Sound and Aerobatics
December 2010 133
[[email protected]]
Radio Control Scale Aerobatics John Glezellis
The Hangar 9 Beast is a great competition model. It is using a three-blade propeller,
which has a great amount of power with the new Desert Aircraft DA-120 engine.
This shows how you can expect a sound meter to be set up at a
local and/or national competition.
Your model’s sound level will be measured as shown at a local
and/or national competition. You can perform this test at the
practice field so that you are aware of your aircraft’s noise level
before attending a major event.
As I Am writing this, the 2010 flying
season is coming to an end for those of us in
the Northeast and building season is fast
approaching.
As each year goes on, it amazes me to
see the increased interest in giant Scale
Aerobatics models. However, as more pilots
are flying these large aircraft, more airfields
are facing sound issues that were
nonexistent in previous years.
I’m going to devote this month’s column
to sound and what can be done to enforce
regulations at the local flying field. Even if
you are not interested in Aerobatics, this
column is for you if you are a giant Scale
enthusiast.
Let’s begin!
Rules, Rules, Rules! In the world of the
International Miniature Aerobatic Club
(IMAC), certain rules on the competition
scene pertain to sound. One is that each
model that is to be flown in a contest must
pass the Ground Sound Level Test. If an
airplane fails this test, its pilot can be
disqualified.
If you are a newcomer, I am sure that
exceptions can be made if you speak to the
CD. However, before you attend your first
competition, check the sound level of your
aircraft and speak to the CD well in advance
if you think you might have an issue. It is
better to be safe than sorry—especially if
you are traveling several hours to attend a
contest!
The maximum sound level is 96 dBA
measured on soft surfaces and 98 dBA
measured on hard surfaces. To test for these
levels, place a sound meter directly facing
the model, perpendicular to the fuselage.
The sound meter must be approximately
25 feet from the airplane centerline and 24
inches off of the ground. Once the aircraft
and meter are correctly placed, the pilot
starts the model and runs up the engine to
full power.
Aside from the Ground Sound Level
Test, each pilot receives a flight score that
takes into account the noise that his or her
airplane produces. During Known and
Unknown flights, each judge enters a Sound
Score in addition to the ratings for each
maneuver.
The Sound Score can be a 0 (too
noisy), a 5 (acceptable), or a 10 (very
quiet). Then that figure is multiplied by a
“K,” which is assigned to each IMAC
class. Those are:
• Unlimited: 5K
• Advanced: 4K
• Intermediate: 3K
• Sportsman: 2K
• Basic: 1K
12sig5x.QXD_00MSTRPG.QXD 10/22/10 8:35 AM Page 133
You shouldn’t decrease the sound of your model only for
competition. As a result of noise issues, many of our beloved flying
sites face opposition from neighboring homes, parks, etc.
The sound level of an airplane can vary greatly, depending on
the type of exhaust and propeller it has. A two-blade propeller is
generally louder than a three-blade type.
The cost of a canister-type exhaust can be overwhelming. If you
don’t want to put forth that amount of money, install a three-blade
propeller on your model and see if that makes the sound acceptable
at your flying field.
If it doesn’t, consider purchasing a used exhaust system from
postings on Web sites such as RC Universe or Flying Giants. Or you
can buy a new exhaust system from a company such as Desert
Aircraft or Aircraft International.
When choosing a three-blade propeller, contact the manufacturer
of your engine to see what propeller is best suited for it. I’ve had a
lot of experience testing different three-blade propellers on a variety
of engines, and I learned that I prefer smaller-diameter propellers on
heavier airplanes and larger-diameter propellers on lighter models.
On a 41-pound giant you might like a 28 x 12 three-blade
propeller. On a 38-pound aircraft you might prefer the power
transition and rpm from either a 28.5 x 12 three-blade propeller or a
29 x 12 three-blade propeller on a typical 150cc-170cc engine.
Following is what has worked for me with Desert Aircraft
engines.
• DA-100: 25 x 12 three-blade on the Hangar 9 35% Extra 260
• DA-120: 25 x 12 three-blade on the Hangar 9 Beast
• DA-150: 29 x 12 three-blade on a Composite-ARF Extra 330 (35
pounds dry) and 28 x 12 three-blade on a Krill Katana (41 pounds)
• DA-170: 28.5 x 12 three-blade on a Thunder Tiger Extra 260 (38
pounds dry)
• DA-200: 29 x 12 three-blade on a Thunder Tiger Extra 260 (42
pounds dry)
I tried a variety of propellers on the preceding airplane/engine
combinations to arrive at the results.
