How much ice accumulation is permissible on aircraft wings?

Ice accumulation on aircraft wings can significantly impact the performance, handling, and safety of the aircraft. The presence of ice changes the aerodynamic properties of the wing surfaces, leading to an increase in stall speed, loss of lift, and potential control issues. For these reasons, no ice accumulation is permissible on aircraft wings prior to takeoff.

When considering the effects of even small ice deposits, such as frost, they can disturb the airflow over the wings, which can contribute to reduced lift and increased drag. Therefore, any amount of ice or frost is a critical concern and requires immediate action, such as de-icing or anti-icing measures, prior to flight.

While some answers might suggest that a certain amount of ice or frost can be tolerated, regulatory standards and safety practices emphasize that any ice accumulation is unacceptable on the critical surfaces of the aircraft, including wings and control surfaces. This maintains the highest margin of safety when operating the aircraft under potentially hazardous conditions.