An aileron roll is a classic aerobatic maneuver in which the airplane executes a full 360 rotation around its longitudinal axis while holding both altitude and heading constant. To start the sequence the pilot raises the nose 20-30° above the horizon, then introduces full aileron deflection. The aircraft rolls cleanly around its longitudinal axis with rudder and elevator kept essentially neutral. Although slow enough to be nick-named ‘slow roll’, the maneuver still subjects the airframe to pronounced positive and negative loading, with the G-meter peaking near +2.5G at the bottom and falling to roughly -0.7G at the top.
Expert behind this article
Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
What is an aileron roll in aerobatics?
An aileron roll is an aerobatic maneuver in which an aircraft does a full 360 roll about its longitudinal axis. This maneuver is usually described as one that can be carried out with light positive G all the way around and no sideslip, and it is commonly one of the first maneuvers taught in basic aerobatics courses.
An aileron roll is an aerobatic maneuver in which the aircraft rotates 360 degrees around its longitudinal axis while following a nearly linear trajectory. During the roll, the ailerons are the primary control surfaces used. The aileron on one wing is deflected upward and the other downward, generating the rolling moment. The elevator remains neutral, and the maneuver can be carried out with light positive G and no sideslip.
Diamond, ballistic, and double variants all retain this core identity: an aileron roll is a maneuver that can be carried out with no sideslip, performed by fully deflecting the ailerons in the direction of the roll. Whether the entry is pitched up to 20 or 30 degrees above the horizon, or whether one or more full rotations are executed, the basic maneuver stays the same.
What is the difference between a barrel roll and an aileron roll?
Although an aileron roll and a barrel roll both rotate the airplane around its longitudinal axis, they differ in path, altitude change, and rotational centre. A barrel roll follows a helical path during which the aircraft gains and then loses height as it first pulls up and then pushes over. The centre of rotation sits farther away from the aircraft itself. This helical motion demands that both roll and loop inputs be blended, so the lateral and longitudinal axes rotate simultaneously. An aileron roll keeps the flight-path effectively straight and level. The nose stays on the original track and altitude changes are negligible. Only the ailerons are used to drive a pure 360-degree turn about the longitudinal axis, so the rotational centre lies almost inside the fuselage. Whereas an aileron roll is finished the moment the wings return to level, a barrel roll is deemed complete only when the airplane has regained the original heading, altitude, and airspeed.
What is the difference between an aileron roll and a snap roll?
An aileron roll is a smooth, continuous 360° rotation around the longitudinal axis driven mainly by aileron deflection, whereas a snap roll is a rapid auto-rotative roll in which the fuselage attitude shows a definite stall-break and the model aircraft is in a stalled attitude throughout.
The snap roll is essentially an autorotation with one wing stalled, a rudder/elevator maneuver performed at a very high angle of attack. The airplane gyrates around an axis parallel to the ground and the rotation is over in about one second. Because the wing is partially stalled, the maneuver dissipates energy quickly and produces a high load factor almost instantly.
The aileron roll maintains un-stalled flight: the ailerons create differential lift to roll the airplane, the nose stays on the original flight path, and the motion is controlled and continuous rather than a flick-type break. Thus, while both are basic types of rolls, the snap roll is an accelerated spin along the existing flight path, and the aileron roll is a clean, aerodynamic rotation without stall.
How to do an aileron roll in an airplane?
To start the aileron roll the pilot pitches the aircraft up and gains some altitude. Then the elevator is neutralized while the pilot applies a full aileron to one side. Ailerons work in opposition so the aircraft will roll to the left when the roll direction is counterclockwise as viewed from front. The controls are maintained in that position till roll is completed, during which the pilot sticks in the direction of roll and the elevator remains neutral so the nose stays on the 45° line of the wing sight that is on the horizon. Because the elevator is neutralized throughout most of the maneuver the pilot can do multiple rolls without climbing or diving, and this technique works even at low altitude provided the pilot raises the nose above the horizon first, then keeps the horizon reference visible so recovery happens before ground proximity becomes dangerous.
