I didn't think it was necessary, but in these days
of frivolous litigations I guess I should include the following:
No pilot should attempt to fly any of these figures in aircraft not certified
for aerobatic flight. Further, no pilot should attempt these figures without
training from a competent aerobatic instructor. Descriptions contained in these
pages are NOT intended as instruction. They are incomplete as instructional
material and will get you into trouble if you believe that they are.
This is a list of areobatic figures that have common names. Some of these
were invented during aerial combat in WW I. I have included a short verbal
description and the IAC symbol for each basic figure.
The symbols for the figures follow the rules of the FAI for depicting
aerobatic figures. The figure starts at the small solid circle and ends at the
vertical bar. All aerobatics figures start and end from horizontal lines in
either upright or inverted flight. In aerobatics competition, most figures can
be entered and/or exited from either upright or inverted flight. This affects
the difficulty numbers for the figures. In general, the altitude at which the
figure is entered does not have to be the same as the exit altitude. Exceptions
are for instance the Cuban Eight, all full loops (regular loop, square loop,
etc). In cases where the entry and exit lines have to be the same altitude, they
are drawn slightly separated to better show them.
The elements used in these figures are horizontal, vertical and 45 degree
lines. These describe straight flight in these directions. Solid lines describe
upright flight, dashed lines describe inverted flight. Parts of loops connect
these line segments (see e.g. the Humpry-Bump). Rolls in 1/4, 1/2, 3/4, etc
increments up to 2 rolls can be added to the lines.
The looping portions in almost all figures have to have the same radius in
all parts of a figure. For instance the quarter loops going into and coming out
of a hammerhead have to have the same radius. There are some figures where this
does not apply completely.
Rolls on vertical lines and on 45 degree lines have to be centered on this
line to score well. Any deviation from the center results in a downgrading
during a competition.
There are other figures that are not in the IAC list of aerobatics figures.
These include for instance the Aileron roll and the Barrel roll. I will try to
include some descriptions of these too as I go along adding figures.
The K-values included with the competition figures give an indication of the
difficulty of each of these maneuvers. Higher K-values mean more difficult
maneuvers.
| Rolls |  |
Rolls can be added to most other figures to increase the
difficulty factor of the figure. There are two basic types of rolls: slow rolls
and snap rolls (flick rolls in european parlance).
Aileron RollsAileron rolls are flown with the rudder and elevator in
the neutral position during the roll. The aileron is fully deflected in the
direction of the roll. This is the easiest of the rolls to fly.
The aileron roll is started by pulling the nose up to 20 - 30 degrees above
the horizon. The elevator is then neutralized and the aileron fully deflected in
the direction of the roll. The controls are maintained in that position till the
roll is completed. After the roll is completed the nose is usually 20 - 30
degrees below the horizon.
The aileron roll is not a competition maneuver.
Slow Rolls
1.) 
(K=10) 2.) 
(K=7)
Slow rolls have to be flown normally on a straight line (exception is the
avalanche). The roll rate has to be constant and the longitudinal axis of the
plane has to go straight. This requires constantly changing rudder and elevator
control inputs throughout the roll. Hesitation or point rolls include stops at
certain roll angles. The number on the base of the roll symbol describes the
number of points the roll would have if it were a 360 degree roll. Allowed are 2
point, 4 point and 8 point rolls. The fraction on the arrow of the roll symbol
describes what fraction of a full roll is to be executed. If no points are
specified, rolling is done without hesitations. If no fraction is specified, a
roll symbol that starts at the line specifies a half roll (see description of
the Immelman). A roll symbol that crosses the line specifies a full roll (first
figure). The second figure shows the symbol for 2 points of a 4 point roll
(adding up to half a roll) from upright to inverted flight.
Snap Rolls
3.) 
(K=13) 4.) 
(K=17)
Snap or flick rolls also have to be flown normally on a straight line. A
snap roll is similar to a horizontal spin. It is an autorotation with one wing
stalled. Figure 3 shows the symbol for a regular snap roll, figure 4 for an
outside snap. In the regular snap, the plane has to be stalled by applying
positive g forces. In an outside snap, the plane is stalled by applying negative
g. In both cases rudder is then used to start autorotation just like in a spin.
| Loop | |
(K=10)
This is one of the most basic maneuvers, but not easy to fly well. It has to
be perfectly round, entry and exit have to be at the same altitude. The
difficulty in flying this manuever well is in correcting for effects of wind
drift. In competition, it helps if you don't have to fly first, so you can watch
what your competitors are doing and judge the wind drift that you have to take
into account.
