon and is roughly 1⁄2 inch in
diameter. Fishing-pole rod used to be used but is far too flexible for the forces
seen now. The tail surfaces are either fiberglass over foam or laminated balsa.
Pushrods are found in many flavors, including carbon rod, stainless steel, or
Spectra fishing line for a “pull-pull” setup.
Garth Warner’s impound crew handled 600-plus successful turnovers during
the weekend, with no reported shoot-downs!
Bill Watson’s “framed” pod. Its components are
mounted within the structure. Nose cone slips
over entire assembly.
Bill Watson developed this delta rudder.
It’s 3⁄4-ounce fiberglass over Spyder foam
with carbon-fiber reinforcements.
The inside wing planform on Bill Watson’s model is longer for more leverage on the
throw. The wing areas are balanced so the glider flies straight.
Several manufacturers kit such gliders, including Don Peters of
Maple Leaf Design (the Encore), Denny Maize of Pole Cat
Aeroplane Works (the XP-4), Jerry Krainock (the Photon), and Oleg
Golovidov (the Taboo). All except the Photon are four-channel
designs with camber control.
The Photon is the only built-up-wing model produced that is
strong enough to take a discus launch. The balsa spar is capped with
carbon fiber top and bottom, wrapped in Kevlar thread, and then
dropped into a preformed carbon-fiber D-tube. It is a remarkably
strong construction technique.
Roughly half of the IHLGF contestants flew home-built designs,
or at least modified designs from manufacturers. Innovation and
experimentation have been hallmarks of this hobby. Mark Drela of
the Massachusetts Institute of Technology has devoted his extensive
knowledge of low-speed aeronautics to the modeling community. He
invented Xfoil, which is a modeling program to analyze the polars of
any airfoil.
In addition, Mark has optimized a set of hand-launch airfoils that
is the standard for all of the manufacturers. The AG44-45-46ct is
used on nearly all of the sailplanes with camber changing because of
its excellent combination of low drag and maximum lift. A fixedcamber
foil—the AG-16—is used on the Photon.
Joe Wurts, who is an engineer for Lockheed Martin, has also
spent considerable time optimizing airfoils and planforms. As has
Mark Drela, he has made his work available to the community.
However, it hasn’t exactly given the answers to the question of how
to fly like Joe. He has won the IHLGF seven times—a remarkable
feat considering the outstanding quality of competing pilots.
Bill Watson is an “innovative prototyper” known for his many
inventions and contributions. These include his participation on the
teams for the Gossamer Albatross (the first man-powered airplane to
cross the English Channel) and the Sunracer by General Motors: the
solar-powered car that crossed the Australian continent.
Bill is a prolific builder and designer who has come up with
several refinements, which include the arrow, or delta rudder, the
asymmetric planform, and the framed pod design. This year he had a
variable-dihedral plan that launched flat and then kicked up a wing
panel, similar in concept to the F1C designs.
Phil Barnes and Phil Pearson work on opposite coasts but have
probably built more wings and gliders than the bulk of the field put
together. Phil Barnes has refined the composite scheme for a wing.
His techniques have been chronicled in an instructional DVD. He is
a master at the Kevlar-over-foam composite technique.
Phil Pearson has led the way in CNC evolution and is now
producing beautiful CNC-machined stabilizers, rudders, and wings.
The setup for this technique is still evolving, using a bed for the parts
January 2005 77
Open Class
Place Pilot Score
1. Phil Barnes 11,768.99
2. Paul Anderson 11,686.92
3. Joe Wurts 11,656.95
4. Bruce Davidson 11,645.40
5. Thomas Kiesling 11,626.18
6. Arthur Markiewicz 1,599.06
7. Michael Smith 11,277.04
8. Mark Drela 11,145.93
9. Gordon Jennings 11,137.37
10. Jim Pearson 11,115.58
Junior Class (15 years and younger)
Place Pilot Score
1. Casey Adamczyk 5,626.22
2. Clark Knudtson 5,216.97
3. Jesse Corven 3,620.62
4. Fateh Singh Khalsa 3,059.31
Eagle Class (55 years and older)
Place Pilot Score
1. Dave Leedom 8,041.57
2. Martyn Cowley 8,002.23
3. Larry Pettyjohn 7,461.59
4. Ron Scharck 7,446.11
5. Jonathan Bryan 6,907.70
6. Cliff Hunter 6,860.75
7. Don Richmond 6,447.05
8. Tom Knudtson 4,553.65
IHLGF Contest Scores
that are held in place by vacuum. However, the results are fantastic;
you can have a perfect airfoil in all parts of the wing, and the
planform can be any shape, including elliptical.
