Scale Aerobatic competition
pushes a pilot to strive for the
best aircraft setup and to search
for the ideal mental and physical
preparation practices to benefi t his
or her fl ying abilities. Throughout
the years, my goal has been to share
my knowledge, and this month is no
different. I want to devote this column
to the Unknown sequence.
If you are starting to participate
in International Miniature Aerobatic
Club (IMAC) competition, you may be
unfamiliar with the term “Unknown.”
The Unknown program is only for the
Sportsman, Intermediate, Advanced,
and Unlimited classes, and is given to
each contestant the night before or the
day of the contest.
It cannot be practiced by any
means. Each competitor is given one
opportunity to fl y this routine in front
of the judges. Most pilots feel that it
is the most challenging program to fl y
during any contest.
First, I will discuss how you, as the
pilot, can better prepare yourself for an
Unknown fl ight. Then I will add a little
twist and take a look at an Unknown
sequence with respect to wind. After
all, fl ying in heavy wind can have a
great impact on your fl ight if you don’t
correct for it and plan ahead.
As Hanno Prettner once said, to
become a successful pilot you need
to fl y in all types of weather, because
you never know what will occur on
competition day. Without further
hesitation, let’s begin!
Exploring the Unknown
Whenever you receive your
Unknown program, take a breath and
carefully examine each individual
maneuver. Many Unknowns are
given without having a formal text
description. Instead, they are in Aresti,
which is the language of aerobatics.
In the past, I have covered a brief tutorial about reading Aresti maneuvers. If this
is a new concept to you, I recommend that you attend a judging seminar, search the
offi cial IMAC website (listed in “Sources”), or talk to fellow aerobatic competitors.
I’ve learned that many people in this hobby are willing to help!
I glance over the routine and take note of which maneuvers are the most
important. These maneuvers will have the highest diffi culty and the highest K-Factor.
K-Factor is a numerical value by which the judges’ score for that given maneuver
will be multiplied—the higher the diffi culty, the higher the K-Factor. Excelling at
these maneuvers will result in higher scores!
I then go
through the
routine and
take notes
on the Aresti
sheet of any
directionspecifi
c
maneuvers. I
look for anything that results in a cross-box exit or entry (occurs on the Z axis).
Suppose that there is a 13/4-turn positive spin in your fl ight and the pilot must
pull to exit the maneuver cross-box. When performed one direction, the airplane
will exit coming toward the pilot and when performed the other direction, the
airplane will exit traveling away from the pilot. You want to give yourself time aftervarious maneuvers and
families of maneuvers that
are derived from the FAI
catalog to better prepare
for the Unknown schedule.
SCA-9
until the maneuver is finished, and tries to assign a grade on overall impression. The later can be erratic and
inconsistent, and also confines grading into a too narrow range. However, as a final check, the score should
be consistent with the figure‘s overall quality.
Every judge should strive for a high degree of consistency and accuracy. The most important
aspect of consistent judging is for each judge to establish his or her standard and then maintain that
standard throughout the contest.
2. FAI Aresti System (Condensed): Scale Aerobatics sequences are based on a catalog of maneuvers
defined by the FAI (Fédération Aéronautique Internationale) for full-scale aircraft aerobatics. The catalog
consists of the following nine (9) families of figures:
i: Family 1 – Lines and Angles
ii: Family 2 – Turns and Rolling Turns
iii: Family 3 – Combinations of Lines
iv: Family 4 – (Not in Use)
v: Family 5 – Stall Turns (Hammerheads)
vi: Family 6 – Tailslides
vii: Family 7 – Loops and Eights
viii: Family 8 – Combinations of lines, Angles, and Loops
ix: Family 9 – Rolls and Spins
It is beyond the scope of this Flying and Judging Guide to explain in detail the structure of the FAI catalog,
and how to read the Aresti drawing language used. A good judge (as well as a pilot) must become very
familiar with the above and should be able to quickly understand the maneuver simply by looking at the
Aresti drawing. The complete catalog of figures is available directly from the FAI Web site at
(http://www.fai.org/aerobatics/catalog/). Judges and pilots are strongly encouraged to download this
document for personal reference.
3. Rules: Scale Aerobatics has several rules that differ from either Full Scale Aerobatics (IAC) or AMA
RC Aerobatics (AMA Pattern). Because the judging pool used in Scale Aerobatics contests sometimes
comes from both or either of those two groups, it is useful to go through the major differences:
Rules Scale Aerobatics IAC Pattern
Downgrade one (1) point for each
deviation of:
10 degrees
(½ point for 5°)
5 degrees 15 degrees
Judging criteria: Flight path Aircraft attitude Flight path
Number of judges 2 minimum 5 standard
3 minimum
2 minimum
completing one maneuver and before
the start of another. If a crosswind is
blowing in, you don’t want to exit the
spin coming toward yourself because it
will rush your next maneuver.
After I have become familiar with
maneuvers and their placements,
I write a complete description of
each maneuver, but
leave space to insert
directions for certain
maneuver elements.
