118 MODEL AVIATION
ONE OF THE clubs I belong to asked me to give a presentation on
IMAC and competing in Scale Aerobatics. The members were
interested to learn about the scale and precision aspects of IMAC,
but many of them were also interested in learning about 3-D flight;
3-D is not scale but is often performed in the IMAC Freestyle event
with our Scale aircraft.
I looked around a bit and asked online if there were any
preformatted guidelines for such an introduction to IMAC—it seems
like something that could be helpful for clubs across the country.
But I could find nothing written as a guide for those who might want
to give a talk to their club members. So I’ve decided to outline my
presentation here so that if you have a fair amount of IMAC
experience, you might use it as a guide to give a presentation to
interested members in your own club.
Start With the Basics: What is IMAC? The International Miniature
Aerobatic Club (IMAC) is formulated to emulate near-scale models
of the type of aircraft that fly in International Aerobatic Club (IAC)
full-scale precision aerobatics. Events, patterns, and figures are
formulated to stay true (within our limitations) to the full scale. But
because of IMAC’s separate evolution, there are some minor
exceptions.
IMAC is competitive precision flying in front of judges the same
way a full-scale competition is held and is also similar to Pattern or
AMA Precision Aerobatics. IMAC events are “contests.” Those who
fly in IMAC invariably have the desire to stand up and be judged on
their flying skills against others by their peers.
What Aircraft Can I Use? Generally, you must fly a model of a
full-scale aircraft capable of competing in an IAC contest. There is
no specific list of eligible aircraft. A Piper Cub or an AT-6 would be
considered legal for IMAC, but superior flight characteristics will
usually cull the diversity of entries down to a dozen or so of the best
full-scale airplanes such as Sukhois, Extras, CAPs, etc.
There are no size or weight requirements or limitations other
than those set forth by AMA for all modeling. Because so many
large airplanes fly in IMAC, some people confuse it with a Giant
Scale organization and think that airplanes must be large to fly in
IMAC. Not so! Any size aircraft is eligible. A lifelike pilot and an
instrument panel are required in the aircraft. The only exception to
Mike Hurley, 11542 Decatur Ct., Westminster CO 80234; E-mail: [email protected]
RADIO CONTROL SCALE AEROBATICS
This was a well-received and -attended IMAC seminar; 100+
people wanted to know more about IMAC Scale Aerobatics.
Working closely with your caller is very important. A good
relationship helps tremendously during the contest.
Full-scale unlimited competitor Matt Chapman shows just how
much our IMAC models resemble the full-scale aircraft.
Freestyle more closely resembles a full-scale air show than an
IAC contest. 3-D flight is unique to models.
07sig4.QXD 4/23/04 12:43 pm Page 118
120 MODEL AVIATION
Pilots often practice and visualize the Unknown portion of the
contest using a “stick” airplane, which is a tiny model.
these rules is in the Basic class, which is designed as a “try it out”
class and can be flown with any aircraft—not necessarily Scale.
Competitive Classes: There are five classes, or levels of
Service & Repairs For Most Radio Control Systems,
Utilizing Calibrated Test Equipment & Spectrum Analyzers.
Futaba, Airtronics, JR, Ace, HiTec, Tower, Cirrus, World Engines & More
D&M ELECTRONICS • 1236 Marigold St. NW, Hartville, OH 44632 • 330-877-1445
Shipping & Insurance Extra – – UPS • U.S. Mail • C.O.D.’s
Visit our home page at http://www.dnmelectronics.com • Email: [email protected]
AMA # 256123-Dave ARRL WB8YSQ
D & M E L E C T R O N I C S
• WE USE GENUINE FACTORY REPLACEMENT PARTS
• Endorsed by AMA/RCMA as Sticker Station #105
• 1991/1998 Narrow Banding & Certification
• FCC Licensed
• Speed Control Repairs
• Quality Service
• Fast Turn Around
• RCD / HITEC R/C Dealer
• Miniature Aircraft Dealer
X-CELL Helicopters
The original Ball engines are now quite rare. They were precision-made in every
detail, assembled by experts; started, run and checked carefully at the factory before
going into the field. We now have a beautiful reproduction Ball which is extremely
well made and faithful to the original in every detail. Each engine is assembled by an
expert and checked carefully at the factory - giving you the most accurate
reproduction engine possible. (Bore .924 in, Stroke .900 in., Disp. .604 cu. in.)
