In aviation, a SWOA is only effective if the runway is what?

A SWOA, or Stopway, is an area at the end of a runway that is intended to provide an additional distance for an aircraft to stop if it overruns the runway. It is designed to enhance safety margins when a runway is not fully available for safe landing or takeoff.

The statement reflects that a SWOA is particularly effective when the runway is contaminated. Contamination can include surfaces covered with substances such as snow, ice, or water, which can increase stopping distances for aircraft. In these conditions, the performance of aircraft during landing or takeoff may be compromised due to reduced friction between the tires and the runway surface.

Therefore, having a SWOA available is crucial because it offers that extra buffer zone to help mitigate the risk of overrunning the runway under those hazardous and uncontrollable conditions. In contrast, when a runway is dry or clear, the chances of aircraft maintaining proper stopping distances are significantly improved, reducing the necessity for the additional safety measures provided by a stopway.