In the event frost is observed on wings and FIKI is approved, what action is typically required before takeoff?

• A. Proceed as planned, no action
• B. De-ice the aircraft
• C. Increase takeoff speed
• D. Land immediately

Answer: (B)

Frost on the wings creates a rough, irregular surface that disrupts the smooth airflow needed to generate lift, which raises the stall speed and reduces handling. Even with FIKI approval, you don’t take off with frost present—the aircraft must be de-iced so the wings are clean and aerodynamically smooth before departure. De-icing fixes the fundamental problem by restoring lift and predictable performance; simply increasing takeoff speed won’t remove the aerodynamic roughness, and the option to land immediately isn’t the required step when frost is observed before takeoff. After de-icing, verify the wings are frost-free and only then proceed with takeoff.