These reproductions are only available for a limited time. $429.50 less spark plug + $12.00 s&h in the USA
(priority mail w/insurance). International call or write for S&H
Reproduction Parts Catalog #8 is now current.
$12.50 USA - $13.50 Canada & Mexico- $20.00 International.
Engineered to operate at
speeds in excess of
20,000 RPM!
Exclusively Available from Woody Bartelt
3706 North 33rd Street, Galesburg, MI 49053
Fax/Phone: (269) 665-9693
e-mail: [email protected]
THE BALL 60!
Send
$3.00 for
listings of
Original and
Reproduction
engines.
proficiency: Basic, Sportsman, Intermediate, Advanced, and
Unlimited. The classes are structured in a way that lays a
foundation of skills onto which new skills are added as you move
up through the classes. You will use the skills you learned in Basic
in every class and every flight for the rest of your flying career. A
half roll with a score of 8 performed in Sportsman would still get a
score of 8 in Unlimited.
Without that foundation you will be at a disadvantage in the
higher classes, so I encourage everybody, even very skilled pilots,
to start in the Basic class and give it some time and practice before
moving to the next level.
All the classes share fundamental elements and all are judged in
the same manner. An element is a single figure such as a loop. As
you move to higher classes, new elements are introduced and more
figures are added to create a more complex figure or maneuver.
Multiple figures can be added to create a single scored maneuver
(such as a loop with a snap at the top), increasing the difficulty but
retaining the foundation of the maneuvers you learned in the lower
classes. In this manner, a pilot’s flying skill increases quickly,
building new maneuvers on proven skills.
Elements of a Contest: There are three main elements in a contest:
the Known schedule, the Unknown schedule, and the Freestyle. The
Known schedule, or “Known sequence” is a series of (usually 10-
14) maneuvers formulated by the IMAC board of directors at the
beginning of each contest season. The sequence will change each
year in IMAC as it does with IAC. There will be a different
sequence for each class, and the bulk of your contest season will be
spent mastering the same sequence of maneuvers all year long.
At each contest, pilots (except the Basic class) will also fly one
round of an Unknown sequence. Before the contest the contest
director creates a unique “unknown” sequence for each class using
the IMAC handbook of standard figures and Aresti patterns. None
of the contestants see the sequence until the evening before they are
to fly it in the contest. Pilots are not allowed to practice the
07sig4.QXD 4/23/04 12:43 pm Page 120
July 2004 121
sequence before they fly it for the judges,
and usually no flying is allowed after the
Unknowns are distributed.
Most IMAC contests are two-day events,
and the Unknown is typically flown first
thing on the morning of the second day.
Memorizing the Unknown flight, visualizing
your performance, and practicing with your
caller are key to succeeding in the Unknown
round. You will often see pilots flying the
sequence with a handheld “stick” airplane to
help with visualization and preparation.
The IMAC Freestyle does not emulate
the full-scale version of the Freestyle event.
The Freestyle is a separate and optional
event, and it is not calculated into your score
for the contest. There are separate awards
for the Freestyle, and a completely different
skill set is used to excel in it. The Freestyle
also uses completely different criteria for
judging and is more reliant on excitement
and emotional impact than on precision
perfection.
IMAC Freestyle does not rely solely on
scale-type maneuvers, and 3-D flight is
often performed along with difficult scale
figures in this four-minute round. Impact is
often enhanced by choreographing a routine
to music, adding smoke or streamers, and
flying extremely low, difficult maneuvers to
increase the wow factor.
Freestyle is your chance to show your
stuff, and far too many competitors don’t
take the chance to fly in it. For me, Freestyle
is the most fun event of the contest! IMAC
Freestyle is more like a full-scale air show
than the contest version of IAC Freestyle.
How Am I Judged? To accommodate 20
or more pilots, most IMAC contests have
two models in the air at the same time.
There are generally two flightlines set up—
one at each end of the runway. There are
typically two judges at each flightline,
although more can be used if more judges
are available.
Each judge is partnered with a scribe,
who reads the maneuvers to him or her as
they are being flown and records the scores
as they are given. Each figure starts with a
perfect score of 10, and as it is flown, each
judge looks for imperfections and deducts
as necessary to determine the final score
(0-10) for each maneuver.
