What must be done if flaps are extended in icing conditions?

When flaps are extended in icing conditions, the primary concern is the potential for ice accumulation on the wing surfaces, which can significantly degrade aerodynamic performance. The use of flaps increases the angle of attack and changes the airflow over the wings, making the wings more susceptible to ice-related issues.

In such conditions, holding—defined as maintaining a steady flight path in a specific area—is particularly hazardous because it can lead to prolonged exposure to icing conditions. This exposure can result in ice building up on the aircraft, which can lead to reduced lift, increased drag, and potentially stall scenarios. Therefore, avoiding holding in icing conditions is a critical safety measure to minimize the risks associated with ice formation on the aircraft's wings and control surfaces.

Other actions, such as reducing airspeed or waiting for de-icing, may not directly address the inherent risks associated with ice buildup while holding. Therefore, the guidance to avoid holding when flaps are extended in icing conditions is the most prudent course of action to ensure safety.