Which condition indicates icing may be present and should be a consideration for flight crew action?

Which condition indicates icing may be present and should be a consideration for flight crew action?

• A. OAT above 15°C with sunny skies
• B. OAT 10°C or below with visible moisture
• C. OAT 20°C with no moisture
• D. OAT -25°C with dry air

Answer: (B)

Icing forms when liquid water droplets are present in visible moisture and the aircraft surfaces are at or near freezing, allowing the droplets to freeze on contact. When the outside air temperature is 10°C or below and there is visible moisture (such as clouds, fog with moisture, rain, drizzle, or mist), there’s a real potential for ice to form on the airframe, so this is a condition flight crews must consider and prepare for with anti-ice/de-ice actions or altered routing/altitude if needed. The other scenarios lack either the moisture or the freezing conditions: warm sunny skies with no moisture won’t produce icing, very cold air but with dry conditions won’t have droplets to freeze, and a moderate warm temperature with no moisture likewise won’t support ice formation.

Icing forms when liquid water droplets are present in visible moisture and the aircraft surfaces are at or near freezing, allowing the droplets to freeze on contact. When the outside air temperature is 10°C or below and there is visible moisture (such as clouds, fog with moisture, rain, drizzle, or mist), there’s a real potential for ice to form on the airframe, so this is a condition flight crews must consider and prepare for with anti-ice/de-ice actions or altered routing/altitude if needed. The other scenarios lack either the moisture or the freezing conditions: warm sunny skies with no moisture won’t produce icing, very cold air but with dry conditions won’t have droplets to freeze, and a moderate warm temperature with no moisture likewise won’t support ice formation.