It would be enough if these contributors just left their designs
for the hobby, but all of them are pilots as well—very good pilots.
The IHLGF’s format is man on man. Each round has a task with a
certain window (working time). An example would be a 10-minute
window in which the tasks would be a one-, two-, three-, and fourminute
flight. A perfect score in this instance would be 600
seconds.
However, this perfection is unobtainable because there is
“downtime” when the pilot catches and then relaunches the glider.
The stopwatch stops when the model hits the ground or the pilot
catches it, and it is started when the sailplane leaves his or her hand.
An off-field landing means a zero for that flight.
The man-on-man format means that all pilots fly in the same air,
so it really comes down to who can work the air the best. Many
other factors come into play, including a predictable afternoon wind
at the Poway field; the tight, fast-moving thermals; and the splitsecond
tactical decision making while flying.
The one who bests the others in the heat (of roughly 10 pilots)
gets 1,000 points, and the other pilots’ scores are normalized to his
or her score. With six rounds flown Saturday, four rounds Sunday
morning, and three rounds for the flyoff of the top 10 pilots, the
field is busy with activity.
Tom Clarkson of the TPG has created a scoring program and a
CD that handles countdown duties. His program, created in
Microsoft Access, has evolved in the last five years and now
instantly scores all pilots and prints out scorecards, pilot tags, and
heat scores, and it even checks for duplicates or “over perfect”
scores that may have been mistakenly recorded. It also generates a
matrix that makes sure the pilots do not fly against the same
competitors too often during the event.
The CD has a recorded voice that announces the prep time left
before the heat begins, the window time, and then the time left all
the way down to a buzzer as time expires. This has become a
familiar sound across the field as each pilot tunes into the task at
hand.
A total of 12,000 points were available for each of the 65
participants, and this year’s winner had 11,769. To illustrate how
competitive the field was, the 10th-place finisher had 11,116
points—only a difference of 654, or roughly 5%. Considering all of
the flying, you could move up or drop several places because of a
single flight within a heat.
There was no room for error, yet with all the pressures of
competition, it was hard to find someone who was not having a
good time. There is much camaraderie and entertainment during the
weekend, and the contest always seems to run without a hitch
because of the TPC club members’ extensive planning and hard
work.
When all of the dust had settled, Phil Barnes was this year’s
winner. He didn’t know he had won until the second-place finisher
was announced. Phil was truly surprised, although the rest of us
were not. He flew very well all weekend, launching high and not
clutching up during the long downwind forays that the conditions
dictated.
Dave Thornburg—the father of HLG—said the following in 1994.
“Hand launch RC has opened up a whole new world to me, a
world of micro-micro-meteorology that takes place in the invisible
air around us every minute … a world of miniature highs and lows,
cold fronts and warm, that sweep and dance across flying fields no
larger than a baseball diamond.”
His words still ring true for the participants of the IHLGF. MA
John Erickson
24443 Zermatt Ln.
Valencia CA 91355
Manufacturers:
Encore:
Maple Leaf Design
www.mapleleafdesign.com/
Taboo XL:
Oleg Golovidov
http://olgol.com/TabooXL/index.html
XP-4:
Pole Cat Aeroplane Works
www.polecataero.com/
Raptor DLG:
Raptor Aerosports
www.raptorrc.com/raptorDLG.html
Photon II:
Jerry’s Models
www.netmeister.net/~jerry/

January 2005 73
by John Erickson
Hand Launch Glider Festival
2004
International
Phil Pearson uses a CNC cutter to shape these Encores’ elliptical tail
surfaces.
The Photon II is one of the few gliders with built-up construction. Its flying
weight is 10.3 ounces. The large center flap is used for glide-path control.
George Joy demonstrates “discus” launching
technique that has become the norm for RC HLGs.
Photo by Oleg Golovidov.
