What does camber refer to in the context of an airfoil?

Camber is a term used to describe the curvature of an airfoil, which is crucial for generating lift during flight. Specifically, it refers to the difference in distance between the upper surface and the lower surface of the airfoil from the leading edge to the trailing edge. An airfoil with camber will typically have a more pronounced curve on one side compared to the other, which assists in directing airflow and creating pressure differences that result in lift.

This curvature is essential for the aerodynamic performance of the aircraft. Airfoils with varying degrees of camber will affect how well the wing generates lift at different angles of attack and speeds. Understanding camber is vital for pilots and engineers alike to optimize wing design for efficient flight performance.

In contrast, the other options refer to different structural or geometrical features of an airfoil. The flatness would concern a lack of curvature, thickness relates to how thick the airfoil is at its maximum point, and width pertains to the span of the airfoil. None of these aspects directly describe the essential characteristic of camber as it relates to the airfoil's ability to generate lift.