During flight in icing conditions, what is a common sign of ice buildup?

• A. Unusual changes in airspeed and control feel.
• B. Changes in airplane performance and de-icing system indications.
• C. Visual icing on cockpit windows only.
• D. Sudden cabin temperature drop.

Answer: (B)

In icing conditions, ice on surfaces changes the airplane’s aerodynamics and how the aircraft feels in the controls. Ice adds weight and increases drag while reducing lift, so you’ll typically see degraded performance: slower acceleration, higher fuel/airspeed requirements to maintain climb or level flight, and a noticeable change in climb rate or handling. At the same time, the ice protection or de-icing system will usually provide cockpit indications—lights, messages, or annunciations—showing that anti-ice/ice protection is active. The combination of performance changes and explicit system indications is a common and reliable sign that ice buildup is affecting the airplane.

Visual icing on cockpit windows alone isn’t a dependable cue for overall ice buildup, and a sudden cabin temperature drop isn’t a specific indicator of wing or surface ice.