When reviewing my choices, take into consideration that the
exhaust systems on the models differed. Some used stock mufflers
and others used canisters, which can make a difference in propeller
choice. Installing a canister system will add weight to your airframe.
If you need advice, talk to fellow modelers or feel free to contact
me with any questions or concerns you have about your setup.
Talking Exhaust: Some ARFs have canister tunnels and brackets in
place. If yours does, your model will be up and running in no time!
However, in the interest of this column I will use an example in
which the canister tunnel is already built. The only thing left for you
to do is install a bracket to properly secure
the canisters in place.
To begin, determine the type of header
and “drop” you will need. After the engine
is secured on your aircraft, measure from
where the exhaust header will make contact
with the cylinder head to the center of the
canister inlet. That is your drop when it
comes time to order a header or headers.
If no manufacturer makes the drop you
need, you might have to solder an adjustable
header. This past summer I built a 37.5%
Yak-54 for someone, and it needed a drop of
only approximately 30mm.
I purchased an adjustable header from
Desert Aircraft that had two ball joints. I
adjusted the headers so that the header
would be parallel to the entry point of the
canisters, and then I removed the headers
from the engine, cleaned the area with
rubbing alcohol, and silver-soldered the ball
joints to properly secure the header.
Now for fastening the canisters into
position. A few methods exist for installing
a canister system.
I recommend that you make a rectangle
from 1/8 or 1/4 light plywood that is the same
dimensions to fit within your canister tunnel.
If the inner length and height of your
canister tunnel is 8 x 6 inches, cut a piece of
plywood to the same dimensions.
Then make a cutout that is close to the
same diameter and shape as the canister; it
will need to slide into this plate. The hole
should be centered on this plate (if using one
canister for a single-cylinder engine or two
cutouts for a two-cylinder engine).
Recess four areas on this circular hole.
You will need to insert fuel tubing (or
similar) into these areas to act as a spacer, so
that the canister is “soft mounted” and
doesn’t make contact with the actual light
plywood plate.
When you have finished the preceding,
glue the mount in place using epoxy and
reinforce—with 1/4-inch triangular stock or
similar—all areas where the plate makes
contact with the canister tunnel.
Tips for Success: The exhaust header will
go to a Teflon coupler, and it will go to the
canister or tuned-pipe exhaust. The first few
flights on your canister-equipped model are
the most critical; they determine whether or
136 MODEL AVIATION
not your installation “seats” properly. If you
install a canister improperly, it can back
away from the Teflon coupler since that area
heats up quite a bit.
Clamps are sold that go over the coupler
to fasten it to both the header and the
canister. Before my first flight on a system, I
apply warmth, via a high-temperature heat
gun, over the two clamps (that are fastened
in position over the header and the canister).
While you are applying heat, the Teflon
coupler will change shape a bit, and there
will be a slightly recessed spot where the
clamp is. When that happens, turn off the
heat gun; the process is complete.
When you go to the flying field, you
should not have to worry about whether or
not your exhaust system will function
properly and you can focus on one thing:
flying!
Now you know about the importance of
sound at an Aerobatics contest, how to make
your model quieter, and how you can install
a canister system on your giant Scale
aircraft.
Even if you do not intend to compete, I
strongly urge you to “go the extra mile”
regarding sound reduction. As I mentioned,
many flying fields across the US face some
sort of noise issue, and it is a true shame to
lose a flying field because of a problem that
can be prevented.
Until next time, fly hard! MA
Sources:
International Miniature Aerobatic Club
www.mini-iac.com
RC Universe
www.rcuniverse.com
Flying Giants
www.flyinggiants.com
Desert Aircraft
(520) 722-0607
www.desertaircraft.com
Aircraft International
(732) 761-0997
www.aircraftinternational.com
Hangar 9
(800) 338-4639
www.hangar-9.com
Composite-ARF
www.carf-models.com
Krill Model
www.krill-model.com
Thunder Tiger:
Ace Hobby
(949) 900-3300
www.acehobby.com
JR
(800) 338-4639
www.jrradios.com
Edition: Model Aviation - 2010/12
Page Numbers: 133,134,136
Edition: Model Aviation - 2010/12
Page Numbers: 133,134,136
Sound and Aerobatics
December 2010 133
[[email protected]]
Radio Control Scale Aerobatics John Glezellis
The Hangar 9 Beast is a great competition model. It is using a three-blade propeller,
which has a great amount of power with the new Desert Aircraft DA-120 engine.
