What should pilots do when flying through visible moisture?

When flying through visible moisture, pilots should be particularly aware of potential icing conditions. Visible moisture, which can manifest as rain, snow, fog, or clouds, increases the likelihood of ice forming on the aircraft, especially when flying at temperatures near freezing.

Ice accumulation on critical surfaces of the plane, such as wings and control surfaces, can adversely affect aircraft performance, handling, and safety. Therefore, recognizing the presence of moisture serves as a cue for pilots to monitor temperature and weather conditions closely and to be prepared to use anti-icing or de-icing systems if the aircraft is equipped with them.

Decisions such as increasing altitude to avoid moisture or reducing speed to comply with specific speed limits do not address the underlying risk associated with icing. Avoiding visible moisture altogether might be impractical or impossible in certain situations, especially during an approach or landing. Thus, having a heightened awareness of icing risks is the most relevant and critical action pilots should take when encountering visible moisture during flight.