|
Control stick inputs for the rolling circle (left-turning right-rolling), showing the typical amount of elevator and rudder input as a function of rolling position.Rolling circle is a maneuver in which an aircraft rolls continuously while turning in a circle. This is arguably one of the most difficult maneuvers to perfect, since varying pitch and yaw corrections are necessary to keep the heading level while maintaining constant roll rate and turning radius.
The standard rolling circle involves 1 roll at each quadrant of the turn, resulting in a total of 4 rolls throughout the 360º horizontal turn. The most logical method to approach the rolling circle is to think of it as 4 slow rolls with turn. The procedure below describes a left-turning right-rolling quadrant:
- Flying straight and level at normal speed, feed right aileron that results in a constant roll rate that would complete a roll in the time required for a 90º horizontal turn. Simultaneously, feed left rudder and down elevator that would result in a desired turning radius while maintaining level.
- As the aircraft rolls from 0º to 360º, input both rudder and elevator sequentially as in slow roll, except with some phase lead for rudder and elevator. The shifted timing for elevator and rudder inputs causes the aircraft to turn while maintaining attitude throughout the roll.
- Once the aircraft completes 360º of roll at ¼ turn, repeat step 2. three more times to complete the entire rolling circle. Neutralize aileron, elevator, and rudder gradually as the rolling circle completes.
Below is a graph that illustrates the elevator and rudder input as a function of rolling position during one turn quadrant. For this case, 60º rudder phase lead and 90º elevator phase lead are used. Actual amplitude and phase leads may vary depending on aircraft behavior.
Control stick inputs for the rolling circle (left-turning right-rolling), showing the typical amount of elevator and rudder input as a function of rolling position
|