This shows how you can expect a sound meter to be set up at a
local and/or national competition.
Your model’s sound level will be measured as shown at a local
and/or national competition. You can perform this test at the
practice field so that you are aware of your aircraft’s noise level
before attending a major event.
As I Am writing this, the 2010 flying
season is coming to an end for those of us in
the Northeast and building season is fast
approaching.
As each year goes on, it amazes me to
see the increased interest in giant Scale
Aerobatics models. However, as more pilots
are flying these large aircraft, more airfields
are facing sound issues that were
nonexistent in previous years.
I’m going to devote this month’s column
to sound and what can be done to enforce
regulations at the local flying field. Even if
you are not interested in Aerobatics, this
column is for you if you are a giant Scale
enthusiast.
Let’s begin!
Rules, Rules, Rules! In the world of the
International Miniature Aerobatic Club
(IMAC), certain rules on the competition
scene pertain to sound. One is that each
model that is to be flown in a contest must
pass the Ground Sound Level Test. If an
airplane fails this test, its pilot can be
disqualified.
If you are a newcomer, I am sure that
exceptions can be made if you speak to the
CD. However, before you attend your first
competition, check the sound level of your
aircraft and speak to the CD well in advance
if you think you might have an issue. It is
better to be safe than sorry—especially if
you are traveling several hours to attend a
contest!
The maximum sound level is 96 dBA
measured on soft surfaces and 98 dBA
measured on hard surfaces. To test for these
levels, place a sound meter directly facing
the model, perpendicular to the fuselage.
The sound meter must be approximately
25 feet from the airplane centerline and 24
inches off of the ground. Once the aircraft
and meter are correctly placed, the pilot
starts the model and runs up the engine to
full power.
Aside from the Ground Sound Level
Test, each pilot receives a flight score that
takes into account the noise that his or her
airplane produces. During Known and
Unknown flights, each judge enters a Sound
Score in addition to the ratings for each
maneuver.
The Sound Score can be a 0 (too
noisy), a 5 (acceptable), or a 10 (very
quiet). Then that figure is multiplied by a
“K,” which is assigned to each IMAC
class. Those are:
• Unlimited: 5K
• Advanced: 4K
• Intermediate: 3K
• Sportsman: 2K
• Basic: 1K
12sig5x.QXD_00MSTRPG.QXD 10/22/10 8:35 AM Page 133
You shouldn’t decrease the sound of your model only for
competition. As a result of noise issues, many of our beloved flying
sites face opposition from neighboring homes, parks, etc.
The sound level of an airplane can vary greatly, depending on
the type of exhaust and propeller it has. A two-blade propeller is
generally louder than a three-blade type.
The cost of a canister-type exhaust can be overwhelming. If you
don’t want to put forth that amount of money, install a three-blade
propeller on your model and see if that makes the sound acceptable
at your flying field.
If it doesn’t, consider purchasing a used exhaust system from
postings on Web sites such as RC Universe or Flying Giants. Or you
can buy a new exhaust system from a company such as Desert
Aircraft or Aircraft International.
When choosing a three-blade propeller, contact the manufacturer
of your engine to see what propeller is best suited for it. I’ve had a
lot of experience testing different three-blade propellers on a variety
of engines, and I learned that I prefer smaller-diameter propellers on
heavier airplanes and larger-diameter propellers on lighter models.
On a 41-pound giant you might like a 28 x 12 three-blade
propeller. On a 38-pound aircraft you might prefer the power
transition and rpm from either a 28.5 x 12 three-blade propeller or a
29 x 12 three-blade propeller on a typical 150cc-170cc engine.
Following is what has worked for me with Desert Aircraft
engines.
• DA-100: 25 x 12 three-blade on the Hangar 9 35% Extra 260
• DA-120: 25 x 12 three-blade on the Hangar 9 Beast
• DA-150: 29 x 12 three-blade on a Composite-ARF Extra 330 (35
pounds dry) and 28 x 12 three-blade on a Krill Katana (41 pounds)
• DA-170: 28.5 x 12 three-blade on a Thunder Tiger Extra 260 (38
pounds dry)
• DA-200: 29 x 12 three-blade on a Thunder Tiger Extra 260 (42
pounds dry)
I tried a variety of propellers on the preceding airplane/engine
combinations to arrive at the results.