As a pilot, you will have a “caller” to
help you through your flight. Your caller
will hold your airplane while you start it,
watch for other aircraft taking off or on
approach, help you determine when it is
okay to take off or land, and spot for you
while you’re flying. Your caller is also
there to read the sequence to you while you
fly it and can even coach you as you fly.
Your caller will communicate with the
judges for you when necessary so you can
just concentrate on flying! It’s a good idea
to practice with the caller you will use in
the contest and get comfortable with each
other so you work well together when it
counts.
When it’s finally your turn to fly, the
judges or a “line boss” will tell you where
and when to start your model. The judge
will indicate the all clear to take off, and
your caller will spot for you. When you get
your aircraft into the air, you are allowed a
short period to trim your airplane and
position yourself for the start of the
sequence. You cannot perform any
aerobatic maneuvers before the sequence
begins or after it is completed.
You must call “In the box” to the
judges when you start the sequence. I tell
my caller, and he makes sure the judges
hear him say it. When the flight is finished,
the caller is diligent about the judges
making no mistake that the flight is over,
calling “Out of the box.” Normally you
will fly two sequences per flight or round,
except in the Unknown. Takeoff and
landing are not judged in IMAC.
Reading Aresti: The sequences are written
in a form of diagrams called Aresti. The
symbols are a way to quickly and precisely
understand what figures you will fly and
where to fly them. Aresti is fairly easy to
figure out with a bit of study. You will
need to learn some basics of reading the
diagrams as you progress in IMAC, but for
ease, the sequences also include a written
description of the figures.
IMAC Practice as a Means to Improve
Sport-Flying Skills: It’s important to
understand that many fliers may not want
to compete. But all of us would like to
improve our flying skills. Nobody can say
that he or she knows it all and can perform
every maneuver in the book perfectly. If
you do not want to compete, IMAC
practice will instill a bit of discipline in
your flying. It will push you to try new
maneuvers in different configurations, and
it will do so in a logical step-by-step
method that improves your flying skill
quickly.
If you want to be a better pilot, I suggest
that you try to fly the Basic sequences and
push yourself to move up through the
sequences each time you have mastered the
previous. You may even feel that flying
Basic IMAC sequences is a pretty big step
backward for you, but try it. I bet you’ll be
surprised at how difficult precision and
positioning is!
For IMAC rules, AMA Scale Aerobatics
rules, Unknown figures catalogs, and a list
of contests by region, go to www.miniiac.
com. You can also find a list of
proposed rules that will go into effect in the
2005 rules cycle. Almost everything you
need to know to enter or run a contest is on
the Web site. Suggested reading for clubs
or anyone who is thinking about running an
IMAC contest for the first time is an article
on the Web site titled “Your First Contest.”
There are many good tips for first-time
competitors in the “Flight School” area.
For information about full-scale
aerobatics, go to www.iac.org/. For the
worldwide Aerobatics organization, go to
www.fai.org/aerobatics/. MA
CST
The Composites Store Inc.
PO Box 622, Tehachapi, CA 93581
Order on-line or by phone
1-800-338-1278
Tech Support: 661-823-0108
• Rods & Tubes
• Carbon,
Aramid &
Fiberglass
Materials
• Epoxy
Systems
• Vacuum
Bagging and
Molding
Supplies
• FREE How-To
Articles on
the web
COMPOSITE MATERIALS
www.cstsales.com
STOCK THE
SHOP FOR
BUILDING
SEASON!
Our Full-Size
Plans List
has hundreds
of models
to choose from.
See page 199
for details.
07sig4.QXD 4/23/04 12:43 pm Page 121
Edition: Model Aviation - 2004/07
Page Numbers: 118,120,121
Edition: Model Aviation - 2004/07
Page Numbers: 118,120,121
118 MODEL AVIATION
ONE OF THE clubs I belong to asked me to give a presentation on
IMAC and competing in Scale Aerobatics. The members were
interested to learn about the scale and precision aspects of IMAC,
but many of them were also interested in learning about 3-D flight;
3-D is not scale but is often performed in the IMAC Freestyle event
with our Scale aircraft.
I looked around a bit and asked online if there were any
preformatted guidelines for such an introduction to IMAC—it seems
like something that could be helpful for clubs across the country.