When the
competition day comes,
winds may change. As
a result, the direction
may change of not only
the sequence that will
be performed, but also
the direction of certain
elements such as the
spin from the earlier example. I’ll usually
fi ll out these critical components roughly
one to one-and-a-half hours before I am
expected to fl y.
Because I began my competitive
career fl ying Precision Aerobatics,
I prefer my sequences to be read a
certain way. For instance, if performing
a simple Humpty Bump with a half roll
up, I want my caller to say, “Perform a
Humpty Bump. Pull to a vertical upline
and perform a half roll. Pull half of a
loop over the top and perform nothing
on the downline. Pull to an upright exit.”
In the lower categories, Unknown
programs will be fairly straightforward.
As you progress to the higher classes,
much attention will be given to the
aircraft’s orientation. Many snapping
elements will be combined throughout a
given maneuver.
To make this easier for myself,
I sometimes write the maneuver
description accordingly. Let’s say that on
our center—which is directly in front of
ourselves—I am to perform 21/4 positive
snap rolls on a vertical upline. If I am
fl ying from left to right, I will pull to a
vertical.
Snapping to the left will result in
seeing the bottom of the airplane and
snapping to the right will reveal the
top of the aircraft. On my description,
which my caller will read, I may write
something such as, “Pull to a vertical
upline and perform 21/4 positive snap
rolls left, see bottom. Pull to inverteWhen the author receives a routine for the rst
time, he marks directions for how he thinks the
winds will prevail when the flight will be flown,
to best present the sequence.
moment, the maneuver will happen
quickly and the orientation of the
airplane is important to set yourself up
for the next maneuver.
Whenever you are unsure how many
rotations you have performed (maybe
because of nervousness), it is best to exit
in the correct manner so that you will
not zero the following maneuver. I have
seen instances in which a pilot will exit a
maneuver in the wrong attitude and will
have to perform an added element to
the following maneuver. As a result, both
maneuvers will receive a score of a zero.
Don’t give away easy points!
Each caller has his or her own style of
calling individual maneuvers. I cannot
stress enough the importance of a pilot
having a caller he or she is familiar with for the Unknown sequence. However, if you are unsure of who your caller may be
when it comes time for the competition day—maybe because you are just starting out in the competition circuit—write out the
sequence as you would like it to be read with some of the pointers I mentioned earlier.
Let’s change gears from our description, which is now written, to catering our fl ight for the best possible presentation—noWhen looking at an Unknown sequence, pay particular attention
to the maneuvers with the highest K-Factor. A lower score on such
a maneuver can have a great impact on your overall score.
Let’s Talk Wind!
There is no doubt that fl ying with a
fair amount of wind will have an impact
on the geometrical appearance of the
various maneuvers that are to be fl own
if the pilot does not correct for the effect
it has on the airplane. When preparing to
fl y an Unknown program, the pilot must
be fl exible.
I have seen many people receive the
Unknown program the day before they
fl y it and write the sequence from one
direction, as if they expect the winds
to favor the direction they chose. Then
competition day comes and the winds
are reversed!
It is not a good idea to practice
the sequence mentally from only
one direction, because strong wind
conditions may prevail. Although the
pilot can choose the direction he or she
wishes to fl y the sequence, a tailwind
will have a major impact on maneuvers
such as the spin because the entry will
appear forced.
Performing a Hammerhead that is not
into the wind can have consequences
because the airplane may “fl op” over the
top if done incorrectly. The wind will
have an impact on all maneuvers that
occur when the aircraft is at a stalled
state.
Keep in mind that you will have to
correct for the wind. This means that
you will need to
establish a crab angle
so that the airplane’s
fl ight path is perfectly
vertical for vertical
maneuvers, and so on.
To highlight this
notion, let’s say that
there is a constant
headwind and you
must perform a
vertical upline. If you
pull 90°, the airplane
will drift with the
wind, which will
result in a downgrade.
Rather, you may
have to only pull the
aircraft 85°, and the
airplane’s path will be
perfectly vertical, which
is the factor that is being
judged. The entry radius may also need
to appear sharp when compared to the
exit radius because the wind may push
the airplane.
When you fl y an Unknown program,
you must remember all that you have
learned throughout the years. It is easy
to forget some of these elements when
you are constantly trying to remember
the next maneuver to perform.
Focus on the entire fl ight. As soon as
you enter the box, take it one maneuver
at a time. Listen to your caller’s
description and focus on each individual
element rather than the entire program.
Final Thoughts
In closing, you have now learned a few
techniques that should help you prepare
for your Unknown fl ight.
The pilot who wins is the one who is
best prepared for that given competition.
This includes having the best airplane
setup possible, being mentally prepared,
and knowing how and when to adjust
certain elements in a sequence for the
best presentation—no matter how
windy it may become!
Although competition may
occasionally be frustrating because of
the diffi culty behind it, never become
discouraged. Take each step as a learning
experience and see how you can benefi t
from it.
