Which parts are typically included in the structure of an airfoil?

The structure of an airfoil is critical in understanding how an aircraft generates lift and maintains stable flight. The leading edge is the front part of the airfoil that first interacts with the oncoming air, helping to streamline airflow and reduce drag. The trailing edge is the rear part of the airfoil where the airflow separates, creating the lift necessary for flight. The chord line is an imaginary straight line that connects the leading edge to the trailing edge, serving as a reference for measuring the airfoil's shape.

This combination of parts—leading edge, trailing edge, and chord line—forms the basic profile of the airfoil, influencing its aerodynamic properties. In contrast, options including components like ailerons, flaps, or control surfaces refer to specific elements of the wing but do not represent the fundamental structural elements of an airfoil itself. The fuselage and airspeed indicator found in other options are parts of the aircraft but not integral to the airfoil's structure.