ADVANCED COURSE
Aerobatic manoeuvres
Low altitude flight
Escort flight
Aerobatic manoeuvres
Some of these may be impossible to do in RB!
Rolls
Slow Rolls
Snap Rolls
Loops
Avalanche
Square Loop
Eight Sided Loop
Immelmann
Split S
Half Cuban Eight
Cuban Eight
Reverse Half Cuban Eight
Reverse Cuban Eight
Inside Outside Eight
Hammer Head
Humpty Dumpty
Coordinated turn
Rolling Turn
Spin
Chandelle
Wing Over
Lazy Eight
Barrel Roll
Elevator
Harrier
Water Fall
Blender
Torque Turn
You can use smoke shift s to evaluate your effectiveness and line of flight for some of these manoeuvres.
This is a list of aerobatic 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.
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).
Slow Rolls
1.)
2.)
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.)
4.)
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
While looping, a pilot has no options until the loop is finished. In addition, you will lose a great deal of altitude. Before starting a loop, make sure you have a lot of airspeed (generally accomplished by diving first) otherwise you'll stall halfway through the loop!
One of the most basic manoeuvres, but not easy to fly well. It has to be perfectly round, entry and exit have to be at the same altitude.
The manoeuvre starts with a pull-up 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.
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.
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.
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 eighth loops that connect the eight sides have to have the same radius at each corner.
The figure starts with a half loop to inverted flight. A half roll then
results in horizontal upright flight.
This is one of the manoeuvres that have been used in WW I to reverse direction.
This manoeuvre does not preserve speed and altitude. It trades speed for
altitude.
The figure starts with a half roll to inverted followed by the second half of a loop downward.
This is another manoeuvre to reverse direction. This one, like the Immelmann, does not preserve speed and altitude. In this case it trades altitude for speed.
Five-eighths of a loop to a down-line at a 45 degree angle. The plane is inverted at this point. Centered on this down line is a half roll from inverted to upright. A pullout to horizontal completes the figure.
This is another one of the manoeuvres that reverse direction. The down line can be used to adjust the altitude and speed at the end of the figure
.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.
This figure starts with a pull to a 45 degree up-line. Centered on this line is a half roll from upright to invert. Five-eighths of a loop completes the figure to horizontal flight.
This again is one of the manoeuvres that have been used to reverse direction while preserving altitude and airspeed.
Like the Cuban Eight, a Reverse Cuban Eight can be formed by flying two Reverse Half Cuban Eights back to back
.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.
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 manoeuvre 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 down line require only aileron input if the plane is trimmed correctly.
This manoeuvre 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 now wing loading during the turn-around, there is no stall (at zero g wing loading, a wing does not stall). The plane is flying throughout the manoeuvre with all the control surfaces effective (even sometimes only marginally so).
This also is one of the manoeuvres that have been used to reverse direction while adjusting altitude and airspeed by changing the length of the down-line.
The figure starts with a quarter of a 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 turns are not the coordinated manoeuvres 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.
This manoeuvre 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 manoeuvre is quite difficult to fly. It requires constantly changing inputs from all three controls (rudder, aileron, and elevator).
Spins also are aerobatics competition manoeuvres. 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 down line 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.
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" manoeuvre. You first establish a medium bank depending on the performance of your aircraft. Then a smooth pull-up 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 manoeuvre 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 manoeuvre.
The Wing-Over is a competition manoeuvre 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 manoeuvre, 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 swallowed. 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 manoeuvre, the plane is at the same altitude as on entry and flying in the opposite direction.
Like the Chandelle, the Lazy Eight is not a competition manoeuvre 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
The Barrel Roll is a not competition manoeuvre.
The Elevator
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What it is:
The plane drops vertically while in a nose-high attitude. Depending on head wind conditions, the model will drop at anywhere from about a 45º angle when it's calm, to vertical or even a little backwards in windy conditions. Throttle is used to determine rate of descent and the nose-high attitude of the model.
CAP set-up:
3D-elevator mode is essential, and your CG will have to be on the mark or slightly aft. If your CG is further aft and the airplane teeters back and forth, program about 1/2" of up aileron with up elevator travel.
How to do it:
At near stall airspeed, up high, slowly feed in up elevator until you have the full 3D rate up in it. With low throttle, the CAP will fall like a rock. To guide it around, use the rudder, not ailerons. Just keep the wings level. Add power to change the plane's altitude.
Trickiest part:
Aside from steering it with the rudder, you'll quickly see that this maneuver is a matter of juggling the throttle and rudder to get the plane to go where you want it to go.
Recovery: Basic-
Add full power, flip off the 3D-rate elevator and fly out
.Advanced-
Take the elevator all the way to the ground, adding slight power before it touches down to slow the descent and transition into a "Harrier" and land. Or, for a little more drama, add power to get the nose to rise to vertical and transition into a Torque Roll. ("Elevator" from a hundred feet down to 20 feet then power up into a torque roll. Oh yeah!!)
Worst way to mess up:
Let your direction control (rudder) get away from you after starting too low- you could snap it right into the ground (ouch!).