THE PILOT LOOKED worried as his 60-inch glider sank steadily toward the
ground. Suddenly one wing tipped upward. The pilot immediately circled the
model back toward an invisible thermal, and it slowly began to rise. He continued
making tight 15-foot circles, and the glider magically corkscrewed skyward. A
look of relief washed over the pilot’s face; he had just performed a “save.” He
was safe for the next minute or two, and then the next task was at hand.
His timer counted down the seconds left, and as he said “clear,” the pilot
caught the glider, spun 360°, and launched the model up at an initial speed of 90
mph. It climbed to approximately 150 feet, where he leveled it out to begin a
thermal search pattern.
The preceding scenario was replayed countless times during the International
Hand Launch Glider Festival (IHLGF), which is held every first weekend in June
in Poway, California. The Torrey Pines Gulls (TPG) club has hosted this dynamic
Mark Drela launches his SuperGee II. This discus
throw will propel the glider to an altitude of
approximately 150 feet.
Photos by Chris Adams except as noted
74 MODEL AVIATION
John Erickson (left) looks for lift while Lex Mierop keeps track of
pertinent flight information.
L-R: CD Don Richmond, assistant CD Keith Finkenbiner,
and scorer Tom Clarkson rest outside tailored IHLGF
headquarters.
Using Microsoft Access, Tom Clarkson developed the
multifunctional scoring program that was used at the event.
Oleg Golovidov launches his Taboo DLG. This wasn’t at Poway
but shows discus launch to good effect. Peter Jensen photo.
event for the last 11 years, and this contest was as exciting as ever.
The first Hand-Launched Glider (HLG) contest took place in
September 1979. There was a strong following in Southern
California, and the Inland Soaring Society (ISS) in Riverside held an
annual event throughout the 1980s.
As the tasks became more difficult, the sailplanes became more
specialized. Airfoils and planforms were optimized for the 1.5-meter
span, and components got smaller. Materials became stronger and
performance improved, as did the piloting skills.
When the TPG got the chance to receive the baton from the ISS,
it jumped headfirst into the details of running a large event. Now—
owing to the extensive work of Ron Scharck, Tom Clarkson, Don
Richmond, Garth Warner, and many other TPG members—this
contest is the benchmark in the hand-launch world.
The modern HLG is simple, yet sophisticated. It has to withstand
the rigors of launch, be able to cruise across long patches of sky in
search of lift, and then settle down into a butterflylike float when it
encounters rising air. It has to be highly maneuverable for lowspeed
handling, yet hands-off stable when flying at the limits of
eyesight. It needs to be light, yet strong.
This list of design criteria has prompted designers to investigate
other aspects of aviation, including free flight as well as large-scale
soaring for inspiration and technical guidance. The first gliders were
tossed overhand. Now, because of the radical concept of discus
launching, all sailplanes are launched by holding one wingtip,
letting the speed and force created by rotation send the model
airborne.
This technique was perfected and introduced to the hand-launch
community by Dick Barker—a retired aerospace engineer from the
January 2005 75
Arthur Markiewicz, on the right, concentrates on his
flying as Paul Anderson counts down his time.
Clean tail group on one of Phil Barnes’ models.
Small piece of stainless steel wire extending past the
rudder is an antenna.
The top 10 fliers take a moment to pose for the camera. See the results box.
This fleet of SuperGees is charging up between rounds. You can see the
throwing pegs in the wingtips.
A happy Phil Barnes holds his
first-place plaque overhead. He
flew strongly during both days of
the competition.
Seattle, Washington, area. He had seen the ease with which high speeds could
be generated via the discus technique. He also realized that it was much easier
on the pilot’s shoulder.
Dick began designing a line of sailplanes that could take the sideways force
of the launch. From that point, roughly five years ago, the prototypical glider
found at the IHGLF owes its lineage to him.
Constructed from Kevlar, fiberglass, and carbon fiber vacuum-bagged over
a foam core, the glider’s wing has to withstand not only the upward force of
the pullout, but also the torsional force from the wing’s twisting caused by the
throw. The pilot holds onto the wing with a small carbon dowel or blade
securely mounted to the wingtip.
