Wing planform

The lift and drag produced by a wing of a given cross-sectional profile are dependent on the dynamic pressure, the angle of attack and the wing plan area. In this chapter, we shall describe how the the wing planform shape also has an important influence.

Aspect ratio

The ratio of the overall wing span (length) to the average chord (width) is known as its aspect ratio. The terms span and chord are defined in Fig. 2.1. A wing such as that shown in Fig. 2.2, has a high aspect ratio, while Concorde, shown in plan view in Fig. 2.24, is a rare example of an aircraft with a wing aspect ratio of less than 1.

The early pioneers noted that the wings of birds always have a much greater span than chord. Simple experiments confirmed that high aspect ratio wings produced a better ratio of lift to drag than short stubby ones for flight at subsonic speeds. The reasons are given later in this chapter.