What conditions require wing anti-ice on the CRJ200 for takeoff?

The requirement for activating wing anti-ice on the CRJ200 during takeoff is determined by the presence of visible moisture combined with an outside air temperature of 5°C or less. This is crucial because when the temperatures are at or below freezing and there is moisture present (such as rain, fog, or snow), this moisture can lead to ice accumulation on the wings, which can adversely affect the aircraft's lift and aerodynamics.

The wing anti-ice system helps to ensure that the wings remain free of ice and that the aircraft maintains optimal performance throughout the takeoff phase. The activation of the anti-ice system when conditions meet these criteria is therefore a critical safety measure.

In contrast, the other conditions mentioned do not necessitate the use of wing anti-ice. For instance, an outside air temperature above 5°C does not warrant the activation of the system as ice is unlikely to form. Similarly, a dry runway does not influence the need for wing anti-ice, since ice formation is primarily related to the aircraft's wings and the surrounding atmospheric conditions rather than the runway surface per se. Lastly, visibility exceeding 1 statute mile also does not determine the necessity for wing anti-ice, as icing conditions are based on temperature and visible