The wing usually has ailerons that control camber and help in slowing the
model. They perform double duty as an aileron and a flap; hence they are
called “flaperons.”
The pod is minimally sized for drag reduction, but it has to be incredibly
strong at the wing-to-pod connection. The pod houses a small 350 mAh NiMH
battery, a six-channel receiver, the elevator and rudder servos, and in some
cases a tiny gyro for the rudder to counteract the glider’s initial yaw during
launch.
The tapered boom is made from wrapped carbon and is roughly 1⁄2 inch in
diameter. Fishing-pole rod used to be used but is far too flexible for the forces
seen now. The tail surfaces are either fiberglass over foam or laminated balsa.
Pushrods are found in many flavors, including carbon rod, stainless steel, or
Spectra fishing line for a “pull-pull” setup.
Garth Warner’s impound crew handled 600-plus successful turnovers during
the weekend, with no reported shoot-downs!
Bill Watson’s “framed” pod. Its components are
mounted within the structure. Nose cone slips
over entire assembly.
Bill Watson developed this delta rudder.
It’s 3⁄4-ounce fiberglass over Spyder foam
with carbon-fiber reinforcements.
The inside wing planform on Bill Watson’s model is longer for more leverage on the
throw. The wing areas are balanced so the glider flies straight.
Several manufacturers kit such gliders, including Don Peters of
Maple Leaf Design (the Encore), Denny Maize of Pole Cat
Aeroplane Works (the XP-4), Jerry Krainock (the Photon), and Oleg
Golovidov (the Taboo). All except the Photon are four-channel
designs with camber control.
The Photon is the only built-up-wing model produced that is
strong enough to take a discus launch. The balsa spar is capped with
carbon fiber top and bottom, wrapped in Kevlar thread, and then
dropped into a preformed carbon-fiber D-tube. It is a remarkably
strong construction technique.
Roughly half of the IHLGF contestants flew home-built designs,
or at least modified designs from manufacturers. Innovation and
experimentation have been hallmarks of this hobby. Mark Drela of
the Massachusetts Institute of Technology has devoted his extensive
knowledge of low-speed aeronautics to the modeling community. He
invented Xfoil, which is a modeling program to analyze the polars of
any airfoil.
In addition, Mark has optimized a set of hand-launch airfoils that
is the standard for all of the manufacturers. The AG44-45-46ct is
used on nearly all of the sailplanes with camber changing because of
its excellent combination of low drag and maximum lift. A fixedcamber
foil—the AG-16—is used on the Photon.
Joe Wurts, who is an engineer for Lockheed Martin, has also
spent considerable time optimizing airfoils and planforms. As has
Mark Drela, he has made his work available to the community.
However, it hasn’t exactly given the answers to the question of how
to fly like Joe. He has won the IHLGF seven times—a remarkable
feat considering the outstanding quality of competing pilots.
Bill Watson is an “innovative prototyper” known for his many
inventions and contributions. These include his participation on the
teams for the Gossamer Albatross (the first man-powered airplane to
cross the English Channel) and the Sunracer by General Motors: the
solar-powered car that crossed the Australian continent.
Bill is a prolific builder and designer who has come up with
several refinements, which include the arrow, or delta rudder, the
asymmetric planform, and the framed pod design. This year he had a
variable-dihedral plan that launched flat and then kicked up a wing
panel, similar in concept to the F1C designs.
Phil Barnes and Phil Pearson work on opposite coasts but have
probably built more wings and gliders than the bulk of the field put
together. Phil Barnes has refined the composite scheme for a wing.
His techniques have been chronicled in an instructional DVD. He is
a master at the Kevlar-over-foam composite technique.
Phil Pearson has led the way in CNC evolution and is now
producing beautiful CNC-machined stabilizers, rudders, and wings.