The maneuver starts with a pullup of about 3 - 4 g. Once past the vertical,
the back pressure on the elevator is slowly relaxed to float over to top of the
loop to keep it round. Past the top, the back pressure is slowly increased again
throughout the back part till horizontal flight. The plane has to stay in one
plane with the wings orthogonal to the flight path. Rudder is used to maintain
the plane of the figure and ailerons are used to maintain the orientation of the
wings.
| Avalanche | |
(K=21)
This is the basic loop with a roll (usually a snap roll) at the top of the
loop. The roll has to be centered at the top of the loop.
| Square Loop | |
(K=14)
This is a variation of the basic loop. The two vertical lines and the
horizontal line on top have to be of the same length. The exit line at the
bottom has to be at least as long as the other three sides. The quarter loops
that connect the four sides have to have the same radius at each corner.
| Eight Sided Loop | |
(K=19)
This is another variation of the basic loop. The two vertical lines, the 45
degree lines and the horizontal line on top all have to be of the same length.
The exit line at the bottom has to be at least as long as the other seven sides.
The eight loops that connect the eight sides have to have the same radius at
each corner.
| Immelman | |
(K=10)
The figure starts with a half loop to inverted flight. A half roll then
results in horizontal upright flight. This is one of the maneuvers that have
been used in WW I to reverse direction. This maneuver does not preserve speed
and altitude. It trades speed for altitude.
| Split-S | |
(K=10)
The figure starts with a half roll to inverted followed by the second half of
a loop downward.
This is another maneuver to reverse direction. This one, like the immelman,
does not preserve speed and altitude. In this case it trades altitude for speed.
| English Bunt | |
(K=8)
This figure also is the second half of a loop downward, this time an outside
loop. You push forward and fly the second half of an outside loop till you are
in horizontal inverted flight. Make sure you are not too fast going into the
maneuver, otherwise you may exceed redline speed.
| Half Cuban Eight | |
(K=14)
Five-eighths of a loop to a down-line at a 45 degree angle. The plane is
inverted at this point. Centered on this downline is a half roll from inverted
to upright. A pullout to horizontal completes the figure.
This is another one of the maneuvers that reverse direction. The downline can
be used to adjust the altitude and speed at the end of the figure.
| Cuban Eight | |
(K=29)
Two Half Cuban Eights can be combined to form a Cuban Eight or Lay-down
Eight. In this figure in competition the two looping parts have to be flown at
the same altitude with the same radius. The exit has to be at the same altitude
as the entrance to the figure.
| Reverse Half Cuban Eight | |
(K=16)
This figure starts with a pull to a 45 degree up-line. Centered on this line
is a half roll from upright to inverted. Five-eighths of a loop complete the
figure to horizontal flight.
This again is one of the maneuvers that have been used to reverse direction
while preserving altitude and airspeed.
| Reverse Cuban Eight | |
Like the Cuban Eight, a Reverse Cuban Eight can be formed by flying two
Reverse Half Cuban Eights back to back.
| Inside-Outside Eight | |
(K=20)
This figure is similar to a Full Cuban Eight, but it does not contain any
rolls. The second loop is an outside loop. Again, the two loops have to have the
same radius and have to be flown at the same altitude. Entry and exit have to be
at the same altitude.
| Hammerhead | |
(K=17)
It starts with a quarter loop into a vertical climb. When the plane stops
climbing, it pivots around its vertical axis (which is now horizontal).The nose
moves in a vertical circle from pointing up through the horizon to pointing
down. After moving vertically down to pick up speed again, the maneuver is
finished with the last quarter of a loop to horizontal flight. This figure can
have optionally rolls on both the up-line and the down-line.
The quarter loop is flown just like the first part of a loop. When the plane
is vertical, the elevator backpressure is released completely. During the
vertical line up, some right aileron and right rudder is needed to maintain the
vertical attitude because of the engine torque and p-factor. When the plane has
slowed enough, full rudder initiates the turnaround. It is followed by
right-forward stick (right aileron and forward elevator) to keep the plane from
torquing off. The pivot is stopped with opposite rudder when the nose points
straight down. When the pivot is completed, the ailerons and rudder are
neutralized. Elevator and rudder are used to keep the nose pointing straight
down. The pivot must be completed within one wingspan. Rolls on the downline
require only aileron input if the plane is trimmed correctly.
This maneuver is sometimes called a hammerhead stall. This is not an accurate
name because the airplane never stalls. The airspeed may be very low, close to
zero, but since there is no wingloading during the turn-around, there is no
stall (at zero g wing loading, a wing does not stall). The plane is flying
throughout the maneuver with all the control surfaces effective (although
sometimes only marginally so).
