A discussion about spins
June 2009 133
[[email protected]]
Radio Control Scale Aerobatics John Glezellis
WHEN I STARTED working for MA, I wrote
a column that was based on the International
Miniature Aerobatic Club (IMAC) Basic
sequence for that year and the various Aresti
figures that the program entailed. This month I
will write about spins. We will look at the
Aresti drawings for the spins in the 2009 Basic,
Sportsman, Intermediate, Advanced, and
Unlimited programs.
As a recap for those of you who are new to
the aerobatic scene, Aresti is the language of
Aerobatics. The reason why it is referred to as
that is simple. Aresti diagrams are drawn
figures of maneuvers. When pilots compete
internationally in Aerobatics, they need a
common system of communication, which is
Aresti.
Let’s begin!
All spins start from level flight. In its most
basic form, the pilot will enter the spin from
upright, level flight at a fairly high altitude.
Then he or she pulls the throttle back so that
the model slows and approaches a stall.
The pilot must feed up-elevator to maintain
the same altitude. Once a wingtip drops, the
pilot must spin the model simultaneously in the
same direction as the wingtip that dropped.
To perform an upright spin, hold upelevator
and same-direction rudder and aileron.
When performing an inverted spin, hold downelevator
and opposite-direction rudder and
elevator.
While spinning, the model will descend
quickly while rotating on an imaginary vertical
line. When the desired amount of rotations has
been completed, release inputs and establish a
vertical down-line. If needed, this down-line
may be wind-corrected.
If a roll is to be performed after the spin, a
brief line segment must be shown between the
spin rotation and the rolling segment. When the
pilot is finished with the spin and after the
vertical down-line is shown, he or she must
either pull or push to exit upright or inverted.
Again, this is a spin in the simplest form.
If you experience difficulty in spinning your
aircraft, look at the control-surface deflection
on your spin rate. I use a flight condition that is
the midposition on my JR 12X radio’s rudder
switch. On this rate, I have a higher amount of
elevator, rudder, and aileron deflection when
compared to my low rate condition.
Also, spinning inputs may differ from
airplane to airplane. Some aircraft can spin
only by using rudder and elevator. Other
models spin better using rudder, elevator, and a
touch of aileron input. Notice how your
airplane wants to execute a spin before getting
discouraged about being unable to perform the
maneuver to the best of your ability.
Before I examine each spin that is covered in
the various 2009 IMAC programs, I’ll describe
the elements that a spin must contain. These
include a clean breaking stall in horizontal
flight (either upright or inverted): a fully stalled
autorotation. The aircraft should not “barrel
roll” through a rotation; if it does, it is
definitely not in a stalled state.
The model must be stopped in a prestated
heading (which I will discuss shortly). The 90°
down-line segment may be wind-corrected
after the airplane stops on its heading.
• Spins within the 2009 Basic routine:
Maneuver 10 of the 2009 Basic program is an
upright two-turn spin. It starts from upright,
level flight and exits while in upright, level
flight.
To perform this maneuver, the pilot must
stall the airplane, and one wingtip will drop.
The pilot must spin in the direction of the break
(which is commonly referred to as the instant
when one wingtip drops).
Once two rotations are completed, the
model must establish and show a vertical
down-line segment. The pilot will slowly add
power while pulling to an upright, level-flight
exit with wings level.
This maneuver begins and ends traveling in
the same direction.
• Spins within the 2009 Sportsman routine:
Maneuver 8 of the
2009 Sportsman
Known program is a
11/2-turn upright spin.
It starts from upright,
level flight and exits
while in upright, level
flight.
Once the model is
stalled and a wingtip
drops, the pilot must
execute a 11/2-turn
rotation. After this is
completed, a vertical
down-line segment
must be shown, and
the aircraft exits the
maneuver by
performing a one-quarter loop to an upright,
level exit.
This maneuver begins and exits traveling in
an opposite direction.
• Spins within the 2009 Intermediate routine:
Maneuver 2 of the 2009 Intermediate Known
program entails a spin, and it has a few
additional elements.
The pilot must perform a 11/2-turn upright
spin followed by a half roll in the opposite
direction. Upon establishing a down-line, the
pilot pulls to a 45° vertical up-line and
performs two points of a four-point roll. Then
the pilot pushes to a horizontal, upright exit. A
brief line segment must exist between the 11/2-
turn rotation and the half roll in the opposite
direction.
• Spins within the 2009 Advanced routine: The
first maneuver of the 2009 Advanced Known
program is a figure 9, but it entails a 11/2-turn
negative spin.
This maneuver begins from inverted flight.
After the aircraft stalls, it performs 11/2 turns of
a negative spin followed by a half roll in the
opposite direction. A brief line segment should
exist between the spin rotation and the half
roll.
Then the pilot pulls three-quarters of an
inside loop to inverted, level flight. Once the
airplane reaches inverted flight, the pilot must
perform an eight-point roll to exit inverted.
This maneuver begins and exits while
traveling in the same direction. In addition, the
model must exit this maneuver at a fairly high
altitude, to prepare the pilot to perform the
second maneuver, which involves a half inside
loop.
