Aerobatic maneuver

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The UK Utterly Butterly display team perform an aerobatic maneuver with their Boeing Stearmans, at an air display in England Utterly.butterly.aerobatics.arp.jpg
The UK Utterly Butterly display team perform an aerobatic maneuver with their Boeing Stearmans, at an air display in England

Aerobatic maneuvers are flight paths putting aircraft in unusual attitudes, in air shows, dogfights or competition aerobatics. Aerobatics can be performed by a single aircraft or in formation with several others. Nearly all aircraft are capable of performing aerobatics maneuvers of some kind, although it may not be legal or safe to do so in certain aircraft.

Contents

Aerobatics consist of five basic maneuvers:

Most aerobatic figures are composites of these basic maneuvers with rolls superimposed.

A loop is when the pilot pulls the plane up into the vertical, continues around until they are heading back in the same direction, like making a 360 degree turn, except it is in the vertical plane instead of the horizontal. The pilot will be inverted (upside down) at the top of the loop. A loop can also be performed by rolling inverted and making the same maneuver but diving towards the ground. It can be visualized as making a loop of ribbon, hence the name it is given (there is an animation depicting a loop on the bottom of this page).

A roll is simply rotating the plane about its roll axis, using the ailerons. It can be done in increments of 360 degrees (i.e. four short 90 degree rolls will bring the aircraft back to its upright position).

A spin is more complex, involving intentionally stalling a single wing, causing the plane to descend spiraling around its yaw axis in a corkscrew motion.

A Hammerhead (also known as a stall turn) is performed by pulling the aircraft up until it is pointing straight up (much like the beginning of a loop), but the pilot continues to fly straight up until their airspeed has dropped to a certain critical point. The pilot then use the rudder to rotate the aircraft around its yaw axis until it has turned 180deg and is pointing straight down, facing the direction from which the aircraft came. The aircraft gains speed, and the pilot continues and returns to level flight, travelling in the opposite direction from which the maneuver began. It is also known as a "tailslide", from the yawing turn, which is different from the typical method of turning an aircraft in the pitch axis.

Table of the basic aerobatic figures

Most of these can be entered either erect or inverted, flown backwards or have extra rolls added.

Where appropriate, the Aresti Catalog symbols have been included. Not all the figures are competition figures, and so some do not have diagrams to accompany the description.

Reading the diagrams, a figure begins at the small solid circle and ends at the short vertical line. Inverted flight (negative g) is depicted by dashed red lines. The small arrow indicates a rolling maneuver.

