In icing conditions, icing is signaled when what annunciates?

• A. ICE annunciated by the ice detection system
• B. Visible moisture alone
• C. Altitude trend is decreasing
• D. Cabin pressure alarm

Answer: (A)

The ICE annunciator from the ice detection system signals icing conditions. The ice detector monitors for ice buildup on its sensor, and when ice is detected it lights ICE to warn the crew and often prompts deployment of anti-ice systems. Seeing visible moisture alone isn’t a reliable indicator of icing, since icing can occur with or without obvious moisture and without a corresponding annunciation. An altitude trend being downward isn’t a direct sign of icing, as icing can occur at various altitudes and isn’t reported by that indicator. A cabin pressure alarm relates to pressurization and has no connection to icing signaling.