But I could find nothing written as a guide for those who might want
to give a talk to their club members. So I’ve decided to outline my
presentation here so that if you have a fair amount of IMAC
experience, you might use it as a guide to give a presentation to
interested members in your own club.
Start With the Basics: What is IMAC? The International Miniature
Aerobatic Club (IMAC) is formulated to emulate near-scale models
of the type of aircraft that fly in International Aerobatic Club (IAC)
full-scale precision aerobatics. Events, patterns, and figures are
formulated to stay true (within our limitations) to the full scale. But
because of IMAC’s separate evolution, there are some minor
exceptions.
IMAC is competitive precision flying in front of judges the same
way a full-scale competition is held and is also similar to Pattern or
AMA Precision Aerobatics. IMAC events are “contests.” Those who
fly in IMAC invariably have the desire to stand up and be judged on
their flying skills against others by their peers.
What Aircraft Can I Use? Generally, you must fly a model of a
full-scale aircraft capable of competing in an IAC contest. There is
no specific list of eligible aircraft. A Piper Cub or an AT-6 would be
considered legal for IMAC, but superior flight characteristics will
usually cull the diversity of entries down to a dozen or so of the best
full-scale airplanes such as Sukhois, Extras, CAPs, etc.
There are no size or weight requirements or limitations other
than those set forth by AMA for all modeling. Because so many
large airplanes fly in IMAC, some people confuse it with a Giant
Scale organization and think that airplanes must be large to fly in
IMAC. Not so! Any size aircraft is eligible. A lifelike pilot and an
instrument panel are required in the aircraft. The only exception to
Mike Hurley, 11542 Decatur Ct., Westminster CO 80234; E-mail: [email protected]
RADIO CONTROL SCALE AEROBATICS
This was a well-received and -attended IMAC seminar; 100+
people wanted to know more about IMAC Scale Aerobatics.
Working closely with your caller is very important. A good
relationship helps tremendously during the contest.
Full-scale unlimited competitor Matt Chapman shows just how
much our IMAC models resemble the full-scale aircraft.
Freestyle more closely resembles a full-scale air show than an
IAC contest. 3-D flight is unique to models.
07sig4.QXD 4/23/04 12:43 pm Page 118
120 MODEL AVIATION
Pilots often practice and visualize the Unknown portion of the
contest using a “stick” airplane, which is a tiny model.
these rules is in the Basic class, which is designed as a “try it out”
class and can be flown with any aircraft—not necessarily Scale.
Competitive Classes: There are five classes, or levels of
Service & Repairs For Most Radio Control Systems,
Utilizing Calibrated Test Equipment & Spectrum Analyzers.
Futaba, Airtronics, JR, Ace, HiTec, Tower, Cirrus, World Engines & More
D&M ELECTRONICS • 1236 Marigold St. NW, Hartville, OH 44632 • 330-877-1445
Shipping & Insurance Extra – – UPS • U.S. Mail • C.O.D.’s
Visit our home page at http://www.dnmelectronics.com • Email: [email protected]
AMA # 256123-Dave ARRL WB8YSQ
D & M E L E C T R O N I C S
• WE USE GENUINE FACTORY REPLACEMENT PARTS
• Endorsed by AMA/RCMA as Sticker Station #105
• 1991/1998 Narrow Banding & Certification
• FCC Licensed
• Speed Control Repairs
• Quality Service
• Fast Turn Around
• RCD / HITEC R/C Dealer
• Miniature Aircraft Dealer
X-CELL Helicopters
The original Ball engines are now quite rare. They were precision-made in every
detail, assembled by experts; started, run and checked carefully at the factory before
going into the field. We now have a beautiful reproduction Ball which is extremely
well made and faithful to the original in every detail. Each engine is assembled by an
expert and checked carefully at the factory - giving you the most accurate
reproduction engine possible. (Bore .924 in, Stroke .900 in., Disp. .604 cu. in.)
These reproductions are only available for a limited time. $429.50 less spark plug + $12.00 s&h in the USA
(priority mail w/insurance). International call or write for S&H
Reproduction Parts Catalog #8 is now current.
$12.50 USA - $13.50 Canada & Mexico- $20.00 International.