When reviewing my choices, take into consideration that the
exhaust systems on the models differed. Some used stock mufflers
and others used canisters, which can make a difference in propeller
choice. Installing a canister system will add weight to your airframe.
If you need advice, talk to fellow modelers or feel free to contact
me with any questions or concerns you have about your setup.
Talking Exhaust: Some ARFs have canister tunnels and brackets in
place. If yours does, your model will be up and running in no time!
However, in the interest of this column I will use an example in
which the canister tunnel is already built. The only thing left for you
to do is install a bracket to properly secure
the canisters in place.
To begin, determine the type of header
and “drop” you will need. After the engine
is secured on your aircraft, measure from
where the exhaust header will make contact
with the cylinder head to the center of the
canister inlet. That is your drop when it
comes time to order a header or headers.
If no manufacturer makes the drop you
need, you might have to solder an adjustable
header. This past summer I built a 37.5%
Yak-54 for someone, and it needed a drop of
only approximately 30mm.
I purchased an adjustable header from
Desert Aircraft that had two ball joints. I
adjusted the headers so that the header
would be parallel to the entry point of the
canisters, and then I removed the headers
from the engine, cleaned the area with
rubbing alcohol, and silver-soldered the ball
joints to properly secure the header.
Now for fastening the canisters into
position. A few methods exist for installing
a canister system.
I recommend that you make a rectangle
from 1/8 or 1/4 light plywood that is the same
dimensions to fit within your canister tunnel.
If the inner length and height of your
canister tunnel is 8 x 6 inches, cut a piece of
plywood to the same dimensions.
Then make a cutout that is close to the
same diameter and shape as the canister; it
will need to slide into this plate. The hole
should be centered on this plate (if using one
canister for a single-cylinder engine or two
cutouts for a two-cylinder engine).
Recess four areas on this circular hole.
You will need to insert fuel tubing (or
similar) into these areas to act as a spacer, so
that the canister is “soft mounted” and
doesn’t make contact with the actual light
plywood plate.
When you have finished the preceding,
glue the mount in place using epoxy and
reinforce—with 1/4-inch triangular stock or
similar—all areas where the plate makes
contact with the canister tunnel.
Tips for Success: The exhaust header will
go to a Teflon coupler, and it will go to the
canister or tuned-pipe exhaust. The first few
flights on your canister-equipped model are
the most critical; they determine whether or
136 MODEL AVIATION
not your installation “seats” properly. If you
install a canister improperly, it can back
away from the Teflon coupler since that area
heats up quite a bit.
Clamps are sold that go over the coupler
to fasten it to both the header and the
canister. Before my first flight on a system, I
apply warmth, via a high-temperature heat
gun, over the two clamps (that are fastened
in position over the header and the canister).
While you are applying heat, the Teflon
coupler will change shape a bit, and there
will be a slightly recessed spot where the
clamp is. When that happens, turn off the
heat gun; the process is complete.
When you go to the flying field, you
should not have to worry about whether or
not your exhaust system will function
properly and you can focus on one thing:
flying!
Now you know about the importance of
sound at an Aerobatics contest, how to make
your model quieter, and how you can install
a canister system on your giant Scale
aircraft.
Even if you do not intend to compete, I
strongly urge you to “go the extra mile”
regarding sound reduction. As I mentioned,
many flying fields across the US face some
sort of noise issue, and it is a true shame to
lose a flying field because of a problem that
can be prevented.
Until next time, fly hard! MA
Sources:
International Miniature Aerobatic Club
www.mini-iac.com
RC Universe
www.rcuniverse.com
Flying Giants
www.flyinggiants.com
Desert Aircraft
(520) 722-0607
www.desertaircraft.com
Aircraft International
(732) 761-0997
www.aircraftinternational.com
Hangar 9
(800) 338-4639
www.hangar-9.com
Composite-ARF
www.carf-models.com
Krill Model
www.krill-model.com
Thunder Tiger:
Ace Hobby
(949) 900-3300
www.acehobby.com
JR
(800) 338-4639
www.jrradios.com
Edition: Model Aviation - 2010/12
Page Numbers: 133,134,136
Sound and Aerobatics
December 2010 133
[[email protected]]
Radio Control Scale Aerobatics John Glezellis
The Hangar 9 Beast is a great competition model. It is using a three-blade propeller,
which has a great amount of power with the new Desert Aircraft DA-120 engine.