The Harrier
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What it is:
Very slow forward flight in a very nose high (about 45º) attitude.
CAP set-up:
The same as the elevator and the raised ailerons help in this maneuver even more.
How to do it:
Start by entering an "Elevator". Let the model drop a little, then slowly add power until the vertical descent stops and it begins to fly forward with the nose very high- holding full up elevator (on 3D rate) all the while. Juggle the power to control the plane's attitude and forward speed. In a head wind, you may also have to juggle the elevator to keep the plane from rotating up to a vertical attitude. Use the rudder to steer the plane around in the Harrier attitude. Try to use the ailerons very little, as they will cause the plane to wobble side to side.
Trickiest Part:
Keeping up with the plane if it begins to wobble.
Recovery: Basic-
Simply add full power and reduce elevator to transition into normal forward flight. Advanced- after you get the hang of flying around in the Harrier, juggle the throttle to slowly lose altitude and do a Harrier landing. The plane will land on the rear of the rudder first, then add a little power so it doesn't smack the landing gear too hard
The Waterfall
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What it is:
A continuous tail-over-nose descending flip. It's not a loop, but the aircraft actually flops around its canopy.
CAP set-up:
Once again, the critical component is having the 3D-elevator travel 4-1/2" of down elevator. An aft CG helps this the most.
How to do it:
Start relatively high. At low throttle, gradually pull the nose up until it's near vertical. Just before it stalls, add full down and full power at the same time. You have to continuously "fly" the rudder and ailerons to keep the plane flipping over in a straight line. To do consecutive Waterfalls, continue to hold full down and "fly" rudder and ailerons, and chop the throttle as the nose comes back up to vertical, then add full power as it flips straight down
.Trickiest part:
No doubt here- flying the rudder and aileron correctly. You really have to "fly" them and make constant corrections. The amount of rudder you add will vary. If you don't do this, the plane will fall off into a knife edge spin.
Recovery:
Just neutralize the elevator and the CAP will quit flipping, but expect some over-rotation, so practice high until you get the feel for it. Fly out straight and level, or stop the rotation while pointed vertical and go into a torque roll.
Worst way to mess up:
Take it down too low, over-control your elevator on recovery and snap into the ground. To avoid this, simply change rates on your elevator to normal 1" travel.
The Blender
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What it is:
The Blender or Panic manoeuvre is a vertical diving roll that virtually stops its descent as it instantaneously enters into a flat spin.
CAP set-up:
3D set-up as described in the manual. Most likely you'll have 60-75% expo with these settings. The CG should be on the mark or aft 1/2". Make sure your wing is strong-this can be an extremely violent, but always exciting manoeuvre.
How to do it:
Start from about 400-500 feet straight and level, chop throttle and push the nose straight down. As soon as the plane is diving straight down at low throttle, add full left aileron. Let it complete 2 or 3 rolls, then quickly transition the sticks to an inverted snap roll position (left aileron, right rudder, down elevator) all at the same time. If you do it right, the airplane will instantly transition from a left roll to a flat spin in the same direction, and the descent will all but stop. Add full throttle just after the spin goes flat making the rotation speed high and helping stop the vertical descent
.Recovery:
Simply release rudder and aileron, and hold just a little down elevator. The plane will stop rotating and begin to fly out. As it gains airspeed, roll back to upright. Remember you're in "3D mode," so don't do anything abrupt or you can stall the airplane.
The Torque Roll
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What it is:
Plane "hovers" vertically in place, rotating left around its roll axis.
CAP set-up:
Full 3D throws in elevator and rudder is a must. An aft CG helps a little also. Some flyers will run their CG back to make this manoeuvre easier without gyros. But gyros provide the best aid to stabilize the aircraft- they won't do the manoeuvre for you, but they'll help. The pros will also tell you to add 3/4 degree of up thrust to your engine. This helps keep your CAP from falling forward in the Torque Roll, and it'll fly straighter up lines in non-3D manoeuvres, too.
With a little aft CG, gyros and up thrust, you'll find your plane will be set-up best so you can concentrate on attitude recognition. Naturally, you'll need lots of power for this one: A Saito 150 is fine when propped with an APC 16x8. Heli 30% fuel is also a good option.
How to do it:
Fly low along the ground at low throttle, and gently add power with up elevator to bring the plane into a vertical position. Some flyers add a little left aileron to get the roll motion started. Add throttle to keep the nose pointed up and make corrections with rudder and elevator to keep things straight.
Trickiest part:
Recognizing your correction when the plane's belly is toward you. (Tip: Think push the rudder toward the low wing when the belly is toward you.) You have to be fast with throttle corrections. Most flyers add "bursts" of power, along with rudder/elevator corrections. If you simply hold full throttle, you'll climb out of the manoeuvre.
Recovery:
Fly out at full throttle
.Worst way to mess up:
An unreliable engine. Torque rolls are tough on engines because they're running at near-peak power with only prop-induced airflow over the head. Some flyers open up the CAP's lower exhaust hole for adequate cooling on hot days.
Taken from Mike MCConville’s aerobatic page