• Spins within the 2009 Unlimited routine: The
fourth maneuver of the Unlimited Known
program entails a spin. The pilot begins by
performing 13/4 positive spins, followed by a
half roll in the opposite direction. Then the
pilot must pull to an upright cross-box exit.
The direction of the spin rotation will
A scene at the 2008 Woodstock [CT]
IMAC event. Before a contest, make sure
you are well practiced with your sequence
and well aware of your model’s flight
characteristics to improve your score.
06sig5.QXD 4/23/09 1:55 PM Page 133
134 MODEL AVIATION
8
1
Aresti diagram for spin in Basic
sequence. Elongated triangles show
that it is a spin; their white filling
indicates that it is a positive (upright)
two-turn spin. Red filling would have
meant that it were a two-turn negative
spin.
Figure 9 in Advanced. Red dotted line on
maneuver entry shows that the model is
inverted. The elongated triangles
(symbolizing a spin in Aresti) colored red
show that the spin is inverted (negative).
This 11/2-turn positive spin is in the
Sportsman sequence. This maneuver
starts and ends in upright, level flight;
that is shown by a solid black line as
the entry and exit.
determine whether the pilot will exit cross-box
in a fashion that is coming toward him or her
or going away from him or her.
You have had an introduction to performing
the upright and inverted spin. In addition, you
have learned about some of the judging criteria
for this maneuver and had a briefing of this
maneuver in the Known program of each of the
IMAC aerobatic classes.
Always remember that practice makes
perfect. If you experience difficulty in
performing this maneuver, look at your
model’s setup; e.g., the elevator throw on your
spin rate, the rudder throw, etc.
Until next time, fly hard! MA
Sources:
IMAC
www.mini-iac.com
Figure in Intermediate
Known. It is described
in the text, but note
that the spin portion
entails a 11/2-turn
positive spin. Ensure
that the model stalls in
the spin’s entry; if it does not, you will zero
the spin portion of the maneuver. Even if
you flawlessly performed the rest of the
maneuver, the score for the entire figure
will be a zero.
A spin in the
U n l i m i t e d
program. At the
end, the pilot must
perform a 90° pull
to exit cross-box in
upright level flight.
Had the exit line
been dotted and
red, the pilot would have to have
performed a 90° push to an inverted
horizontal cross-box exit.
06sig5.QXD 4/23/09 1:55 PM Page 134
Edition: Model Aviation - 2009/06
Page Numbers: 133,134
Edition: Model Aviation - 2009/06
Page Numbers: 133,134
A discussion about spins
June 2009 133
[[email protected]]
Radio Control Scale Aerobatics John Glezellis
WHEN I STARTED working for MA, I wrote
a column that was based on the International
Miniature Aerobatic Club (IMAC) Basic
sequence for that year and the various Aresti
figures that the program entailed. This month I
will write about spins. We will look at the
Aresti drawings for the spins in the 2009 Basic,
Sportsman, Intermediate, Advanced, and
Unlimited programs.
As a recap for those of you who are new to
the aerobatic scene, Aresti is the language of
Aerobatics. The reason why it is referred to as
that is simple. Aresti diagrams are drawn
figures of maneuvers. When pilots compete
internationally in Aerobatics, they need a
common system of communication, which is
Aresti.
Let’s begin!
All spins start from level flight. In its most
basic form, the pilot will enter the spin from
upright, level flight at a fairly high altitude.
Then he or she pulls the throttle back so that
the model slows and approaches a stall.
The pilot must feed up-elevator to maintain
the same altitude. Once a wingtip drops, the
pilot must spin the model simultaneously in the
same direction as the wingtip that dropped.
To perform an upright spin, hold upelevator
and same-direction rudder and aileron.
When performing an inverted spin, hold downelevator
and opposite-direction rudder and
elevator.
While spinning, the model will descend
quickly while rotating on an imaginary vertical
line. When the desired amount of rotations has
been completed, release inputs and establish a
vertical down-line. If needed, this down-line
may be wind-corrected.
If a roll is to be performed after the spin, a
brief line segment must be shown between the
spin rotation and the rolling segment. When the
pilot is finished with the spin and after the
vertical down-line is shown, he or she must
either pull or push to exit upright or inverted.
Again, this is a spin in the simplest form.
If you experience difficulty in spinning your
aircraft, look at the control-surface deflection
on your spin rate. I use a flight condition that is
the midposition on my JR 12X radio’s rudder
switch. On this rate, I have a higher amount of
elevator, rudder, and aileron deflection when
compared to my low rate condition.
Also, spinning inputs may differ from
airplane to airplane. Some aircraft can spin
only by using rudder and elevator. Other
models spin better using rudder, elevator, and a
touch of aileron input. Notice how your
airplane wants to execute a spin before getting
discouraged about being unable to perform the
maneuver to the best of your ability.
