What does "aspect ratio" refer to in aircraft wings?

Aspect ratio in aircraft wings is a crucial aerodynamic concept that refers specifically to the ratio of the wingspan to the average wing width. It is calculated by dividing the span of the wing (the distance from tip to tip) by the mean chord (the average width of the wing from leading edge to trailing edge).

A higher aspect ratio typically indicates longer, narrower wings, which can be beneficial for efficient flight, especially at higher altitudes and speeds, as they tend to produce less drag and generate more lift per unit of drag. This efficiency is why gliders, for example, often have very high aspect ratios. Conversely, lower aspect ratios are found on wings that require more structural strength and maneuverability, such as those on fighter jets.

Understanding the aspect ratio helps pilots and engineers design wings suited to specific flight conditions and requirements, improving overall aircraft performance.