How is aspect ratio defined in aviation?

Aspect ratio in aviation is defined as the ratio of the wingspan to the mean geometric chord of the wing. This measurement provides important insights into the performance characteristics of the aircraft. A higher aspect ratio typically indicates a longer, narrower wing, which can enhance aerodynamic efficiency by reducing induced drag during flight. This is particularly beneficial for gliders and long-distance aircraft, as it allows for better lift-to-drag ratios.

Understanding aspect ratio is crucial for aircraft design; it influences the stability, control, and overall performance of the aircraft. The other options present different concepts related to wings or aerodynamics but do not accurately define the aspect ratio as used in aviation terminology.