Enjoy the friends you have and make
new ones; after all, the best
Edition: Model Aviation - 2012/12
Page Numbers: 113,114,115,116
Edition: Model Aviation - 2012/12
Page Numbers: 113,114,115,116
Scale Aerobatic competition
pushes a pilot to strive for the
best aircraft setup and to search
for the ideal mental and physical
preparation practices to benefi t his
or her fl ying abilities. Throughout
the years, my goal has been to share
my knowledge, and this month is no
different. I want to devote this column
to the Unknown sequence.
If you are starting to participate
in International Miniature Aerobatic
Club (IMAC) competition, you may be
unfamiliar with the term “Unknown.”
The Unknown program is only for the
Sportsman, Intermediate, Advanced,
and Unlimited classes, and is given to
each contestant the night before or the
day of the contest.
It cannot be practiced by any
means. Each competitor is given one
opportunity to fl y this routine in front
of the judges. Most pilots feel that it
is the most challenging program to fl y
during any contest.
First, I will discuss how you, as the
pilot, can better prepare yourself for an
Unknown fl ight. Then I will add a little
twist and take a look at an Unknown
sequence with respect to wind. After
all, fl ying in heavy wind can have a
great impact on your fl ight if you don’t
correct for it and plan ahead.
As Hanno Prettner once said, to
become a successful pilot you need
to fl y in all types of weather, because
you never know what will occur on
competition day. Without further
hesitation, let’s begin!
Exploring the Unknown
Whenever you receive your
Unknown program, take a breath and
carefully examine each individual
maneuver. Many Unknowns are
given without having a formal text
description. Instead, they are in Aresti,
which is the language of aerobatics.
In the past, I have covered a brief tutorial about reading Aresti maneuvers. If this
is a new concept to you, I recommend that you attend a judging seminar, search the
offi cial IMAC website (listed in “Sources”), or talk to fellow aerobatic competitors.
I’ve learned that many people in this hobby are willing to help!
I glance over the routine and take note of which maneuvers are the most
important. These maneuvers will have the highest diffi culty and the highest K-Factor.
K-Factor is a numerical value by which the judges’ score for that given maneuver
will be multiplied—the higher the diffi culty, the higher the K-Factor. Excelling at
these maneuvers will result in higher scores!
I then go
through the
routine and
take notes
on the Aresti
sheet of any
directionspecifi
c
maneuvers. I
look for anything that results in a cross-box exit or entry (occurs on the Z axis).
Suppose that there is a 13/4-turn positive spin in your fl ight and the pilot must
pull to exit the maneuver cross-box. When performed one direction, the airplane
will exit coming toward the pilot and when performed the other direction, the
airplane will exit traveling away from the pilot. You want to give yourself time aftervarious maneuvers and
families of maneuvers that
are derived from the FAI
catalog to better prepare
for the Unknown schedule.
SCA-9
until the maneuver is finished, and tries to assign a grade on overall impression. The later can be erratic and
inconsistent, and also confines grading into a too narrow range. However, as a final check, the score should
be consistent with the figure‘s overall quality.
Every judge should strive for a high degree of consistency and accuracy. The most important
aspect of consistent judging is for each judge to establish his or her standard and then maintain that
standard throughout the contest.
2. FAI Aresti System (Condensed): Scale Aerobatics sequences are based on a catalog of maneuvers
defined by the FAI (Fédération Aéronautique Internationale) for full-scale aircraft aerobatics. The catalog
consists of the following nine (9) families of figures:
i: Family 1 – Lines and Angles
ii: Family 2 – Turns and Rolling Turns
iii: Family 3 – Combinations of Lines
iv: Family 4 – (Not in Use)
v: Family 5 – Stall Turns (Hammerheads)
vi: Family 6 – Tailslides
vii: Family 7 – Loops and Eights
viii: Family 8 – Combinations of lines, Angles, and Loops
ix: Family 9 – Rolls and Spins
It is beyond the scope of this Flying and Judging Guide to explain in detail the structure of the FAI catalog,
and how to read the Aresti drawing language used. A good judge (as well as a pilot) must become very
familiar with the above and should be able to quickly understand the maneuver simply by looking at the
Aresti drawing. The complete catalog of figures is available directly from the FAI Web site at
(http://www.fai.org/aerobatics/catalog/). Judges and pilots are strongly encouraged to download this
document for personal reference.
3. Rules: Scale Aerobatics has several rules that differ from either Full Scale Aerobatics (IAC) or AMA
RC Aerobatics (AMA Pattern). Because the judging pool used in Scale Aerobatics contests sometimes
comes from both or either of those two groups, it is useful to go through the major differences:
Rules Scale Aerobatics IAC Pattern
Downgrade one (1) point for each
deviation of:
10 degrees
(½ point for 5°)
5 degrees 15 degrees
Judging criteria: Flight path Aircraft attitude Flight path
Number of judges 2 minimum 5 standard
3 minimum
2 minimum
completing one maneuver and before
the start of another. If a crosswind is
blowing in, you don’t want to exit the
spin coming toward yourself because it
will rush your next maneuver.
After I have become familiar with
maneuvers and their placements,
I write a complete description of
each maneuver, but
leave space to insert
directions for certain
maneuver elements.