Engineered to operate at
speeds in excess of
20,000 RPM!
Exclusively Available from Woody Bartelt
3706 North 33rd Street, Galesburg, MI 49053
Fax/Phone: (269) 665-9693
e-mail: [email protected]
THE BALL 60!
Send
$3.00 for
listings of
Original and
Reproduction
engines.
proficiency: Basic, Sportsman, Intermediate, Advanced, and
Unlimited. The classes are structured in a way that lays a
foundation of skills onto which new skills are added as you move
up through the classes. You will use the skills you learned in Basic
in every class and every flight for the rest of your flying career. A
half roll with a score of 8 performed in Sportsman would still get a
score of 8 in Unlimited.
Without that foundation you will be at a disadvantage in the
higher classes, so I encourage everybody, even very skilled pilots,
to start in the Basic class and give it some time and practice before
moving to the next level.
All the classes share fundamental elements and all are judged in
the same manner. An element is a single figure such as a loop. As
you move to higher classes, new elements are introduced and more
figures are added to create a more complex figure or maneuver.
Multiple figures can be added to create a single scored maneuver
(such as a loop with a snap at the top), increasing the difficulty but
retaining the foundation of the maneuvers you learned in the lower
classes. In this manner, a pilot’s flying skill increases quickly,
building new maneuvers on proven skills.
Elements of a Contest: There are three main elements in a contest:
the Known schedule, the Unknown schedule, and the Freestyle. The
Known schedule, or “Known sequence” is a series of (usually 10-
14) maneuvers formulated by the IMAC board of directors at the
beginning of each contest season. The sequence will change each
year in IMAC as it does with IAC. There will be a different
sequence for each class, and the bulk of your contest season will be
spent mastering the same sequence of maneuvers all year long.
At each contest, pilots (except the Basic class) will also fly one
round of an Unknown sequence. Before the contest the contest
director creates a unique “unknown” sequence for each class using
the IMAC handbook of standard figures and Aresti patterns. None
of the contestants see the sequence until the evening before they are
to fly it in the contest. Pilots are not allowed to practice the
07sig4.QXD 4/23/04 12:43 pm Page 120
July 2004 121
sequence before they fly it for the judges,
and usually no flying is allowed after the
Unknowns are distributed.
Most IMAC contests are two-day events,
and the Unknown is typically flown first
thing on the morning of the second day.
Memorizing the Unknown flight, visualizing
your performance, and practicing with your
caller are key to succeeding in the Unknown
round. You will often see pilots flying the
sequence with a handheld “stick” airplane to
help with visualization and preparation.
The IMAC Freestyle does not emulate
the full-scale version of the Freestyle event.
The Freestyle is a separate and optional
event, and it is not calculated into your score
for the contest. There are separate awards
for the Freestyle, and a completely different
skill set is used to excel in it. The Freestyle
also uses completely different criteria for
judging and is more reliant on excitement
and emotional impact than on precision
perfection.
IMAC Freestyle does not rely solely on
scale-type maneuvers, and 3-D flight is
often performed along with difficult scale
figures in this four-minute round. Impact is
often enhanced by choreographing a routine
to music, adding smoke or streamers, and
flying extremely low, difficult maneuvers to
increase the wow factor.
Freestyle is your chance to show your
stuff, and far too many competitors don’t
take the chance to fly in it. For me, Freestyle
is the most fun event of the contest! IMAC
Freestyle is more like a full-scale air show
than the contest version of IAC Freestyle.
How Am I Judged? To accommodate 20
or more pilots, most IMAC contests have
two models in the air at the same time.
There are generally two flightlines set up—
one at each end of the runway. There are
typically two judges at each flightline,
although more can be used if more judges
are available.
Each judge is partnered with a scribe,
who reads the maneuvers to him or her as
they are being flown and records the scores
as they are given. Each figure starts with a
perfect score of 10, and as it is flown, each
judge looks for imperfections and deducts
as necessary to determine the final score
(0-10) for each maneuver.
As a pilot, you will have a “caller” to
help you through your flight. Your caller
will hold your airplane while you start it,
watch for other aircraft taking off or on
approach, help you determine when it is
okay to take off or land, and spot for you
while you’re flying. Your caller is also
there to read the sequence to you while you
fly it and can even coach you as you fly.
