What weather condition needs to be present for icing conditions in flight?

Icing conditions in flight are primarily determined by the temperature of the air surrounding the aircraft and the presence of moisture. TAT, or Total Air Temperature, is crucial in understanding these conditions, as it measures the temperature the aircraft experiences, factoring in humidity and wind chill at speed.

When TAT is below 10°C, it indicates that the conditions may be conducive to the formation of ice, particularly when flying through clouds or precipitation. In these environments, visible moisture comes in contact with the aircraft's surfaces, and if the temperature is low enough, ice can begin to accumulate. This is significant because it can impact the aircraft's performance, control surfaces, and overall safety.

On the other hand, when OAT (Outside Air Temperature) is mentioned, temperatures above certain thresholds (like 10°C or 5°C) are generally considered to be less likely to contribute to icing, as warm air holds more moisture in vapor form rather than liquid water that can freeze.

Having a clear understanding of TAT readings is essential for pilots to assess the potential risks and take necessary precautions when flying in conditions that could lead to ice formation.