When the
competition day comes,
winds may change. As
a result, the direction
may change of not only
the sequence that will
be performed, but also
the direction of certain
elements such as the
spin from the earlier example. I’ll usually
fi ll out these critical components roughly
one to one-and-a-half hours before I am
expected to fl y.
Because I began my competitive
career fl ying Precision Aerobatics,
I prefer my sequences to be read a
certain way. For instance, if performing
a simple Humpty Bump with a half roll
up, I want my caller to say, “Perform a
Humpty Bump. Pull to a vertical upline
and perform a half roll. Pull half of a
loop over the top and perform nothing
on the downline. Pull to an upright exit.”
In the lower categories, Unknown
programs will be fairly straightforward.
As you progress to the higher classes,
much attention will be given to the
aircraft’s orientation. Many snapping
elements will be combined throughout a
given maneuver.
To make this easier for myself,
I sometimes write the maneuver
description accordingly. Let’s say that on
our center—which is directly in front of
ourselves—I am to perform 21/4 positive
snap rolls on a vertical upline. If I am
fl ying from left to right, I will pull to a
vertical.
Snapping to the left will result in
seeing the bottom of the airplane and
snapping to the right will reveal the
top of the aircraft. On my description,
which my caller will read, I may write
something such as, “Pull to a vertical
upline and perform 21/4 positive snap
rolls left, see bottom. Pull to inverteWhen the author receives a routine for the rst
time, he marks directions for how he thinks the
winds will prevail when the flight will be flown,
to best present the sequence.
moment, the maneuver will happen
quickly and the orientation of the
airplane is important to set yourself up
for the next maneuver.
Whenever you are unsure how many
rotations you have performed (maybe
because of nervousness), it is best to exit
in the correct manner so that you will
not zero the following maneuver. I have
seen instances in which a pilot will exit a
maneuver in the wrong attitude and will
have to perform an added element to
the following maneuver. As a result, both
maneuvers will receive a score of a zero.
Don’t give away easy points!
Each caller has his or her own style of
calling individual maneuvers. I cannot
stress enough the importance of a pilot
having a caller he or she is familiar with for the Unknown sequence. However, if you are unsure of who your caller may be
when it comes time for the competition day—maybe because you are just starting out in the competition circuit—write out the
sequence as you would like it to be read with some of the pointers I mentioned earlier.
Let’s change gears from our description, which is now written, to catering our fl ight for the best possible presentation—noWhen looking at an Unknown sequence, pay particular attention
to the maneuvers with the highest K-Factor. A lower score on such
a maneuver can have a great impact on your overall score.
Let’s Talk Wind!
There is no doubt that fl ying with a
fair amount of wind will have an impact
on the geometrical appearance of the
various maneuvers that are to be fl own
if the pilot does not correct for the effect
it has on the airplane. When preparing to
fl y an Unknown program, the pilot must
be fl exible.
I have seen many people receive the
Unknown program the day before they
fl y it and write the sequence from one
direction, as if they expect the winds
to favor the direction they chose. Then
competition day comes and the winds
are reversed!
It is not a good idea to practice
the sequence mentally from only
one direction, because strong wind
conditions may prevail. Although the
pilot can choose the direction he or she
wishes to fl y the sequence, a tailwind
will have a major impact on maneuvers
such as the spin because the entry will
appear forced.
Performing a Hammerhead that is not
into the wind can have consequences
because the airplane may “fl op” over the
top if done incorrectly. The wind will
have an impact on all maneuvers that
occur when the aircraft is at a stalled
state.
Keep in mind that you will have to
correct for the wind. This means that
you will need to
establish a crab angle
so that the airplane’s
fl ight path is perfectly
vertical for vertical
maneuvers, and so on.
To highlight this
notion, let’s say that
there is a constant
headwind and you
must perform a
vertical upline. If you
pull 90°, the airplane
will drift with the
wind, which will
result in a downgrade.
Rather, you may
have to only pull the
aircraft 85°, and the
airplane’s path will be
perfectly vertical, which
is the factor that is being
judged. The entry radius may also need
to appear sharp when compared to the
exit radius because the wind may push
the airplane.
When you fl y an Unknown program,
you must remember all that you have
learned throughout the years. It is easy
to forget some of these elements when
you are constantly trying to remember
the next maneuver to perform.
Focus on the entire fl ight. As soon as
you enter the box, take it one maneuver
at a time. Listen to your caller’s
description and focus on each individual
element rather than the entire program.
Final Thoughts
In closing, you have now learned a few
techniques that should help you prepare
for your Unknown fl ight.
The pilot who wins is the one who is
best prepared for that given competition.
This includes having the best airplane
setup possible, being mentally prepared,
and knowing how and when to adjust
certain elements in a sequence for the
best presentation—no matter how
windy it may become!
Although competition may
occasionally be frustrating because of
the diffi culty behind it, never become
discouraged. Take each step as a learning
experience and see how you can benefi t
from it.