Your caller will communicate with the
judges for you when necessary so you can
just concentrate on flying! It’s a good idea
to practice with the caller you will use in
the contest and get comfortable with each
other so you work well together when it
counts.
When it’s finally your turn to fly, the
judges or a “line boss” will tell you where
and when to start your model. The judge
will indicate the all clear to take off, and
your caller will spot for you. When you get
your aircraft into the air, you are allowed a
short period to trim your airplane and
position yourself for the start of the
sequence. You cannot perform any
aerobatic maneuvers before the sequence
begins or after it is completed.
You must call “In the box” to the
judges when you start the sequence. I tell
my caller, and he makes sure the judges
hear him say it. When the flight is finished,
the caller is diligent about the judges
making no mistake that the flight is over,
calling “Out of the box.” Normally you
will fly two sequences per flight or round,
except in the Unknown. Takeoff and
landing are not judged in IMAC.
Reading Aresti: The sequences are written
in a form of diagrams called Aresti. The
symbols are a way to quickly and precisely
understand what figures you will fly and
where to fly them. Aresti is fairly easy to
figure out with a bit of study. You will
need to learn some basics of reading the
diagrams as you progress in IMAC, but for
ease, the sequences also include a written
description of the figures.
IMAC Practice as a Means to Improve
Sport-Flying Skills: It’s important to
understand that many fliers may not want
to compete. But all of us would like to
improve our flying skills. Nobody can say
that he or she knows it all and can perform
every maneuver in the book perfectly. If
you do not want to compete, IMAC
practice will instill a bit of discipline in
your flying. It will push you to try new
maneuvers in different configurations, and
it will do so in a logical step-by-step
method that improves your flying skill
quickly.
If you want to be a better pilot, I suggest
that you try to fly the Basic sequences and
push yourself to move up through the
sequences each time you have mastered the
previous. You may even feel that flying
Basic IMAC sequences is a pretty big step
backward for you, but try it. I bet you’ll be
surprised at how difficult precision and
positioning is!
For IMAC rules, AMA Scale Aerobatics
rules, Unknown figures catalogs, and a list
of contests by region, go to www.miniiac.
com. You can also find a list of
proposed rules that will go into effect in the
2005 rules cycle. Almost everything you
need to know to enter or run a contest is on
the Web site. Suggested reading for clubs
or anyone who is thinking about running an
IMAC contest for the first time is an article
on the Web site titled “Your First Contest.”
There are many good tips for first-time
competitors in the “Flight School” area.
For information about full-scale
aerobatics, go to www.iac.org/. For the
worldwide Aerobatics organization, go to
www.fai.org/aerobatics/. MA
CST
The Composites Store Inc.
PO Box 622, Tehachapi, CA 93581
Order on-line or by phone
1-800-338-1278
Tech Support: 661-823-0108
• Rods & Tubes
• Carbon,
Aramid &
Fiberglass
Materials
• Epoxy
Systems
• Vacuum
Bagging and
Molding
Supplies
• FREE How-To
Articles on
the web
COMPOSITE MATERIALS
www.cstsales.com
STOCK THE
SHOP FOR
BUILDING
SEASON!
Our Full-Size
Plans List
has hundreds
of models
to choose from.
See page 199
for details.
07sig4.QXD 4/23/04 12:43 pm Page 121
Edition: Model Aviation - 2004/07
Page Numbers: 118,120,121
118 MODEL AVIATION
ONE OF THE clubs I belong to asked me to give a presentation on
IMAC and competing in Scale Aerobatics. The members were
interested to learn about the scale and precision aspects of IMAC,
but many of them were also interested in learning about 3-D flight;
3-D is not scale but is often performed in the IMAC Freestyle event
with our Scale aircraft.
I looked around a bit and asked online if there were any
preformatted guidelines for such an introduction to IMAC—it seems
like something that could be helpful for clubs across the country.
But I could find nothing written as a guide for those who might want
to give a talk to their club members. So I’ve decided to outline my
presentation here so that if you have a fair amount of IMAC
experience, you might use it as a guide to give a presentation to
interested members in your own club.
Start With the Basics: What is IMAC? The International Miniature
Aerobatic Club (IMAC) is formulated to emulate near-scale models
of the type of aircraft that fly in International Aerobatic Club (IAC)
full-scale precision aerobatics. Events, patterns, and figures are
formulated to stay true (within our limitations) to the full scale. But
because of IMAC’s separate evolution, there are some minor
exceptions.