The setup for this technique is still evolving, using a bed for the parts
January 2005 77
Open Class
Place Pilot Score
1. Phil Barnes 11,768.99
2. Paul Anderson 11,686.92
3. Joe Wurts 11,656.95
4. Bruce Davidson 11,645.40
5. Thomas Kiesling 11,626.18
6. Arthur Markiewicz 1,599.06
7. Michael Smith 11,277.04
8. Mark Drela 11,145.93
9. Gordon Jennings 11,137.37
10. Jim Pearson 11,115.58
Junior Class (15 years and younger)
Place Pilot Score
1. Casey Adamczyk 5,626.22
2. Clark Knudtson 5,216.97
3. Jesse Corven 3,620.62
4. Fateh Singh Khalsa 3,059.31
Eagle Class (55 years and older)
Place Pilot Score
1. Dave Leedom 8,041.57
2. Martyn Cowley 8,002.23
3. Larry Pettyjohn 7,461.59
4. Ron Scharck 7,446.11
5. Jonathan Bryan 6,907.70
6. Cliff Hunter 6,860.75
7. Don Richmond 6,447.05
8. Tom Knudtson 4,553.65
IHLGF Contest Scores
that are held in place by vacuum. However, the results are fantastic;
you can have a perfect airfoil in all parts of the wing, and the
planform can be any shape, including elliptical.
It would be enough if these contributors just left their designs
for the hobby, but all of them are pilots as well—very good pilots.
The IHLGF’s format is man on man. Each round has a task with a
certain window (working time). An example would be a 10-minute
window in which the tasks would be a one-, two-, three-, and fourminute
flight. A perfect score in this instance would be 600
seconds.
However, this perfection is unobtainable because there is
“downtime” when the pilot catches and then relaunches the glider.
The stopwatch stops when the model hits the ground or the pilot
catches it, and it is started when the sailplane leaves his or her hand.
An off-field landing means a zero for that flight.
The man-on-man format means that all pilots fly in the same air,
so it really comes down to who can work the air the best. Many
other factors come into play, including a predictable afternoon wind
at the Poway field; the tight, fast-moving thermals; and the splitsecond
tactical decision making while flying.
The one who bests the others in the heat (of roughly 10 pilots)
gets 1,000 points, and the other pilots’ scores are normalized to his
or her score. With six rounds flown Saturday, four rounds Sunday
morning, and three rounds for the flyoff of the top 10 pilots, the
field is busy with activity.
Tom Clarkson of the TPG has created a scoring program and a
CD that handles countdown duties. His program, created in
Microsoft Access, has evolved in the last five years and now
instantly scores all pilots and prints out scorecards, pilot tags, and
heat scores, and it even checks for duplicates or “over perfect”
scores that may have been mistakenly recorded. It also generates a
matrix that makes sure the pilots do not fly against the same
competitors too often during the event.
The CD has a recorded voice that announces the prep time left
before the heat begins, the window time, and then the time left all
the way down to a buzzer as time expires. This has become a
familiar sound across the field as each pilot tunes into the task at
hand.
A total of 12,000 points were available for each of the 65
participants, and this year’s winner had 11,769. To illustrate how
competitive the field was, the 10th-place finisher had 11,116
points—only a difference of 654, or roughly 5%. Considering all of
the flying, you could move up or drop several places because of a
single flight within a heat.
There was no room for error, yet with all the pressures of
competition, it was hard to find someone who was not having a
good time. There is much camaraderie and entertainment during the
weekend, and the contest always seems to run without a hitch
because of the TPC club members’ extensive planning and hard
work.
When all of the dust had settled, Phil Barnes was this year’s
winner. He didn’t know he had won until the second-place finisher
was announced. Phil was truly surprised, although the rest of us
were not. He flew very well all weekend, launching high and not
clutching up during the long downwind forays that the conditions
dictated.
Dave Thornburg—the father of HLG—said the following in 1994.
“Hand launch RC has opened up a whole new world to me, a
world of micro-micro-meteorology that takes place in the invisible
air around us every minute … a world of miniature highs and lows,
cold fronts and warm, that sweep and dance across flying fields no
larger than a baseball diamond.”
His words still ring true for the participants of the IHLGF. MA
John Erickson
24443 Zermatt Ln.
Valencia CA 91355
Manufacturers:
Encore:
Maple Leaf Design
www.mapleleafdesign.com/
Taboo XL:
Oleg Golovidov
http://olgol.com/TabooXL/index.html
XP-4:
Pole Cat Aeroplane Works
www.polecataero.com/
Raptor DLG:
Raptor Aerosports
www.raptorrc.com/raptorDLG.html
Photon II:
Jerry’s Models
www.netmeister.net/~jerry/