Enjoy the friends you have and make
new ones; after all, the best
Edition: Model Aviation - 2012/12
Page Numbers: 113,114,115,116
Scale Aerobatic competition
pushes a pilot to strive for the
best aircraft setup and to search
for the ideal mental and physical
preparation practices to benefi t his
or her fl ying abilities. Throughout
the years, my goal has been to share
my knowledge, and this month is no
different. I want to devote this column
to the Unknown sequence.
If you are starting to participate
in International Miniature Aerobatic
Club (IMAC) competition, you may be
unfamiliar with the term “Unknown.”
The Unknown program is only for the
Sportsman, Intermediate, Advanced,
and Unlimited classes, and is given to
each contestant the night before or the
day of the contest.
It cannot be practiced by any
means. Each competitor is given one
opportunity to fl y this routine in front
of the judges. Most pilots feel that it
is the most challenging program to fl y
during any contest.
First, I will discuss how you, as the
pilot, can better prepare yourself for an
Unknown fl ight. Then I will add a little
twist and take a look at an Unknown
sequence with respect to wind. After
all, fl ying in heavy wind can have a
great impact on your fl ight if you don’t
correct for it and plan ahead.
As Hanno Prettner once said, to
become a successful pilot you need
to fl y in all types of weather, because
you never know what will occur on
competition day. Without further
hesitation, let’s begin!
Exploring the Unknown
Whenever you receive your
Unknown program, take a breath and
carefully examine each individual
maneuver. Many Unknowns are
given without having a formal text
description. Instead, they are in Aresti,
which is the language of aerobatics.
In the past, I have covered a brief tutorial about reading Aresti maneuvers. If this
is a new concept to you, I recommend that you attend a judging seminar, search the
offi cial IMAC website (listed in “Sources”), or talk to fellow aerobatic competitors.
I’ve learned that many people in this hobby are willing to help!
I glance over the routine and take note of which maneuvers are the most
important. These maneuvers will have the highest diffi culty and the highest K-Factor.
K-Factor is a numerical value by which the judges’ score for that given maneuver
will be multiplied—the higher the diffi culty, the higher the K-Factor. Excelling at
these maneuvers will result in higher scores!
I then go
through the
routine and
take notes
on the Aresti
sheet of any
directionspecifi
c
maneuvers. I
look for anything that results in a cross-box exit or entry (occurs on the Z axis).
Suppose that there is a 13/4-turn positive spin in your fl ight and the pilot must
pull to exit the maneuver cross-box. When performed one direction, the airplane
will exit coming toward the pilot and when performed the other direction, the
airplane will exit traveling away from the pilot. You want to give yourself time aftervarious maneuvers and
families of maneuvers that
are derived from the FAI
catalog to better prepare
for the Unknown schedule.
SCA-9
until the maneuver is finished, and tries to assign a grade on overall impression. The later can be erratic and
inconsistent, and also confines grading into a too narrow range. However, as a final check, the score should
be consistent with the figure‘s overall quality.
Every judge should strive for a high degree of consistency and accuracy. The most important
aspect of consistent judging is for each judge to establish his or her standard and then maintain that
standard throughout the contest.
2. FAI Aresti System (Condensed): Scale Aerobatics sequences are based on a catalog of maneuvers
defined by the FAI (Fédération Aéronautique Internationale) for full-scale aircraft aerobatics. The catalog
consists of the following nine (9) families of figures:
i: Family 1 – Lines and Angles
ii: Family 2 – Turns and Rolling Turns
iii: Family 3 – Combinations of Lines
iv: Family 4 – (Not in Use)
v: Family 5 – Stall Turns (Hammerheads)
vi: Family 6 – Tailslides
vii: Family 7 – Loops and Eights
viii: Family 8 – Combinations of lines, Angles, and Loops
ix: Family 9 – Rolls and Spins
It is beyond the scope of this Flying and Judging Guide to explain in detail the structure of the FAI catalog,
and how to read the Aresti drawing language used. A good judge (as well as a pilot) must become very
familiar with the above and should be able to quickly understand the maneuver simply by looking at the
Aresti drawing. The complete catalog of figures is available directly from the FAI Web site at
(http://www.fai.org/aerobatics/catalog/). Judges and pilots are strongly encouraged to download this
document for personal reference.
3. Rules: Scale Aerobatics has several rules that differ from either Full Scale Aerobatics (IAC) or AMA
RC Aerobatics (AMA Pattern). Because the judging pool used in Scale Aerobatics contests sometimes
comes from both or either of those two groups, it is useful to go through the major differences:
Rules Scale Aerobatics IAC Pattern
Downgrade one (1) point for each
deviation of:
10 degrees
(½ point for 5°)
5 degrees 15 degrees
Judging criteria: Flight path Aircraft attitude Flight path
Number of judges 2 minimum 5 standard
3 minimum
2 minimum
completing one maneuver and before
the start of another. If a crosswind is
blowing in, you don’t want to exit the
spin coming toward yourself because it
will rush your next maneuver.
After I have become familiar with
maneuvers and their placements,
I write a complete description of
each maneuver, but
leave space to insert
directions for certain
maneuver elements.