IMAC is competitive precision flying in front of judges the same
way a full-scale competition is held and is also similar to Pattern or
AMA Precision Aerobatics. IMAC events are “contests.” Those who
fly in IMAC invariably have the desire to stand up and be judged on
their flying skills against others by their peers.
What Aircraft Can I Use? Generally, you must fly a model of a
full-scale aircraft capable of competing in an IAC contest. There is
no specific list of eligible aircraft. A Piper Cub or an AT-6 would be
considered legal for IMAC, but superior flight characteristics will
usually cull the diversity of entries down to a dozen or so of the best
full-scale airplanes such as Sukhois, Extras, CAPs, etc.
There are no size or weight requirements or limitations other
than those set forth by AMA for all modeling. Because so many
large airplanes fly in IMAC, some people confuse it with a Giant
Scale organization and think that airplanes must be large to fly in
IMAC. Not so! Any size aircraft is eligible. A lifelike pilot and an
instrument panel are required in the aircraft. The only exception to
Mike Hurley, 11542 Decatur Ct., Westminster CO 80234; E-mail: [email protected]
RADIO CONTROL SCALE AEROBATICS
This was a well-received and -attended IMAC seminar; 100+
people wanted to know more about IMAC Scale Aerobatics.
Working closely with your caller is very important. A good
relationship helps tremendously during the contest.
Full-scale unlimited competitor Matt Chapman shows just how
much our IMAC models resemble the full-scale aircraft.
Freestyle more closely resembles a full-scale air show than an
IAC contest. 3-D flight is unique to models.
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120 MODEL AVIATION
Pilots often practice and visualize the Unknown portion of the
contest using a “stick” airplane, which is a tiny model.
these rules is in the Basic class, which is designed as a “try it out”
class and can be flown with any aircraft—not necessarily Scale.
Competitive Classes: There are five classes, or levels of
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proficiency: Basic, Sportsman, Intermediate, Advanced, and
Unlimited. The classes are structured in a way that lays a
foundation of skills onto which new skills are added as you move
up through the classes. You will use the skills you learned in Basic
in every class and every flight for the rest of your flying career. A
half roll with a score of 8 performed in Sportsman would still get a
score of 8 in Unlimited.
Without that foundation you will be at a disadvantage in the
higher classes, so I encourage everybody, even very skilled pilots,
to start in the Basic class and give it some time and practice before
moving to the next level.
All the classes share fundamental elements and all are judged in
the same manner. An element is a single figure such as a loop. As
you move to higher classes, new elements are introduced and more
figures are added to create a more complex figure or maneuver.
Multiple figures can be added to create a single scored maneuver
(such as a loop with a snap at the top), increasing the difficulty but
retaining the foundation of the maneuvers you learned in the lower
classes. In this manner, a pilot’s flying skill increases quickly,
building new maneuvers on proven skills.
Elements of a Contest: There are three main elements in a contest:
the Known schedule, the Unknown schedule, and the Freestyle. The
Known schedule, or “Known sequence” is a series of (usually 10-
14) maneuvers formulated by the IMAC board of directors at the
beginning of each contest season. The sequence will change each
year in IMAC as it does with IAC. There will be a different
sequence for each class, and the bulk of your contest season will be
spent mastering the same sequence of maneuvers all year long.
At each contest, pilots (except the Basic class) will also fly one
round of an Unknown sequence. Before the contest the contest
director creates a unique “unknown” sequence for each class using
the IMAC handbook of standard figures and Aresti patterns. None
of the contestants see the sequence until the evening before they are
to fly it in the contest. Pilots are not allowed to practice the
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July 2004 121
sequence before they fly it for the judges,
and usually no flying is allowed after the
Unknowns are distributed.
Most IMAC contests are two-day events,
and the Unknown is typically flown first
thing on the morning of the second day.
Memorizing the Unknown flight, visualizing
your performance, and practicing with your
caller are key to succeeding in the Unknown
round. You will often see pilots flying the
sequence with a handheld “stick” airplane to
help with visualization and preparation.
The IMAC Freestyle does not emulate
the full-scale version of the Freestyle event.