Figure NameDescription Aresti Symbol
Chandelle
Chandelle Consists of a maximum climb, maximum bank combination to obtain the greatest altitude gain for a given airspeed and at the same time making a 180° course reversal. (Low, positive g maneuver can be performed in all aircraft.)(Not a competition figure.)
Cuban Eight
Cuban Eight 5/8s of a loop to the 45 degree line, 1/2 roll,3/4s of a loop to the 45 degree line, 1/2 roll, 1/8s of a loop to level flight (half of the Cuban Eight is called a "half Cuban Eight", and the figure can be flown backwards, known as a "Reverse Cuban Eight").
Aeros fig cuban8.svg
Half Cuban Eight From level flight, 5/8s loop to the inverted 45° line, 1/2 roll to erect down 45° line, pull to level flight.
Aeros fig halfcuban8.svg
Reverse Half Cuban Eight From level flight pull to the 45° up line, 1/2 roll to inverted 45° up line, then 5/8s of a loop to level flight.
Aeros fig revhalfcuban8.svg
Hammerhead; Stall Turn
Hammerhead; Stall Turn 1/4 loop (pull or push) to vertical, as momentum/airspeed decreases, rudder is applied and the aircraft rotates around its yaw axis, the nose falls through the horizon and points towards the ground, a momentary pause is made to draw the vertical down line, and 1/4 loop to level flight. This figure is sometimes called a stall turn which is a misnomer because the aircraft never actually stalls. The manoeuvre is performed when the aeroplane decelerates through 20 - 30kts (more or less, depending on the aeroplane flown) of airspeed. The cartwheel portion of the hammerhead is performed with full rudder and full opposite aileron. Gyroscopic forces from the propeller during the rapid rate of yaw will produce a pitching and rolling moment and a degree of forward stick will be required to keep the aeroplane from coming off-line over the top. The yaw is stopped with opposite rudder while the ailerons and elevator remain in position, then once the yaw is stopped and the aeroplane is pointed down vertically, all controls are returned to neutral together. Although they can be flown left or right in any aeroplane with the proper technique, a hammerhead is best flown to the left with a clockwise rotating prop, and to the right with an anticlockwise rotating prop (as in a Yakovlev type), due to propeller torque/gyroscopic effects.
Aeros fig hammerhead.svg
Immelmann; Roll-off-the-top; Split S
Immelmann; Immelmann turn; Roll-off-the-top; half loop, half roll1/2 looping up followed by half a roll. There should be no pause between the end of the looping section and the start of the roll to erect flight.
Aeros fig Immelmann.svg
Split S Essentially an Immelmann in reverse. Half roll (from erect to inverted) followed by positive pitch to give a half loop. Converts altitude to airspeed, and reverses direction.
Aeros fig splits.svg
Up lines
Vertical upFly the aircraft so that the fuselage is perpendicular to the ground (along the wings' zero lift axis). The attitude of the aircraft is judged, not the flightpath, therefore the aircraft may drift downwind during a vertical maneuver.
Aeros fig vertup.svg
45° up lineFly the vertical attitude plus or minus 45°. As for vertical lines the attitude of the aircraft is judged, not the flightpath as viewed by a ground observer, which may differ depending on whether the figure is flown into or with the wind, and the wind strength.
Aeros fig 45up.svg
Loop
Inside loopA vertical circle entered from straight and erect level flight. A positive pitching movement is used at all points in the loop to draw the circle, so that the aeroplane canopy is pointing inwards. Both the inside and outside loop are sometimes casually referred to as a 'loop the loop'.
Aeros fig insideloop.svg
Outside loopA vertical circle entered from straight and erect level flight, canopy pointing out of the loop. Loop can be above or below the straight and level entry altitude, from erect or inverted attitude. (Draws extreme negative G)
Aeros fig outsideloop.svg
English buntHalf an outside loop starting from upright, straight and erect level flight. (The pilot pushes the stick forward and draws a half circle in the sky from the top down).
Aeros fig englishbunt.svg
Spin
Erect spin; Inverted spin; Flat spin A family of auto-rotational maneuvers, consisting of normal or "flat" spins, either upright or inverted. Two components must exist to spin an aircraft: 1) critical angle of attack (COA), which means that the aircraft is stalled, and 2) yaw.
Aeros fig spin.svg
Tailslide
Bell Tailslide 1/4 looping up, straight vertical (full power) until the aircraft loses momentum. The aircraft falls backwards, tail first, until the nose drops through the horizon to a vertical down position. 1/4 loop (push or pull) to recover to level flight.
Aeros fig tailslide.svg
Snap Roll; Flick roll; Flick
Snap roll; Flick roll; FlickA family of rapid autorotational or "horizontal spins," not unlike spins. Rotation is induced by a rapid pitch input followed by rapid yaw input, thus stalling one wing further than the other. This imbalance in lift causes the high speed roll.
Aeros fig flickroll.svg

See also

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In flight dynamics a spin is a special category of stall resulting in autorotation about the aircraft's longitudinal axis and a shallow, rotating, downward path approximately centred on a vertical axis. Spins can be entered intentionally or unintentionally, from any flight attitude if the aircraft has sufficient yaw while at the stall point. In a normal spin, the wing on the inside of the turn stalls while the outside wing remains flying. It is possible for both wings to stall, but the angle of attack of each wing, and consequently its lift and drag, are different.

Flight control surfaces Surface that allows a pilot to adjust and control an aircrafts flight attitude

Aircraft flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude.

Stall turn Aerobatics turn-around maneuver

The hammerhead turn, stall turn, or Fieseler is an aerobatics turn-around maneuver.

Slip (aerodynamics) Aerobatic maneuver

A slip is an aerodynamic state where an aircraft is moving somewhat sideways as well as forward relative to the oncoming airflow or relative wind. In other words, for a conventional aircraft, the nose will be pointing in the opposite direction to the bank of the wing(s). The aircraft is not in coordinated flight and therefore is flying inefficiently.

Dutch roll Aircraft motion combining rolling and yawing

Dutch roll is a type of aircraft motion consisting of an out-of-phase combination of "tail-wagging" (yaw) and rocking from side to side (roll). This yaw-roll coupling is one of the basic flight dynamic modes. This motion is normally well damped in most light aircraft, though some aircraft with well-damped Dutch roll modes can experience a degradation in damping as airspeed decreases and altitude increases. Dutch roll stability can be artificially increased by the installation of a yaw damper. Wings placed well above the center of gravity, sweepback and dihedral wings tend to increase the roll restoring force, and therefore increase the Dutch roll tendencies; this is why high-winged aircraft often are slightly anhedral, and transport-category swept-wing aircraft are equipped with yaw dampers. A similar phenomenon can happen in a trailer pulled by a car.

Flight mechanics are relevant to fixed wing and rotary wing (helicopters) aircraft. An aeroplane, is defined in ICAO Document 9110 as, "a power-driven heavier than air aircraft, deriving its lift chiefly from aerodynamic reactions on surface which remain fixed under given conditions of flight".