When the
competition day comes,
winds may change. As
a result, the direction
may change of not only
the sequence that will
be performed, but also
the direction of certain
elements such as the
spin from the earlier example. I’ll usually
fi ll out these critical components roughly
one to one-and-a-half hours before I am
expected to fl y.
Because I began my competitive
career fl ying Precision Aerobatics,
I prefer my sequences to be read a
certain way. For instance, if performing
a simple Humpty Bump with a half roll
up, I want my caller to say, “Perform a
Humpty Bump. Pull to a vertical upline
and perform a half roll. Pull half of a
loop over the top and perform nothing
on the downline. Pull to an upright exit.”
In the lower categories, Unknown
programs will be fairly straightforward.
As you progress to the higher classes,
much attention will be given to the
aircraft’s orientation. Many snapping
elements will be combined throughout a
given maneuver.
To make this easier for myself,
I sometimes write the maneuver
description accordingly. Let’s say that on
our center—which is directly in front of
ourselves—I am to perform 21/4 positive
snap rolls on a vertical upline. If I am
fl ying from left to right, I will pull to a
vertical.
Snapping to the left will result in
seeing the bottom of the airplane and
snapping to the right will reveal the
top of the aircraft. On my description,
which my caller will read, I may write
something such as, “Pull to a vertical
upline and perform 21/4 positive snap
rolls left, see bottom. Pull to inverteWhen the author receives a routine for the rst
time, he marks directions for how he thinks the
winds will prevail when the flight will be flown,
to best present the sequence.
moment, the maneuver will happen
quickly and the orientation of the
airplane is important to set yourself up
for the next maneuver.
Whenever you are unsure how many
rotations you have performed (maybe
because of nervousness), it is best to exit
in the correct manner so that you will
not zero the following maneuver. I have
seen instances in which a pilot will exit a
maneuver in the wrong attitude and will
have to perform an added element to
the following maneuver. As a result, both
maneuvers will receive a score of a zero.
Don’t give away easy points!
Each caller has his or her own style of
calling individual maneuvers. I cannot
stress enough the importance of a pilot
having a caller he or she is familiar with for the Unknown sequence. However, if you are unsure of who your caller may be
when it comes time for the competition day—maybe because you are just starting out in the competition circuit—write out the
sequence as you would like it to be read with some of the pointers I mentioned earlier.
Let’s change gears from our description, which is now written, to catering our fl ight for the best possible presentation—noWhen looking at an Unknown sequence, pay particular attention
to the maneuvers with the highest K-Factor. A lower score on such
a maneuver can have a great impact on your overall score.
Let’s Talk Wind!
There is no doubt that fl ying with a
fair amount of wind will have an impact
on the geometrical appearance of the
various maneuvers that are to be fl own
if the pilot does not correct for the effect
it has on the airplane. When preparing to
fl y an Unknown program, the pilot must
be fl exible.
I have seen many people receive the
Unknown program the day before they
fl y it and write the sequence from one
direction, as if they expect the winds
to favor the direction they chose. Then
competition day comes and the winds
are reversed!
It is not a good idea to practice
the sequence mentally from only
one direction, because strong wind
conditions may prevail. Although the
pilot can choose the direction he or she
wishes to fl y the sequence, a tailwind
will have a major impact on maneuvers
such as the spin because the entry will
appear forced.
Performing a Hammerhead that is not
into the wind can have consequences
because the airplane may “fl op” over the
top if done incorrectly. The wind will
have an impact on all maneuvers that
occur when the aircraft is at a stalled
state.
Keep in mind that you will have to
correct for the wind. This means that
you will need to
establish a crab angle
so that the airplane’s
fl ight path is perfectly
vertical for vertical
maneuvers, and so on.
To highlight this
notion, let’s say that
there is a constant
headwind and you
must perform a
vertical upline. If you
pull 90°, the airplane
will drift with the
wind, which will
result in a downgrade.
Rather, you may
have to only pull the
aircraft 85°, and the
airplane’s path will be
perfectly vertical, which
is the factor that is being
judged. The entry radius may also need
to appear sharp when compared to the
exit radius because the wind may push
the airplane.
When you fl y an Unknown program,
you must remember all that you have
learned throughout the years. It is easy
to forget some of these elements when
you are constantly trying to remember
the next maneuver to perform.
Focus on the entire fl ight. As soon as
you enter the box, take it one maneuver
at a time. Listen to your caller’s
description and focus on each individual
element rather than the entire program.
Final Thoughts
In closing, you have now learned a few
techniques that should help you prepare
for your Unknown fl ight.
The pilot who wins is the one who is
best prepared for that given competition.
This includes having the best airplane
setup possible, being mentally prepared,
and knowing how and when to adjust
certain elements in a sequence for the
best presentation—no matter how
windy it may become!
Although competition may
occasionally be frustrating because of
the diffi culty behind it, never become
discouraged. Take each step as a learning
experience and see how you can benefi t
from it.