The Freestyle is a separate and optional
event, and it is not calculated into your score
for the contest. There are separate awards
for the Freestyle, and a completely different
skill set is used to excel in it. The Freestyle
also uses completely different criteria for
judging and is more reliant on excitement
and emotional impact than on precision
perfection.
IMAC Freestyle does not rely solely on
scale-type maneuvers, and 3-D flight is
often performed along with difficult scale
figures in this four-minute round. Impact is
often enhanced by choreographing a routine
to music, adding smoke or streamers, and
flying extremely low, difficult maneuvers to
increase the wow factor.
Freestyle is your chance to show your
stuff, and far too many competitors don’t
take the chance to fly in it. For me, Freestyle
is the most fun event of the contest! IMAC
Freestyle is more like a full-scale air show
than the contest version of IAC Freestyle.
How Am I Judged? To accommodate 20
or more pilots, most IMAC contests have
two models in the air at the same time.
There are generally two flightlines set up—
one at each end of the runway. There are
typically two judges at each flightline,
although more can be used if more judges
are available.
Each judge is partnered with a scribe,
who reads the maneuvers to him or her as
they are being flown and records the scores
as they are given. Each figure starts with a
perfect score of 10, and as it is flown, each
judge looks for imperfections and deducts
as necessary to determine the final score
(0-10) for each maneuver.
As a pilot, you will have a “caller” to
help you through your flight. Your caller
will hold your airplane while you start it,
watch for other aircraft taking off or on
approach, help you determine when it is
okay to take off or land, and spot for you
while you’re flying. Your caller is also
there to read the sequence to you while you
fly it and can even coach you as you fly.
Your caller will communicate with the
judges for you when necessary so you can
just concentrate on flying! It’s a good idea
to practice with the caller you will use in
the contest and get comfortable with each
other so you work well together when it
counts.
When it’s finally your turn to fly, the
judges or a “line boss” will tell you where
and when to start your model. The judge
will indicate the all clear to take off, and
your caller will spot for you. When you get
your aircraft into the air, you are allowed a
short period to trim your airplane and
position yourself for the start of the
sequence. You cannot perform any
aerobatic maneuvers before the sequence
begins or after it is completed.
You must call “In the box” to the
judges when you start the sequence. I tell
my caller, and he makes sure the judges
hear him say it. When the flight is finished,
the caller is diligent about the judges
making no mistake that the flight is over,
calling “Out of the box.” Normally you
will fly two sequences per flight or round,
except in the Unknown. Takeoff and
landing are not judged in IMAC.
Reading Aresti: The sequences are written
in a form of diagrams called Aresti. The
symbols are a way to quickly and precisely
understand what figures you will fly and
where to fly them. Aresti is fairly easy to
figure out with a bit of study. You will
need to learn some basics of reading the
diagrams as you progress in IMAC, but for
ease, the sequences also include a written
description of the figures.
IMAC Practice as a Means to Improve
Sport-Flying Skills: It’s important to
understand that many fliers may not want
to compete. But all of us would like to
improve our flying skills. Nobody can say
that he or she knows it all and can perform
every maneuver in the book perfectly. If
you do not want to compete, IMAC
practice will instill a bit of discipline in
your flying. It will push you to try new
maneuvers in different configurations, and
it will do so in a logical step-by-step
method that improves your flying skill
quickly.
If you want to be a better pilot, I suggest
that you try to fly the Basic sequences and
push yourself to move up through the
sequences each time you have mastered the
previous. You may even feel that flying
Basic IMAC sequences is a pretty big step
backward for you, but try it. I bet you’ll be
surprised at how difficult precision and
positioning is!
For IMAC rules, AMA Scale Aerobatics
rules, Unknown figures catalogs, and a list
of contests by region, go to www.miniiac.
com. You can also find a list of
proposed rules that will go into effect in the
2005 rules cycle. Almost everything you
need to know to enter or run a contest is on
the Web site. Suggested reading for clubs
or anyone who is thinking about running an
IMAC contest for the first time is an article
on the Web site titled “Your First Contest.”
There are many good tips for first-time
competitors in the “Flight School” area.
For information about full-scale
aerobatics, go to www.iac.org/. For the
worldwide Aerobatics organization, go to
www.fai.org/aerobatics/. MA
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