Private Pilot Private Exam

Carburetor icing can occur even when the ambient air temperature is...

1. Below 20ºF and humidity is low

2. As high as 70ºF and humidity is high

3. Consistently above 80ºF

4. Constantly below freezing

The correct answer is: As high as 70ºF and humidity is high

Carburetor icing is a phenomenon that can happen in various atmospheric conditions and is particularly influenced by humidity and temperature. The correct response highlights that carburetor icing can occur at temperatures as high as 70ºF when humidity is high. This is because the process of vaporization of the fuel in the carburetor absorbs heat, which can lower the temperature of the air-fuel mixture significantly, reaching the dew point and potentially leading to ice formation. High humidity provides more moisture in the air, increasing the likelihood of icing under specific temperature conditions. Therefore, during high humidity episodes, even at temperatures that might seem warm enough to prevent icing under normal circumstances, the conditions created in the carburetor can still lead to icing. Understanding these factors is crucial for pilots to recognize the possibility of carburetor icing and take appropriate measures regardless of the outdoor temperature being in what seems to be a safe range.