Enjoy the friends you have and make
new ones; after all, the best
Edition: Model Aviation - 2012/12
Page Numbers: 113,114,115,116
Scale Aerobatic competition
pushes a pilot to strive for the
best aircraft setup and to search
for the ideal mental and physical
preparation practices to benefi t his
or her fl ying abilities. Throughout
the years, my goal has been to share
my knowledge, and this month is no
different. I want to devote this column
to the Unknown sequence.
If you are starting to participate
in International Miniature Aerobatic
Club (IMAC) competition, you may be
unfamiliar with the term “Unknown.”
The Unknown program is only for the
Sportsman, Intermediate, Advanced,
and Unlimited classes, and is given to
each contestant the night before or the
day of the contest.
It cannot be practiced by any
means. Each competitor is given one
opportunity to fl y this routine in front
of the judges. Most pilots feel that it
is the most challenging program to fl y
during any contest.
First, I will discuss how you, as the
pilot, can better prepare yourself for an
Unknown fl ight. Then I will add a little
twist and take a look at an Unknown
sequence with respect to wind. After
all, fl ying in heavy wind can have a
great impact on your fl ight if you don’t
correct for it and plan ahead.
As Hanno Prettner once said, to
become a successful pilot you need
to fl y in all types of weather, because
you never know what will occur on
competition day. Without further
hesitation, let’s begin!
Exploring the Unknown
Whenever you receive your
Unknown program, take a breath and
carefully examine each individual
maneuver. Many Unknowns are
given without having a formal text
description. Instead, they are in Aresti,
which is the language of aerobatics.
In the past, I have covered a brief tutorial about reading Aresti maneuvers. If this
is a new concept to you, I recommend that you attend a judging seminar, search the
offi cial IMAC website (listed in “Sources”), or talk to fellow aerobatic competitors.
I’ve learned that many people in this hobby are willing to help!
I glance over the routine and take note of which maneuvers are the most
important. These maneuvers will have the highest diffi culty and the highest K-Factor.
K-Factor is a numerical value by which the judges’ score for that given maneuver
will be multiplied—the higher the diffi culty, the higher the K-Factor. Excelling at
these maneuvers will result in higher scores!
I then go
through the
routine and
take notes
on the Aresti
sheet of any
directionspecifi
c
maneuvers. I
look for anything that results in a cross-box exit or entry (occurs on the Z axis).
Suppose that there is a 13/4-turn positive spin in your fl ight and the pilot must
pull to exit the maneuver cross-box. When performed one direction, the airplane
will exit coming toward the pilot and when performed the other direction, the
airplane will exit traveling away from the pilot. You want to give yourself time aftervarious maneuvers and
families of maneuvers that
are derived from the FAI
catalog to better prepare
for the Unknown schedule.
SCA-9
until the maneuver is finished, and tries to assign a grade on overall impression. The later can be erratic and
inconsistent, and also confines grading into a too narrow range. However, as a final check, the score should
be consistent with the figure‘s overall quality.
Every judge should strive for a high degree of consistency and accuracy. The most important
aspect of consistent judging is for each judge to establish his or her standard and then maintain that
standard throughout the contest.
2. FAI Aresti System (Condensed): Scale Aerobatics sequences are based on a catalog of maneuvers
defined by the FAI (Fédération Aéronautique Internationale) for full-scale aircraft aerobatics. The catalog
consists of the following nine (9) families of figures:
i: Family 1 – Lines and Angles
ii: Family 2 – Turns and Rolling Turns
iii: Family 3 – Combinations of Lines
iv: Family 4 – (Not in Use)
v: Family 5 – Stall Turns (Hammerheads)
vi: Family 6 – Tailslides
vii: Family 7 – Loops and Eights
viii: Family 8 – Combinations of lines, Angles, and Loops
ix: Family 9 – Rolls and Spins
It is beyond the scope of this Flying and Judging Guide to explain in detail the structure of the FAI catalog,
and how to read the Aresti drawing language used. A good judge (as well as a pilot) must become very
familiar with the above and should be able to quickly understand the maneuver simply by looking at the
Aresti drawing. The complete catalog of figures is available directly from the FAI Web site at
(http://www.fai.org/aerobatics/catalog/). Judges and pilots are strongly encouraged to download this
document for personal reference.
3. Rules: Scale Aerobatics has several rules that differ from either Full Scale Aerobatics (IAC) or AMA
RC Aerobatics (AMA Pattern). Because the judging pool used in Scale Aerobatics contests sometimes
comes from both or either of those two groups, it is useful to go through the major differences:
Rules Scale Aerobatics IAC Pattern
Downgrade one (1) point for each
deviation of:
10 degrees
(½ point for 5°)
5 degrees 15 degrees
Judging criteria: Flight path Aircraft attitude Flight path
Number of judges 2 minimum 5 standard
3 minimum
2 minimum
completing one maneuver and before
the start of another. If a crosswind is
blowing in, you don’t want to exit the
spin coming toward yourself because it
will rush your next maneuver.
After I have become familiar with
maneuvers and their placements,
I write a complete description of
each maneuver, but
leave space to insert
directions for certain
maneuver elements.
