Ground operations: Wing anti-ice ON when OAT is which condition?

Ground operations: Wing anti-ice ON when OAT is which condition?

• A. OAT is above 5C with moisture present
• B. OAT 5C or below with visible moisture or contaminated runway
• C. OAT is 0C with no moisture
• D. OAT 15C with a clean ramp

Answer: (B)

Wing anti-ice on the ground is required when there’s a real icing risk: the outside air temperature is 5°C or below and there is visible moisture (fog, mist, rain, clouds) or the surface is contaminated (slush, standing water, ice). In those conditions, ice can start forming on the wing leading edges during taxi or while on the ramp, so applying heat helps prevent icing. If the temperature is above 5°C or there’s no moisture or contamination, the likelihood of ice formation is low and anti-ice isn’t needed. So the best description is OAT 5°C or below with visible moisture or a contaminated runway.

Wing anti-ice on the ground is required when there’s a real icing risk: the outside air temperature is 5°C or below and there is visible moisture (fog, mist, rain, clouds) or the surface is contaminated (slush, standing water, ice). In those conditions, ice can start forming on the wing leading edges during taxi or while on the ramp, so applying heat helps prevent icing. If the temperature is above 5°C or there’s no moisture or contamination, the likelihood of ice formation is low and anti-ice isn’t needed. So the best description is OAT 5°C or below with visible moisture or a contaminated runway.