This shows how you can expect a sound meter to be set up at a
local and/or national competition.
Your model’s sound level will be measured as shown at a local
and/or national competition. You can perform this test at the
practice field so that you are aware of your aircraft’s noise level
before attending a major event.
As I Am writing this, the 2010 flying
season is coming to an end for those of us in
the Northeast and building season is fast
approaching.
As each year goes on, it amazes me to
see the increased interest in giant Scale
Aerobatics models. However, as more pilots
are flying these large aircraft, more airfields
are facing sound issues that were
nonexistent in previous years.
I’m going to devote this month’s column
to sound and what can be done to enforce
regulations at the local flying field. Even if
you are not interested in Aerobatics, this
column is for you if you are a giant Scale
enthusiast.
Let’s begin!
Rules, Rules, Rules! In the world of the
International Miniature Aerobatic Club
(IMAC), certain rules on the competition
scene pertain to sound. One is that each
model that is to be flown in a contest must
pass the Ground Sound Level Test. If an
airplane fails this test, its pilot can be
disqualified.
If you are a newcomer, I am sure that
exceptions can be made if you speak to the
CD. However, before you attend your first
competition, check the sound level of your
aircraft and speak to the CD well in advance
if you think you might have an issue. It is
better to be safe than sorry—especially if
you are traveling several hours to attend a
contest!
The maximum sound level is 96 dBA
measured on soft surfaces and 98 dBA
measured on hard surfaces. To test for these
levels, place a sound meter directly facing
the model, perpendicular to the fuselage.
The sound meter must be approximately
25 feet from the airplane centerline and 24
inches off of the ground. Once the aircraft
and meter are correctly placed, the pilot
starts the model and runs up the engine to
full power.
Aside from the Ground Sound Level
Test, each pilot receives a flight score that
takes into account the noise that his or her
airplane produces. During Known and
Unknown flights, each judge enters a Sound
Score in addition to the ratings for each
maneuver.
The Sound Score can be a 0 (too
noisy), a 5 (acceptable), or a 10 (very
quiet). Then that figure is multiplied by a
“K,” which is assigned to each IMAC
class. Those are:
• Unlimited: 5K
• Advanced: 4K
• Intermediate: 3K
• Sportsman: 2K
• Basic: 1K
12sig5x.QXD_00MSTRPG.QXD 10/22/10 8:35 AM Page 133
You shouldn’t decrease the sound of your model only for
competition. As a result of noise issues, many of our beloved flying
sites face opposition from neighboring homes, parks, etc.
The sound level of an airplane can vary greatly, depending on
the type of exhaust and propeller it has. A two-blade propeller is
generally louder than a three-blade type.
The cost of a canister-type exhaust can be overwhelming. If you
don’t want to put forth that amount of money, install a three-blade
propeller on your model and see if that makes the sound acceptable
at your flying field.
If it doesn’t, consider purchasing a used exhaust system from
postings on Web sites such as RC Universe or Flying Giants. Or you
can buy a new exhaust system from a company such as Desert
Aircraft or Aircraft International.
When choosing a three-blade propeller, contact the manufacturer
of your engine to see what propeller is best suited for it. I’ve had a
lot of experience testing different three-blade propellers on a variety
of engines, and I learned that I prefer smaller-diameter propellers on
heavier airplanes and larger-diameter propellers on lighter models.
On a 41-pound giant you might like a 28 x 12 three-blade
propeller. On a 38-pound aircraft you might prefer the power
transition and rpm from either a 28.5 x 12 three-blade propeller or a
29 x 12 three-blade propeller on a typical 150cc-170cc engine.
Following is what has worked for me with Desert Aircraft
engines.
• DA-100: 25 x 12 three-blade on the Hangar 9 35% Extra 260
• DA-120: 25 x 12 three-blade on the Hangar 9 Beast
• DA-150: 29 x 12 three-blade on a Composite-ARF Extra 330 (35
pounds dry) and 28 x 12 three-blade on a Krill Katana (41 pounds)
• DA-170: 28.5 x 12 three-blade on a Thunder Tiger Extra 260 (38
pounds dry)
• DA-200: 29 x 12 three-blade on a Thunder Tiger Extra 260 (42
pounds dry)
I tried a variety of propellers on the preceding airplane/engine
combinations to arrive at the results.