When the
competition day comes,
winds may change. As
a result, the direction
may change of not only
the sequence that will
be performed, but also
the direction of certain
elements such as the
spin from the earlier example. I’ll usually
fi ll out these critical components roughly
one to one-and-a-half hours before I am
expected to fl y.
Because I began my competitive
career fl ying Precision Aerobatics,
I prefer my sequences to be read a
certain way. For instance, if performing
a simple Humpty Bump with a half roll
up, I want my caller to say, “Perform a
Humpty Bump. Pull to a vertical upline
and perform a half roll. Pull half of a
loop over the top and perform nothing
on the downline. Pull to an upright exit.”
In the lower categories, Unknown
programs will be fairly straightforward.
As you progress to the higher classes,
much attention will be given to the
aircraft’s orientation. Many snapping
elements will be combined throughout a
given maneuver.
To make this easier for myself,
I sometimes write the maneuver
description accordingly. Let’s say that on
our center—which is directly in front of
ourselves—I am to perform 21/4 positive
snap rolls on a vertical upline. If I am
fl ying from left to right, I will pull to a
vertical.
Snapping to the left will result in
seeing the bottom of the airplane and
snapping to the right will reveal the
top of the aircraft. On my description,
which my caller will read, I may write
something such as, “Pull to a vertical
upline and perform 21/4 positive snap
rolls left, see bottom. Pull to inverteWhen the author receives a routine for the rst
time, he marks directions for how he thinks the
winds will prevail when the flight will be flown,
to best present the sequence.
moment, the maneuver will happen
quickly and the orientation of the
airplane is important to set yourself up
for the next maneuver.
Whenever you are unsure how many
rotations you have performed (maybe
because of nervousness), it is best to exit
in the correct manner so that you will
not zero the following maneuver. I have
seen instances in which a pilot will exit a
maneuver in the wrong attitude and will
have to perform an added element to
the following maneuver. As a result, both
maneuvers will receive a score of a zero.
Don’t give away easy points!
Each caller has his or her own style of
calling individual maneuvers. I cannot
stress enough the importance of a pilot
having a caller he or she is familiar with for the Unknown sequence. However, if you are unsure of who your caller may be
when it comes time for the competition day—maybe because you are just starting out in the competition circuit—write out the
sequence as you would like it to be read with some of the pointers I mentioned earlier.
Let’s change gears from our description, which is now written, to catering our fl ight for the best possible presentation—noWhen looking at an Unknown sequence, pay particular attention
to the maneuvers with the highest K-Factor. A lower score on such
a maneuver can have a great impact on your overall score.
Let’s Talk Wind!
There is no doubt that fl ying with a
fair amount of wind will have an impact
on the geometrical appearance of the
various maneuvers that are to be fl own
if the pilot does not correct for the effect
it has on the airplane. When preparing to
fl y an Unknown program, the pilot must
be fl exible.
I have seen many people receive the
Unknown program the day before they
fl y it and write the sequence from one
direction, as if they expect the winds
to favor the direction they chose. Then
competition day comes and the winds
are reversed!
It is not a good idea to practice
the sequence mentally from only
one direction, because strong wind
conditions may prevail. Although the
pilot can choose the direction he or she
wishes to fl y the sequence, a tailwind
will have a major impact on maneuvers
such as the spin because the entry will
appear forced.
Performing a Hammerhead that is not
into the wind can have consequences
because the airplane may “fl op” over the
top if done incorrectly. The wind will
have an impact on all maneuvers that
occur when the aircraft is at a stalled
state.
Keep in mind that you will have to
correct for the wind. This means that
you will need to
establish a crab angle
so that the airplane’s
fl ight path is perfectly
vertical for vertical
maneuvers, and so on.
To highlight this
notion, let’s say that
there is a constant
headwind and you
must perform a
vertical upline. If you
pull 90°, the airplane
will drift with the
wind, which will
result in a downgrade.
Rather, you may
have to only pull the
aircraft 85°, and the
airplane’s path will be
perfectly vertical, which
is the factor that is being
judged. The entry radius may also need
to appear sharp when compared to the
exit radius because the wind may push
the airplane.
When you fl y an Unknown program,
you must remember all that you have
learned throughout the years. It is easy
to forget some of these elements when
you are constantly trying to remember
the next maneuver to perform.
Focus on the entire fl ight. As soon as
you enter the box, take it one maneuver
at a time. Listen to your caller’s
description and focus on each individual
element rather than the entire program.
Final Thoughts
In closing, you have now learned a few
techniques that should help you prepare
for your Unknown fl ight.
The pilot who wins is the one who is
best prepared for that given competition.
This includes having the best airplane
setup possible, being mentally prepared,
and knowing how and when to adjust
certain elements in a sequence for the
best presentation—no matter how
windy it may become!
Although competition may
occasionally be frustrating because of
the diffi culty behind it, never become
discouraged. Take each step as a learning
experience and see how you can benefi t
from it.
Enjoy the friends you have and make
new ones; after all, the best
