When should the wing anti-ice be on for taxi in the CRJ 200?

The correct answer is based on the operational guidelines for the CRJ 200 regarding the use of wing anti-ice during taxi. The wing anti-ice should be activated when the outside air temperature (OAT) is less than or equal to 5°C to prevent ice from forming on the wings, which can adversely affect the aircraft's performance and handling characteristics during takeoff and flight.

At temperatures at or below this threshold, there is a risk of icing conditions, particularly if moisture is present in the air, which can lead to ice accumulation on the wing surfaces. This ice buildup could disrupt the airflow and reduce lift, making it essential to ensure that the wings are clear before takeoff.

Taxiing with the wing anti-ice engaged under the specified conditions ensures a safer operational environment and compliance with the aircraft's performance standards.

The other choices relate to scenarios where wing anti-ice should not necessarily be activated. When OAT is higher than 5°C, the risk of icing is significantly reduced, and using the system at that point may not be necessary. Keeping it on at all times during taxi could lead to unnecessary wear on the system and increase fuel consumption. Activating it only when snow is present may not account for other icing conditions