Glossary
Aileron—A control surface set into or near the trailing edge of an airplane wing, extending, when in the wing, toward the tip and usually within the contour of the wing, and used to control the longitudinal axis of an airplane.
Airborne—Of an airplane or other winged craft: Supported entirely by aerodynamic forces, flying.
Airfoil—A surface or body, as a wing, propeller blade, rudder, or the like, especially designed to obtain a reaction, as lift or thrust, from the air through which it moves.
Angle of attack—The acute angle between the chord of an airfoil, and a line representing the undisturbed relative airflow. Any other acute angle between two reference lines designating the cant of an airfoil relative to oncoming air.
Aspect ratio—The ratio between the span of an airfoil and its chord.
Camber—The curve of an airfoil section from the leading edge to the trailing edge. Camber is usually expressed as the distance from the chord line to the upper or lower surface of an airfoil.
Center-of-pressure travel—The movement, or the amount of movement, of the center of pressure along a chord of an airfoil as the latter is inclined through its normal angles of attack.
Chord—An assumed straight-line tangent to the lower surface of an airfoil section at two points, or a straight line between the leading and trailing edges of an airfoil section, or between the ends of the mean line of an airfoil section; the distance between the leading and trailing edges of an airfoil section.
Drag—A resistant force exerted in a direction opposite to the direction of motion and parallel to the relative gas or air Stream.