When reviewing my choices, take into consideration that the
exhaust systems on the models differed. Some used stock mufflers
and others used canisters, which can make a difference in propeller
choice. Installing a canister system will add weight to your airframe.
If you need advice, talk to fellow modelers or feel free to contact
me with any questions or concerns you have about your setup.
Talking Exhaust: Some ARFs have canister tunnels and brackets in
place. If yours does, your model will be up and running in no time!
However, in the interest of this column I will use an example in
which the canister tunnel is already built. The only thing left for you
to do is install a bracket to properly secure
the canisters in place.
To begin, determine the type of header
and “drop” you will need. After the engine
is secured on your aircraft, measure from
where the exhaust header will make contact
with the cylinder head to the center of the
canister inlet. That is your drop when it
comes time to order a header or headers.
If no manufacturer makes the drop you
need, you might have to solder an adjustable
header. This past summer I built a 37.5%
Yak-54 for someone, and it needed a drop of
only approximately 30mm.
I purchased an adjustable header from
Desert Aircraft that had two ball joints. I
adjusted the headers so that the header
would be parallel to the entry point of the
canisters, and then I removed the headers
from the engine, cleaned the area with
rubbing alcohol, and silver-soldered the ball
joints to properly secure the header.
Now for fastening the canisters into
position. A few methods exist for installing
a canister system.
I recommend that you make a rectangle
from 1/8 or 1/4 light plywood that is the same
dimensions to fit within your canister tunnel.
If the inner length and height of your
canister tunnel is 8 x 6 inches, cut a piece of
plywood to the same dimensions.
Then make a cutout that is close to the
same diameter and shape as the canister; it
will need to slide into this plate. The hole
should be centered on this plate (if using one
canister for a single-cylinder engine or two
cutouts for a two-cylinder engine).
Recess four areas on this circular hole.
You will need to insert fuel tubing (or
similar) into these areas to act as a spacer, so
that the canister is “soft mounted” and
doesn’t make contact with the actual light
plywood plate.
When you have finished the preceding,
glue the mount in place using epoxy and
reinforce—with 1/4-inch triangular stock or
similar—all areas where the plate makes
contact with the canister tunnel.
Tips for Success: The exhaust header will
go to a Teflon coupler, and it will go to the
canister or tuned-pipe exhaust. The first few
flights on your canister-equipped model are
the most critical; they determine whether or
136 MODEL AVIATION
not your installation “seats” properly. If you
install a canister improperly, it can back
away from the Teflon coupler since that area
heats up quite a bit.
Clamps are sold that go over the coupler
to fasten it to both the header and the
canister. Before my first flight on a system, I
apply warmth, via a high-temperature heat
gun, over the two clamps (that are fastened
in position over the header and the canister).
While you are applying heat, the Teflon
coupler will change shape a bit, and there
will be a slightly recessed spot where the
clamp is. When that happens, turn off the
heat gun; the process is complete.
When you go to the flying field, you
should not have to worry about whether or
not your exhaust system will function
properly and you can focus on one thing:
flying!
Now you know about the importance of
sound at an Aerobatics contest, how to make
your model quieter, and how you can install
a canister system on your giant Scale
aircraft.
Even if you do not intend to compete, I
strongly urge you to “go the extra mile”
regarding sound reduction. As I mentioned,
many flying fields across the US face some
sort of noise issue, and it is a true shame to
lose a flying field because of a problem that
can be prevented.
Until next time, fly hard! MA
Sources:
International Miniature Aerobatic Club
www.mini-iac.com
RC Universe
www.rcuniverse.com
Flying Giants
www.flyinggiants.com
Desert Aircraft
(520) 722-0607
www.desertaircraft.com
Aircraft International
(732) 761-0997
www.aircraftinternational.com
Hangar 9
(800) 338-4639
www.hangar-9.com
Composite-ARF
www.carf-models.com
Krill Model
www.krill-model.com
Thunder Tiger:
Ace Hobby
(949) 900-3300
www.acehobby.com
JR
(800) 338-4639
www.jrradios.com