How is the rudder used in an aileron roll?
The rudder plays a supporting, not directing, part in an aileron roll. As the pilot applies the aileron to start rotation about the aircraft's longitudinal axis, two things demand a small rudder movement. First, adverse yaw produced by the downward-going aileron momentarily drags that wing aft, so the airplane will want to yaw to the left around its vertical axis during a roll to the right, and vice-versa. A momentary dab of opposite rudder counters adverse yaw and keeps yaw zero when applying ailerons.
Second, gravity ceases to work through the vertical fin once the wings are near knife-edge. A little rudder at just the right time can help keep the nose up when gravity is otherwise not countered, acting like an airfoil to create lift that yaws the nose directly into the relative wind. Throughout the roll the pilot uses sufficient rudder to keep the nose from yawing opposite the direction of roll and to keep the aeroplane from sagging in the sides of the figure. Large aileron deflections produce more adverse yaw, calling for more rudder input. The elevator, not the rudder, prevents the aircraft from descending during the maneuver.
What is aileron roll reversal?
Aileron roll reversal can occur when the wing is not stiff enough torsionally to prevent twisting about the aircraft's lateral axis when a control input is made, and this undesired rolling moment implies the aileron has lost its effectiveness. The phenomenon is referred to as aileron reversal and can occur at high speed.
Aileron reversal is the loss or reversal of roll authority that appears at high speed because the wing is not torsionally stiff. When the pilot commands a roll, the aileron's own aerodynamic force twists the flexible wing in the opposite sense. The twist tilts the local lift vector so that the rolling moment produced is smaller, zero, or even reversed. The speed at which the aileron rolling moment becomes exactly zero is called the aileron reversal speed and above this speed the aircraft will roll opposite to the stick input unless another roll device is used. Modern high-speed aircraft postpone the phenomenon by increasing wing torsional rigidity, moving the ailerons inboard, or replacing them with spoilerons.
An aileron roll causes a crash with a certain probability. If reversal occurs in flight, the aircraft rolls against the pilot's command, leading to loss of control and, in extreme cases, a crash. Historical accidents include the Piper Arrow (2017) in which reversed aileron rigging gave roll commands of the wrong sign, and the Embraer ERJ 190 (2018) ferry flight where rigging errors produced an uncommanded roll. Structural failure is not required; the aerodynamic reversal alone destabilizes and potentially endangers.
How many Gs is an aileron roll?
If executed properly, an aileron roll is a 1G maneuver throughout, so passengers feel only 1G of pressure from the seat and the G force remains constant. Because the lift vector stays nearly aligned with the vertical axis, the airframe is positively loaded around 1.5-2G (6.6-8.9 m/s) while the pilot feels only 0.5-1G g (2.2-4.4 m/s ) at the top, and the minimum experienced is about 0.5G (2.2 m/s ).
In practice, the maximum rises to about 2.5-3G (8.9-10.7 m/s ). We pulled exactly 3G (10.7 m/s) in demonstration flights. Rolling-G limits do not appear in most civilian airplane operating handbooks, yet proper pilot training is VITAL to keep the roll rate constant and avoid exceeding the load factor.
Can a helicopter perform an aileron roll?
A helicopter is not able to perform an aileron roll because the control principle used by airplanes - differential aileron deflection - is absent. Any helicopter can do a barrel roll providing it can maintain a positive 1-1.5G load on the rotor system at all times, yet helicopters cannot complete a full barrel roll without unloading the disc and risking blade stall. Experienced display pilots have shown that helicopters can do rolls, loops, and certain aerobatics provided they have a strong main rotorhead and fuselage. Red Bull's MBB BO-105C helicopters are capable of an aerial stunt somewhere in between an aileron and barrel roll, while Westland Lynx, BO-105, Bell 407, and many others have been shown to do aerobatics. Even an X-Cell 60 model rotorcraft performed a 360-degree aileron roll at high speed, leveled itself, and continued to fly, demonstrating that helicopters can do certain aerobatics, but not all helicopters can do aerobatics and trying aerobatics in the wrong helicopter will be fatal.