This also is one of the maneuvers that have been used to reverse direction
while adjusting altitude and airspeed by changing the length of the down-line.
| Humpty-Bump | |
(K=13)
The figure starts with a quarter loop to a vertical climb. A half loop then
results in a vertical down-line. The figure completes with another quarter loop
to horizontal flight. The looping part on the top of the figure does not have to
be the same radius as the two other looping portions (the quarter loops going
into and coming out of the humpty). Again the figure can have optionally rolls
on both the up-line and the down-line.
| Competition Turn | |
(K=5)
Competition turns are not the coordinated maneuvers that you use in normal
flying. In a competition turn you first roll to the desired bank. It has to be
at least 60 degrees. My experience shows that the steeper the bank, the better
the scores. I try to get close to 90 degrees bank. Once the bank is established
the turn is started. The plane has to maintain a constant bank and altitude
throughout the turn. At the end of the turn the turn is stopped and then the
wings leveled for horizontal flight. The example shows the symbol for a 270
degree turn.
| Rolling Turn | |
(K=20)
This maneuver combines a turn with rolls. The example shows a 360 degree turn
with four rolls to the inside. The plane has to maintain a constant roll rate,
constant turn rate and constant altitude throughout the rolling turn. This
maneuver is quite difficult to fly. It requires constantly changing inputs from
all three controls (rudder, aileron, elevator).
| Tailslides | |
(K=15) 
(K=15)
These
maneuvers involve bringing the airplane to a complete stop in a vertical
attitude and then sliding back a visible amount. The airplane must then tip over
and fall through a vertical down position. The left figure indicates a tailslide
with the wheels down during the flip, the right figure is a tailslide with the
wheels up (inverted) during the flip. Going into the figure and coming out, the
same rules apply as for other figures (quarter loops of constant and equal
radius, vertical lines).
| Spin | |
(K=14) 
(K=18)
Spins also are aerobatics competition maneuvers. The two figures show a
regular and an inverted crossover one turn spin. Spins come in 3/4, one, 1 1/4
and 1 1/2 turns.
During spin entry, the plane has to show a stall break, followed by the
auto-rotation. The rotation has to stop exactly after the specified number of
turns. Once the rotation has stopped, a vertical downline has to be established.
In a crossover spin, the plane is first stalled upright. At the stall break,
the nose is pushed forward to get into an inverted spin while maintaining the
stall. The inverted spin is then completed as it would be for an inverted spin
with entry from inverted flight.
| Chandelle | |
The Chandelle is not a figure for aerobatics competition.
On the FAA power commercial pilots test a Chandelle is defined as a maximum
performance climbing turn through 180 degrees while maintaining a constant turn
rate. The idea is that this is a "plan ahead" maneuver. You first establish a
medium bank depending on the performance of your aircraft. Then a smooth pullup
is started. The angle of bank stays constant during the first 90 degrees of
turn, while the pitch angle increases steadily. At the 90 degree point the plane
has the maximum pitch angle which should be close to the critical angle of
attack. During the second 90 degrees of turn, the pitch angle is held constant,
while the bank angle is smoothly decreased to reach 0 degrees of bank at 180
degrees of turn with the airspeed close to the stall speed. The plane should not
settle during the last part of the maneuver and the recovery. The decreasing
bank angle during the second half of the Chandelle will maintain a constant turn
rate together with the decreasing airspeed. The turn needs to be kept
coordinated by applying the right amount of rudder. A Chandelle to the left is
quite different than one to the right because of the ever increasing amount of
p-factor in the second half of the maneuver.
| Wing Over | |
(K=6)
The Wing-Over is a competition maneuver in glider aerobatics. You pull up and
at the same time bank the plane. When the bank increases past 45 degrees, the
nose will start to drop while the bank keeps increasing and the plane keeps
turning. Halfway through the maneuver, the plane has turned 90 degrees, the
fuselage is level with the horizon and the bank is 90 degrees. The plane is
above the original flight path. The nose then keeps dropping below the horizon
and the plane keeps turning, while the bank is shallowed. When the bank drops
below 45 degrees, the nose is pulled up towards the horizon and the plane
reaches horizontal flight with wings level after 180 degrees of turn. At the
completion of the maneuver, the plane is at the same altitude as on entry and
flying in the opposite direction.
| Lazy Eight | |
Like the Chandelle, the Lazy Eight is not a competition
maneuver but is required for the power commercial pilot test. The aerobatics
version of the Lazy Eight is two wingovers back to back. The FAA commercial
pilot version is similar but the maximum bank is only 45 degrees instead of 90
degrees. The name Lazy Eight comes from the fact that the nose of the airplane
is following a figure 8 on its side on the horizon
| Barrel Roll | |
The Barrel Roll is a not competition maneuver. The barrel roll is a
combination between a loop and a roll. You complete one loop while completing
one roll at the same time. The flight path during a barrel roll has the shape of
a horizontal cork screw. Imagine a big barrel, with the airplanes wheels rolling
along the inside of the barrel in a cork screw path. During a barrel roll, the
pilot experiences always positive G's. The maximum is about 2.5 to 3 G, the
minimum about 0.5 G.