Before I examine each spin that is covered in
the various 2009 IMAC programs, I’ll describe
the elements that a spin must contain. These
include a clean breaking stall in horizontal
flight (either upright or inverted): a fully stalled
autorotation. The aircraft should not “barrel
roll” through a rotation; if it does, it is
definitely not in a stalled state.
The model must be stopped in a prestated
heading (which I will discuss shortly). The 90°
down-line segment may be wind-corrected
after the airplane stops on its heading.
• Spins within the 2009 Basic routine:
Maneuver 10 of the 2009 Basic program is an
upright two-turn spin. It starts from upright,
level flight and exits while in upright, level
flight.
To perform this maneuver, the pilot must
stall the airplane, and one wingtip will drop.
The pilot must spin in the direction of the break
(which is commonly referred to as the instant
when one wingtip drops).
Once two rotations are completed, the
model must establish and show a vertical
down-line segment. The pilot will slowly add
power while pulling to an upright, level-flight
exit with wings level.
This maneuver begins and ends traveling in
the same direction.
• Spins within the 2009 Sportsman routine:
Maneuver 8 of the
2009 Sportsman
Known program is a
11/2-turn upright spin.
It starts from upright,
level flight and exits
while in upright, level
flight.
Once the model is
stalled and a wingtip
drops, the pilot must
execute a 11/2-turn
rotation. After this is
completed, a vertical
down-line segment
must be shown, and
the aircraft exits the
maneuver by
performing a one-quarter loop to an upright,
level exit.
This maneuver begins and exits traveling in
an opposite direction.
• Spins within the 2009 Intermediate routine:
Maneuver 2 of the 2009 Intermediate Known
program entails a spin, and it has a few
additional elements.
The pilot must perform a 11/2-turn upright
spin followed by a half roll in the opposite
direction. Upon establishing a down-line, the
pilot pulls to a 45° vertical up-line and
performs two points of a four-point roll. Then
the pilot pushes to a horizontal, upright exit. A
brief line segment must exist between the 11/2-
turn rotation and the half roll in the opposite
direction.
• Spins within the 2009 Advanced routine: The
first maneuver of the 2009 Advanced Known
program is a figure 9, but it entails a 11/2-turn
negative spin.
This maneuver begins from inverted flight.
After the aircraft stalls, it performs 11/2 turns of
a negative spin followed by a half roll in the
opposite direction. A brief line segment should
exist between the spin rotation and the half
roll.
Then the pilot pulls three-quarters of an
inside loop to inverted, level flight. Once the
airplane reaches inverted flight, the pilot must
perform an eight-point roll to exit inverted.
This maneuver begins and exits while
traveling in the same direction. In addition, the
model must exit this maneuver at a fairly high
altitude, to prepare the pilot to perform the
second maneuver, which involves a half inside
loop.
• Spins within the 2009 Unlimited routine: The
fourth maneuver of the Unlimited Known
program entails a spin. The pilot begins by
performing 13/4 positive spins, followed by a
half roll in the opposite direction. Then the
pilot must pull to an upright cross-box exit.
The direction of the spin rotation will
A scene at the 2008 Woodstock [CT]
IMAC event. Before a contest, make sure
you are well practiced with your sequence
and well aware of your model’s flight
characteristics to improve your score.
06sig5.QXD 4/23/09 1:55 PM Page 133
134 MODEL AVIATION
8
1
Aresti diagram for spin in Basic
sequence. Elongated triangles show
that it is a spin; their white filling
indicates that it is a positive (upright)
two-turn spin. Red filling would have
meant that it were a two-turn negative
spin.
Figure 9 in Advanced. Red dotted line on
maneuver entry shows that the model is
inverted. The elongated triangles
(symbolizing a spin in Aresti) colored red
show that the spin is inverted (negative).
This 11/2-turn positive spin is in the
Sportsman sequence. This maneuver
starts and ends in upright, level flight;
that is shown by a solid black line as
the entry and exit.
determine whether the pilot will exit cross-box
in a fashion that is coming toward him or her
or going away from him or her.
You have had an introduction to performing
the upright and inverted spin. In addition, you
have learned about some of the judging criteria
for this maneuver and had a briefing of this
maneuver in the Known program of each of the
IMAC aerobatic classes.
Always remember that practice makes
perfect. If you experience difficulty in
performing this maneuver, look at your
model’s setup; e.g., the elevator throw on your
spin rate, the rudder throw, etc.
Until next time, fly hard! MA
Sources:
IMAC
www.mini-iac.com
Figure in Intermediate
Known. It is described
in the text, but note
that the spin portion
entails a 11/2-turn
positive spin. Ensure
that the model stalls in
the spin’s entry; if it does not, you will zero
the spin portion of the maneuver. Even if
you flawlessly performed the rest of the
maneuver, the score for the entire figure
will be a zero.
A spin in the
U n l i m i t e d
program. At the
end, the pilot must
perform a 90° pull
to exit cross-box in
upright level flight.
Had the exit line
been dotted and
red, the pilot would have to have
performed a 90° push to an inverted
horizontal cross-box exit.
06sig5.QXD 4/23/09 1:55 PM Page 134