Basic fighter maneuvers Tactical movements performed by fighter aircraft during air combat maneuvering

Basic fighter maneuvers (BFM) are tactical movements performed by fighter aircraft during air combat maneuvering, to gain a positional advantage over the opponent. BFM combines the fundamentals of aerodynamic flight and the geometry of pursuit, with the physics of managing the aircraft's energy-to-weight ratio, called its specific energy.

Barrel roll

A barrel roll is an aerial maneuver in which an airplane makes a complete rotation on both its longitudinal and lateral axes, causing it to follow a helical path, approximately maintaining its original direction. It is sometimes described as a "combination of a loop and a roll." The g-force is kept positive on the object throughout the maneuver, commonly between 2–3 g, and no less than 0.5 g. The barrel roll is commonly confused with an aileron roll.

Immelmann turn Aerial maneuver

The term Immelmann turn, named after German World War One Eindecker fighter ace Leutnant Max Immelmann, refers to two different aircraft maneuvers. In World War I aerial combat, an Immelmann turn was a maneuver used after an attack on another aircraft to reposition the attacking aircraft for another attack. In modern aerobatics, an Immelmann turn is an aerobatic maneuver that results in level flight in the opposite direction at a higher altitude.

P-factor

P-factor, also known as asymmetric blade effect and asymmetric disc effect, is an aerodynamic phenomenon experienced by a moving propeller, where the propeller's center of thrust moves off-center when the aircraft is at a high angle of attack. This shift in the location of the center of thrust will exert a yawing moment on the aircraft, causing it to yaw slightly to one side. A rudder input is required to counteract the yawing tendency.

A Lomcovák is a family of extreme aerobatic maneuvers where the aircraft, with almost no forward speed, rotates on chosen axes due to the gyroscopic precession and torque of the rotating propeller.

Chandelle aircraft control maneuver where the pilot combines a 180° turn with a climb

The chandelle is an aircraft control maneuver where the pilot combines a 180° turn with a climb.

Aircraft principal axes

An aircraft in flight is free to rotate in three dimensions: yaw, nose left or right about an axis running up and down; pitch, nose up or down about an axis running from wing to wing; and roll, rotation about an axis running from nose to tail. The axes are alternatively designated as vertical, transverse, and longitudinal respectively. These axes move with the vehicle and rotate relative to the Earth along with the craft. These definitions were analogously applied to spacecraft when the first manned spacecraft were designed in the late 1950s.

Aileron roll Aerial maneuver

The aileron roll is an aerobatic maneuver in which an aircraft does a full 360° revolution about its longitudinal axis. When executed properly, there is no appreciable change in altitude and the aircraft exits the maneuver on the same heading as it entered. This is commonly one of the first maneuvers taught in basic aerobatics courses. The aileron roll is commonly confused with a barrel roll.

Radio-controlled aerobatics

Radio-controlled aerobatics is the practice of flying radio-controlled aircraft in maneuvers involving aircraft attitudes that are not used in normal flight.

3D Aerobatics or 3D flying is a form of flying using flying aircraft to perform specific aerial maneuvers. They are usually performed when the aircraft had been intentionally placed in a stalled position.

Slow roll (aeronautics)

A slow roll is a roll made by an airplane, in which the plane makes a complete rotation around its roll axis while keeping the aircraft flying a straight and level flightpath. A slow roll is performed more slowly than an aileron roll; although it is not necessarily performed very slowly, it is performed slowly enough to allow the pilot to maintain balance, keeping a steady flightpath, pitch angle, and height (altitude) throughout the maneuver. The maneuver is performed by rolling the airplane at a controlled rate with the ailerons, and moving the elevators and rudder in opposition, or "cross-controlling," to keep the plane on a steady, level flightpath.

A wingover is an aerobatic maneuver in which an airplane makes a steep climb, followed by a vertical flat-turn. The maneuver ends with a short dive as the plane gently levels out, flying in the opposite direction from which the maneuver began.

Falling leaf

A falling leaf is an aerobatic maneuver in which an aircraft performs a wings-level stall which begins to induce a spin. This spin is countered with the rudder, which begins a spin in the opposite direction that must be countered with rudder, and the process is repeated as many times as the pilot determines. During the maneuver, the plane resembles a leaf falling from the sky; first slipping to one side, stopping, and then slipping to the other direction; continuing a side-to-side motion as it drifts toward the ground.

The Hineri-komi was an air combat maneuver widely used by fighter pilots of Imperial Japanese Navy Air Service (IJNAS) through the Second Sino-Japanese War and the Pacific War. It allows an aircraft, which is being pursued by an enemy, to come at the pursuer's tail or to gain an opportunity to take a shot at it.

References

  1. Williams, Neil (1975). "Chapter 23". Aerobatics. Airlife Publishing.