What should be done if an aircraft experiences ice after de-icing?

If an aircraft experiences ice after the de-icing process, returning for additional de-icing before departure is the appropriate action. Ice accumulation can significantly affect an aircraft's performance by altering lift, drag, and handling characteristics, compromising safety. It is crucial to ensure that the aircraft is thoroughly free of ice, snow, and frost before takeoff to maintain optimal aerodynamic efficiency and control.

De-icing is not only a critical step in preparation for flight but must also be monitored closely, especially in conditions where the potential for re-icing exists after de-icing has been completed. If ice has formed again, it indicates that the prior de-icing measures were ineffective under the circumstances, and additional treatment is required to ensure the aircraft is safe for takeoff.

The other options do not prioritize safety in the same way. Proceeding with takeoff without addressing the ice issue can lead to dangerous flight conditions. Using heated air on only the wings does not adequately rectify the situation, as ice may be present in other areas critical for flight safety, such as the control surfaces. Contacting the aircraft manufacturer might provide valuable guidance but is not an immediate corrective action that resolves the issue at hand before flight.